--- chapter: doi: 10.7930/NCA4.2018.CH17 identifier: sectoral-interdependencies-and-compounding-stressors number: 17 report_identifier: nca4 sort_key: 117 title: 'Sector Interactions, Multiple Stressors, and Complex Systems' url: https://nca2018.globalchange.gov/chapter/17/ chapter_identifier: sectoral-interdependencies-and-compounding-stressors cited_by: [] confidence: '

We have high confidence in this Key Message because there is high agreement that a multisector perspective alters risk assessment, as is reflected in recent climate change assessments. However, the evidence basis for multisector evaluations is emerging.

' contributors: [] evidence: "

Recent climate change assessments (e.g., Oppenheimer et al. 2014, Houser et al. 2015{{< tbib '45' '0ea6d723-5df9-4b45-8d5f-be269119ccf8' >}},{{}}) emphasize that a multisector perspective expands the scope of relevant risks and uncertainties associated with climate change impacts. Assessing these risks requires attention to multiple interacting sectors, geographic regions, and stressors, such as 1) interactions in the management of water, land, and energy (see Box 17.3), or 2) spatial compounding of impacts if, for example, multiple infrastructure systems fail within a city (see Box 17.1). Risk assessment also requires attention to indirect and long-distance climate change impacts, for instance resulting from human migration or conflict.{{< tbib '45' '0ea6d723-5df9-4b45-8d5f-be269119ccf8' >}},{{}} Analyses of historical events (see Box 17.5), evaluations of statistical risk (e.g., Carleton and Hsiang 2016{{< tbib '101' 'a73835ed-0558-4fe3-bccf-e61b4014ed63' >}}), and process-based modeling projections are some of the methods demonstrating these complex interactions across sectors, scales, and stressors.

Different tools and approaches are required to assess multisector risks. Approaches can be applied to integrate diverse evidence, combining quantitative and qualitative results and drawing from the natural and social sciences and other forms of analysis.{{< tbib '47' '0bf999f3-8291-493a-bf19-525a26af5125' >}},{{}},{{}} For instance, models and expert judgment have been used together to inform our understanding of future sea level rise,{{< tbib '52' '843b8feb-de6f-42be-88f9-657915e75601' >}} and scenarios can also be used to explore preparedness across possible futures.{{< tbib '53' 'ae138b1a-a619-4312-a671-0f671a85662b' >}},{{}},{{}}

" files: [] gcmd_keywords: - definition: 'Climate Change Impact Assessment Models examine and predict the vulnerabilities of human populations to future climate change, including associated sea-level rise and changes in the frequency and intensity of climate extremes such as floods, droughts, heat waves and windstorms, and taking into account potential impacts on water resources, agriculture and food security, human health, coastal and other types of settlements, and economic activities. These models can be used to assess the potential responses of natural environments and the wildlife that inhabit them to future climate change and identifies environments at particular risk.' href: https://data.globalchange.gov/gcmd_keyword/ea5ccefb-e390-43d5-8202-33e004565beb.yaml identifier: ea5ccefb-e390-43d5-8202-33e004565beb label: CLIMATE CHANGE IMPACT ASSESSMENT MODELS parent_identifier: e1f20631-b5b9-438c-b5c2-b1fa0fce100a uri: /gcmd_keyword/ea5ccefb-e390-43d5-8202-33e004565beb - definition: 'The systematic identification and evaluation of the potential impacts of proposed projects, plans, programs, policies, or legislative actions upon the physical, chemical, biological, cultural, and socioeconomic components of the environment.' href: https://data.globalchange.gov/gcmd_keyword/079724fa-ff86-4195-aee0-51a4d6dd73bb.yaml identifier: 079724fa-ff86-4195-aee0-51a4d6dd73bb label: ENVIRONMENTAL ASSESSMENTS parent_identifier: d81b77be-0177-4e26-942c-aa911239482d uri: /gcmd_keyword/079724fa-ff86-4195-aee0-51a4d6dd73bb - definition: |- Planning refers to the formulation of a course of action to be taken in the event of a hazard emergency. href: https://data.globalchange.gov/gcmd_keyword/5c14b001-518f-460b-90fe-139bf192d1f2.yaml identifier: 5c14b001-518f-460b-90fe-139bf192d1f2 label: HAZARDS PLANNING parent_identifier: 464de0a5-2bb9-4172-9fd3-1634cbc4e739 uri: /gcmd_keyword/5c14b001-518f-460b-90fe-139bf192d1f2 - definition: 'Any behavior caused by or affecting another individual, usually of the same species.' href: https://data.globalchange.gov/gcmd_keyword/c8317644-4cb2-4e37-b536-c762f7e670ab.yaml identifier: c8317644-4cb2-4e37-b536-c762f7e670ab label: SOCIAL BEHAVIOR parent_identifier: fb93d937-c17c-45d0-a9e3-ca5c8a800ca8 uri: /gcmd_keyword/c8317644-4cb2-4e37-b536-c762f7e670ab - definition: 'An uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, peat fire, vegetation fire, and veldfire may be used to describe the same phenomenon depending on the type of vegetation being burned. A wildfire differs from other fires by its extensive size, the speed at which it can spread out from its original source, its potential to change direction unexpectedly, and its ability to jump gaps such as roads, rivers and fire breaks. Wildfires are characterized in terms of the cause of ignition, their physical properties such as speed of propagation, the combustible material present, and the effect of weather on the fire.' href: https://data.globalchange.gov/gcmd_keyword/868b87a1-d8c2-49b3-8bbd-9cbbed115271.yaml identifier: 868b87a1-d8c2-49b3-8bbd-9cbbed115271 label: WILDFIRES parent_identifier: ec0e2762-f57a-4fdc-b395-c8d7d5590d18 uri: /gcmd_keyword/868b87a1-d8c2-49b3-8bbd-9cbbed115271 - definition: Describes coupled dynamics of human-ecological systems href: https://data.globalchange.gov/gcmd_keyword/6bef0291-a9ca-4832-bbb4-80459dc1493f.yaml identifier: 6bef0291-a9ca-4832-bbb4-80459dc1493f label: ECOLOGICAL DYNAMICS parent_identifier: 91c64c46-d040-4daa-b26c-61952fdfaf50 uri: /gcmd_keyword/6bef0291-a9ca-4832-bbb4-80459dc1493f href: https://data.globalchange.gov/report/nca4/chapter/sectoral-interdependencies-and-compounding-stressors/finding/key-message-17-2.yaml identifier: key-message-17-2 ordinal: 2 parents: [] process: '

