--- - chapter_identifier: temperature-related-death-and-illness confidence: 'There is high confidence that heat deaths will very likely increase in the future compared to a future without climate change, based on high agreement and a large number of studies as well as consistency across scenarios and regions. Because there are fewer studies on winter mortality, and because studies exist that suggest that winter mortality is not strongly linked to temperatures, there is medium confidence that deaths due to extreme cold will very likely decrease. The majority of the studies that examine both heat and cold deaths find that the increase in heat deaths due to climate change will likely be larger than the decrease in cold deaths in most regions, but there are a limited number of such studies, leading to an assessment of medium confidence.' evidence: 'An extensive literature examines projections of mortality due to increasing temperatures. In particular, nine studies were identified that provide heat mortality projections in the United States for at least 10% of the U.S. population.d4613be9-fc30-44b5-afdb-e6d6daf4b490,e805bfdc-c4c2-43a0-b2e5-5a66945c74e4,48d08f16-c2bb-4591-831d-22c262d869fb,6b3cd0ec-1e3e-42e8-ad82-5c12ed7ab0e8,14e7930d-648f-4a7a-a41d-2eb61b7f9894,fe80908b-c181-4da8-8163-5abaade99c7e,18e73954-8b13-4c4a-acd1-9687b8d811d2,638cccd2-9ae4-469e-a1d7-6123abec2780,49407e4c-351c-4240-9c91-50e36a83849d Each of these studies projected an increase in heat-related mortality due to projections of future warming, though several noted the potential modification effect of adaptation (discussed in Key Finding #3). In general, the magnitude of projected increases in annual premature deaths in these studies was in the hundreds to thousands by mid-century, and thousands to tens of thousands by the end of the century, when scaled to the total U.S. population. These conclusions are further supported by studies at the city, county, and state level.e60cb47e-4a48-4e92-a2d3-97516836e8f3,9e1170c5-e68e-4aab-bf70-33e4b69e46bf,315edcf2-107b-449d-b694-5d5a3c87ebbb,b3760069-032c-4bb6-9d34-9771c08f0171,04f852ec-7b1e-4fd0-a517-283b25468694,97024533-f9d5-4ee9-abb6-56733744a4d0,ba31f764-b679-480d-adc9-a66cd2354c10,6168163c-2f61-4593-810e-fe389a8f7834,a5c47ded-9ce3-4075-b4d4-c5c3ce9036cd

The Third National Climate Assessment (2014 NCA) found that “While deaths and injuries related to cold events are projected to decline due to climate change, these reductions are not expected to compensate for the increase in heat-related deaths,”61fd6e32-63d0-4f5a-bbbb-f68262376a37 and studies published since that time have further supported this finding. Of those studies that examine both heat and cold at the national scale, only Barreca found that the reductions in cold deaths would more than compensate for the increase in heat deaths.d4613be9-fc30-44b5-afdb-e6d6daf4b490,e805bfdc-c4c2-43a0-b2e5-5a66945c74e4,48d08f16-c2bb-4591-831d-22c262d869fb,14e7930d-648f-4a7a-a41d-2eb61b7f9894,18e73954-8b13-4c4a-acd1-9687b8d811d2 Barreca’s study was novel in terms of its treatment of humidity, finding that weather that was both cold and dry, or both hot and humid, was associated with higher mortality. However, this treatment of humidity was not the cause of the difference with other studies, as leaving out humidity actually showed a greater benefit from future climate change. Instead, the author stated that the reduction in net deaths was a result of relying on counties with over 100,000 inhabitants, and that using a state-level model covering all U.S. deaths would lead to a prediction of an increase of 1.7% in mortality rates rather than a decrease of 0.1%. The finding by the majority of studies at a national scale that heat deaths will increase more than cold deaths will decrease is consistent with studies at smaller spatial scales.9e1170c5-e68e-4aab-bf70-33e4b69e46bf Moreover, several studies provide rationales for why heat mortality is expected to outpace cold mortality,bdea0759-701d-4183-9966-cee3ce977e08,d4613be9-fc30-44b5-afdb-e6d6daf4b490,e805bfdc-c4c2-43a0-b2e5-5a66945c74e4 and some studies suggest that cold mortality may not be responsive to warming.2cee671a-e17f-4e66-b37d-0c29a35f7210,de50864a-6264-4114-bef0-399a41bc44a8,fbceb8d9-2504-47a6-a3df-50e173f578c9 Barnett et al. (2012) showed that cold waves were not generally associated with an increase in deaths beyond the mortality already associated with cold weather, in contrast to heat waves.5b3848ca-bd86-4549-a937-dea708342827' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/temperature-related-death-and-illness/finding/future-increases-temperature-related-deaths.yaml identifier: future-increases-temperature-related-deaths ordinal: 1 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2–3.

The content of this chapter was determined after reviewing the collected literature. The authors determined that there was substantial literature available to characterize both observed and projected mortality from elevated temperatures, with sufficient literature available to also characterize mortality from cold as well as cold-related hospitalizations and illness. Populations of concern were also considered to be a high priority for this chapter. As discussed in the chapter, there were limitations in terms of the state of the literature on understanding how future adaptation will influence climate-related changes in temperature-related mortality, addressing the impact of temperature on rural populations, and examining health-related endpoints other than mortality and morbidity.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Based on present-day sensitivity to heat, an increase of thousands to tens of thousands of premature heat-related deaths in the summer [Very Likely, High Confidence] and a decrease of premature cold-related deaths in the winter [Very Likely, Medium Confidence] are projected each year as a result of climate change by the end of the century. Future adaptation will very likely reduce these impacts (see Changing Tolerance to Extreme Heat Finding). The reduction in cold-related deaths is projected to be smaller than the increase in heat-related deaths in most regions [Likely, Medium Confidence]. ' uncertainties: 'The largest remaining uncertainties concern questions of future adaptation, which are discussed in Key Finding #3. A related uncertainty involves the link between the temperatures measured at weather stations and the temperatures experienced by individuals. As long as the relationship between the weather station and the microclimate or indoor/outdoor difference remains constant, this should not impair projections. However, as microclimates, building construction, or behavior change, the relationship between recorded weather station temperature and actual temperature exposure will change. This is related to, but broader than, the question of adaptation. Additionally, there are uncertainties regarding the non-linearities of heat response with increasing temperatures.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/temperature-related-death-and-illness/finding/future-increases-temperature-related-deaths url: ~ - chapter_identifier: temperature-related-death-and-illness confidence: 'There is very high confidence in the relationship between extreme temperatures and premature deaths due to the consistency and strength of the literature, particularly given the different study designs that produce this result. There is high confidence that small temperature deviations from normal temperatures contribute to premature mortality due to high agreement among those studies that have examined the issue. Though some studies indicate that for these small temperature differences, mortality displacement may play a larger role than for more extreme temperatures. Fewer studies have examined the role of these smaller temperature differences in projections, but the directionality of the effect is clear, so the determination of the authors was that not including this effect would likely lead to an underestimate of future mortality, with high confidence.' evidence: 'Two well-recognized conclusions from the literature are that extreme temperatures lead to illness and premature death and that these extreme temperatures are best described in relation to local average seasonal temperatures rather than absolute temperature values. Epidemiological studies find an increase in mortality at temperatures that are high related to the local average.a6714dce-b324-4324-a88e-d31d31fa2d95,ad5fb3ba-9924-4df9-a68f-1e94822f78f9,bdea0759-701d-4183-9966-cee3ce977e08,32af3968-aefd-4a28-810f-aed7277d6f3a,b9525432-c24b-4aee-9b0f-1783af53f48d,48d08f16-c2bb-4591-831d-22c262d869fb Based on absolute temperatures, Anderson and Bell 2011 found that cities in the South and Southeast were the least sensitive to heat, demonstrating acclimatization.a6714dce-b324-4324-a88e-d31d31fa2d95

Illness has been linked with hot daily average temperature6dd31085-f435-4888-bc08-d55718abd744,7be7dd5f-5970-45ec-a14c-1fed7851517b,ac0d1490-bc44-4738-af3d-90d6a499dcbe,c3c2dea7-0420-4f9a-b18b-41ac5641255a,ff5550b2-6d4a-436c-866f-232c6d8f7ad6 and apparent temperature, among other metrics.da62c30f-01b4-4dc6-b3c6-197bd77eaf30,6b8418a6-978f-4196-8c50-c8ce246910ad,176b5759-b07b-4209-b8ff-8c55768c6aee,9e5154e8-cddf-4c83-ac36-1c43a2d88d7b Across studies, adverse health episodes were most strongly associated with exposures to high temperatures that occurred on the same day or the previous day.da62c30f-01b4-4dc6-b3c6-197bd77eaf30,ac0d1490-bc44-4738-af3d-90d6a499dcbe However, a cumulative effect of heat was also observed at periods of up to one week after exposure, tapering off beyond seven days.c3c2dea7-0420-4f9a-b18b-41ac5641255a,3735f126-9595-4fee-a491-0510b8fc9cd2 Cardiovascular and respiratory illness has been most commonly examined in relation to extreme heat, but the association is more varied for illness than for mortality due to effects across age groupsc3c2dea7-0420-4f9a-b18b-41ac5641255a,c7fdbd26-6a4b-48e4-a94e-56cf436e0b2fand differences in morbidity risk associated with emergency room records versus hospital admissions.6dd31085-f435-4888-bc08-d55718abd744,7be7dd5f-5970-45ec-a14c-1fed7851517b,7ca0e947-163a-46f3-9274-cea209b94510,ac0d1490-bc44-4738-af3d-90d6a499dcbe,6b8418a6-978f-4196-8c50-c8ce246910ad,9a85ffc5-67e9-465a-8af8-d82b15d5c98b,176b5759-b07b-4209-b8ff-8c55768c6aee,c3c2dea7-0420-4f9a-b18b-41ac5641255a,c7fdbd26-6a4b-48e4-a94e-56cf436e0b2f

The evidence for mortality is clearest for extreme temperatures, as addressed in threshold-based studies,bdea0759-701d-4183-9966-cee3ce977e08 but studies that account for smaller changes in temperature found mortality changes even for small deviations of temperature.1dd78be0-0355-46a2-81b7-9a55154cc564,e805bfdc-c4c2-43a0-b2e5-5a66945c74e4 This is consistent with studies showing a U-shaped relationship of temperature and mortality—while there may be some plateau near the optimal temperature, the plateau is often small, and not always coincident with the seasonal average temperature.1dd78be0-0355-46a2-81b7-9a55154cc564,7513f4d2-671e-4a73-b3a3-cd354fa62c29 However, some of the individuals who die in response to elevated temperatures were already near death, and so the temperature event is sometimes considered to have “displaced” the death by a matter of days rather than created an additional death. Studies have found that this effect is generally below 50% of the total deaths, and is much smaller than that (10% or less) for the most extreme events, such as the 2003 European heat wave.bdea0759-701d-4183-9966-cee3ce977e08,8fcb835f-34bc-483b-ace3-650ef439b7b4,2cee671a-e17f-4e66-b37d-0c29a35f7210,6d040a6e-0001-4475-81a6-06a198e63b28 In contrast, one recent study found that in seven U.S. cities mortality displacement was greater than 80% for small temperature deviations and around 50% even for the 3% of warmest events in the study sample.eaabcdba-02ea-478b-899b-d0924862128b' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/temperature-related-death-and-illness/finding/even-small-differences-seasonal-average-temperatures-result-illness-death.yaml identifier: even-small-differences-seasonal-average-temperatures-result-illness-death ordinal: 2 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2–3.

The content of this chapter was determined after reviewing the collected literature. The authors determined that there was substantial literature available to characterize both observed and projected mortality from elevated temperatures, with sufficient literature available to also characterize mortality from cold as well as cold-related hospitalizations and illness. Populations of concern were also considered to be a high priority for this chapter. As discussed in the chapter, there were limitations in terms of the state of the literature on understanding how future adaptation will influence climate-related changes in temperature-related mortality, addressing the impact of temperature on rural populations, and examining health-related endpoints other than mortality and morbidity.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Days that are hotter than usual in the summer or colder than usual in the winter are both associated with increased illness and death [Very High Confidence]. Mortality effects are observed even for small differences from seasonal average temperatures [High Confidence]. Because small temperature differences occur much more frequently than large temperature differences, not accounting for the effect of these small differences would lead to underestimating the future impact of climate change [Likely, High Confidence].' uncertainties: 'This finding reflects consideration of a number of recent studiesb9525432-c24b-4aee-9b0f-1783af53f48d,6b3cd0ec-1e3e-42e8-ad82-5c12ed7ab0e8 not referenced in the recent 2014 NCA.61fd6e32-63d0-4f5a-bbbb-f68262376a37 There is a consensus of studies linking extreme temperatures and mortality, and a growing body of literature demonstrating that smaller differences in temperature are also linked with mortality. However, the mortality displacement effect, and the fact that deaths that do not occur during an identified heat wave are less likely to be directly attributed to extreme heat, contribute to continuing uncertainty about the magnitude of the effect of temperature on mortality.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/temperature-related-death-and-illness/finding/even-small-differences-seasonal-average-temperatures-result-illness-death url: ~ - chapter_identifier: temperature-related-death-and-illness confidence: 'There is very high confidence that a decrease in sensitivity to heat events has occurred based on high agreement between studies, but only medium confidence that this decrease is due to some specific combination of air conditioning prevalence, physiological adaptation, presence of green space, and improved social responses because of the challenges involved in attribution. There is very high confidence that mortality due to heat will very likely be reduced compared to a no-adaptation scenario when adaptation is included, because all studies examined were in agreement with this conclusion, though the magnitude of this reduction is poorly constrained.' evidence: 'The increasing tolerance of the U.S. population to extreme heat has been shown by a number of studies.a6714dce-b324-4324-a88e-d31d31fa2d95,ad5fb3ba-9924-4df9-a68f-1e94822f78f9,6b3cd0ec-1e3e-42e8-ad82-5c12ed7ab0e8 However, there is less confidence in attributing this increase in tolerance: increased prevalence and use of air conditioning, physiological adaptation, available green space, and improved social responses have all been proposed as explanatory factors. There have been some indications (Sheridan et al. 2009)9096905c-dc99-46c1-ac2c-2e5f8d58f8d9 that tolerance improvements in the United States might have plateaued, but Bobb et al. 2014 found continuing improvements through 2005.6b3cd0ec-1e3e-42e8-ad82-5c12ed7ab0e8

Several approaches to including adaptation have been used in temperature mortality projection studies. For example, two studies used an “analog city” approach, where the response of the population to future temperatures in a given city is assumed to be equal to that of a city with a hotter present-day climate.d4613be9-fc30-44b5-afdb-e6d6daf4b490,04f852ec-7b1e-4fd0-a517-283b25468694 Another approach is to assume that critical temperature thresholds change by some quantity over time.e60cb47e-4a48-4e92-a2d3-97516836e8f3,b10f189e-fbfa-44fc-b7b5-48966591f9ba A third approach is to calculate sensitivity to air conditioning prevalence in the present, and make assumptions about air conditioning in the future.a5c47ded-9ce3-4075-b4d4-c5c3ce9036cd In general, inclusion of adaptation limits the projected increase in deaths, sometimes modestly, other times dramatically. However, approaches used to account for adaptation may be optimistic. Historically, adaptive measures have occurred as a response to extreme events, and therefore could be expected to lag warming.315edcf2-107b-449d-b694-5d5a3c87ebbb,46f2571e-7661-4163-9178-bee1d153a827 While the increase in mortality projected in these studies is reduced, the studies generally found that mortality increases compared to present day even under optimistic adaptation assumptions.e60cb47e-4a48-4e92-a2d3-97516836e8f3,d4613be9-fc30-44b5-afdb-e6d6daf4b490,04f852ec-7b1e-4fd0-a517-283b25468694,a5c47ded-9ce3-4075-b4d4-c5c3ce9036cd A limit to adaptation may be seen in that even in cities with nearly 100% air conditioning penetration, heat deaths are observed today.' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/temperature-related-death-and-illness/finding/changing-tolerance-extreme-heat.yaml identifier: changing-tolerance-extreme-heat ordinal: 3 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2–3.

