--- - chapter_identifier: agriculture-and-rural-communities confidence: "
The USGCRP{{< tbib '84' '75cf1c0b-cc62-4ca4-96a7-082afdfe2ab1' >}} determined that recent droughts and associated heat waves have reached record intensities in some regions of the United States; however, by geographic scale and duration, the 1930s Dust Bowl remains the benchmark drought and extreme heat event in the historical record since 1895 (very high confidence). The confidence is high that drought negatively impacts crop yield and quality, increases the risk of range wildfires, and accelerates the depletion of water supplies (very likely and high confidence).
" evidence: "The Key Message and supporting text summarize extensive evidence documented in the U.S. Global Change Research Program’s (USGCRP) Climate Science Special Report{{< tbib '84' '75cf1c0b-cc62-4ca4-96a7-082afdfe2ab1' >}} indicating increasing drought frequency or severity in many parts of the United States, increased temperature, and increased frost-free days. An increased probability of hot days concurrent with drought has been reported by Mueller and Seneviratne (2012),{{< tbib '235' '77718bdb-b632-4762-b8a5-d4151785f65b' >}} Mazdiyasni and AghaKouchak (2015),{{< tbib '236' '38b0ec9f-8c00-428f-9ec9-6214f617515d' >}} and Diffenbaugh et al. (2015).{{< tbib '107' '89e08a41-6091-45fa-a92e-6168a90a8151' >}} The warming of minimum temperatures (lack of hard freezes) is contributing to expanding ranges for many insect, disease, and weed species.{{< tbib '237' '5aeba9d1-c405-45a2-b259-bd95dcf17a05' >}} Bebber et al. (2013){{< tbib '238' 'b3855765-38da-4fd9-8288-874a43b16607' >}} report an average poleward shift of 2.7 km/year (1.68 miles/year) since 1960 of numerous pests and pathogens.
Agricultural production: Walthall et al. (2012){{< tbib '38' '3baf471f-751f-4d68-9227-4197fdbb6e5d' >}} synthesize a wide body of literature that documents the impacts of climate, including drought, on crop and livestock productivity and on the natural resources that support agricultural production. Marshall et al. 2015{{< tbib '97' 'bc6c6b92-e049-4b86-b772-8d35032d3cb0' >}} also quantified climate change impacts on the yield of major U.S. crops as well as the reduced ability in the future to mitigate drought by irrigation. Havstad et al. (2016){{< tbib '239' 'c779538d-b066-4e38-8527-ff3f7552f26e' >}} describe the resilience of livestock production on rangelands in the Southwest and identify adaptation management strategies needed in an increasingly arid and variable climatic environment. Liang et al. (2017){{< tbib '240' 'c5857041-2594-47cf-a6bc-3fab052fa903' >}} found that total factor productivity (TFP) for the U.S. agriculture sector is related to regional and seasonal temperature and precipitation factors. Rosenzweig et al. (2014){{< tbib '241' 'b84b193b-ca98-479c-b5ef-fe94e5ffd39c' >}} indicated strong negative effects of climate change on crop yields, particularly at higher levels of warming and lower latitudes. While technological improvements have outweighed the aggregate negative impacts of climate to date, projected climate change indicates that U.S. agriculture TFP could drop to pre-1980s levels by 2050. Ray et al. (2015){{< tbib '242' 'dcf14e95-6370-4d19-b975-33fc290cffae' >}} estimate that climate accounts for about one-third of global yield variability.
