Climate Change refers to the long-term changes in Earth’s climate caused by human activity, such as burning fossil fuels (coal, oil and natural gas) that emit heat-trapping greenhouse gases. These gases warm the atmosphere by trapping solar energy and preventing it from dissipating.
Temperatures are already rising globally, and many climate impacts are being felt in the United States, including more frequent and intense heat waves, changing snowfall patterns, increasing wildfire risk, and more flooding and droughts. In addition, the number of people displaced by climate-related disasters and conflict is projected to rise. Displacement is a significant health threat, increasing exposure to trauma, stress, malnutrition, and infectious diseases.
Climate change affects every person and place differently. Some communities may benefit from opportunities to diversify their economies by developing new industries, such as agritourism, aquaculture, or ecotourism, while others may struggle with reduced access to land, water, and jobs. People in lower-income countries and communities tend to suffer more than others from the adverse effects of climate change, but even wealthy nations, such as the United States, have not been immune to its impact.
Scientists predict that the impacts of climate change will become more severe as greenhouse gases continue to build up in the atmosphere, causing glaciers and ice sheets to melt, rivers and lakes to warm and dry up earlier, and plants and animals to move or disappear from their current geographic ranges. This warming will likely lead to more frequent and intense heat waves, a growing number of floods and droughts, and more extreme weather events such as hurricanes and tornadoes.
The best way to slow the pace of climate change is to limit the amount of carbon that is emitted into the atmosphere. This requires reversing more than a century of rising emissions and reaching net zero by the middle of this century.
Investing in renewable energy and switching to electricity from fossil fuels is one of the most effective ways individuals can make this change. Another key action is eating less meat, which not only reduces greenhouse gas emissions but also improves health outcomes.
Although scientists are continuing to make progress in understanding the science of climate change, some important uncertainties remain. These include feedback processes that will dampen or reinforce the effects of human activities, such as polar ice sheet melt and ocean circulation changes; and unavoidable natural influences on the climate, such as volcanic eruptions. Also, there are several thresholds that, if crossed, could trigger irreversible climate change and lead to much more rapid warming than is currently predicted. These thresholds are referred to as climate tipping points. The IPCC has issued an urgent call to action to avert them.