The content of this chapter was determined after reviewing the collected literature. The authors determined that there was substantial literature available to characterize both observed and projected mortality from elevated temperatures, with sufficient literature available to also characterize mortality from cold as well as cold-related hospitalizations and illness. Populations of concern were also considered to be a high priority for this chapter. As discussed in the chapter, there were limitations in terms of the state of the literature on understanding how future adaptation will influence climate-related changes in temperature-related mortality, addressing the impact of temperature on rural populations, and examining health-related endpoints other than mortality and morbidity.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'An increase in population tolerance to extreme heat has been observed over time [Very High Confidence]. Changes in this tolerance have been associated with increased use of air conditioning, improved social responses, and/or physiological acclimatization, among other factors [Medium Confidence]. Expected future increases in this tolerance will reduce the projected increase in deaths from heat [Very Likely, Very High Confidence].' uncertainties: 'While studies have been published in recent years that include adaptation in sensitivity analyses,d4613be9-fc30-44b5-afdb-e6d6daf4b490 this remains a challenging area of research. Difficulties in attributing observed increases in tolerance make it challenging to project future changes in tolerance, whether due to autonomous adaptation by individuals or planned adjustments by governments. Extrapolation of acclimatization is limited as there must be an increase in temperature beyond which acclimatization will not be possible.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/temperature-related-death-and-illness/finding/changing-tolerance-extreme-heat url: ~ - chapter_identifier: temperature-related-death-and-illness confidence: 'Although some details regarding causation and identifying the most vulnerable subpopulations still require research, there is a large body of literature that demonstrates the increased vulnerability to extreme heat of a number of groups, and therefore there is very high confidence that the listed populations of concern are at greater risk of temperature-related death and illness.' evidence: 'The relationship between increased temperatures and deaths in elderly populations is well-understood. An increased risk of respiratory and cardiovascular death is observed in elderly populations during temperature extremes due to reduced thermoregulation.b9525432-c24b-4aee-9b0f-1783af53f48d,8bf8d41a-8b94-4ec2-95f0-cfd77b48685e,199eb13a-09ce-4af0-bc70-e26881a28c33,e2f39823-225f-43ea-ae65-dfc3d73bf9a6

Studies cite dehydration, electrolyte imbalance, fever, heat stress, hyperthermia, and renal disease as the primary health conditions in children exposed to heat waves. Causes of heat-related illness in children include inefficient thermoregulation, reduced cardiovascular output, and heightened metabolic rate. Children also spend a considerable amount of time outdoors and participating in vigorous activities.b9525432-c24b-4aee-9b0f-1783af53f48d,8bf8d41a-8b94-4ec2-95f0-cfd77b48685e,8e74af6d-bae1-4355-92b9-c186e2d09b8c,2a0a09ec-bc6f-4662-9894-ff2ea09c1f57 A limited number of studies found evidence of cold-related mortality in children; however, no study has examined the relationship between cold temperature and cause-specific mortality.8e74af6d-bae1-4355-92b9-c186e2d09b8c

Certain occupational groups that spend a great deal of time exposed to extreme temperatures, such as agricultural workers, construction workers, and electricity and pipeline utility workers, are at increased risk for heat- and cold-related illness, especially where jobs involve heavy exertion.de5b6f9d-388d-4f67-8115-ad5fca6a95d5,ec85e5b1-7c3e-48b7-9919-f04bdb7afce3,480e807c-24a2-43ab-9d53-6cff5cd095f2 Lack of heat-illness-prevention programs in the workplace that include provisions for acclimatization was found to be a factor strongly associated with extreme temperature-related death.ec85e5b1-7c3e-48b7-9919-f04bdb7afce3

Race, ethnicity, and socioeconomic status have been shown to impact vulnerability to temperature extremes. Several studies have identified non-Hispanic Black populations to be more vulnerable than other racial and ethnic groups for experiencing detrimental consequences of exposure to temperature extremes.b9525432-c24b-4aee-9b0f-1783af53f48d,8bf8d41a-8b94-4ec2-95f0-cfd77b48685e,199eb13a-09ce-4af0-bc70-e26881a28c33,2a0a09ec-bc6f-4662-9894-ff2ea09c1f57,2de8f6a6-933e-4bc7-8224-e754696e2a53 Studies suggest comorbidities that enhance susceptibility to higher temperatures, availability and use of air conditioning, disparities in heat risk-related land cover characteristics, and other environmental justice issues contribute to increased vulnerability of non-Hispanic Blacks.b9525432-c24b-4aee-9b0f-1783af53f48d,8bf8d41a-8b94-4ec2-95f0-cfd77b48685e,1aca1900-c64c-4624-a696-3aab59ba6673,2de8f6a6-933e-4bc7-8224-e754696e2a53,29da63ed-20d4-4ac6-9ec7-ac886a25c040

Dementia, mood disorders, neurosis and stress-related illnesses, and substance abuse are shown to be impacted by extreme heat.de5b6f9d-388d-4f67-8115-ad5fca6a95d5,922bcd50-dd07-4e05-afc7-fe3bcb1a953a,1e9a7907-02f2-4da8-9e93-131f92515dbc,2a9775ae-a280-4260-985f-0e66d0ef8c11 Some medications interfere with thermoregulation, increasing vulnerability to heat.1e9a7907-02f2-4da8-9e93-131f92515dbc' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/temperature-related-death-and-illness/finding/some-populations-greater-risk.yaml identifier: some-populations-greater-risk ordinal: 4 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2–3.

The content of this chapter was determined after reviewing the collected literature. The authors determined that there was substantial literature available to characterize both observed and projected mortality from elevated temperatures, with sufficient literature available to also characterize mortality from cold as well as cold-related hospitalizations and illness. Populations of concern were also considered to be a high priority for this chapter. As discussed in the chapter, there were limitations in terms of the state of the literature on understanding how future adaptation will influence climate-related changes in temperature-related mortality, addressing the impact of temperature on rural populations, and examining health-related endpoints other than mortality and morbidity.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Older adults and children have a higher risk of dying or becoming ill due to extreme heat [Very High Confidence]. People working outdoors, the socially isolated and economically disadvantaged, those with chronic illnesses, as well as some communities of color, are also especially vulnerable to death or illness [Very High Confidence].' uncertainties: 'The literature available at the time of the development of the 2014 NCA had identified a number of vulnerable populations that were disproportionately at risk during heat waves, and literature since that time has only strengthened the understanding of the elevated risks for these populations. There continues to be a need for better understanding of the relative importance of genetics and environmental justice issues with regards to the observed higher risk for non-Hispanic Blacks, more work on understanding the risks to pregnant women from extreme temperature events, and a better understanding of the relationship between extreme cold vulnerabilities in populations of concern.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/temperature-related-death-and-illness/finding/some-populations-greater-risk url: ~ - chapter_identifier: air-quality-impacts confidence: 'Given the known relationship between temperature and ozone, as well as the numerous air quality modeling studies that suggest climate-driven meteorological changes will yield conditions more favorable for ozone formation in the future, there is high confidence that ozone levels will likely increase due to climate change, unless offset by reductions in ozone precursor emissions. Based on observed relationships between ozone concentrations and human health responses, there is high confidence that any climate-driven increases in ozone will likely cause additional cases of premature mortality, as well as increasingly frequent cases of hospital visits and lost school days due to respiratory impacts.' evidence: 'The Intergovernmental Panel on Climate Change (IPCC) has concluded that warming of the global climate system is unequivocal and that continued increases in greenhouse gas emissions will cause further temperature increases.f03117be-ccfe-4f88-b70a-ffd4351b8190,dd5b893d-4462-4bb3-9205-67b532919566 At the same time, there is a well-established relationship between measured temperature and monitored peak ozone levels in the United States.552e0a6a-98c6-4d6c-b7ff-fdcc572fa914,1994b6dc-9753-44a1-a1b2-1d1566c39287 Numerous climate and air quality modeling studies have also confirmed that increasing temperatures, along with other changes in meteorological variables, are likely to lead to higher peak ozone levels in the future over the United States,afbd60ab-ba9f-4547-88e3-968bc3a4b949,b4038a28-b14b-4ae8-b783-0de19e3cffdd if ozone precursor emissions remain unchanged.

Risk assessments using concentration–response relationships from the epidemiological literature and modeled air quality data have projected substantial health impacts associated with climate-induced changes in air quality.54a66159-1675-43bb-b5d3-a9b7f283e4de,fe6d1c69-790d-46cc-89c4-26dc24585dcf,8e802a4f-d4f1-4f72-a0ae-aefbbece477e,c275ae44-75e4-4974-81ea-fe7119474ffb,d6e399c7-1efe-4f91-927e-f957965e3aaa,d3df6d52-0441-47cc-a939-6d09f57ea48d This literature reports a range of potential changes in ozone-related, non-accidental mortality due to modeled climate change between the present and 2030 or 2050, depending upon the scenario modeled, the climate and air quality models used, and assumptions about the concentration–response function and future populations. Many of the studies suggest that tens to thousands of premature deaths could occur in the future due to climate change impacts on air quality.54a66159-1675-43bb-b5d3-a9b7f283e4de,fe6d1c69-790d-46cc-89c4-26dc24585dcf At the same time, hundreds of thousands of days of missed school and hundreds of thousands to millions of cases of acute respiratory symptoms also result from the climate-driven ozone increases in the United States.54a66159-1675-43bb-b5d3-a9b7f283e4de' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/air-quality-impacts/finding/exacerbated-ozone-health-impacts.yaml identifier: exacerbated-ozone-health-impacts ordinal: 1 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2–3.

In addition, the author team held an all-day meeting at the U.S. Environmental Protection Agency National Center for Environmental Assessment in Crystal City, Virginia, on October 15, 2014, to discuss the chapter and develop initial drafts of the Key Findings. A quorum of the authors participated and represented each of the three sections of the chapter—outdoor air quality, aeroallergens, and indoor air quality. These discussions were informed by the results of the literature review as well as the research highlights focused on outdoor air quality and indoor air quality. The team developed Key Finding 2 in response to comments from the National Research Council review panel and the general public.

The Key Findings for outdoor ozone, wildfires, and aeroallergen impacts reflect strong empirical evidence linking changes in climate to these outcomes. When characterizing the human health impacts from outdoor ozone, the team considered the strength of the toxicological, clinical, and epidemiological evidence evaluated in the Ozone Integrated Science Assessment.e00fb4e2-6406-40be-90f8-071dfc43cca3 Because there is increasing evidence that climate change will increase the frequency and intensity of wildfire events, this outcome was included as a key finding, despite the inability to quantify this impact with the available tools and data. Because altered patterns of precipitation and increasing levels of CO2 are anticipated to promote the level of aeroallergens, this outcome is also included as a Key Finding. Finally, because the empirical evidence linking climate change to indoor air quality was more equivocal, we identified this topic as an emerging issue.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Climate change will make it harder for any given regulatory approach to reduce ground-level ozone pollution in the future as meteorological conditions become increasingly conducive to forming ozone over most of the United States [Likely, High Confidence]. Unless offset by additional emissions reductions of ozone precursors, these climate-driven increases in ozone will cause premature deaths, hospital visits, lost school days, and acute respiratory symptoms [Likely, High Confidence].' uncertainties: 'Climate projections are driven by greenhouse gas emission scenarios, which vary substantially depending on assumptions for economic growth and climate change mitigation policies. There is significant internal variability in the climate system, which leads to additional uncertainties in climate projections, particularly on a regional basis. Ozone concentrations also depend on emissions that are influenced indirectly by climate change (for example, incidence of wildfires, changes in energy use, energy technology choices), which further compounds the uncertainty. Studies projecting human health impacts apply concentration–response relationships from existing epidemiological studies characterizing historical air quality changes; it is unclear how future changes in the relationship between air quality, population exposure, and baseline health may affect the concentration–response relationship. Finally, these studies do not account for the possibility of a physiological interaction between air pollutants and temperature, which could lead to increases or decreases in air pollution-related deaths and illnesses.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/air-quality-impacts/finding/exacerbated-ozone-health-impacts url: ~ - chapter_identifier: air-quality-impacts confidence: 'Given the known association between PM and health outcomes and between wildfires and PM concentrations, there is high confidence that an increase in wildfire frequency and severity will likely lead to an increase in adverse respiratory and cardiac health outcomes. Based on the robustness of the projection by global climate models that precipitation amounts will decrease in parts of the United States, and that summer temperatures will increase, there is high confidence that the frequency and severity of wildfire occurrence will likely increase, particularly in the western United States.' evidence: 'The harmful effects of PM concentrations on human health have been well-documented, and there is equally strong evidence linking wildfires to higher PM concentrations regionally. Recent studies have established linkages between wildfire incidence and adverse health outcomes in the nearby population.250b4ec3-1264-4570-8417-c00e6d8752a8,21efa9a6-60df-4820-a8e4-71456cce1288 Though projections of climate change impacts on precipitation patterns are less certain than those on temperature, there is greater agreement across models that precipitation will decrease in the western United States.a6a312ba-6fd1-4006-9a60-45112db52190 Rising temperatures, decreasing precipitation, and earlier springtime onset of snowmelt are projected to lead to increased frequency and severity of wildfires.a92b6912-a92c-482b-a8e7-f43d324947e3,99baa64e-2877-4db9-b257-3f41149e73fe,b95e9226-076c-4eb5-9367-472499624084' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/air-quality-impacts/finding/increased-health-impacts-from-wildfires.yaml identifier: increased-health-impacts-from-wildfires ordinal: 2 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2–3.

In addition, the author team held an all-day meeting at the U.S. Environmental Protection Agency National Center for Environmental Assessment in Crystal City, Virginia, on October 15, 2014, to discuss the chapter and develop initial drafts of the Key Findings. A quorum of the authors participated and represented each of the three sections of the chapter—outdoor air quality, aeroallergens, and indoor air quality. These discussions were informed by the results of the literature review as well as the research highlights focused on outdoor air quality and indoor air quality. The team developed Key Finding 2 in response to comments from the National Research Council review panel and the general public.

The Key Findings for outdoor ozone, wildfires, and aeroallergen impacts reflect strong empirical evidence linking changes in climate to these outcomes. When characterizing the human health impacts from outdoor ozone, the team considered the strength of the toxicological, clinical, and epidemiological evidence evaluated in the Ozone Integrated Science Assessment.e00fb4e2-6406-40be-90f8-071dfc43cca3 Because there is increasing evidence that climate change will increase the frequency and intensity of wildfire events, this outcome was included as a key finding, despite the inability to quantify this impact with the available tools and data. Because altered patterns of precipitation and increasing levels of CO2 are anticipated to promote the level of aeroallergens, this outcome is also included as a Key Finding. Finally, because the empirical evidence linking climate change to indoor air quality was more equivocal, we identified this topic as an emerging issue.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Wildfires emit fine particles and ozone precursors that in turn increase the risk of premature death and adverse chronic and acute cardiovascular and respiratory health outcomes [Likely, High Confidence]. Climate change is projected to increase the number of naturally occurring wildfires in parts of the United States, increasing emissions of particulate matter and ozone precursors and resulting in additional adverse health outcomes [Likely, High Confidence]' uncertainties: 'Future climate projections, especially projections of precipitation, are subject to considerable uncertainty. Land management practices, including possible adaptive measures taken to mitigate risk, could alter the frequency and severity of wildfires, the emissions from wildfires, and the associated human exposure to smoke.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/air-quality-impacts/finding/increased-health-impacts-from-wildfires url: ~ - chapter_identifier: air-quality-impacts confidence: 'The scientific literature suggests that there is high confidence that changes in climate, including rising temperatures and altered precipitation patterns, will affect the concentration, allergenicity, season length, and spatial distribution of a number of aeroallergens, and these changes are expected to impact the prevalence of some allergic diseases, including asthma attacks.' evidence: 'There is a large body of evidence supporting the observation that climate change will alter the production, allergenicity, distribution, and timing of aeroallergens. Historical trends show that climate change has led to changes in the length of the growing season for certain allergenic pollens. Climate change also contributes to changes in allergic illnesses as greater concentrations of CO2, together with higher temperatures and changes in precipitation, extend the start or duration of the growing season, increase the quantity and allergenicity of pollen, and expand the spatial distribution of pollens.c60ed28e-5ec3-4b9b-8b41-c6c29e4fda70,14835bc7-3df6-4fac-9e9a-2863c09e800a,fa0649b9-2a09-43a3-a2ce-b57dbe0080a7,aac0f087-3ed8-49a3-b1c9-07ce3fdf7f24,7dff169a-bb19-4f80-bdc9-9aae8d13a86f While the role of weather on the initiation or exacerbation of allergic symptoms in sensitive persons is not entirely understood,7eaad122-f1a7-4062-bbfc-c4c9ad7d3078,a033e39f-2028-453b-b37b-ec698f155b25 increases in intensity and frequency of rainfall and storminess over the coming decades is expected to be associated with spikes in aeroallergen concentrations and the potential for related increases in the number and severity of allergic illnesses.025515fc-f83a-47ff-b547-92ade9513c15,713cd919-826b-426d-bf51-761a58ec7f22

These changes in exposure to aeroallergens contribute to the severity and prevalence of allergic disease in humans. Given that aeroallergen exposure is not the sole, or even necessarily the most significant, factor associated with allergic illnesses, that relationship is part of a complex pathway that links exposure to aeroallergens to the prevalence of allergic illnesses.b9370347-fe7c-4b6f-9d49-af723ed931a4 There is consistent and robust evidence that aeroallergen exposure contributes significantly to the occurrence of asthma episodes, hay fever, sinusitis, conjunctivitis, hives, and anaphylaxis.c60ed28e-5ec3-4b9b-8b41-c6c29e4fda70,f89543d6-09bf-436c-8f7e-c0f908473457 There is also compelling evidence that allergic diseases develop in response to complex and multiple interactions among both genetic and non-genetic factors, including a developing immune system, environmental exposures (such as ambient air pollution or weather conditions), and socioeconomic and demographic factors.49a88ae9-9f4c-4a99-92fa-3da34bf2a70f,7eaad122-f1a7-4062-bbfc-c4c9ad7d3078,d9f760b1-0caa-450c-a807-e65c2097c0fb Finally, there is evidence that potential non-linear interactions between aeroallergens and ambient air pollutants is likely to increase health risks for people who are simultaneously exposed.d9f760b1-0caa-450c-a807-e65c2097c0fb,f89543d6-09bf-436c-8f7e-c0f908473457,036ba27d-8341-4f6d-ad66-1288e53dee65,025515fc-f83a-47ff-b547-92ade9513c15,a5b5448f-6f88-4e74-a3a9-2f34aab42ecb,6d18401d-b332-4805-8b3b-07e4f6e01d13,a52668d8-0468-4b90-9b62-c32a86cae478,203adb04-2d0d-4b2e-ac47-bbaeb3befedd,98a7b7be-a84e-4adf-bbe0-72f34256c87f' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/air-quality-impacts/finding/worsened-allergy-asthma-conditions.yaml identifier: worsened-allergy-asthma-conditions ordinal: 3 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2–3.

