People and communities are differentially exposed to hazards and disproportionately affected by climate-related health risks (high confidence). Populations experiencing greater health risks include children, older adults, low-income communities, and some communities of color (high confidence).

This finding is from chapter 14 of Impacts, Risks, and Adaptation in the United States: The Fourth National Climate Assessment, Volume II.

Process for developing key messages:

The chapter evaluated the scientific evidence of the health risks of climate change, focusing primarily on the literature published since the cut off date (approximately fall 2015) of the U.S. Climate and Health Assessment.f1e633d5-070a-4a7d-935b-a2281a0c9cb6 A comprehensive literature search was performed by federal contractors in December 2016 for studies published since January 1, 2014, using PubMed, Scopus, and Web of Science. An Excel file containing 2,477 peer-reviewed studies was provided to the author team for it to consider in this assessment. In addition to the literature review, the authors considered recommended studies submitted in comments by the public, the National Academies of Sciences, Engineering, and Medicine, and federal agencies. The focus of the literature was on health risks in the United States, with limited citations from other countries providing insights into risks Americans are or will likely face with climate change. A full description of the search strategy can be found at https://www.niehs.nih.gov/CCHH_Search_Strategy_NCA4_508.pdf. The chapter authors were chosen based on their expertise in the health risks of climate change. Teleconferences were held with interested researchers and practitioners in climate change and health and with authors in other chapters of this Fourth National Climate Assessment (NCA4).

The U.S. Climate and Health Assessmentf1e633d5-070a-4a7d-935b-a2281a0c9cb6 did not consider adaptation or mitigation, including economic costs and benefits, so the literature cited includes research from earlier years where additional information was relevant to this assessment.

For NCA4, Air Quality was added as a report chapter. Therefore, while Key Messages in this Health chapter include consideration of threats to human health from worsened air quality, the assessment of these risks and impacts are covered in Chapter 13: Air Quality. Similarly, co-benefits of reducing greenhouse gas emissions are covered in the Air Quality chapter.

Description of evidence base:

Multiple lines of evidence demonstrate that low-income communities and some communities of color are experiencing higher rates of exposure to adverse environmental conditions and social conditions that can reduce their resilience to the impacts of climate change.c76d7935-9da3-4c4b-9186-86dc658bcc74^,efed1341-a8a0-4743-8ec6-5fa87142a4e3^,b9638744-8ff8-41bd-a741-27b2fda9face^,409668a7-2e7b-461b-953a-ac0d6fb90725^,289728b3-ae8b-417e-920e-96af1a5e64b3 Populations with increased health and social vulnerability typically have less access to information, resources, institutions, and other factors to prepare for and avoid the health risks of climate change.efed1341-a8a0-4743-8ec6-5fa87142a4e3^,85c390fe-4d9b-4713-95d1-2e6b83c01478^,edf0082f-a1b6-48ef-b8d4-e20a458e4bc8 Across all climate-related health risks, children, older adults, low-income communities, and some communities of color are disproportionately impacted. There is high agreement among experts but fewer analyses demonstrating that other populations with increased vulnerability include outdoor workers, communities disproportionately burdened by poor environmental quality, communities in the rural southeastern United States, women, pregnant women, those experiencing gender discrimination, persons with chronic physical and mental illness, persons with various disabilities (such as those affecting mobility, long-term health, sensory perception, cognition), the homeless, those living alone, Indigenous people, people displaced because of weather and climate, low-income residents who lack a social network, poorly planned communities, the disenfranchised, those with less access to healthcare, the uninsured and underinsured, those living in inadequate housing, and those with limited financial resources to rebound from disasters.c76d7935-9da3-4c4b-9186-86dc658bcc74^,efed1341-a8a0-4743-8ec6-5fa87142a4e3^,b9638744-8ff8-41bd-a741-27b2fda9face^,289728b3-ae8b-417e-920e-96af1a5e64b3^,f85a7ac1-b6ad-49b6-ba44-881259d28775

Adaptation can increase the climate resilience of populations when the process of developing and implementing policies and measures includes understanding the ethical and human rights dimensions of climate change, meeting human needs in a sustainable and equitable way, and engaging with representatives of the most impacted communities to assess the challenges they face and to define the climate solutions.7f89e40a-7681-4475-a754-91e81baabd95^,35b1782d-ec59-40d5-b051-c5a80e2516e1

New information and remaining uncertainties:

The role of non-climate factors, including socioeconomic conditions, discrimination (racial and ethnic, gender, persons with disabilities), psychosocial stressors, and the continued challenge to measure the cumulative effects of past, present, and future environmental exposures on certain people and communities will continue to make it challenging to attribute injuries, illnesses, and deaths to climate change. While there is no universal framework for building more resilient communities that can address the unique situations across the United States, factors integral to community resilience include the importance of social networks, the value of including community voice in the planning and execution of solutions, and the co-benefits of institutional readiness to address the physical, health, and social needs of impacted communities. These remain hard to quantify.cab3885c-a808-40f4-9b4a-79808bbdf202^,6ffe484d-3eb7-494b-ad4c-678657585f98

Assessment of confidence based on evidence:

There is high confidence that climate change is disproportionately affecting the health of children, older adults, low-income communities, communities of color, tribal and Indigenous communities, and many other distinct populations. And there is high confidence that some of the most vulnerable populations experience greater barriers to accessing resources, information, and tools to build resilience.

Provenance

This finding was derived from scenario rcp_4_5
This finding was derived from scenario rcp_8_5