As the world’s climate continues to change, nearly every person in the world will be impacted by the repercussions.

About 85% of the world’s population is already being affected by human-driven climate change, an October study in Nature Climate Change finds. From worsening storms to more frequent wildfires, dangerous weather conditions are threatening health. This year alone, 18 climate-driven weather disasters struck the U.S., killing over 380 people, according to the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information.

In the new global study, researchers analyzed over 100,000 studies on weather events, finding that 80% of the world's land mass has been impacted by climate change, influencing most of the world’s 7.7 billion people.

The machine-learning approach used in the study means scientists can consider a wide breadth of evidence on climate, researchers said. It also lays the foundation for real-time updating of data, offering a “living evidence map” improved by adding additional sources to track the climate crisis.Artistic design of colored leaves with pro-climate quotes

“Our world map of climate impacts provides guidance for the global fight against global heating, for regional and local risk assessments and also for on-the-ground action on climate adaptation,” study lead author Max Callaghan, MPP, a postdoctoral researcher at the Mercator Research Institute on Global Commons and Climate Change, said in a news release.

As national and global leaders work to stem climate change, they must take health equity into account, according to the 2021 U.S. brief from the Lancet Countdown on health and climate change, released Oct. 20. The brief documents the ways climate change is already harming health in the U.S., citing wildfire smoke’s impact on children, the effects of heat waves on older adults and the spread of mosquito-borne infectious diseases. Climate change disproportionately affects low-income communities and people of color, worsening inequities, noted the brief, which APHA partnered to release.

“The data in this report are more than just alarming statistics and trends,” Renee Salas, MD, MPH, MS, lead author of the U.S. brief and a fellow at the Harvard T.H. Chan School of Public Health, said in a news release. “These numbers represent patients that I care for, such as those with worsening asthma attacks, Lyme disease or life-threatening illnesses from extreme heat. Acting on climate change is, first and foremost, a way for us to improve health in the U.S. and advance equity.”

Climate change is threatening more than just physical health, an October report finds. Over 75% of Americans are concerned about climate change, while 25% say they are “alarmed” by it, according to the American Psychological Association and ecoAmerica report.

Survivors of weather disasters report numerous psychological harms, such as depression, anxiety, PTSD, feelings of abandonment and suicidal thoughts. To help residents cope, behavioral health professionals should be incentivized to work in underserved communities and crisis teams need to better mobilize into hard-hit areas after weather disasters, the report recommended. Stricter regulations governing pollution standards and better policies that protect community residents are also needed.

“Climate change is one of the most crucial issues facing our nation and the world today, and it is already taking a huge toll on the mental health of people around the globe,” said Arthur Evans, PhD, CEO of the American Psychological Association, in a news release. “Psychology, as the science of behavior, will be pivotal to making the wholesale changes that are imperative to slow — and, we hope, stop — its advance.”

On Oct. 31, representatives from 200 countries began meeting in Glasgow for the 26th U.N. Climate Change Conference, working on goals for reducing global greenhouse gases. Countries agreed to take action to limit global warming, such as by phasing out coal, curtailing deforestation, pursuing electric-auto technology and investing in energy renewables. 

Almost 50 nations at the climate conference committed to the COP26 Health Program, which supports sustainable, climate-resilient health systems. One of the countries is Fiji, which committed to build climate-resilient health infrastructure, strengthen its health workforce and provide health care facilities with sustainable energy services.

“The future of health must be built on health systems that are resilient to the impacts of epidemics, pandemics and other emergencies, but also to the impacts of climate change, including extreme weather events and the increasing burden of various diseases related to air pollution and our warming planet,” said Tedros Adhanom Ghebreyesus, PhD, MSc, director-general of the World Health Organization, in a news release

For resources on climate change and health, visit APHA’s website.


A piece of art at the COP26 meeting bears a message calling for limits on fossil fuel emissions. Photo by Kiara Worth, courtesy UNFCCC via Flickr.