As stated in the introduction to the most recent US National Climate Assessment, “Climate change, once considered an issue for a distant future, has moved firmly into the present” . The current impacts of climate change include increases in certain types of extreme weather (e.g., heat waves, heavy precipitation) and climatic events (droughts), increased water and food insecurity, rising sea levels and ocean acidification, damage to ecosystems and biodiversity, damage to societal infrastructures, and most directly germane to this article, a range of direct and indirect harms to human health .
The US Climate and Health Assessment identified seven major categories of health impacts from climate change, including increased morbidity and mortality from increasing extreme temperatures; temporary reductions in air quality from smog and smoke; increases in extreme weather and climatic events; increasing vector-borne diseases; increasing water-related illness; decreasing food safety, nutrition, and distribution; and mental health conditions including anxiety, depression, and substance use. While anyone’s health can be harmed by climate change, some people are at greatly increased risk including young children, pregnant women, older adults, people with chronic illnesses and disabilities, outdoor workers, and people with fewer resources . Some of these health impacts are just now emerging, but others have been harming the public’s health for years .
Although much remains to be learned about the impacts of climate change on human health, the fact that climate change is a major public health threat has been observed by local communities around the world and has been well documented by climate and health experts . Indeed, climate change is seen by some experts as “the biggest global health threat of the 21st century” . The extent to which the general public and practicing health professionals—including clinical and population health professionals—around the world are aware of the health relevance of climate change, however, is unclear.