In addition, the author team held an all-day meeting at the U.S. Environmental Protection Agency National Center for Environmental Assessment in Crystal City, Virginia, on October 15, 2014, to discuss the chapter and develop initial drafts of the Key Findings. A quorum of the authors participated and represented each of the three sections of the chapter—outdoor air quality, aeroallergens, and indoor air quality. These discussions were informed by the results of the literature review as well as the research highlights focused on outdoor air quality and indoor air quality. The team developed Key Finding 2 in response to comments from the National Research Council review panel and the general public.

The Key Findings for outdoor ozone, wildfires, and aeroallergen impacts reflect strong empirical evidence linking changes in climate to these outcomes. When characterizing the human health impacts from outdoor ozone, the team considered the strength of the toxicological, clinical, and epidemiological evidence evaluated in the Ozone Integrated Science Assessment.e00fb4e2-6406-40be-90f8-071dfc43cca3 Because there is increasing evidence that climate change will increase the frequency and intensity of wildfire events, this outcome was included as a key finding, despite the inability to quantify this impact with the available tools and data. Because altered patterns of precipitation and increasing levels of CO2 are anticipated to promote the level of aeroallergens, this outcome is also included as a Key Finding. Finally, because the empirical evidence linking climate change to indoor air quality was more equivocal, we identified this topic as an emerging issue.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Changes in climate, specifically rising temperatures, altered precipitation patterns, and increasing concentrations of atmospheric carbon dioxide, are expected to contribute to increases in the levels of some airborne allergens and associated increases in asthma episodes and other allergic illnesses [High Confidence].' uncertainties: 'The interrelationships between climate variability and change and exposure to aeroallergens are complex. Where they exist, differences in findings from across the relevant scientific literature may be due to study designs, references to certain species of pollen, geographic characteristics, climate variables, and degree of allergy sensitization.b1d1a01e-78e1-4b26-a8b4-513c43a7240c There are also uncertainties with respect to the role of climate change and the extent and nature of its effects as they contribute to aeroallergen-related diseases, especially asthma.14835bc7-3df6-4fac-9e9a-2863c09e800a Existing uncertainties can be addressed through the development of standardized approaches for measuring exposures and tracking outcomes across a range of allergic illnesses, vulnerable populations, and geographic proximity to exposures.9d0046a1-8cd1-4a6d-a8c1-ab853fd1fb2a' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/air-quality-impacts/finding/worsened-allergy-asthma-conditions url: ~ - chapter_identifier: extreme-events confidence: 'There is high confidence that the types of health impacts associated with climate-related changes in extremes include death, injury, or illness; exacerbation of underlying medical conditions; and adverse effects on mental health (see Table 1). Based on the evidence presented in the peer-reviewed literature, there is medium confidence regarding increases in exposure to health hazards associated with projected increases in the frequency and/or intensity of extreme precipitation, hurricanes, coastal inundation, drought, and wildfires in some regions of the United States.

Many qualitative studies have been published about the potential or expected health hazards from these events, but few draw strong or definitive conclusions that exposure to health hazards will increase due to climate change. Thus, the evidence is suggestive and supports a medium confidence level that, to the extent that these extreme events are projected to increase in some regions of the United States, people are expected to be at greater risk of exposure to health hazards. There is no quantitative information on which to base probability estimates of the likelihood of increasing exposure to health hazards associated with extreme precipitation, hurricanes, coastal inundation, drought, and wildfires.' evidence: 'The Third National Climate Assessment (2014 NCA) provides the most recent, peer-reviewed assessment conclusions for projected increases in the frequency and/or intensity of extreme precipitation, hurricanes, coastal inundation, drought, and wildfires in the United States.dd5b893d-4462-4bb3-9205-67b532919566 To the extent that these extreme events are projected to increase in some regions of the United States, people are expected to be at greater risk of exposure to health hazards.

Flooding associated with extreme precipitation, hurricanes, and coastal storms is expected to increase in some regions of the United States due to climate change, thereby increasing exposure to a variety of health hazards.3f2402c5-22aa-4f75-861e-f6aca127cd1f,c4dc57e5-707f-4967-ab31-2b6e2b94fde5,61fd6e32-63d0-4f5a-bbbb-f68262376a37 The health impacts of floods and storms include death, injury, and illness; exacerbation of underlying medical conditions; and adverse effects on mental health.3be13957-eae2-4796-8504-ef2597b91b09,57f88e8c-2e4f-4e00-91e8-aea256ca3128,c43fa066-6d7b-481b-9a85-22da8c27243a,aa29148e-c86c-443d-9c1d-5a1d7fbc3437,858d9e98-4217-4278-92bf-d113e5561c39,692dfb63-86b7-4268-be18-725585651b27,3a569dc6-4596-488a-8c30-c0b6f884677f,60be18ee-b5bc-4503-8f77-102561b193fb

Climate change is projected to lengthen or intensify droughts, especially in the Southwest,dd5b893d-4462-4bb3-9205-67b532919566,99baa64e-2877-4db9-b257-3f41149e73fe which may increase exposure to a broad set of health hazards.3f2402c5-22aa-4f75-861e-f6aca127cd1f,61fd6e32-63d0-4f5a-bbbb-f68262376a37 The potential health impacts of drought include: illness associated with reduced water quality and quantity f60a6281-fa30-444d-9acd-0d132a6d1683,54b0ebb2-d56b-4863-b32f-b8722abc2d32,6a9eaa35-c30c-4059-9b6b-331950df3f79,8c50c794-b09b-4215-b46c-6c24931faf6e,b6607393-a0f4-47fb-8269-94bd378b6d61 and reduced air quality,792a6471-f6d3-4e85-bdb8-0e6efe9a24a9,eec73554-f1d8-4ab5-a618-c395429c086d,ea9e8c20-fe7c-4a4e-b628-91ac3d300fb8 associations with increased rates of some infectious diseases,52d82168-d4c8-41b0-a318-501dcefb5ff8,6c4943e6-2a76-4989-b80e-8b4d9bacd78a,c8b9489e-b737-4806-8685-4ebda89c8568,79d19ab8-4961-4f28-b678-78b213cdbdf3,f86c2421-ca6f-4634-822b-73de01b5168f and adverse mental health impacts.cd642a0a-9d8e-4c25-a56d-a64260553be6,9845a991-d58b-409b-91b9-670cc383d030,e24d8f4b-4c92-439c-ad81-c17bbbdfc682,dcb9ec60-0e20-442c-928e-cc47a25959bb,c22caf01-8728-44cb-af5b-47fac06d1b68

Large, intense wildfires will occur more frequently in some regions of the United States, particularly in the western United States and Alaska,dd5b893d-4462-4bb3-9205-67b532919566 and this is expected to increase exposure to wildfire-related health risks.61fd6e32-63d0-4f5a-bbbb-f68262376a37,99baa64e-2877-4db9-b257-3f41149e73fe The health impacts of wildfire include death, injury, and illness,bc6db90e-3e83-4c12-8270-83da70318f67,35bb9e8b-e26b-4d68-85a3-c6fcbf8a7e6f,9cdc89b2-5f7e-4739-9bf6-788268921e03,d2b28363-411c-4444-9b05-8204ff607e36,a31388fc-07fd-4ca6-a6a4-7dc7b207e14a,8a6d6f43-acbf-4127-8912-10071eda9093,250b4ec3-1264-4570-8417-c00e6d8752a8,3f73c3f1-422d-44f0-8b31-889628464021,c8a01a08-ba4a-4d6c-af36-dd599317f471,4ee18e43-0d8d-4276-ad51-b87db1d8b7bc,d0bcbc01-6c2e-48bb-a52c-dbd504505758,bf639de9-c45a-40d0-a115-5b1a5e45e5ee,107c077e-4d44-49d7-99a5-84a81f62b7e0,064a28ed-78a7-4e9c-b27f-052db874e800,a1fb85fd-306f-4b7a-8eb1-13925bc31f94 including exacerbation of underlying medical conditions.250b4ec3-1264-4570-8417-c00e6d8752a8,1a72beb2-f4a0-4db9-bac8-eac55cbf676d,47451452-d69e-4cd8-9565-7151ba299836' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/extreme-events/finding/increased-exposure-to-extreme-events.yaml identifier: increased-exposure-to-extreme-events ordinal: 1 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation of the report authors at several workshops, teleconferences, and email exchanges. Authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, please see Appendices 2-3.

The health outcomes selected and prioritized for the chapter were based primarily on those that had substantial peer-reviewed literature to support statements. While many connections between changes in extreme events due to climate change and human health impacts appear intuitive, in some cases there may not be a robust body of peer-reviewed literature to support statements about direct effects. For example, while it is believed that droughts have the ability to impact water quality, which could in turn impact health, there are few studies documenting specific health consequences in the United States.f60a6281-fa30-444d-9acd-0d132a6d1683

In addition, due to space constraints, the authors did not intend to exhaustively identify all possible health impacts from every type of extreme event addressed in this chapter. Instead, the authors have provided an overview of possible impacts from different types of extreme events and provided a framework for understanding what additional factors (for example, population vulnerability, existing quality of infrastructure, etc.) can exacerbate or reduce adverse health outcomes.

Due to limited space and the uncertainty around future projections of tornadoes, we do not include detailed discussion of this topic in this chapter. We recognize that tornadoes can cause significant infrastructure damage and significant health impacts, and understanding how climate change will impact tornado intensity, frequency, and geographic distribution is an area of active scientific investigation.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Health impacts associated with climate-related changes in exposure to extreme events include death, injury, or illness; exacerbation of underlying medical conditions; and adverse effects on mental health [High Confidence]. Climate change will increase exposure risk in some regions of the United States due to projected increases in the frequency and/or intensity of drought, wildfires, and flooding related to extreme precipitation and hurricanes [Medium Confidence].' uncertainties: 'The role of climate change in observed shifts in and future projections of the frequency, intensity, geographic distribution, and duration of certain extreme events is an ongoing, active area of research. For example, although the 2014 NCAdd5b893d-4462-4bb3-9205-67b532919566 concluded that extreme events will increase in some regions of the United States, uncertainties remain with respect to projections of climate impacts at smaller, more local scales and the timing of such impacts (see Table 1). Climate change related projections of winter storms and severe storms, including tornadoes, hail, and thunderstorms, are still uncertain.

The human health implications of the changes in extreme events have not received as much research attention to date, and there are currently no published, national-scale, quantitative projections of changes in exposure risks for the four categories of extreme events addressed in this chapter. Relevant health surveillance and epidemiological data for extreme events are limited by underreporting, underestimation, and lack of a common definition of what constitutes an adverse health impact from an extreme event.91c3ced0-65bc-43f7-b50c-11742eb657d5,c43fa066-6d7b-481b-9a85-22da8c27243a For drought in particular, there are few studies documenting specific health consequences in the United States.f60a6281-fa30-444d-9acd-0d132a6d1683 Challenges to quantitatively estimating future human health risks for the four types of extreme events addressed in this chapter include limited data availability and lack of comprehensive modeling methods. For winter storms and severe storms especially, scientists need a better understanding of how climate change will affect future storm trends before they can make projections of future health impacts.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/extreme-events/finding/increased-exposure-to-extreme-events url: ~ - chapter_identifier: extreme-events confidence: 'There is high confidence that many types of extreme events can cause disruption of essential infrastructure (such as water, transportation, and power systems), and that such disruption can adversely affect human health. Many qualitative studies have been published about the effects of these factors on health impacts from an extreme event (noted above), and the evidence is of good quality and consistent.' evidence: 'The frequency, intensity, and duration of extreme events determines their physical impacts and the extent to which essential infrastructure is disrupted. There is strong, consistent evidence from multiple studies that infrastructure can either exacerbate or moderate the physical impacts of extreme events, influencing the ultimate nature and severity of health impacts. Projections of increasing frequency and/or intensity of some extreme events suggest that they pose threats to essential infrastructure, such as water, transportation, and power systems.089d8050-f4c8-4d07-bc35-25bf61691be3,686dd899-0f98-4423-ba29-fce90af74586,5a79e12b-b65c-40ef-8f80-7bcb04d57a1d,13d048c9-77d7-4bbb-beeb-ee49842d2719 Disruption of essential infrastructure and services after extreme events can increase population exposure to health hazards and reduce their adaptive capacity.089d8050-f4c8-4d07-bc35-25bf61691be3 There is substantial, high-quality literature supporting a finding that serious health risks can arise from utility outages; infrastructure and housing damage; and disruption or loss of access to sanitation, safe food and water supplies, health care, communication, and transportation.3be13957-eae2-4796-8504-ef2597b91b09,57f88e8c-2e4f-4e00-91e8-aea256ca3128,91c3ced0-65bc-43f7-b50c-11742eb657d5,c43fa066-6d7b-481b-9a85-22da8c27243a,53acdf32-e868-45b1-a669-83c0fa419f53,13d048c9-77d7-4bbb-beeb-ee49842d2719,dd072932-2da1-4e6c-b18a-6f7649969625,9a6c7a87-5c0f-4d64-904c-c707f68f2115,aa29148e-c86c-443d-9c1d-5a1d7fbc3437,ad3c4329-eac0-47ea-8342-be6ca602610c,eec8bc7b-93a6-4b99-92e7-18bf3e25bc9d,d887debf-59d6-423b-8f0f-433b49f9c9ca,858d9e98-4217-4278-92bf-d113e5561c39,692dfb63-86b7-4268-be18-725585651b27,3a569dc6-4596-488a-8c30-c0b6f884677f,81e4da11-12ba-4f0e-8bdb-ca6a8dadd63d,60be18ee-b5bc-4503-8f77-102561b193fb,e3439854-edb7-4acd-9e4f-b6ae0477f688

Infrastructure disruptions can have more or less impact on human health depending on the underlying vulnerability of the affected people and communities.089d8050-f4c8-4d07-bc35-25bf61691be3 Urban populations face unique exposure risks due to their dependence on complex, often interdependent infrastructure systems that can be severely disrupted during extreme events.dd5b893d-4462-4bb3-9205-67b532919566,df8dbdfc-912f-40b7-88a7-b3acbf026856 Rural communities also have vulnerabilities that are different from those faced by urban communities. For example, power and communications can take longer to restore after an outage.d57129df-a14f-4f92-9e8b-0140ee6672bb

Existing infrastructure is generally designed to perform at its engineered capacity assuming historical weather patterns, and these systems could be more vulnerable to failure in response to weather-related stressors under future climate scenarios.089d8050-f4c8-4d07-bc35-25bf61691be3,686dd899-0f98-4423-ba29-fce90af74586,a31abb74-51b0-46a9-a1db-cf9c708a457a Shifts in the frequency or intensity of extreme events outside their historical range pose infrastructure risks that may be compounded by the fact that much of the existing critical infrastructure in the United States, including water and sewage systems, roads, bridges, and power plants, are aging and in need of repair or replacement.089d8050-f4c8-4d07-bc35-25bf61691be3,5a79e12b-b65c-40ef-8f80-7bcb04d57a1d' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/extreme-events/finding/disruption-of-essential-infrastructure.yaml identifier: disruption-of-essential-infrastructure ordinal: 2 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation of the report authors at several workshops, teleconferences, and email exchanges. Authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, please see Appendices 2–3.

The health outcomes selected and prioritized for the chapter were based primarily on those that had substantial peer-reviewed literature to support statements. While many connections between changes in extreme events due to climate change and human health impacts appear intuitive, in some cases there may not be a robust body of peer-reviewed literature to support statements about direct effects. For example, while it is believed that droughts have the ability to impact water quality, which could in turn impact health, there are few studies documenting specific health consequences in the United States.f60a6281-fa30-444d-9acd-0d132a6d1683

In addition, due to space constraints, the authors did not intend to exhaustively identify all possible health impacts from every type of extreme event addressed in this chapter. Instead, the authors have provided an overview of possible impacts from different types of extreme events and provided a framework for understanding what additional factors (for example, population vulnerability, existing quality of infrastructure, etc.) can exacerbate or reduce adverse health outcomes.

