Impacts from climate change are happening now. These impacts extend well beyond an increase in temperature, affecting ecosystems and communities in the United States and around the world. Things that we depend upon and value — water, energy, transportation, wildlife, agriculture, ecosystems, and human health — are experiencing the effects of a changing climate.
Water
Changes to water resources can have a big impact on people's lives. In some regions, particularly in the western United States, drought is an important factor affecting communities. Less snow accumulation in the mountains is important in the West and Alaska, where the snowpack stores water for later use. In the Midwest and northeastern states, the frequency of heavy downpours has increased. In many regions, floods and water quality problems are likely to be worse because of climate change.
Food
Our food supply depends on climate and weather conditions. Although agricultural practices may be adaptable, changes like increased temperatures, water stress, diseases, and weather extremes create challenges for the farmers and ranchers who put food on our tables.
Health
Human health is vulnerable to climate change. The changing environment is expected to cause more heat stress, an increase in waterborne diseases, poor air quality, and diseases transmitted by insects and rodents. Extreme weather events can compound many of these health threats.
The environment
Ecosystems are also affected by climate change. Habitats are being modified, the timing of events such as flowering and egg laying are shifting, and species are altering their home ranges.
Changes are also occurring to the ocean. The ocean absorbs about 30% of the carbon dioxide that is released into the atmosphere from the burning of fossil fuels. As a result, the ocean is becoming more acidic, affecting marine life. Rising sea levels due to thermal expansion and melting land ice sheets and glaciers put coastal areas at greater risk of erosion and storm surge.
