Aging Initiative

General Information on Climate Change

Climate change affects people, plants, and animals. Scientists are working to better understand future climate change and how the effects will vary by region and over time. Scientists have observed that some changes are already occurring. Observed effects include sea level rise, shrinking glaciers, changes in the range and distribution of plants and animals, trees blooming earlier, lengthening of growing seasons, ice on rivers and lakes freezing later and breaking up earlier, and thawing of permafrost. For more general information on climate change.

Health and Environmental Effects

Human health can be affected directly and indirectly by climate change in part through extreme periods of heat and cold, storms, and climate-sensitive diseases such as malaria, and smog episodes. For more information on these and other environmental effects, please visit the Health and Environmental Effects section of EPA’s website on climate change.

Extreme temperatures can lead directly to loss of life, while climate-related disturbances in ecological systems, such as changes in the range of infective parasites, can indirectly impact the incidence of serious infectious diseases. Higher temperatures may increase concentrations of air contaminants in some regions of the country and more intense periods of precipitation can increase the risk of water contamination, both of which have documented human health consequences.

Older Adults

Human health is strongly affected by social, political, economic, environmental and technological factors, including urbanization, affluence, scientific developments, individual behavior and individual vulnerability. For example, genetic makeup, nutritional status, emotional well-being, gender, economic status and age are all factors that can affect vulnerability. The extent and nature of climate change impacts on human health vary by region, by relative vulnerability of population groups, by the extent and duration of exposure to climate change itself and by society’s ability to adapt to or cope with the change.

Direct Temperature Effects

Climate change may directly affect human health through increases in average temperature. This may lead to more extreme heat waves during summer months and less extreme cold weather during winter months. Rising average temperatures are predicted to increase the incidence of heat waves and hot extremes. In the United States, Chicago is projected to experience 25 percent more frequent heat waves and Los Angeles a four-to-eight-fold increase in heat wave days by the end of the century (IPCC, 2007). Particular segments of the population such as those with heart problems, asthma, older adults, the very young and the homeless can be especially vulnerable to extreme heat.