Due to limited space and the uncertainty around future projections of tornadoes, we do not include detailed discussion of this topic in this chapter. We recognize that tornadoes can cause significant infrastructure damage and significant health impacts, and understanding how climate change will impact tornado intensity, frequency, and geographic distribution is an area of active scientific investigation.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Many types of extreme events related to climate change cause disruption of infrastructure, including power, water, transportation, and communication systems, that are essential to maintaining access to health care and emergency response services and safeguarding human health [High Confidence].' uncertainties: 'Many of the uncertainties are similar to those of the previous key finding. There are few studies directly linking infrastructure impacts to health outcomes, and most are not longitudinal. Health impacts may occur after the event as a result of loss of infrastructure and public services. These impacts can be distributed over longer periods of time, making them harder to observe and quantify. Thus, the actual impact is likely underreported.

Uncertainties remain with respect to projecting how climate change will affect the severity of the physical impacts, including on infrastructure, of extreme events at smaller, more local scales and the timing of such impacts. Therefore, the subsequent impact on infrastructure also has a great deal of uncertainty. Thus, the key finding does not make any statements about future impacts. Instead the focus is on impacts that have occurred to date because there is supporting peer-reviewed literature. The extent to which infrastructure is exposed to extreme events, and the adaptive capacity of a community to repair infrastructure in a timely manner both influence the extent of the health outcomes. Thus, while the chapter makes general statements about trends in impacts due to extremes, there are uncertainties in the extent to which any specific location or infrastructure system could be impacted and the resulting health outcomes.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/extreme-events/finding/disruption-of-essential-infrastructure url: ~ - chapter_identifier: extreme-events confidence: 'Based on the evidence presented in the peer-reviewed literature, there is high confidence that coastal flooding will increase in the United States, and that age, health status, socioeconomic status, race/ethnicity, and occupation are key risk factors that individually and collectively affect a population’s vulnerability to health impacts from coastal flooding. Many qualitative studies have been published regarding how these key risk factors interact with and contribute to the exposure, sensitivity, and adaptive capacity of a population, and this evidence is of good quality and consistent.' evidence: 'The evidence in the peer-reviewed literature that climate change will increase coastal flooding in the future is very robust.dd5b893d-4462-4bb3-9205-67b532919566,089d8050-f4c8-4d07-bc35-25bf61691be3 Global sea level has risen by about 8 inches since reliable record keeping began in 1880 and it is projected to rise another 1 to 4 feet by 2100.dd5b893d-4462-4bb3-9205-67b532919566 Rates of sea level rise are not uniform along U.S. coasts and can be exacerbated locally by land subsidence or reduced by uplift. In the next several decades, storm surges and high tides could combine with sea level rise and land subsidence to further increase coastal flooding in many regions. The U.S. East and Gulf coasts, Hawaii, and the U.S.-affiliated Pacific Islands are particularly at risk. In addition, recurrent weather-related stressors, such as “nuisance flooding” (frequent coastal flooding causing public inconveniences), contribute to overall deterioration of infrastructure like stormwater drainage systems and roads (see Ch. 6: Water-Related Illness).bbf3043e-9999-4f0e-8d0c-6012450d9d84 These systems are important in the context of health because drainage helps to avoid sewage overflows and maintain water quality,067c087d-ac72-448f-8a8f-c554d7897519 and roads are vital for evacuations and emergency response during and after extreme events.53acdf32-e868-45b1-a669-83c0fa419f53

There is strong, consistent evidence in the literature that coastal flooding will increase exposure to a variety of health hazards—for example, direct physical impacts and impacts associated with disruption of essential infrastructure—which can result in death, injury, or illness; exacerbation of underlying medical conditions; and adverse effects on mental health.3be13957-eae2-4796-8504-ef2597b91b09,57f88e8c-2e4f-4e00-91e8-aea256ca3128,c43fa066-6d7b-481b-9a85-22da8c27243a,aa29148e-c86c-443d-9c1d-5a1d7fbc3437,858d9e98-4217-4278-92bf-d113e5561c39,692dfb63-86b7-4268-be18-725585651b27,3a569dc6-4596-488a-8c30-c0b6f884677f,60be18ee-b5bc-4503-8f77-102561b193fb Multiple studies also consistently identify certain populations as especially vulnerable to the health impacts of coastal flooding. These populations include older adults (especially those who are frail, medically incapacitated, or residing in nursing or assisted living facilities), children, those reliant on electrically powered medical equipment like ventilators and oxygen supplies, those with preexisting health conditions, and people with disabilities.3be13957-eae2-4796-8504-ef2597b91b09,61b95c91-09b7-4f17-b551-dce616662ae6,b00a1349-fb5f-4e2d-b1bc-cfceb0863de2,13d048c9-77d7-4bbb-beeb-ee49842d2719,dd072932-2da1-4e6c-b18a-6f7649969625,3a569dc6-4596-488a-8c30-c0b6f884677f,81e4da11-12ba-4f0e-8bdb-ca6a8dadd63d,6a74b0ff-705b-433e-8b26-59b7284cca88,fd7edbac-5131-49ad-9f44-d3f05e098b75,8204e372-0cb0-48ee-8d15-f6a7318d0fda In addition, differences in exposure, sensitivity, and adaptive capacity lead to a disproportionate number of flood-related fatalities among older adults, males, and some low-income communities of color.57f88e8c-2e4f-4e00-91e8-aea256ca3128 Floods and storms also create occupational health risks to first responders and other emergency workers and to people involved in cleanup activities, construction, public utilities restoration, and security/policing.3be13957-eae2-4796-8504-ef2597b91b09,c4dc57e5-707f-4967-ab31-2b6e2b94fde5,e3439854-edb7-4acd-9e4f-b6ae0477f688,895a462d-2faa-44e3-a888-31efb349f44d' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/extreme-events/finding/vulnerability-to-coastal-flooding.yaml identifier: vulnerability-to-coastal-flooding ordinal: 3 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation of the report authors at several workshops, teleconferences, and email exchanges. Authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, please see Appendices 2–3.

The health outcomes selected and prioritized for the chapter were based primarily on those that had substantial peer-reviewed literature to support statements. While many connections between changes in extreme events due to climate change and human health impacts appear intuitive, in some cases there may not be a robust body of peer-reviewed literature to support statements about direct effects. For example, while it is believed that droughts have the ability to impact water quality, which could in turn impact health, there are few studies documenting specific health consequences in the United States.f60a6281-fa30-444d-9acd-0d132a6d1683

In addition, due to space constraints, the authors did not intend to exhaustively identify all possible health impacts from every type of extreme event addressed in this chapter. Instead, the authors have provided an overview of possible impacts from different types of extreme events and provided a framework for understanding what additional factors (for example, population vulnerability, existing quality of infrastructure, etc.) can exacerbate or reduce adverse health outcomes.

Due to limited space and the uncertainty around future projections of tornadoes, we do not include detailed discussion of this topic in this chapter. We recognize that tornadoes can cause significant infrastructure damage and significant health impacts, and understanding how climate change will impact tornado intensity, frequency, and geographic distribution is an area of active scientific investigation.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Coastal populations with greater vulnerability to health impacts from coastal flooding include persons with disabilities or other access and functional needs, certain populations of color, older adults, pregnant women and children, low-income populations, and some occupational groups [High Confidence]. Climate change will increase exposure risk to coastal flooding due to increases in extreme precipitation and in hurricane intensity and rainfall rates, as well as sea level rise and the resulting increases in storm surge [High Confidence].' uncertainties: 'It is nearly certain that coastal flooding will increase in the United States. There are varying estimates regarding the exact degree of flooding at any particular location along the coast. Modeling does provide estimated ranges with varying levels of confidence depending on the location. There is greater uncertainty about how coastal flooding will impact the health of specific populations. There are various ways in which these key risk factors interact with and contribute to the vulnerability (comprised of exposure, sensitivity, and adaptive capacity) of a population. Some uncertainties exist regarding the relative importance of each of these factors in determining a population’s vulnerability to health impacts from extreme events. In addition, there is some uncertainty regarding how future demographic and population changes may affect the relative importance of each of these factors.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/extreme-events/finding/vulnerability-to-coastal-flooding url: ~ - chapter_identifier: vectorborne-diseases confidence: 'Based on the evidence that climate change will influence the temporal and spatial distributions of vectors, pathogens, and animal reservoirs, there is high confidence that climate change is likely to alter the geographic and seasonal distributions of vectors and vector-borne diseases.' evidence: 'Vector-borne diseases result from complex interactions involving vectors, reservoirs, humans, and both climate and non-climate factors. Numerous studies explain how climate variables influence the relationships between vectors, animal reservoirs, humans, and other non-climate factors to ultimately influence the spatial and temporal distribution of vector-borne disease.cc7c424e-b684-414f-8896-af2d2fee05b6,77f948ec-3f41-4367-a120-6096a78706f5,2471c8e7-348f-40c2-9a28-0d46d3d1f1df,eb0e35fc-5e5e-4df4-900c-b85fc4f26d28,c3fa0d45-e602-4539-b0d8-98516bcee406,8fdde45b-cdd1-49de-b74f-966c15770b2d,d8fa9745-f20f-4681-8eec-586cc6b8d369,945868ae-7a42-4c03-aecf-42d9f4b39a65,68125763-fcdc-4e32-81d2-a42e88a85a31,0cdb219f-c600-4fbf-b4c6-2d89f77d2868' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/vectorborne-diseases/finding/changing-distributions-vectors-vectorborne-diseases.yaml identifier: changing-distributions-vectors-vectorborne-diseases ordinal: 1 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2 and 3.

The approach and organization of this chapter was decided after conducting a comprehensive literature review. Two case studies, Lyme disease and West Nile virus, were chosen as representative examples of vector-borne diseases in the United States for this chapter because of their high incidence rates and the body of literature available on the association between climatic and meteorological variables and occurrence of these diseases.

Regarding human outcomes related to vector-borne diseases, there is a much greater volume of published literature available on meteorological and climatic influences on vectors. As a result, our certainty in how climate change is likely to influence the vectors far exceeds our certainty in how changing climatic conditions are likely to affect when, where, and how many cases of vector-borne diseases are likely to occur.

Although the topic of zoonotic diseases was included in the original prospectus, it was later removed due to space constraints. Additionally, since both West Nile virus infection and Lyme disease are zoonotic diseases, these case studies address concepts that are common to both vector-borne and zoonotic diseases.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Climate change is expected to alter the geographic and seasonal distributions of existing vectors and vecto-rborne diseases [Likely, High Confidence].' uncertainties: 'It is certain that climate change will alter the geographic and seasonal distribution of existing vectors, pathogens, and reservoirs; the influence of climate change on the timing, prevalence, and location of specific vector-borne disease outbreaks is likely to vary depending on the influence of other significant non-climate drivers of disease occurrence.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/vectorborne-diseases/finding/changing-distributions-vectors-vectorborne-diseases url: ~ - chapter_identifier: vectorborne-diseases confidence: 'Based on the evidence, there is high confidence that climate change, especially temperature change, is likely to cause shifts in the geographical distribution of ticks capable of carrying B. burgdorferi to more northern latitudes, the timing of host-seeking activity of ticks, and the timing of Lyme disease case occurrence. While these changes are likely to influence human disease, due to the few sources with limited consistency, incomplete models with methods still emerging, and some competing schools of thought, there is medium confidence surrounding how, and how much, climate change will influence the risk of human exposure to ticks carrying B. burgdorferi.' evidence: 'There is strong evidence that temperature affects the geographical distribution of ticks,77f948ec-3f41-4367-a120-6096a78706f5,2471c8e7-348f-40c2-9a28-0d46d3d1f1df,eb0e35fc-5e5e-4df4-900c-b85fc4f26d28,c50c2ea8-a6e8-4d12-80cc-272598748b84 the timing of host-seeking activity of ticks,4902bb7e-2914-469b-b0ee-06dc728f00c5,d9419ba6-ddc5-40dc-bc5d-ec5e2aa49fd3,3089e09f-56d0-4d4b-88ec-0449550a27c5 and even the timing of Lyme disease case occurrence.0360d0f9-db3c-40a7-841c-a286027e0e7b However, the abundance of ticks infected with Lyme disease spirochetes, which is considered a better predictor of human risk for Lyme disease compared with nymphal density alone, has rarely been found to be strongly associated with meteorological variables.94cb8d14-af54-4ab8-9c54-d502f5e0ea45 Studies aimed at identifying meteorological variables associated with the geographical distribution of human Lyme disease vary in their support for demonstrating positive associations between temperature and Lyme disease.d35c84bd-e490-4662-8da2-241de3090e3f,197d65cd-c05e-4ddb-8a9d-5a9aed134974,bc29c835-8d1d-4608-abe9-6320f34a1b16' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/vectorborne-diseases/finding/earlier-tick-activity-northward-range-expansion.yaml identifier: earlier-tick-activity-northward-range-expansion ordinal: 2 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2 and 3.

The approach and organization of this chapter was decided after conducting a comprehensive literature review. Two case studies, Lyme disease and West Nile virus, were chosen as representative examples of vector-borne diseases in the United States for this chapter because of their high incidence rates and the body of literature available on the association between climatic and meteorological variables and occurrence of these diseases.

Regarding human outcomes related to vector-borne diseases, there is a much greater volume of published literature available on meteorological and climatic influences on vectors. As a result, our certainty in how climate change is likely to influence the vectors far exceeds our certainty in how changing climatic conditions are likely to affect when, where, and how many cases of vector-borne diseases are likely to occur.

Although the topic of zoonotic diseases was included in the original prospectus, it was later removed due to space constraints. Additionally, since both West Nile virus infection and Lyme disease are zoonotic diseases, these case studies address concepts that are common to both vector-borne and zoonotic diseases.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Ticks capable of carrying the bacteria that cause Lyme disease and other pathogens will show earlier seasonal activity and a generally northward expansion in response to increasing temperatures associated with climate change [Likely, High Confidence]. Longer seasonal activity and expanding geographic range of these ticks will increase the risk of human exposure to ticks [Likely, Medium Confidence].' uncertainties: 'While the effects of temperature, precipitation, and humidity on the spatial distribution of ticks and the timing of their host-seeking activity have been clearly established in both the eastern and western regions of the United States, where Lyme disease is common, the degree to which climate change will alter Lyme disease incidence remains uncertain. The observation that meteorological variables play a lesser role than other variables in predicting the density of nymphs infected with Lyme disease bacteria raises uncertainty in how climate change will affect the distribution and magnitude of Lyme disease incidence. This uncertainty is reflected in results from models aiming to associate meteorological variables with Lyme disease incidence that yielded inconsistent findings.d35c84bd-e490-4662-8da2-241de3090e3f,197d65cd-c05e-4ddb-8a9d-5a9aed134974,bc29c835-8d1d-4608-abe9-6320f34a1b16' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/vectorborne-diseases/finding/earlier-tick-activity-northward-range-expansion url: ~ - chapter_identifier: vectorborne-diseases confidence: 'Based on the evidence, there is high confidence that climate change is very likely to influence mosquito distribution, abundance, and infection prevalence by altering habitat availability and mosquito and viral reproduction rates. While this is very likely to influence human disease, due to the few sources with limited consistency, incomplete models with methods still emerging, and some competing schools of thought, there is medium confidence surrounding how, and how much, climate change will influence human incidence of disease.' evidence: 'Higher temperatures affect the West Nile virus (WNV) system by accelerating mosquito development6cb63356-47f7-4ba2-aa75-dbc7517b5399,8fdde45b-cdd1-49de-b74f-966c15770b2d and virus reproduction rates,c3fa0d45-e602-4539-b0d8-98516bcee406,8c5c5e1d-4d05-4c0e-8587-95895e42c7f3,133275d2-6318-44fd-b5be-2e3ab47b5d2b,2a946904-7173-4d32-8f15-db4f8f45f5f5 increasing egg-laying and biting frequency,fe14b0e8-c6e8-4e81-bd63-955c7d780308 and affecting mosquito survival.6cb63356-47f7-4ba2-aa75-dbc7517b5399,b18cdaac-0f7f-48ef-a9b9-ec3e27006924 Increased WNV activity has been associated with warm temperatures, mild winters, and drought.c3fa0d45-e602-4539-b0d8-98516bcee406,5bd8de26-58f4-44b9-9919-885bb217bfb1,945868ae-7a42-4c03-aecf-42d9f4b39a65 Very few studies have used climate variables to predict the occurrence of human WNV cases in the United States in response to climate change (for example, Harrigan et al. 2014),132133f3-1705-42ed-b505-8ccbaa497968 but available results suggest that areas of WNV transmission will expand in the northern latitudes and higher elevations driven by increasing temperature, while WNV transmission may decrease in the South if increasing temperatures reduce mosquito survival or limit availability of surface water, such as that provided by agricultural irrigation.' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/vectorborne-diseases/finding/changing-mosquitoborne-disease-dynamics.yaml identifier: changing-mosquitoborne-disease-dynamics ordinal: 3 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2 and 3.