Crop heat stress: Novick et al. (2016){{< tbib '243' '3a3fae72-1abc-4a9e-a816-02252ac7c6fe' >}} indicate that atmospheric vapor pressure deficits play a critical role in plant function and productivity and that it will become more important at higher temperatures as an independent factor, relative to available soil moisture. For instance, high temperature has been documented to decrease yields of major crops, including wheat, corn, rice, and soybean.{{< tbib '92' '79853924-784a-4bc1-8c47-551d3e6d9bc1' >}},{{
Wildfire and rangelands: Margolis et al. (2017){{< tbib '255' 'a5604aed-9a6f-468e-acf4-f4a0bb574d3e' >}} report that fire scars in tree rings for the years 1599–1899 indicate that large grassland fires in New Mexico are strongly influenced by the current year cool-season moisture, but that fires burning mid-summer to fall are also influenced by monsoon moisture. Wet conditions several years prior to the fire year, resulting in increased fuel load, are also important for spring through late-summer fires. Persistent cool-season drought lasting longer than three years may inhibit fires due to the lack of moisture to replenish surface fuels. Donovan et al. (2017){{< tbib '95' '81917ef2-289f-4700-bc1a-254feb5156e5' >}} reported that wildfires greater than 400 hectares increased from 33.4 ± 5.6 per year during the period 1985–1994 to 116.8 ± 28.8 wildfires per year for the period 2005–2014 and that the total area burned in the Great Plains by large wildfires increased 400%.
Water supply: Dai and Zhao (2017){{< tbib '256' '476ae3ff-66e2-4cea-8e8f-6e9946356ed0' >}} quantify historical trends in drought based on indices derived from the self-calibrated Palmer Drought Severity Index and the Penman–Monteith potential evapotranspiration index. For greater reliability, they compare these results with observed precipitation change patterns, streamflow, and runoff in three different periods: 1950–2012, 1955–2000, and 1980–2012. They indicate that spatially consistent patterns of drying have occurred in many parts of the Americas, that evaporation trends were slightly negative or slightly positive (exclusive of 1950–1980), and that drought has been increasingly linked to increased vapor pressure deficits since the 1980s.
Pest pressures: Integrated pest management is rapidly evolving in the face of intensifying pest challenges to crop production.{{< tbib '257' '9be3da44-0c39-418f-8dbb-1aca0400d6f7' >}} There is considerable capacity for genetic improvement in agricultural crops and livestock breeds, but the ultimate ability to breed increased heat and drought tolerance into germplasm while retaining desired agronomic or horticultural attributes remains uncertain.{{< tbib '258' 'aa176a1e-7be0-4a50-9099-3656f2bb7d42' >}} The ability to breed pest-resistant varieties into a wide range of species to address rapidly evolving disease, insect, and weed species{{< tbib '237' '5aeba9d1-c405-45a2-b259-bd95dcf17a05' >}} is also uncertain.
" href: https://data.globalchange.gov/report/nca4/chapter/agriculture-and-rural-communities/finding/key-message-10-1.yaml identifier: key-message-10-1 ordinal: 1 process: 'Each regional author team organized a stakeholder engagement process to identify the highest-priority concerns, including priorities for agriculture and rural communities. Due to the heterogeneous nature of agriculture and rural communities, the national chapter leads (NCLs) and coauthor team put in place a structured process to gather and synthesize input from the regional stakeholder meetings. Where possible, one or more of the authors or the chapter lead author listened to stakeholder input during regional stakeholder listening sessions. Information about agriculture and rural communities was synthesized from the written reports from each regional engagement workshop. During the all-authors meeting on April 2–3, 2017, the NCL met with authors from each region and other national author teams to identify issues relevant to this chapter. To finalize our regional roll-up, a teleconference was scheduled with each regional author team to discuss agriculture and rural community issues. Most of the regional author teams identified issues related to agricultural productivity, with underlying topics dominated by drought, temperature, and changing seasonality. Grassland wildfire was identified as a concern in the Northern and Southern Great Plains. All regional author teams identified soil and water vulnerabilities as concerns, particularly as they relate to soil and water quality impacts and a depleting water supply, as well as reduced field operation days due to wet soils and an increased risk of soil erosion due to precipitation on frozen soil. Heat stress in rural communities and among agricultural workers was of concern in the Southeast, Southern Great Plains, Northwest, Hawaiʻi and Pacific Islands, U.S. Caribbean, and Northeast. Livestock health was identified as a concern in the Northeast, Midwest, U.S. Caribbean, and Southern Great Plains. Additional health-related concerns were smoke from wildfire, pesticide impacts, allergens, changing disease vectors, and mental health issues related to disasters and climate change. Issues related to the vulnerability and adaptive capacity of rural communities were identified by all regions. Discussions with the regional teams were followed by expert deliberation on the draft Key Messages by the authors and targeted consultation with additional experts. Information was then synthesized into Key Messages, which were refined based on published literature and professional judgment.
