U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Environmental Factor

Environmental Factor

Your Online Source for NIEHS News

December 2023

Fifth National Climate Assessment released

NIEHS and others at NIH are leading efforts to address climate and health research gaps outlined in congressionally mandated report.

The Fifth National Climate Assessment (NCA5) released Nov. 14 is the U.S. government’s preeminent report on climate change impacts, risks, and responses with more than 30 chapters providing the scientific foundation to support informed decision-making. Staff working on the cross-cutting National Institutes of Health (NIH) Climate Change and Health Initiative will pay careful attention to the NCA5's conclusions.

Led by the U.S. Global Change Research Program and its 14 member agencies, NCA5 draws on the expertise of nearly 500 authors and 250 contributors from every state, as well as Guam, Puerto Rico, and the U.S. Virgin Islands. NCA5 is the most comprehensive analysis of the state of climate change in the United States, providing authoritative, decision-relevant information on how people across the country are experiencing climate change, the risks people face now and will face in the future, and actions underway to reduce carbon pollution and build resilience.

NCA5 also featured the work of 92 artists, including Ritika S., an eighth grader who was honored as a youth entry award winner. (Image courtesy of NCA5)
NCA5 also featured the work of 92 artists, including Ritika S., an eighth grader who was honored as a youth entry award winner. (Image courtesy of NCA5)

“The report highlights national and regional effects related to climate change and assesses existing efforts to adapt and reduce those effects,” said Gwen Collman, Ph.D., of NIEHS, who reviewed the human health chapter describing the negative effects of climate change on many human health outcomes. “It is an invaluable resource for researchers seeking to develop new approaches to address the intersection of climate change and health.”

The report meets the requirements of the Global Change Research Act, which mandates an assessment at least every four years of our understanding of global change and its impacts on the United States.

Climate-related health disparities

NCA5 documents climate change’s severe health impacts on many populations and highlights the especially strong risk of climate-related harms to people with few material resources. This analysis is contained in the chapter devoted exclusively to health, in each regional chapter, and in many topical chapters.

Chapter 15 of NCA5 outlines the health risks from a changing climate, including an increase in tick- and mosquito-borne diseases.
Chapter 15 of NCA5 outlines the health risks from a changing climate, including an increase in tick- and mosquito-borne diseases. (Image courtesy of Los Alamos National Laboratory, CDC, Columbia University, University of Arizona, and University of Colorado / NCA5)

Risks to health include higher rates of heat-related morbidity and mortality; increases in the geographic range of some infectious diseases; greater exposure to poor air quality; increases in some adverse pregnancy outcomes; higher rates of pulmonary, neurological, and cardiovascular diseases; and worsening mental health. The report points to the emergence of scientific evidence on these risks in populations in the U.S. and around the world. It provides continued validation of disproportionate impacts on under-resourced and overburdened communities and individuals.

The NCA5 assesses the heightened vulnerability of Black, Indigenous, and other People of Color (BIPOC) communities and the increased risks faced by sexual and gender minorities and people with disabilities. NCA5 discusses adaptation options and other solutions through a social equity lens. In addition, the report expands understanding of both the physical and mental impact these environmental shocks and long-term changes are having.

NIEHS led efforts

“Climate change is harming physical, mental, spiritual, and community health through the increasing frequency and intensity of extreme events, higher incidences of infectious and vector-borne diseases, and declines in food and water security,” wrote the report authors. “These impacts worsen social inequities.”

To address these mounting challenges, the NIH formed the NIH Climate Change and Health Initiative. The Initiative, which is led by NIEHS, with great support throughout the NIH, brings forward the power of the research community in helping to address these urgent issues.

Research supported by the NIH will address some of the research gaps identified in the Fifth National Climate Assessment. Partnerships with other agencies will further strengthen the work. Building transdisciplinary teams that work with communities to understand the real-world impacts of climate change and health will inform improved ways to address environmental justice and health equity issues in climate change and health and to improve health for all.

(This article was adapted from a Nov. 14 Factsheet written by the U.S. Department of Health and Human Services.)

Back To Top