The approach and organization of this chapter was decided after conducting a comprehensive literature review. Two case studies, Lyme disease and West Nile virus, were chosen as representative examples of vector-borne diseases in the United States for this chapter because of their high incidence rates and the body of literature available on the association between climatic and meteorological variables and occurrence of these diseases.

Regarding human outcomes related to vector-borne diseases, there is a much greater volume of published literature available on meteorological and climatic influences on vectors. As a result, our certainty in how climate change is likely to influence the vectors far exceeds our certainty in how changing climatic conditions are likely to affect when, where, and how many cases of vector-borne diseases are likely to occur.

Although the topic of zoonotic diseases was included in the original prospectus, it was later removed due to space constraints. Additionally, since both West Nile virus infection and Lyme disease are zoonotic diseases, these case studies address concepts that are common to both vector-borne and zoonotic diseases.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Rising temperatures, changing precipitation patterns, and a higher frequency of some extreme weather events associated with climate change will influence the distribution, abundance, and prevalence of infection in the mosquitoes that transmit West Nile virus and other pathogens by altering habitat availability and mosquito and viral reproduction rates [Very Likely, High Confidence]. Alterations in the distribution, abundance, and infection rate of mosquitoes will influence human exposure to bites from infected mosquitoes, which is expected to alter risk for human disease [Very Likely, Medium Confidence].' uncertainties: 'While the influence of temperature and precipitation on mosquito and WNV biology are fairly well-understood, these relationships vary across the United States depending on the local mosquito vector species, land use, and human activity.8a6987a1-ec6c-4027-9a29-315c7bfdbdd2,56d62d2b-1544-45fa-9336-aaf3708df8d0 For mosquitoes in urban areas, droughts may lead to stagnation of water and increased mosquito populations that enhance WNV transmission,5bd8de26-58f4-44b9-9919-885bb217bfb1,6c4943e6-2a76-4989-b80e-8b4d9bacd78a while in rural or agricultural areas, droughts may reduce mosquito populations by reducing available mosquito habitat for breeding,c3fa0d45-e602-4539-b0d8-98516bcee406 except when irrigation compensates for drought conditions.56d62d2b-1544-45fa-9336-aaf3708df8d0 Long-term projections of human WNV risk under climate change scenarios are still in the early stages of development and are impeded by the complexities of the disease transmission cycle. Evolution of the virus, improvements in mosquito control, and the potential for long-term changes in human behavior that may affect exposure to WNV are key sources of uncertainty. For this reason, short-term, seasonal forecasts of WNV may be more fruitful in the near term and may provide information for seasonal resource allocation and public health planning.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/vectorborne-diseases/finding/changing-mosquitoborne-disease-dynamics url: ~ - chapter_identifier: vectorborne-diseases confidence: 'Based on the evidence, there is high confidence that a multitude of interacting factors, one of which being climate change, will likely influence the emergence or reemergence of vector-borne pathogens to the United States. Additionally, there is high confidence that the influence of climate change on human disease is likely to be limited by the adaptive capacity of a population.' evidence: 'The literature shows that climate change must be considered together with the many other non-climate factors of disease emergencecc7c424e-b684-414f-8896-af2d2fee05b6,6a97bff6-1f26-4e47-aba2-4a513d63ef47 and the availability of other mitigating factors, such as air conditioning, screens on windows, and vector control practices,c00f6a68-4fab-428d-92c6-fb5e266448a8,10d79a4e-fb2f-4f3a-ae97-6bd6c583da69,10973e71-74e8-4308-864b-a90aadfba382,e4eeb858-5dc4-4af9-8633-b1be0fca7f60 in order to appropriately quantify the impact climate has on the risk of emerging or reemerging exotic pathogens and vectors.' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/vectorborne-diseases/finding/emergence-new-vectorborne-pathogens.yaml identifier: emergence-new-vectorborne-pathogens ordinal: 4 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2 and 3.

The approach and organization of this chapter was decided after conducting a comprehensive literature review. Two case studies, Lyme disease and West Nile virus, were chosen as representative examples of vector-borne diseases in the United States for this chapter because of their high incidence rates and the body of literature available on the association between climatic and meteorological variables and occurrence of these diseases.

Regarding human outcomes related to vector-borne diseases, there is a much greater volume of published literature available on meteorological and climatic influences on vectors. As a result, our certainty in how climate change is likely to influence the vectors far exceeds our certainty in how changing climatic conditions are likely to affect when, where, and how many cases of vector-borne diseases are likely to occur.

Although the topic of zoonotic diseases was included in the original prospectus, it was later removed due to space constraints. Additionally, since both West Nile virus infection and Lyme disease are zoonotic diseases, these case studies address concepts that are common to both vector-borne and zoonotic diseases.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Vector-borne pathogens are expected to emerge or reemerge due to the interactions of climate factors with many other drivers, such as changing land-use patterns [Likely, High Confidence]. However, the impacts to human disease will be limited by the adaptive capacity of human populations, such as vector control practices or personal protective measures [Likely, High Confidence].' uncertainties: 'It remains uncertain how climate interacts as a driver with travel-related exposures and evolutionary adaptation of invasive vectors and pathogens to affect human disease. Improved longitudinal datasets and empirical models that include vector–host interaction, host immunity, and pathogen evolution as well as socioeconomic drivers of transmission are needed to address these knowledge gaps in research on climate sensitive diseases.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/vectorborne-diseases/finding/emergence-new-vectorborne-pathogens url: ~ - chapter_identifier: water-related-illnesses confidence: 'Based on the evidence, there is medium confidence that, with changing climate, the annual seasonal and the geographic range for Vibrio and certain marine harmful algae will expand. The assessment of medium confidence is due to less certainty from modeling results regarding the magnitude of projected changes in abundance. The conclusions were deemed very likely to occur for Vibrio and likely for marine harmful algae based on good levels of agreement found in the published quantitative modeling projections for both Vibrio and marine harmful algae (Alexandrium and Gambieridiscus) cited above. This conclusion takes into consideration that for some marine algae (for example, Gambieridiscus), lower latitudes may become too warm and risk may decline in those areas as it increases at higher latitudes. For freshwater harmful algae, there is high confidence that annual season and geographic range will expand with changing climate, which will also prolong the time for exposure and the potential for public health impacts. Consistent and high-quality evidence from a limited number of laboratory studies, modeling efforts, field surveys, and comparisons of historic and contemporary conditions support this assessment. The conclusion was deemed very likely to occur for freshwater harmful algae with high confidence based on laboratory studies and field observations, as well as a greater fundamental understanding of inland hydrodynamics and bloom ecology as indicated in the literature cited in the chapter. There is medium confidence regarding increased risk to human health from a longer potential time for exposure to waterborne pathogens and algal toxins and potential exposure for a wider (or novel) population. This confidence level was chosen due to less certainty stemming from a relative lack of quantitative data and projections for future illness rates in the peer-reviewed literature.' evidence: 'Vibrio, a genus of naturally occurring waterborne pathogens, thrives in water temperatures above a 15¡C/59¡F threshold.8640a3db-35fa-4089-8fb5-d52dc8b35c71,2b04b041-511c-4b3f-9e44-70d0cfae3052,7965c0b9-f4c0-43c4-8c4c-8e918935f88e,918354f7-f16e-4cad-9289-20d41305abb8 Rising sea surface temperatures have contributed to an expanded geographic and seasonal range in outbreaks of human illness associated with Vibrio in shellfish.dcfc6226-3871-4225-86f7-948f7db208fb,2b04b041-511c-4b3f-9e44-70d0cfae3052,84bc6e97-2f18-4ebd-b36a-a576fa710edd,7965c0b9-f4c0-43c4-8c4c-8e918935f88e,9cef4119-4454-439b-829a-bdb8f458dd15 In recreational waters, projected increases in sea surface temperatures are expected to lengthen the seasonal window of growth and expand geographic range of Vibrio.dcfc6226-3871-4225-86f7-948f7db208fb,8640a3db-35fa-4089-8fb5-d52dc8b35c71 Like other heterotrophic bacteria, growth of Vibrio is ultimately limited by availability of carbon substrate, though the coastal areas where Vibrio exposure is most likely, either through recreation or consumption of shellfish, generally have sufficient dissolved organic carbon.e3dacc9e-e7ee-4513-b8e1-f867412428f5 Reported rates of all Vibrio infections have tripled since 1996 in the United States, with V. alginolyticus infections having increased by 40-fold.59b468e2-b673-4b43-9daf-6b01b4084163 Increasing sea surface temperatures, changes in precipitation and freshwater delivery to coastal waters, and sea level rise will continue to affect Vibrio growth and are expected to increase human exposure.dcfc6226-3871-4225-86f7-948f7db208fb,226d31a2-0831-48a5-b8fd-f1093c62db54,2b04b041-511c-4b3f-9e44-70d0cfae3052,918354f7-f16e-4cad-9289-20d41305abb8

Most harmful algae, including freshwater cyanobacteria that can contaminate drinking water and marine dinoflagellate species that can contaminate fish and shellfish with natural toxins, thrive during the warm summer season or when water temperatures are higher than usual. As the climate continues to warm, water temperatures will rise above thresholds that promote bloom development earlier in the spring and will persist longer into the fall and expand into higher latitudes. This will result in a longer seasonal window and expanded geographic range for human exposure into higher latitudes.1dd93561-606a-43ea-a054-c2626750c5f0,1fd644a4-c88d-4a0f-9353-bdb018ed2ccf,204a45ba-2f11-48f2-82e0-8075379b0a7d,3cfcb05a-9a2a-4fb1-89be-6377ea83e5d0,0ccd902c-2e71-4609-a8e8-67d8370f0042,b4b8411d-3670-43ec-a0a0-506018d910bd,be655d0c-74e0-4fb4-afa3-2f4a0770dc38,3325ef64-347b-4c33-9289-9e05e905dcbe,db612cfb-eafa-45fc-8083-1606aa5c5801,69d04f03-5ba1-46a6-a7e3-fa449d448bea,d8dfdb53-b50a-49f5-b1e1-4886738b1297 Climate change, especially continued warming, will increase the burden of some marine HAB-related diseases, particularly ciguatera fish poisoning, in some regions of the United States.' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/water-related-illnesses/finding/seasonal-geographic-changes-waternborne-illness-risk.yaml identifier: seasonal-geographic-changes-waternborne-illness-risk ordinal: 1 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. Authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2 and 3.

Many water-related illnesses are of critical importance globally, such as cholera and hepatitis E virus, and they affect U.S. interests abroad, but the focus of this chapter is to address climate impacts on water-related illnesses of primary importance to human health within the United States. In addition, although climate change has the potential to impact national as well as global seafood supplies, this chapter does not cover these types of impacts because the peer-reviewed literature is not yet robust enough to make connections to human health outcomes in the United States. Even with those constraints, the impacts of climate on water-related illness are regionally or locally specific and may include increased risks as well as benefits. For example, the projected geographic range shifts of some Gambieridiscus species to more northern latitudes may mean that dominant ciguatera fish poisoning toxins enter the marine food web through different species, with increases of toxins in new areas where waters are warming and potential decreases in areas such as the Yucatan and eastern Caribbean Sea.1dfd14e0-eae8-46d9-9c3e-0fa3f0c37da4' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Increases in water temperatures associated with climate change will alter the seasonal windows of growth and the geographic range of suitable habitat for freshwater toxin-producing harmful algae [Very Likely, High Confidence], certain naturally occurring Vibrio bacteria [Very Likely, Medium Confidence], and marine toxin-producing harmful algae [Likely, Medium Confidence]. These changes will increase the risk of exposure to waterborne pathogens and algal toxins that can cause a variety of illnesses [Medium Confidence].' uncertainties: 'Uncertainty remains regarding the relative importance of additional factors that may also act on naturally occurring pathogens and harmful algae at local or regional levels to influence their growth, distribution, and toxicity. In many cases, it is uncertain how these multiple factors may interact with each other to influence the seasonal windows and geographic range for pathogens and harmful algae, especially in dynamic coastal marine environments. For example, changes in salinity, competition with other plankton, and presence of viruses or other organisms that consume plankton or bacteria can affect abundance.d0d412e3-c46b-45a3-b4e5-c3e54c896c36,cb3ad7db-a5a1-473e-bda9-ff18f5f06b6f Changing distribution patterns for some marine species of harmful algae is not well understood and some regions may become too warm for certain species of harmful algae to grow, shifting (without changing in total size) or even shrinking their geographic range.

Additionally, there are limited studies on projections for changes in illness rates due to naturally occurring waterborne pathogens and harmful algae. Uncertainty remains regarding appropriate methods for projecting changes in illness rates, including how to integrate considerations of human behavior into modeling (current methods to assess exposure risk assume similar human behavior across time scales and geography). Methodological challenges are related to 1) underreporting and underdiagnosis of cases that affect the accuracy of baseline estimates of illness, 2) ability to project changes in strain virulence, 3) accounting for the effects of potential adaptation strategies/public health interventions (for example, public service announcements on how to avoid exposure), and 4) accounting for changes in public healthcare infrastructure and access that can reduce the risk of exposure or illness/death if exposed.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/water-related-illnesses/finding/seasonal-geographic-changes-waternborne-illness-risk url: ~ - chapter_identifier: water-related-illnesses confidence: 'Based on the evidence, there is high confidence that increasing frequency or intensity of extreme precipitation events will compromise recreational waters and sources of drinking water with pathogens, nutrients, and chemical contaminants from agricultural, wildlife, and urban sources.

There is consistent qualitative evidence that flooding associated with extreme precipitation events and storm surge results in loading of pathogens and nutrients to surface and groundwater (and drinking water distribution systems) through stormwater runoff and sewage overflows. However, other human and social factors modify risk, and there are no national-level studies upon which to draw conclusions regarding quantitative projections of increased exposure. Thus, the limited number of studies supports a medium confidence level that human exposure risk will increase due to changes in extreme events.' evidence: 'Extreme precipitation can mobilize pathogens, nutrients, and chemical contaminants from agricultural, wildlife, and urban sources. Waterborne illness and outbreaks from pathogens following heavy precipitation events have been well documented in multiple studies using both passive and active surveillance on a local and regional level.dba82efa-be61-4edd-af85-ee5e3ed07139,686b4c04-41ae-4e4f-b66d-c091a81fbf2b,b2f32879-6a7c-4f28-b53e-4e04a8aa0b1e,21e1cee8-0687-41e3-89f0-b6ccf4321f40,75de5138-1833-4aaa-8c2b-646287f3d33c,3e64a90d-f0c2-4f1a-a286-ce437bd95e60,0753011f-53bd-40b8-a4b9-f22040fe617f,662c61dc-9cc8-44ac-b867-053086299e68,74c63f7c-61a8-4f16-8107-302340e75bac Likewise, extreme precipitation events and subsequent increases in runoff are key climate factors that increase nutrient loading in freshwater and marine recreational waters, shellfish harvesting waters, and sources of drinking water, which in turn increases the likelihood of harmful cyanobacterial blooms that produce algal toxins.9224c0ef-9655-4335-a810-ce86baf5a502 The drinking water treatment process can remove cyanobacterial blooms; however, efficacy of the treatment processes may vary from 60% to 99.9%. Ineffective treatment could compromise water quality and may lead to severe treatment disruption or treatment plant shutdown.04e8c401-42e8-4f96-a1fc-98fcf05e240c,05f2b7a8-ce88-4e38-b426-917720b9c324,ef7ca73d-ff36-45d1-acfb-6941b4072a58,9224c0ef-9655-4335-a810-ce86baf5a502 More frequent and intense extreme precipitation events are projected for many regions in the United States as climate changes. Consistent, high-quality evidence from multiple studies supports a finding that increased runoff and flooding events are expected to increase contamination of source waters (for drinking water supply) and surface waters used for recreation, which may increase people’s exposure to pathogens and algal toxins that cause illness.030e3539-a620-441c-adb6-042db1a3fa6e,8c50c794-b09b-4215-b46c-6c24931faf6e,067c087d-ac72-448f-8a8f-c554d7897519,f60a6281-fa30-444d-9acd-0d132a6d1683,446ef7fa-5acc-45df-9247-b042fc1fac39,a7f52e54-2ce0-46fc-b0a2-60729757a8c0,a815bd0f-e3a7-4090-a35e-2f12381d9428,123e376c-79da-456f-96da-773e6f1e76ca,67a32928-4a0c-487d-9cd8-f442e47cb8ae,812fc19e-0fb3-4740-a4c7-bfef0e560666,3e34582d-ee92-45b3-9240-924ca5e98824,d4066a1c-799d-4b50-948b-ae6b71e19ad5,e4ad4655-b747-4844-9737-ee6da2650b39,603e74e7-cfae-45ff-bf78-4c38f32aa678 Other factors may modify these risks, such as increased air or water temperatures, residence time in the environment, lower water levels, or dilution.' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/water-related-illnesses/finding/exposure-risk-from-extreme-precipitation-events.yaml identifier: exposure-risk-from-extreme-precipitation-events ordinal: 2 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. Authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2 and 3.