' report_identifier: nca4 statement: 'Food and forage production will decline in regions experiencing increased frequency and duration of drought (high confidence). Shifting precipitation patterns, when associated with high temperatures, will intensify wildfires that reduce forage on rangelands, accelerate the depletion of water supplies for irrigation, and expand the distribution and incidence of pests and diseases for crops and livestock (very likely, high confidence). Modern breeding approaches and the use of novel genes from crop wild relatives are being employed to develop higher-yielding, stress-tolerant crops.
' uncertainties: "Drought impacts on crop yields and forage are critical at the farm economic scale and are well documented.{{< tbib '38' '3baf471f-751f-4d68-9227-4197fdbb6e5d' >}},{{
The evidence on increasing precipitation intensity, with the largest increases occurring in the Northeast, is high (very likely, high confidence). The increase in flooding is less certain (likely, medium confidence). The evidence of the impact of precipitation extremes on infrastructure losses, soil erosion, and contaminant transport to water bodies is well established (very likely, high confidence). Based on medium confidence on flooding but high confidence in increasing precipitation intensity and the impacts of precipitation extremes, there is high confidence in this Key Message.
' evidence: "Evidence of long-term changes in precipitation is based on analyses of daily precipitation observations from the National Weather Service’s Cooperative Observer Network.{{< tbib '261' 'e8089a19-413e-4bc5-8c4a-7610399e268c' >}}
Groisman et al. (2012){{< tbib '262' '5d909426-fab3-4dc8-af56-e5fe414ca97a' >}} reported that for the central United States, the frequency of very heavy precipitation increased by 20% from 1979–2009 compared to 1948–1978. Slater and Villarini (2016){{< tbib '263' 'a0905615-ac31-42ba-a70f-592a5729fdf7' >}} report a significant increase in flooding frequency in the Southern Plains, California, and northern Minnesota; a smaller increase in the Southeast; and a decrease in the Northern Plains and Northwest. Mallakpour and Villarini (2015){{< tbib '264' 'd2af0d06-91aa-4e53-99e1-4dad2ac9195a' >}} report an increasing frequency of flooding in the Midwest, primarily in summer, but find limited evidence of a change in magnitude of flood peaks.
Infrastructure: Severe local storms constituted the largest class of billion-dollar natural disasters from 1980 to 2011, followed by tropical cyclones and nontropical floods.{{< tbib '265' '4fe32146-a968-4dde-8a2b-df2aa2eabdd4' >}} Špitalar et al. (2014){{< tbib '266' '3f57831b-3c94-4ca9-863b-594a81f51b20' >}} evaluate flash floods from 2006 to 2012 and find that the floods with the highest human impacts, based on injuries and fatalities, are associated with small catchment areas in rural areas. Rural areas face particular challenges with road networks and connectivity.{{< tbib '267' '40fd4927-7950-49c8-b022-31a8fbafa9d4' >}}
Soil and water: Soil carbon on agricultural lands is decreased due to land-use change and tillage,{{< tbib '268' 'fecb7170-32c4-498a-95c0-b374d9ce845b' >}},{{
Each regional author team organized a stakeholder engagement process to identify the highest-priority concerns, including priorities for agriculture and rural communities. Due to the heterogeneous nature of agriculture and rural communities, the national chapter leads (NCLs) and coauthor team put in place a structured process to gather and synthesize input from the regional stakeholder meetings. Where possible, one or more of the authors or the chapter lead author listened to stakeholder input during regional stakeholder listening sessions. Information about agriculture and rural communities was synthesized from the written reports from each regional engagement workshop. During the all-authors meeting on April 2–3, 2017, the NCL met with authors from each region and other national author teams to identify issues relevant to this chapter. To finalize our regional roll-up, a teleconference was scheduled with each regional author team to discuss agriculture and rural community issues. Most of the regional author teams identified issues related to agricultural productivity, with underlying topics dominated by drought, temperature, and changing seasonality. Grassland wildfire was identified as a concern in the Northern and Southern Great Plains. All regional author teams identified soil and water vulnerabilities as concerns, particularly as they relate to soil and water quality impacts and a depleting water supply, as well as reduced field operation days due to wet soils and an increased risk of soil erosion due to precipitation on frozen soil. Heat stress in rural communities and among agricultural workers was of concern in the Southeast, Southern Great Plains, Northwest, Hawaiʻi and Pacific Islands, U.S. Caribbean, and Northeast. Livestock health was identified as a concern in the Northeast, Midwest, U.S. Caribbean, and Southern Great Plains. Additional health-related concerns were smoke from wildfire, pesticide impacts, allergens, changing disease vectors, and mental health issues related to disasters and climate change. Issues related to the vulnerability and adaptive capacity of rural communities were identified by all regions. Discussions with the regional teams were followed by expert deliberation on the draft Key Messages by the authors and targeted consultation with additional experts. Information was then synthesized into Key Messages, which were refined based on published literature and professional judgment.