The scope of this chapter was developed to fill a gap in previous National Climate Assessments (NCAs), notably the risks that emerge from interactions among sectors. Previous NCAs have touched on this subject, for example the energy, water, and land use chapter in the Third National Climate Assessment (NCA3). However, these assessments never included a chapter specifically focused on a general treatment of this topic. Emerging scientific research is highlighting the links between sectors and the potential complexity and implications of these interactions, from complex system dynamics such as cascading failures to management approaches and approaches to risk. These concepts were then incorporated into a detailed terms of reference for the chapter, outlining the scope and the general content to be included in the document.

The author team for this chapter was constructed to bring together the necessary diverse experience, expertise, and perspectives. Our authors brought expertise and experience in multiscale, multisector research and modeling, with a focus in specific sectors or sectoral combinations including critical infrastructure, energy–water–land interactions, and ecosystems. The authors also had expertise in complex systems science and previous experience in assessment processes.

The chapter was developed through technical discussions, a literature review, and expert deliberation by chapter authors through email and phone discussions. The team evaluated the state of the science on the analysis of sectoral interdependencies, compounding stressors, and complex system science. Case studies were drawn from a range of sources intended to represent the key themes in the chapter.

' references: - href: https://data.globalchange.gov/reference/0bf999f3-8291-493a-bf19-525a26af5125.yaml uri: /reference/0bf999f3-8291-493a-bf19-525a26af5125 - href: https://data.globalchange.gov/reference/0ea6d723-5df9-4b45-8d5f-be269119ccf8.yaml uri: /reference/0ea6d723-5df9-4b45-8d5f-be269119ccf8 - href: https://data.globalchange.gov/reference/42c619a3-768b-4a22-9dd6-73b52af9426c.yaml uri: /reference/42c619a3-768b-4a22-9dd6-73b52af9426c - href: https://data.globalchange.gov/reference/843b8feb-de6f-42be-88f9-657915e75601.yaml uri: /reference/843b8feb-de6f-42be-88f9-657915e75601 - href: https://data.globalchange.gov/reference/9c909a77-a1d9-477d-82fc-468a6b1af771.yaml uri: /reference/9c909a77-a1d9-477d-82fc-468a6b1af771 - href: https://data.globalchange.gov/reference/a73835ed-0558-4fe3-bccf-e61b4014ed63.yaml uri: /reference/a73835ed-0558-4fe3-bccf-e61b4014ed63 - href: https://data.globalchange.gov/reference/ae138b1a-a619-4312-a671-0f671a85662b.yaml uri: /reference/ae138b1a-a619-4312-a671-0f671a85662b - href: https://data.globalchange.gov/reference/bbca6337-718b-4289-b6e7-0a2f6c1cb8f1.yaml uri: /reference/bbca6337-718b-4289-b6e7-0a2f6c1cb8f1 - href: https://data.globalchange.gov/reference/c7f36e83-1f30-491a-b7b8-79cfc181d011.yaml uri: /reference/c7f36e83-1f30-491a-b7b8-79cfc181d011 - href: https://data.globalchange.gov/reference/d5216e42-45ce-457b-bda8-b2e445d23c0d.yaml uri: /reference/d5216e42-45ce-457b-bda8-b2e445d23c0d - href: https://data.globalchange.gov/reference/df27d677-4c3e-49ee-87ef-4d46c1e47087.yaml uri: /reference/df27d677-4c3e-49ee-87ef-4d46c1e47087 regions: [] report_identifier: nca4 statement: '

Climate change risk assessment benefits from a multisector perspective, encompassing interactions among sectors and both climate and non-climate stressors. Because such interactions and their consequences can be challenging to identify in advance, effectively assessing multisector risks requires tools and approaches that integrate diverse evidence and that consider a wide range of possible outcomes. (High Confidence)

' uncertainties: '

For interdependent systems affected by multiple stressors, the number and complexity of possible interactions are greater, presenting deeper uncertainties. It is often difficult or impossible to represent all relevant processes and interactions in analyses of risks, especially quantitatively. For example, quantitative projections can evaluate probabilities of well-understood sectoral interactions but will be limited by processes or parameters that are poorly known or unknowable. This is why the integration of diverse evidence and attention to deeper uncertainties are important in multisector risk assessment.

' uri: /report/nca4/chapter/sectoral-interdependencies-and-compounding-stressors/finding/key-message-17-2 url: ~