Many water-related illnesses are of critical importance globally, such as cholera and hepatitis E virus, and they affect U.S. interests abroad, but the focus of this chapter is to address climate impacts on water-related illnesses of primary importance to human health within the United States. In addition, although climate change has the potential to impact national as well as global seafood supplies, this chapter does not cover these types of impacts because the peer-reviewed literature is not yet robust enough to make connections to human health outcomes in the United States. Even with those constraints, the impacts of climate on water-related illness are regionally or locally specific and may include increased risks as well as benefits. For example, the projected geographic range shifts of some Gambieridiscus species to more northern latitudes may mean that dominant ciguatera fish poisoning toxins enter the marine food web through different species, with increases of toxins in new areas where waters are warming and potential decreases in areas such as the Yucatan and eastern Caribbean Sea.1dfd14e0-eae8-46d9-9c3e-0fa3f0c37da4' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Runoff from more frequent and intense extreme precipitation events will increasingly compromise recreational waters, shellfish harvesting waters, and sources of drinking water through increased introduction of pathogens and prevalence of toxic algal blooms [High Confidence]. As a result, the risk of human exposure to agents of water-related illness will increase [Medium Confidence].' uncertainties: 'Changes in exposure and risk are attributable to many factors in addition to climate. While extreme precipitation and flooding events introduce contaminants and pathogens to water to varying degrees depending on the characteristics of each individual event, they may not always result in increases in exposure due to planning and adaptive actions. There are limited studies on actual projections for changes in illness rates due to increasing frequency or intensity of extreme precipitation events. Uncertainty remains regarding appropriate methods for projecting changes in illness rates, including how to integrate considerations of human behavior into modeling (current methods to assess exposure risk assume similar human behavior across time scales and geography). Methodological challenges are related to 1) baseline case reporting issues (underreporting and underdiagnosis), 2) accounting for the effects of potential adaptation strategies/public health interventions (for example, public service announcements about how to avoid exposure), and 3) accounting for changes in public healthcare infrastructure and access that can reduce the risk of exposure or of illness/death.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/water-related-illnesses/finding/exposure-risk-from-extreme-precipitation-events url: ~ - chapter_identifier: water-related-illnesses confidence: 'Based on the evidence found in the peer-reviewed literature, there is high confidence that the anticipated climate change related increases in some extreme weather events and in storm surge will increase the risk that water infrastructure for drinking water, wastewater, and stormwater will fail through either damage or exceedance of system capacity, with aging infrastructure being particularly vulnerable. Evidence shows contamination to or from these systems occurs with heavy precipitation and other extreme weather events. There is consistent qualitative evidence suggesting that projected climate change effects on extreme weather patterns—particularly extreme precipitation and storm surge—can adversely affect water infrastructure and lead to increased loading of pathogens, algal toxins, and contaminants. However, there are no national-level studies upon which to draw conclusions regarding quantitative projections of increased exposure. Thus, the limited number of studies supports a medium confidence level regarding risk of exposure.' evidence: 'Water infrastructure in the United States is aging and may be inadequate or deteriorating. Combined sewers in many older cities were not designed to handle extreme precipitation events that are becoming more frequent with climate change. Multiple studies provide consistent, high-quality evidence that these systems are at risk of being overwhelmed during flood events or may be further damaged during other extreme weather events (e.g., storm surge), allowing contaminated surface water to run off into drinking water and recreational water sources.030e3539-a620-441c-adb6-042db1a3fa6e,8c50c794-b09b-4215-b46c-6c24931faf6e,067c087d-ac72-448f-8a8f-c554d7897519,f60a6281-fa30-444d-9acd-0d132a6d1683,123e376c-79da-456f-96da-773e6f1e76ca,812fc19e-0fb3-4740-a4c7-bfef0e560666 Drinking water source contamination may be exacerbated or insufficiently addressed by treatment processes at the plant or the distribution system. Drinking water treatment plants may be challenged by high pathogen loads and toxic cyanobacterial bloom events.8c50c794-b09b-4215-b46c-6c24931faf6e,ef7ca73d-ff36-45d1-acfb-6941b4072a58,9224c0ef-9655-4335-a810-ce86baf5a502 Multiple studies support a finding that climate change will place additional stresses on the capacity of drinking water treatment facilities and may increase the risk that water infrastructure, especially aging infrastructure, will fail through either damage or exceedance of system capacity.e51f35c4-b5ba-4e95-8090-582e2897754b,f60a6281-fa30-444d-9acd-0d132a6d1683,19adfcfa-88e4-4728-9242-d9934063bb69,19d0c5a6-be45-4234-8d62-6d3eff596da5' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/water-related-illnesses/finding/water-infrastructure-failure.yaml identifier: water-infrastructure-failure ordinal: 3 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. Authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2 and 3.

Many water-related illnesses are of critical importance globally, such as cholera and hepatitis E virus, and they affect U.S. interests abroad, but the focus of this chapter is to address climate impacts on water-related illnesses of primary importance to human health within the United States. In addition, although climate change has the potential to impact national as well as global seafood supplies, this chapter does not cover these types of impacts because the peer-reviewed literature is not yet robust enough to make connections to human health outcomes in the United States. Even with those constraints, the impacts of climate on water-related illness are regionally or locally specific and may include increased risks as well as benefits. For example, the projected geographic range shifts of some Gambieridiscus species to more northern latitudes may mean that dominant ciguatera fish poisoning toxins enter the marine food web through different species, with increases of toxins in new areas where waters are warming and potential decreases in areas such as the Yucatan and eastern Caribbean Sea.1dfd14e0-eae8-46d9-9c3e-0fa3f0c37da4' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Increases in some extreme weather events and storm surges will increase the risk that infrastructure for drinking water, wastewater, and stormwater will fail due to either damage or exceedance of system capacity, especially in areas with aging infrastructure [High Confidence]. As a result, the risk of exposure to water-related pathogens, chemicals, and algal toxins will increase in recreational and shellfish harvesting waters and in drinking water where treatment barriers break down [Medium Confidence].' uncertainties: 'The human health consequences of aging water infrastructure failure depend not only on the local and regional climate factors that contribute to damage or capacity challenges but also the nature of the system and the pressures on it, the population affected, and the timeliness and adequacy of the response—all of which are inherently local or regional factors. Due to the complicated local and regional specificity, there are no national projections of the human health impact of water infrastructure failure. Uncertainty remains regarding appropriate methods for projecting changes in illness rates, including how to integrate considerations of human behavior into modeling (current methods to assess exposure risk assume similar human behavior across time scales and geography). Methodological challenges are related to 1) baseline case reporting issues (underreporting and underdiagnosis), 2) accounting for the effects of potential adaptation strategies/public health interventions (for example, mitigating risk with improvements to current water and sewerage systems), and 3) accounting for changes in public healthcare infrastructure and access that can reduce the risk of exposure or of illness/death if exposed.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/water-related-illnesses/finding/water-infrastructure-failure url: ~ - chapter_identifier: food-safety-nutrition-and-distribution confidence: 'There is high confidence that rising temperature and increases in flooding, runoff events, and drought will likely lead to increases in the occurrence and transport of pathogens in agricultural environments, which will increase the risk of food contamination and human exposure to pathogens and toxins. However, the actual prevalence of disease will depend on the response of regulatory systems and, for certain pathogens, the relative importance of multiple climate drivers with opposing impacts on exposure. Thus there is medium confidence that these impacts of climate change on exposure to pathogens and toxins will likely lead to negative health outcomes. There is a high confidence that the actual incidence of foodborne illness will depend on the efficacy of practices that safeguard food in the United States.' evidence: 'Multiple lines of research have shown that changes in weather extremes, such as increased extreme precipitation (leading to flooding and runoff events), can result in increased microbial and chemical contamination of crops and water in agricultural environments, with increases in human exposure.19d0c5a6-be45-4234-8d62-6d3eff596da5,696355ed-9253-428a-a2b5-ad114a79bdd3,01c49cdf-06bb-41ef-95be-37a8553295b7 During times of drought, plants become weaker and more susceptible to stress, which can result in mold growth and mycotoxin production if plants are held in warm, moist environments.1ca7e70d-66b3-42e1-9a68-31b976d2622f,40aee056-3c0d-407d-997f-e4f254962f81

While studies that link climate change to specific outbreaks of foodborne illness are limited, numerous studies have documented that many microbial foodborne illnesses increase with increasing ambient temperature.b6d4024a-eeca-4900-8198-d65b084285a2,02b85405-4cd5-4185-a14f-07e4fc6cc4e9 There is very strong evidence that certain bacteria grow more rapidly at higher temperatures and can increase the prevalence of pathogens and toxins in food.1ca7e70d-66b3-42e1-9a68-31b976d2622f,8bce78b9-816b-480d-a6bf-18ded7984f5b,e573afb0-9fee-45a5-bbd6-e3abdf6e5bd8 Case studies have demonstrated that lack of refrigerated storage, particularly during very warm weather, leads to increases in microbial growth and higher exposure to pathogens.67bff3c8-bddd-4bbb-975d-bec307df5f72,b6d4024a-eeca-4900-8198-d65b084285a2,02b85405-4cd5-4185-a14f-07e4fc6cc4e9,0ad0a878-82e3-4980-ae61-7341036f50aa,c912323b-ab87-4865-ab9f-5dc13a730e64' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/food-safety-nutrition-and-distribution/finding/increased-risk-of-foodborne-illness.yaml identifier: increased-risk-of-foodborne-illness ordinal: 1 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2 and 3. The author team also engaged in targeted consultations during multiple exchanges with contributing authors, who provided additional expertise on subsets of the Traceable Accounts associated with each Key Finding.

Because the impacts of climate change on food production, prices, and trade for the United States and globally have been widely examined elsewhere, including in the most recent report from the Intergovernmental Panel on Climate Change,fcd24eab-974a-46aa-8434-78b8cd3f0ef0,c04c5716-c318-4a4c-9774-ae61ce97d305,d0c735f3-4b2c-4dec-907c-09e81818b288,67bff3c8-bddd-4bbb-975d-bec307df5f72,3baf471f-751f-4d68-9227-4197fdbb6e5d,c390e13f-8517-40a9-a236-ac4dede3a7a0 this chapter focuses only on the impacts of climate change on food safety, nutrition, and distribution in the context of human health in the United States. Many nutritional deficiencies and food-related illnesses are of critical importance globally, particularly those causing diarrheal epidemics or mycotoxin poisoning, and affect U.S. interests abroad; but the primary focus of this chapter is to address climate impacts on the food safety concerns most important in the United States. Thus, the literature cited in this chapter is specific to the United States or of demonstrated relevance to developed countries. The placement of health threats from seafood was determined based on pre- and post-ingestion risks: while ingestion of contaminated seafood is discussed in this chapter, details on the exposure pathways of water-related pathogens (for example, through recreational or drinking water) are discussed in Chapter 6: Water-Related Illness.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Climate change, including rising temperatures and changes in weather extremes, is expected to increase the exposure of food to certain pathogens and toxins [Likely, High Confidence]. This will increase the risk of negative health impacts [Likely, Medium Confidence], but actual incidence of foodborne illness will depend on the efficacy of practices that safeguard food in the United States [High Confidence]. ' uncertainties: 'Concentrations of pathogens and toxins in food are expected to increase, resulting in an increase in the risk of human exposure to infectious foodborne pathogens and toxins. However, the number or severity of foodborne illnesses due to climate change is uncertain. Much of this uncertainty is due to having controls in place to protect public health. For example, contaminated crops are likely to be destroyed before consumption, and certain pathogens in food, like mycotoxins, are highly regulated in the United States. Consequently, the extent of exposure and foodborne illness will depend on regulatory, surveillance, monitoring, and communication systems, and on how, and to what extent, climate change alters these adaptive capacities. Furthermore, for certain pathogens, it is not yet clear whether the impact of climate change on a pathogen will be positive or negative. For example, climate change could lead to fewer cases of norovirus infection in the winter, but worsening health outcomes are also possible due to elevated transmission of norovirus during floods. Similarly drought can reduce water quality, increase runoff, and increase pathogen concentration, but can also decrease the survivability of certain foodborne pathogens.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/food-safety-nutrition-and-distribution/finding/increased-risk-of-foodborne-illness url: ~ - chapter_identifier: food-safety-nutrition-and-distribution confidence: 'Although it is likely that climate change will increase human exposure to chemical contaminants, the specific pathway(s) of exposure have varying levels of uncertainty associated with them and hence there is medium confidence regarding the overall extent of exposure. This chapter focuses on three such pathways. First, it is likely that elevated sea surface temperatures will result in increased bioaccumulation of mercury in seafood, but there is medium confidence regarding human illness because rates of accumulation and exposure vary according to the type of seafood ingested, and because of the role of varying individual sensitivity and individual or institutional adaptive capacity (particularly behavioral choices). Similarly, it is likely that extreme events will increase contaminants into agricultural soil and the food chain. However, there is medium confidence regarding exposure because the specific nature of the contaminant and the food source will vary, and because the extent of exposure will depend on risk management, communication of public health threats, and the effectiveness of regulatory, surveillance, and monitoring systems within the current food safety network. There is high confidence that it is very likely that rising CO2 and climate change will alter pest incidence and distribution. There is medium confidence that such changes in incidence and distribution are likely to increase chemical management and the use of veterinary drugs in livestock. However, in all these pathways, the specific consequences on human health in the Unites States are uncertain, due primarily to the variability in type of pathogen or contaminant, time and duration of exposures, individual sensitivity (for example, genetic predisposition), and individual or institutional adaptive capacity.' evidence: 'There are a number of established pathways by which climate change will intensify chemical contaminants within the food chain. Multiple studies have shown that increases in ocean temperatures are likely to increase the potential for mercury exposure, likely due to the increased uptake and concentration of mercury in fish and mammals at higher metabolic rates associated with warmer ambient temperatures.28025deb-e0a3-4b76-b1d4-770bc897aa71,67bf0866-1dd9-49ce-a909-848cc3f69a77,0677152e-5892-427e-967b-540e16d30628,90048433-9538-4100-a94f-3ecb8940519f Another pathway includes extreme weather events, which can move chemical contaminants such as lead into agricultural fields and pastures (as well as into drinking or recreational water sources—see Chapter 6: Water-Related Illness).3bfe667e-40cb-4dc3-9da4-75df2ab699ce,443c29a9-352d-4e29-b787-cbf549968901,d30a33b7-b186-4ef5-9629-da98ca21ee8b A final pathway is through rising minimum winter temperatures and longer growing seasons, which will very likely alter pest distribution and populations. A large body of literature shows that temperature, carbon dioxide (CO2) concentrations, and water availability are also likely to affect pest development, number of pest generations per year, changes in pest range, rate of infestation, and host plant and animal susceptibility.c04c5716-c318-4a4c-9774-ae61ce97d305,4b0cbc38-2722-418e-a982-5e04837291b0,bf92266b-c107-4d7c-9bbb-1e4a08fa0fc7,afc4d024-e3a0-436c-b037-28a2397bf4c7,1985bce4-5738-4ba6-ac9a-0d676d2ce4a3 Empirical models and an analysis of long-term in situ data indicate that rising temperatures will result in increased pest pressures.c11c6252-a26d-431f-b450-2d590921cdc7,722318af-75e4-4a36-a2bb-6ba291901c7a,4c6335ac-bf06-4a51-8d12-677ce9b21f55 These changes are expected to result in increased use of pesticides,c11c6252-a26d-431f-b450-2d590921cdc7,c37a868d-ab73-4775-988e-1ad89e14f20e which can lead to increased human exposure.32be7b58-9a19-4710-ad79-cea600732146' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/food-safety-nutrition-and-distribution/finding/chemical-contaminants-in-the-food-chain.yaml identifier: chemical-contaminants-in-the-food-chain ordinal: 2 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2 and 3. The author team also engaged in targeted consultations during multiple exchanges with contributing authors, who provided additional expertise on subsets of the Traceable Accounts associated with each Key Finding.