' report_identifier: nca4 statement: 'The degradation of critical soil and water resources will expand as extreme precipitation events increase across our agricultural landscape (high confidence). Sustainable crop production is threatened by excessive runoff, leaching, and flooding, which results in soil erosion, degraded water quality in lakes and streams, and damage to rural community infrastructure (very likely, very high confidence,). Management practices to restore soil structure and the hydrologic function of landscapes are essential for improving resilience to these challenges.
' uncertainties: "Floods are highly variable in space and time,{{< tbib '86' 'a29b612b-8c28-4c93-9c18-19314babce89' >}} and their characteristics are influenced by a number of non-climate factors.{{< tbib '275' 'b8d001bf-c47f-40f8-91f1-a252a46381b8' >}} Groissman et al. (2012){{< tbib '262' '5d909426-fab3-4dc8-af56-e5fe414ca97a' >}} note that the lack of sub-daily data to analyze precipitation intensity means that daily data are normally used, which limits the ability to detect the most intense precipitation rates. While many practices are available to protect soil and reduce nutrient runoff from agricultural lands,{{< tbib '268' 'fecb7170-32c4-498a-95c0-b374d9ce845b' >}},{{
Extreme temperatures are projected to increase even more than average temperatures. The temperatures of extremely cold days and extremely warm days are both projected to increase. Cold waves are projected to become less intense, while heat waves will become more intense (very likely, very high confidence).{{< tbib '293' '29960c69-6168-4fb0-9af0-d50bdd91acd3' >}}
Lehner et al. (2017){{< tbib '294' '53448a8f-22bd-4111-8212-b2204e4d4864' >}} indicate a high likelihood and high confidence that there will be increased record-breaking summer temperatures by the end of the century. Evidence of challenges to human and livestock health due to temperature extremes is well established (very likely, very high confidence).