Because the impacts of climate change on food production, prices, and trade for the United States and globally have been widely examined elsewhere, including in the most recent report from the Intergovernmental Panel on Climate Change,fcd24eab-974a-46aa-8434-78b8cd3f0ef0,c04c5716-c318-4a4c-9774-ae61ce97d305,d0c735f3-4b2c-4dec-907c-09e81818b288,67bff3c8-bddd-4bbb-975d-bec307df5f72,3baf471f-751f-4d68-9227-4197fdbb6e5d,c390e13f-8517-40a9-a236-ac4dede3a7a0 this chapter focuses only on the impacts of climate change on food safety, nutrition, and distribution in the context of human health in the United States. Many nutritional deficiencies and food-related illnesses are of critical importance globally, particularly those causing diarrheal epidemics or mycotoxin poisoning, and affect U.S. interests abroad; but the primary focus of this chapter is to address climate impacts on the food safety concerns most important in the United States. Thus, the literature cited in this chapter is specific to the United States or of demonstrated relevance to developed countries. The placement of health threats from seafood was determined based on pre- and post-ingestion risks: while ingestion of contaminated seafood is discussed in this chapter, details on the exposure pathways of water-related pathogens (for example, through recreational or drinking water) are discussed in Chapter 6: Water-Related Illness.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Climate change will increase human exposure to chemical contaminants in food through several pathways [Likely, Medium Confidence]. Elevated sea surface temperatures will lead to greater accumulation of mercury in seafood [Likely, Medium Confidence], while increases in extreme weather events will introduce contaminants into the food chain [Likely, Medium Confidence]. Rising carbon dioxide concentrations and climate change will alter incidence and distribution of pests, parasites, and microbes [Very Likely, High Confidence], leading to increases in the use of pesticides and veterinary drugs [Likely, Medium Confidence].' uncertainties: 'Each of the pathways described in the evidence base has variable levels of uncertainty associated with each step of the exposure pathway.c0419502-0517-447b-886f-ece5ec4cda6c For all these pathways, projecting the specific consequences on human health in the Unites States is challenging, due to the variability in type of pathogen or contaminant, time and duration of exposures, individual sensitivity (for example, genetic predisposition) and individual or institutional adaptive capacity. While increasing exposure to chemicals will exacerbate potential health risks, the nature of those risks will depend on the specific epidemiological links between exposure and human health as well as availability and access to health services. Resulting incidence of illness will depend on the genetic predisposition of the person exposed, type of contaminant, and extent of exposure over time.32be7b58-9a19-4710-ad79-cea600732146' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/food-safety-nutrition-and-distribution/finding/chemical-contaminants-in-the-food-chain url: ~ - chapter_identifier: food-safety-nutrition-and-distribution confidence: 'Based on the evidence, there is high confidence that the rapid increase in atmospheric CO2 has resulted in a reduction in the level of protein and minerals relative to the amount of carbohydrates present for a number of important crop species (including a number of globally important cereals such as wheat, barley and rice), and will very likely continue to do so as atmospheric CO2 concentration continues to rise.' evidence: 'The nutritional response of crops to rising carbon dioxide is well documented, particularly among C3 cereals such as rice and wheat, which make up the bulk of human caloric input. C3 species are about 95% of all plant species and represent those species most likely to respond to an increase in atmospheric CO2 concentrations.

There is strong evidence and consensus that protein concentrations in plants strongly correlate with nitrogen concentrations. CO2-induced declines in nitrogen concentrations have been observed in nearly a hundred individual studies and several meta-analyses.de07adc8-7f48-4455-8b2a-6707520acd59,25f24b69-e072-4bba-9a18-282938f62190,31ae7e0e-a0fc-44c4-ac4f-0070aae519a6,1e90a679-d2ce-4cd4-85f3-2cbb63939d35,1f461bf1-02cd-49d5-973b-32961301ddff A meta-analysis of the effect of CO2 on protein by crop covers 228 observations on wheat, rice, soybeans, barley and potato, 6f0fe842-95ce-481a-b3f6-473975719843 and was recently repeated for the United States, Japan, and Australia,7287b49d-8c0d-4f11-95f2-c565c2dd2ee9 covering 138 mean observations on nitrogen/protein in wheat, rice, peas, maize, and sorghum. There is very strong evidence that rising CO2 reduces protein content in non-leguminous C3 crops, including wheat, rice, potato, and barley. There is also good agreement across studies that the ongoing increase in CO2 elevates the overall carbohydrate content in C3 plants.de07adc8-7f48-4455-8b2a-6707520acd59

Another meta-analysis quantifies the role of increasing CO2 in altering the ionome (the mineral nutrient and trace element composition of an organism) of plants, including major crops.de07adc8-7f48-4455-8b2a-6707520acd59 This meta-analysis of 7,761 observations indicates that increasing CO2 also significantly reduces the mineral concentrations (calcium, magnesium, iron, zinc, copper, sulfur, potassium, and phosphorus) in C3 plants, including grains and edible parts of other crops, while also substantially increasing the ratio of total non-structural carbohydrates (starch and sugars) to minerals and to protein.

Furthermore, these studies show the quality of current crops to be lower relative to the crops raised in the past with respect to protein and minerals.de07adc8-7f48-4455-8b2a-6707520acd59,6f0fe842-95ce-481a-b3f6-473975719843 Direct experimental evidence shows that protein concentrations in wheat flour progressively declined with rising CO2 concentrations representing levels in 1900 (approximately 290 ppm), 2008 (approximately 385 ppm), and the CO2 concentrations projected to occur later in this century (approximately 715 ppm).d763a364-656a-4a46-96cc-82800edc3ac2' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/food-safety-nutrition-and-distribution/finding/rising-carbon-dioxide-lowers-nutritional-value-of-food.yaml identifier: rising-carbon-dioxide-lowers-nutritional-value-of-food ordinal: 3 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2 and 3. The author team also engaged in targeted consultations during multiple exchanges with contributing authors, who provided additional expertise on subsets of the Traceable Accounts associated with each Key Finding.

Because the impacts of climate change on food production, prices, and trade for the United States and globally have been widely examined elsewhere, including in the most recent report from the Intergovernmental Panel on Climate Change,fcd24eab-974a-46aa-8434-78b8cd3f0ef0,c04c5716-c318-4a4c-9774-ae61ce97d305,d0c735f3-4b2c-4dec-907c-09e81818b288,67bff3c8-bddd-4bbb-975d-bec307df5f72,3baf471f-751f-4d68-9227-4197fdbb6e5d,c390e13f-8517-40a9-a236-ac4dede3a7a0 this chapter focuses only on the impacts of climate change on food safety, nutrition, and distribution in the context of human health in the United States. Many nutritional deficiencies and food-related illnesses are of critical importance globally, particularly those causing diarrheal epidemics or mycotoxin poisoning, and affect U.S. interests abroad; but the primary focus of this chapter is to address climate impacts on the food safety concerns most important in the United States. Thus, the literature cited in this chapter is specific to the United States or of demonstrated relevance to developed countries. The placement of health threats from seafood was determined based on pre- and post-ingestion risks: while ingestion of contaminated seafood is discussed in this chapter, details on the exposure pathways of water-related pathogens (for example, through recreational or drinking water) are discussed in Chapter 6: Water-Related Illness.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'The nutritional value of agriculturally important food crops, such as wheat and rice, will decrease as rising levels of atmospheric carbon dioxide continue to reduce the concentrations of protein and essential minerals in most plant species [Very Likely, High Confidence].' uncertainties: 'While the general response and the direction in the change of crop quality is evident; there is uncertainty in the extent of variation in both protein and ionome among different crop varieties. There is little evidence regarding the CO2 effects on complex micronutrients such as carotenoids (vitamin A, lutein, and zeaxanthin). Although protein, micronutrients, and ratio of carbohydrates to protein are all essential aspects of human dietary needs, the projected human health impacts of nutritional changes with increasing CO2 are still being evaluated. There remains a high level of uncertainty regarding how reductions in crop quality affect human nutrition by contributing to or aggravating existing chronic dietary deficiencies and obesity risks, particularly in the United States where dietary protein deficiencies are uncommon.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/food-safety-nutrition-and-distribution/finding/rising-carbon-dioxide-lowers-nutritional-value-of-food url: ~ - chapter_identifier: food-safety-nutrition-and-distribution confidence: 'Given the evidence base and current uncertainties, there is high confidence that projected increases in the frequency and severity of extreme events will likely lead to damage of existing food supplies and disruptions to food distribution infrastructure. There is medium confidence that these damages and disruptions will increase risk for food damage, spoilage, or contamination, which will limit availability and access to safe and nutritious foods because of uncertainties surrounding the extent of the disruptions and individual, community, or institutional sensitivity to impacts. There are further uncertainties surrounding how the specific dynamics of the extreme event, such as the geographic location in which it occurs, as well as the social vulnerabilities or adaptive capacity of the populations at risk, will impact human health.' evidence: 'It is well documented in assessment literature that climate models project an increase in the frequency and intensity of some extreme weather events.2ad39d48-c8d4-46cf-9a5c-0bc65a4da57c,a6a312ba-6fd1-4006-9a60-45112db52190 Because the food transportation system moves large volumes at a time, has limited alternative routes, and is dependent on the timing of the growing and harvest seasons, it is likely that the projected increase in the frequency and intensity of extreme weather events089d8050-f4c8-4d07-bc35-25bf61691be3,2ad39d48-c8d4-46cf-9a5c-0bc65a4da57c will also increase the frequency of food supply chain disruptions (including risks to food availability and access)82a76f89-8c28-4fc6-aecc-31420462c4a4,8f90eee3-73f3-4782-b3e0-374f1207be77,a03f3148-6495-417f-b241-f21d677e7f0d,7a0e9531-8d92-4501-b738-b11e71c18813,2198cdb0-da69-4b2d-919f-a88f85c70091,580f7af6-b0eb-4ebb-8da4-ab0a0b8ef68b,57ffaa62-7363-4a5f-915f-b1930da3ac82 and the risk for food spoilage and contamination.580f7af6-b0eb-4ebb-8da4-ab0a0b8ef68b,b4dfdd6a-ffce-44a3-b6b7-5770f5c70fbb Recent extreme events have demonstrated a clear linkage to the disruption of food distribution and access.2198cdb0-da69-4b2d-919f-a88f85c70091,17380d26-bc60-4dcd-be46-9bf40616bfbd Case studies show that such events, particularly those that result in power outages, may also expose food to temperatures inadequate for safe storage,580f7af6-b0eb-4ebb-8da4-ab0a0b8ef68b with increased risk of illness. For example, New York City’s Department of Health and Mental Hygiene detected a statistically significant citywide increase in diarrheal illness resulting from consumption of spoiled foods due to lost refrigeration capabilities after a 2003 power outage.d03f5405-42ed-46bd-9f7f-23ba5f71bdf3' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/food-safety-nutrition-and-distribution/finding/extreme-weather-limits-access-to-safe-foods.yaml identifier: extreme-weather-limits-access-to-safe-foods ordinal: 4 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2 and 3. The author team also engaged in targeted consultations during multiple exchanges with contributing authors, who provided additional expertise on subsets of the Traceable Accounts associated with each Key Finding.

Because the impacts of climate change on food production, prices, and trade for the United States and globally have been widely examined elsewhere, including in the most recent report from the Intergovernmental Panel on Climate Change,fcd24eab-974a-46aa-8434-78b8cd3f0ef0,c04c5716-c318-4a4c-9774-ae61ce97d305,d0c735f3-4b2c-4dec-907c-09e81818b288,67bff3c8-bddd-4bbb-975d-bec307df5f72,3baf471f-751f-4d68-9227-4197fdbb6e5d,c390e13f-8517-40a9-a236-ac4dede3a7a0 this chapter focuses only on the impacts of climate change on food safety, nutrition, and distribution in the context of human health in the United States. Many nutritional deficiencies and food-related illnesses are of critical importance globally, particularly those causing diarrheal epidemics or mycotoxin poisoning, and affect U.S. interests abroad; but the primary focus of this chapter is to address climate impacts on the food safety concerns most important in the United States. Thus, the literature cited in this chapter is specific to the United States or of demonstrated relevance to developed countries. The placement of health threats from seafood was determined based on pre- and post-ingestion risks: while ingestion of contaminated seafood is discussed in this chapter, details on the exposure pathways of water-related pathogens (for example, through recreational or drinking water) are discussed in Chapter 6: Water-Related Illness.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Increases in the frequency or intensity of some extreme weather events associated with climate change will increase disruptions of food distribution by damaging existing infrastructure or slowing food shipments [Likely, High Confidence]. These impediments lead to increased risk for food damage, spoilage, or contamination, which will limit availability of and access to safe and nutritious food, depending on the extent of disruption and the resilience of food distribution infrastructure [Medium Confidence].' uncertainties: 'The extent to which climate-related disruptions to the food distribution system will affect food supply, safety, and human health, including incidences of illnesses, remains uncertain. This is because the impacts of any one extreme weather event are determined by the type, severity, and intensity of the event, the geographic location in which it occurs, infrastructure resiliency, and the social vulnerabilities or adaptive capacity of the populations at risk.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/food-safety-nutrition-and-distribution/finding/extreme-weather-limits-access-to-safe-foods url: ~ - chapter_identifier: mental-health-and-well-being confidence: 'Numerous and recent studies have examined the mental health and wellness impacts of climate- and weather-related events among a variety of populations. Taken as a whole, the strength of this scientific evidence provides very high confidence regarding the adverse impacts of environmental changes and events associated with global climate change on individual and societal mental health and well-being, and high confidence that these impacts will be long-lasting for a significant portion of the impacted population.' evidence: 'Very strong evidence from multiple studies shows a consensus that many people exposed to climate- or weather-related natural disasters experience stress reactions and serious psychological harm, which often occur simultaneously.ef435f7f-82b0-426c-b518-cb23f76612ff,9502bb11-b920-48a6-a4ae-c6453a55d3a7,1357006d-175e-4414-9793-761618338c8d,a9cc82e3-1eb0-451c-90d3-dbe883c203d7,f8e99ff1-f5d6-4b9b-a844-2007310584f8 Though many of these studies describe the mental health impacts of specific historical events, they demonstrate the types of mental health issues that will continue to arise as climate change leads to increases in the frequency, severity, and duration of extreme climate- and weather-related events such as floods, hurricanes, droughts, and wildfires.c3776534-f010-44e8-ae2f-6d069cfaba37,569a5671-661e-457c-aa75-8a221911ac26,8702da89-76d0-44e1-9eda-b04dc6a26385,a95f121c-2fa2-4d4a-affe-576dad344217,9047c320-e8cb-4429-920d-b2d2d7f01ffc,0acc2713-8395-425c-b4ff-9754b7257048,15b8a671-4186-4cdb-aa80-d9e7012840e5,4489b5a2-b658-4e62-8a8a-c3805b6dccf1,1617ae90-36e2-48f5-b5ef-f5fb1aafb399,89d2438b-bddd-4ded-8e17-1cf498b28571,1a78f1ef-1f10-44b7-b040-b8109748255c,7d8b53d6-8f6b-4933-a116-41f415292792,0e71e17a-442f-46d8-b62f-cc3213f85208,8abc0ed4-9d56-40bf-8995-35313552618c,a7957dc8-1ead-4328-8250-a695f5f62c30 Strong support is found in a number of recent studies for the potential for climate change-related psychological effects, including grief/bereavement, increased substance use or misuse, and thoughts of suicide.8702da89-76d0-44e1-9eda-b04dc6a26385,dd605fa4-98b4-486a-8d7c-07311b957d30,de8ce512-2778-48ef-8874-aae2ed5afce8,895a462d-2faa-44e3-a888-31efb349f44d,d49018ea-2172-4983-8a51-f61feccb6e11,1231497d-b014-4c16-abda-cb4e00b2b695

Research on individual resilience and recovery shows that a majority of individuals psychologically affected by a traumatic event will recover over time. However, a convincing body of recent research shows that a significant proportion (typically up to 20%) of individuals directly exposed to the event will develop chronic levels of psychological dysfunction, which may not get better or be resolved.9047c320-e8cb-4429-920d-b2d2d7f01ffc,dd605fa4-98b4-486a-8d7c-07311b957d30,5aff4109-04b3-4ac6-a945-58664490b6fe,11180485-b3b5-4d33-85df-be175655dcca,11ed1918-b422-41d3-b704-05d14e45b278,97358ea1-2cd7-4dcf-a444-cbe7cd2e9cf0,a8e44cff-cd49-46f4-a54c-7a365097cbdf,3bc7615b-d281-4fd6-a367-c94022d367a8' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/mental-health-and-well-being/finding/exposure-weather-related-disasters-results-mental-health-consequences.yaml identifier: exposure-weather-related-disasters-results-mental-health-consequences ordinal: 1 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2–3.