" evidence: "The Key Message and supporting text summarize extensive evidence documented in the USGCRP’s Climate Science Special Report.{{< tbib '84' '75cf1c0b-cc62-4ca4-96a7-082afdfe2ab1' >}}
Humans: Houghton et al. (2017){{< tbib '274' 'ced8505a-f36f-4c7b-8a0d-ec7f08482297' >}} synthesize the literature that presents strong evidence of climate change impacts on human health in rural areas. Anderson et al. (2018){{< tbib '277' '200c4ff2-90da-45da-bc7a-f4565dbd2fbb' >}} find that heat waves pose risks to human mortality but that the risk associated with any single heat wave depends on many factors, including heat wave length, timing, and intensity. On average, heat waves increase daily mortality risk by approximately 4% in the United States,{{< tbib '278' 'a6714dce-b324-4324-a88e-d31d31fa2d95' >}} but extreme heat waves present significantly higher risks. While research on heat-related morbidity has focused on urban areas, Jagai et al. (2017){{< tbib '279' 'e518fff1-caa5-4ed1-8fdc-b512da7cbe3b' >}} analyzed heat waves in Illinois over 1987–2014 and found that there were 1.16 hospitalizations per 100,000 people in the most rural, thinly populated areas, compared to 0.45 hospitalizations per 100,000 in metropolitan areas. Consequently, a 1.8°F (1°C) increase in maximum monthly temperature was associated with a 0.34 increase in hospitalization rates in rural areas compared to an increase of 0.02 per 100,000 in urbanized counties. The mean cost per hospital stay was $20,050. Fechter-Leggett et al. (2016),{{< tbib '280' '9d4b4e3f-1739-4e8f-ab0b-610dd5276da3' >}} Hess et al. (2014),{{< tbib '281' '7d16ea3a-c4dc-4ebd-8d38-c3d6a64a3e66' >}} and Sugg et al. (2016){{< tbib '282' 'a0403ee4-f787-4078-bcba-64cdd6cc9cb1' >}} also report an elevated risk in rural areas for emergency room visits for heat stress. Additionally, rural areas have a high proportion of outdoor workers who are at additional risk for heat stress.{{< tbib '279' 'e518fff1-caa5-4ed1-8fdc-b512da7cbe3b' >}},{{
Each regional author team organized a stakeholder engagement process to identify the highest-priority concerns, including priorities for agriculture and rural communities. Due to the heterogeneous nature of agriculture and rural communities, the national chapter leads (NCLs) and coauthor team put in place a structured process to gather and synthesize input from the regional stakeholder meetings. Where possible, one or more of the authors or the chapter lead author listened to stakeholder input during regional stakeholder listening sessions. Information about agriculture and rural communities was synthesized from the written reports from each regional engagement workshop. During the all-authors meeting on April 2–3, 2017, the NCL met with authors from each region and other national author teams to identify issues relevant to this chapter. To finalize our regional roll-up, a teleconference was scheduled with each regional author team to discuss agriculture and rural community issues. Most of the regional author teams identified issues related to agricultural productivity, with underlying topics dominated by drought, temperature, and changing seasonality. Grassland wildfire was identified as a concern in the Northern and Southern Great Plains. All regional author teams identified soil and water vulnerabilities as concerns, particularly as they relate to soil and water quality impacts and a depleting water supply, as well as reduced field operation days due to wet soils and an increased risk of soil erosion due to precipitation on frozen soil. Heat stress in rural communities and among agricultural workers was of concern in the Southeast, Southern Great Plains, Northwest, Hawaiʻi and Pacific Islands, U.S. Caribbean, and Northeast. Livestock health was identified as a concern in the Northeast, Midwest, U.S. Caribbean, and Southern Great Plains. Additional health-related concerns were smoke from wildfire, pesticide impacts, allergens, changing disease vectors, and mental health issues related to disasters and climate change. Issues related to the vulnerability and adaptive capacity of rural communities were identified by all regions. Discussions with the regional teams were followed by expert deliberation on the draft Key Messages by the authors and targeted consultation with additional experts. Information was then synthesized into Key Messages, which were refined based on published literature and professional judgment.
' report_identifier: nca4 statement: 'Challenges to human and livestock health are growing due to the increased frequency and intensity of high temperature extremes (very likely, high confidence). Extreme heat conditions contribute to heat exhaustion, heatstroke, and heart attacks in humans (very likely, high confidence). Heat stress in livestock results in large economic losses for producers (very likely, high confidence). Expanded health services in rural areas, heat-tolerant livestock, and improved design of confined animal housing are all important advances to minimize these challenges.
' uncertainties: "Humans: Much of the literature focuses on heat-related mortality in urban areas (e.g., Oleson et al. 2015; Marsha et al. 2017{{< tbib '286' 'a5d430bc-5756-42d1-924f-3dbc927e69c4' >}},{{
Livestock: Walthall et al. (2012){{< tbib '38' '3baf471f-751f-4d68-9227-4197fdbb6e5d' >}} synthesize a wide body of literature that documents the impacts of extreme temperature effects on livestock health and productivity. Ruminant livestock support rural livelihoods and produce high-quality food products from land that is otherwise unsuited to crop agriculture.{{< tbib '291' '831b4c27-416e-4b98-94e6-3969a3b34031' >}},{{
Lower levels of education, poverty, limited infrastructure, and lack of access to resources will limit the adaptive capacity of individuals and communities (very likely, high confidence). Adaptive capacity in rural communities is being increased through federal, state, and local capacity building efforts (likely, low to medium confidence). However, the outreach to rural communities varies greatly in different parts of the United States.
' evidence: "A wealth of data shows that residents of rural areas generally have lower levels of education and lower wages for a given level of education compared to residents of urban areas.{{< tbib '295' '5a980b1c-524c-4a24-9c35-55974a05a0df' >}} Higher levels of poverty, particularly childhood poverty,{{< tbib '7' 'ec982e73-ed8b-460e-9042-e9da15ca84ca' >}} and food insecurity in rural compared to urban areas are also well documented.{{< tbib '49' 'abcd2b28-87f9-499e-9be5-736d6208d3c2' >}} There is also research that documents the disproportionate impacts of climate change on areas with multiple socioeconomic disadvantages, such as an increased risk of exposure to extreme heat and poor air quality, lack of access to basic necessities, and fewer job opportunities.{{< tbib '229' '2fb19c54-72ed-460d-a72f-78f257decd7c' >}}
" href: https://data.globalchange.gov/report/nca4/chapter/agriculture-and-rural-communities/finding/key-message-10-4.yaml identifier: key-message-10-4 ordinal: 4 process: 'Each regional author team organized a stakeholder engagement process to identify the highest-priority concerns, including priorities for agriculture and rural communities. Due to the heterogeneous nature of agriculture and rural communities, the national chapter leads (NCLs) and coauthor team put in place a structured process to gather and synthesize input from the regional stakeholder meetings. Where possible, one or more of the authors or the chapter lead author listened to stakeholder input during regional stakeholder listening sessions. Information about agriculture and rural communities was synthesized from the written reports from each regional engagement workshop. During the all-authors meeting on April 2–3, 2017, the NCL met with authors from each region and other national author teams to identify issues relevant to this chapter. To finalize our regional roll-up, a teleconference was scheduled with each regional author team to discuss agriculture and rural community issues. Most of the regional author teams identified issues related to agricultural productivity, with underlying topics dominated by drought, temperature, and changing seasonality. Grassland wildfire was identified as a concern in the Northern and Southern Great Plains. All regional author teams identified soil and water vulnerabilities as concerns, particularly as they relate to soil and water quality impacts and a depleting water supply, as well as reduced field operation days due to wet soils and an increased risk of soil erosion due to precipitation on frozen soil. Heat stress in rural communities and among agricultural workers was of concern in the Southeast, Southern Great Plains, Northwest, Hawaiʻi and Pacific Islands, U.S. Caribbean, and Northeast. Livestock health was identified as a concern in the Northeast, Midwest, U.S. Caribbean, and Southern Great Plains. Additional health-related concerns were smoke from wildfire, pesticide impacts, allergens, changing disease vectors, and mental health issues related to disasters and climate change. Issues related to the vulnerability and adaptive capacity of rural communities were identified by all regions. Discussions with the regional teams were followed by expert deliberation on the draft Key Messages by the authors and targeted consultation with additional experts. Information was then synthesized into Key Messages, which were refined based on published literature and professional judgment.
' report_identifier: nca4 statement: 'Residents in rural communities often have limited capacity to respond to climate change impacts, due to poverty and limitations in community resources (very likely, high confidence). Communication, transportation, water, and sanitary infrastructure are vulnerable to disruption from climate stressors (very likely, high confidence). Achieving social resilience to these challenges would require increases in local capacity to make adaptive improvements in shared community resources.
' uncertainties: "There is uncertainty about future economic activity and employment in rural U.S. communities. However, the patterns of lower education levels, higher poverty levels, and high unemployment have been persistent and are likely to require long-term, focused efforts to reverse.{{< tbib '6' 'a2a02512-dacf-46f0-8f9f-9cb51892a884' >}},{{