Areas of focus for the Mental Health and Well-Being chapter were determined based on the most relevant available scientific literature relating to mental health, wellness, and climate change, as well as the mental health impacts of events associated with climate change. Much of the evidence on these impacts has been compiled in countries outside the United States; however, the scenarios are similar and the evidence directly relevant to the situation in the United States, and thus this literature has been considered in the chapter. The evidence-base on mental health and wellness following extreme weather disasters is both well-established and relevant to climate change. The existence of highly relevant scientific literature on specific concerns directly influenced by climate change—such as the effects of extreme heat, stress associated with the threat and perception of climate change, and special population risks—resulted in the inclusion of these more targeted topics. Although significant scientific literature for resilience exists, in-depth discussions of adaptation, coping, and treatment approaches are outside the scope of this chapter, but are discussed in brief in the Resilience and Recovery section.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Many people exposed to climate-related or weather-related disasters experience stress and serious mental health consequences. Depending on the type of the disaster, these serious mental health consequences include post-traumatic stress disorder (PTSD), depression, and general anxiety, which often occur at the same time [Very High Confidence]. The majority of affected people recover over time, although a significant proportion of exposed individuals develop chronic psychological dysfunction [High Confidence].' uncertainties: 'There remains some uncertainty about the degree to which future extreme weather and climate events will impact mental health and wellness. An increase in the scope, frequency, or severity of these events will increase the number of people impacted and the degree to which they are affected. However, efforts that effectively increase preparation for both the physical and psychological consequences of extreme weather- and climate-related events could decrease the impact on mental health and well-being.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/mental-health-and-well-being/finding/exposure-weather-related-disasters-results-mental-health-consequences url: ~ - chapter_identifier: mental-health-and-well-being confidence: The combined breadth and strength of the scientific literature supports high confidence that certain vulnerable populations will face psychological tolls in the aftermath of climate-related disasters. An increase in adverse climate-related events will result in increased exposure of such populations of concern and an increased likelihood of elevated risk for mental health consequences. There is also high confidence that natural-resource-dependent communities and populations living in areas most susceptible to specific climate change events are at increased risk for adverse mental health outcomes. evidence: 'Multiple studies have identified specific populations within the United States that are particularly vulnerable to the mental health impacts of climate change events.34647534-8863-4fde-b8d0-f24bcdc4fcc6,9467cf71-753b-49a7-891b-04da863e71ad,67687fbe-a13c-48f9-99a3-158b1dae0fff,abe2ce03-59c1-461d-8801-3e12df93a8e1,30024cab-09f2-4778-86b0-e848ccf603c7,faadfa3a-2035-4c63-99e1-642f0c1d4e4e Some evidence suggests that children are at particular risk for distress, anxiety, and PTSD.36e4a94f-8c92-4eab-be3d-4521b7770716,800172f5-06ce-47cd-8e88-2860961c2c40,db242424-f22c-4d81-943d-7e1f583bc866 Highly cited studies of the elderly show that high rates of physical and mental health disorders leave them more vulnerable to the impacts of climate change.c3776534-f010-44e8-ae2f-6d069cfaba37,30024cab-09f2-4778-86b0-e848ccf603c7,d025518a-8085-4ef9-ba42-c0ac239d98f1,88885fc4-a6c8-454f-881d-51a8e2739bb5 A large body of post-disaster studies shows that women often have a higher prevalence of PTSD9c789c49-b1dd-4ed8-ac02-5942fb6674de and other adverse psychological outcomes. f66b946f-c672-4a4b-8f71-1b05738e029e,de2250cc-0ffe-40c6-b7f7-5de37d4b4131,9845a991-d58b-409b-91b9-670cc383d030,871e1113-59cb-4f06-a415-284137b17c51,36e4a94f-8c92-4eab-be3d-4521b7770716,66c76115-365d-4a76-9087-cf38d6afdc2e,e52c6b87-47d7-47dc-9018-f78cad2a35af,12114eeb-754e-46a7-92af-abce1e9d23cf,5f6029f9-9de1-4d32-b772-cf836ac4e048 Research strongly suggests that people who currently suffer from psychological disorders will face additional challenges from climate change impacts.922bcd50-dd07-4e05-afc7-fe3bcb1a953a,1e9a7907-02f2-4da8-9e93-131f92515dbc,2a9775ae-a280-4260-985f-0e66d0ef8c11,987707c1-8e54-41d8-8555-c5e1d4bcc661,17cd07d1-5250-4980-8b98-689b4caf0bb1 Strong evidence suggests that people living in poverty disproportionately experience the most negative impacts,abe2ce03-59c1-461d-8801-3e12df93a8e1,faadfa3a-2035-4c63-99e1-642f0c1d4e4e in part because they have less capacity to evacuate to avoid natural disasters, and because they are more frequently exposed to harmful environmental conditions such as heat waves and poor air quality.8dd99031-877d-4006-96c8-0890df6d1d8c Similarly, the majority (91%) of homeless populations live in urban and suburban areas, where they are more vulnerable to certain weather- and climate-related health risks.6a74b0ff-705b-433e-8b26-59b7284cca88

A number of studies of disaster responders point to an increased risk of mental and physical health problems following climate-related disasters.eb4e88e8-fdd1-492f-94a0-a8af7ffc598e,c1170f20-6345-4a49-b0fd-455bbd1c3264,12326139-d074-4882-9ac6-555855b08a51,ce9790d9-36c1-483d-a5c8-e8f21bf4e07d More frequent and intense weather events will increase the likelihood of this threat.895a462d-2faa-44e3-a888-31efb349f44d,ca705054-749f-4c0a-b184-9d14fbbf79e9,76c677ab-1bce-4095-adbe-90322f33d6af

Several studies show that those living in drought-prone areas are vulnerable to high levels of distress.67687fbe-a13c-48f9-99a3-158b1dae0fff,6cd7a528-3fc0-4e91-bec3-86e4eeee0cdb,61272d35-f059-4d3f-bc66-8556455ebd87 In addition, evidence suggests those living in Arctic or other coastal areas, such as Indigenous communities or tribes, tend to be more reliant on natural resources that could be diminished by climate change, which can lead to an increased risk of poor mental health outcomes.a6856e1f-e371-40f1-83d0-bce369e2289f,42269c56-1785-48ec-a81b-6eeb784de417,e46294e5-1bf3-4384-af37-7739b0a8f693,905ad03b-729c-447b-b894-c4ce8f9fec30,ef2b1084-10a4-475b-aeff-6093f8000e17,0a222ad6-2bcb-4fdc-91c8-de37bb70b04f' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/mental-health-and-well-being/finding/specific-groups-people-higher-risk.yaml identifier: specific-groups-people-higher-risk ordinal: 2 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2–3.

Areas of focus for the Mental Health and Well-Being chapter were determined based on the most relevant available scientific literature relating to mental health, wellness, and climate change, as well as the mental health impacts of events associated with climate change. Much of the evidence on these impacts has been compiled in countries outside the United States; however, the scenarios are similar and the evidence directly relevant to the situation in the United States, and thus this literature has been considered in the chapter. The evidence-base on mental health and wellness following extreme weather disasters is both well-established and relevant to climate change. The existence of highly relevant scientific literature on specific concerns directly influenced by climate change—such as the effects of extreme heat, stress associated with the threat and perception of climate change, and special population risks—resulted in the inclusion of these more targeted topics. Although significant scientific literature for resilience exists, in-depth discussions of adaptation, coping, and treatment approaches are outside the scope of this chapter, but are discussed in brief in the Resilience and Recovery section.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Specific groups of people are at higher risk for distress and other adverse mental health consequences from exposure to climate-related or weather-related disasters. These groups include children, the elderly, women (especially pregnant and post-partum women), people with preexisting mental illness, the economically disadvantaged, the homeless, and first responders [High Confidence]. Communities that rely on the natural environment for sustenance and livelihood, as well as populations living in areas most susceptible to specific climate change events, are at increased risk for adverse mental health outcomes [High Confidence].' uncertainties: 'While there is uncertainty around the magnitude of effect, there is general agreement that climate-related disasters cause emotional and behavioral responses that will increase the likelihood of a mental illness or effect. Understanding how exposure, sensitivity, and adaptive capacity change over time and location for specific populations of concern is challenging. Uncertainties remain with respect to the underlying social determinants of health, public health interventions or outreach, adaptation options, and climate impacts at fine local scales.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/mental-health-and-well-being/finding/specific-groups-people-higher-risk url: ~ - chapter_identifier: mental-health-and-well-being confidence: 'The large body of well-documented scientific evidence provides high confidence that adverse mental health outcomes and social impacts can result from the threat of climate change, the perceived experience of climate change,and changes to one’s local environment. Emerging evidence suggests there is medium confidence that media representations of climate change influence stress responses and mental health and well-being.' evidence: 'A strong combination of mental health epidemiological research, social science-based national survey research, social and clinical psychology, environmental risk perception research, and disaster mental health research supports the finding that the threat of climate change and perceptions of its related physical environment changes and extreme events together constitute a significant environmental stressor.1497a2db-b62f-4bcb-8e53-f22692c416b4,9fcf79bd-416e-4ede-9e00-262b39095cab,9467cf71-753b-49a7-891b-04da863e71ad,9ce52883-f68f-48dc-875f-88f932e8f916,efd704ca-586c-4ba0-a447-4bcb800c6792,a7957dc8-1ead-4328-8250-a695f5f62c30,1033040b-fcff-419e-ad20-8a3a7b0c5013,1dad28b6-fe27-4e03-9630-8fda36305ec5,bd32de10-ebf5-44eb-9f99-4857be1f5ad4,40b214b0-1829-4411-9371-4aa06136f493,ca70d728-88f3-44ae-aa3b-e67710ea350b,de7e26bd-2384-4c8f-ae73-96417407d9f5,7ad54684-f950-46c7-a03a-92535cea27bf,6488df22-3c4d-4530-b988-10e3e5b9ab3e,c55d46b4-accb-418b-84fe-cda125422327,a2ef9cb1-3891-49f7-aa87-7d232b1bc47b

A large number of recent studies that have evaluated responses to the hybrid risk (risk that is part natural and part human-caused) of climate change impacts specifically reveal that many individuals experience a range of adverse psychological responses.34647534-8863-4fde-b8d0-f24bcdc4fcc6,dc84de0a-35da-4c00-a6e1-a0ba66dcaea0,f66b946f-c672-4a4b-8f71-1b05738e029e,8eccc146-c874-49ff-ba79-160c0e12c158,9845a991-d58b-409b-91b9-670cc383d030,2a7f3b81-6429-4752-904e-7f5fa3686d29,947e6dc0-63cf-4a74-947b-b24b9f2ab9c9,169b6908-d301-4da7-aeee-43cce986c86c,b8589fd7-68ca-4045-aadf-f7be886662ed,26a30317-5e80-4272-9f1e-eb6d2a800a4d' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/mental-health-and-well-being/finding/climate-change-threats-result-mental-health-consequences-social-impacts.yaml identifier: climate-change-threats-result-mental-health-consequences-social-impacts ordinal: 3 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2–3.

Areas of focus for the Mental Health and Well-Being chapter were determined based on the most relevant available scientific literature relating to mental health, wellness, and climate change, as well as the mental health impacts of events associated with climate change. Much of the evidence on these impacts has been compiled in countries outside the United States; however, the scenarios are similar and the evidence directly relevant to the situation in the United States, and thus this literature has been considered in the chapter. The evidence-base on mental health and wellness following extreme weather disasters is both well-established and relevant to climate change. The existence of highly relevant scientific literature on specific concerns directly influenced by climate change—such as the effects of extreme heat, stress associated with the threat and perception of climate change, and special population risks—resulted in the inclusion of these more targeted topics. Although significant scientific literature for resilience exists, in-depth discussions of adaptation, coping, and treatment approaches are outside the scope of this chapter, but are discussed in brief in the Resilience and Recovery section.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'Many people will experience adverse mental health outcomes and social impacts from the threat of climate change, the perceived direct experience of climate change, and changes to one’s local environment [High Confidence]. Media and popular culture representations of climate change influence stress responses and mental health and well-being [Medium Confidence].' uncertainties: 'Major uncertainties derive from the distinction between people’s objective and subjective exposure and experience of environmental threats. The multimedia information environment to which individuals are exposed and its coverage of climate change and related events can contribute to complicated public perceptions and strong emotional responses related to climate change as a social, environmental, and political issue.9fcf79bd-416e-4ede-9e00-262b39095cab,ee00465f-610d-41e8-9505-77214f0d31bd,88a64708-aabf-40b4-8677-0021edda378f If media exposure is inaccurate or discouraging, that could cause undue stress. However, accurate risk information dissemination can result in adaptive and preventive individual and collective action.dc84de0a-35da-4c00-a6e1-a0ba66dcaea0,f66b946f-c672-4a4b-8f71-1b05738e029e,a9f1a3ec-7f21-4d47-9a4c-84f0029ff6a2,d9ae20d0-403b-4871-b0f8-e0ed301e841b,e360e51f-21af-42d7-b4b3-293e10615681,56e6c997-9cde-4f3e-8dd7-e6e737a5a157 The relative dearth of long term impact assessment and monitoring programs relating to the psychosocial impacts of climate change necessitates reliance on smaller-scale, typically cross-sectional studies and research surveys that are often limited by their use of single-item indicators rather than standardized, climate change-specific, multi-item psychometric measures.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/mental-health-and-well-being/finding/climate-change-threats-result-mental-health-consequences-social-impacts url: ~ - chapter_identifier: mental-health-and-well-being confidence: 'A large body of established scientific evidence shows there is high confidence that people with mental illness are at greater risk for poor physical and mental health outcomes from climate change. Similarly, there is high confidence that exposure to extreme heat will exacerbate such outcomes, particularly for the elderly and those who take certain prescription medications to treat their mental illnesses. Given predictions of growth in the subgroup of the population who have mental health conditions and who take pharmaceuticals that sensitize them to heat, increases in the number of people experiencing related negative health outcomes due to climate change is expected to occur.' evidence: 'Mental, behavioral, and cognitive disorders can be triggered or exacerbated by heat waves. An increased susceptibility to heat due to medication use for psychiatric and other mental health disorders, as well as for alcohol- and drug-dependent people, is supported by numerous studies,922bcd50-dd07-4e05-afc7-fe3bcb1a953a,898dabcf-7205-4007-8782-7f8fb4afa797,682bbf49-5c57-4e69-b031-d185d2480cf2,c142a857-65af-499e-9f99-3e1666903eca,7ed50d22-b382-4c8a-8794-7ec131587ebe,35822aeb-7ea0-4f88-8b90-6b8bd6c9c9cf,459504bb-a64e-4d70-8643-144ca33cb7fb and the influence of dehydration on the effects of psychotropic medications is well-documented.1e9a7907-02f2-4da8-9e93-131f92515dbc,898dabcf-7205-4007-8782-7f8fb4afa797,114cd0b9-5577-4c58-b5b1-24c822dd4ad7

A significant body of evidence shows that the combination of mental illness and extreme heat can result in increases in hospitalizations and even death.922bcd50-dd07-4e05-afc7-fe3bcb1a953a,1e9a7907-02f2-4da8-9e93-131f92515dbc,2a9775ae-a280-4260-985f-0e66d0ef8c11,987707c1-8e54-41d8-8555-c5e1d4bcc661,17cd07d1-5250-4980-8b98-689b4caf0bb1 Furthermore, six case-control studies, involving 1,065 heat wave-related deaths, have found that preexisting mental illness tripled the risk of death.e7927819-0782-42ff-a491-6e125f61600e In a more recent heat wave study, close to 52% of the heat-related fatalities were of people with at least one mental illness and half of those were taking a psychotropic medication.222f1cca-24a5-4d3f-b436-39ec256114ba' href: https://data.globalchange.gov/report/usgcrp-climate-human-health-assessment-2016/chapter/mental-health-and-well-being/finding/extreme-heat-increases-risks-people-mental-illness.yaml identifier: extreme-heat-increases-risks-people-mental-illness ordinal: 4 process: 'The chapter was developed through technical discussions of relevant evidence and expert deliberation by the report authors at several workshops, teleconferences, and email exchanges. The authors considered inputs and comments submitted by the public, the National Academies of Sciences, and Federal agencies. For additional information on the overall report process, see Appendices 2–3.

Areas of focus for the Mental Health and Well-Being chapter were determined based on the most relevant available scientific literature relating to mental health, wellness, and climate change, as well as the mental health impacts of events associated with climate change. Much of the evidence on these impacts has been compiled in countries outside the United States; however, the scenarios are similar and the evidence directly relevant to the situation in the United States, and thus this literature has been considered in the chapter. The evidence-base on mental health and wellness following extreme weather disasters is both well-established and relevant to climate change. The existence of highly relevant scientific literature on specific concerns directly influenced by climate change—such as the effects of extreme heat, stress associated with the threat and perception of climate change, and special population risks—resulted in the inclusion of these more targeted topics. Although significant scientific literature for resilience exists, in-depth discussions of adaptation, coping, and treatment approaches are outside the scope of this chapter, but are discussed in brief in the Resilience and Recovery section.' report_identifier: usgcrp-climate-human-health-assessment-2016 statement: 'People with mental illness are at higher risk for poor physical and mental health due to extreme heat [High Confidence]. Increases in extreme heat will increase the risk of disease and death for people with mental illness, including elderly populations and those taking prescription medications that impair the body’s ability to regulate temperature [High Confidence].' uncertainties: 'Uncertainties include whether pharmaceutical companies will develop new medications to treat mental illness and other health conditions that make individuals less susceptible to heat, whether strategies for prevention of heat-related illness and death are implemented, and whether individuals begin to adapt over time to increases in heat. Prevention, detection, and treatment of mental illness without the use of medications that negatively impact the body’s ability to regulate heat could moderate the magnitude of extreme heat’s impact on those predicted to have psychiatric and stress related disorders.' uri: /report/usgcrp-climate-human-health-assessment-2016/chapter/mental-health-and-well-being/finding/extreme-heat-increases-risks-people-mental-illness url: ~