Climate change is a long-term shift in the Earth’s temperature, which can affect every living thing on it. It’s caused by burning fossil fuels (coal, oil, and natural gas), deforestation, land-use changes, and other human activities that increase the level of heat-trapping greenhouse gases in the atmosphere.
Scientists say that warming temperatures are driving many changes, including higher sea levels, melting glaciers and ice sheets, and warmer air and water. Without significant reductions in carbon emissions, these changes are expected to get worse.
Warming is also changing rainfall patterns. For example, warmer air holds more moisture than cooler air, and this contributes to increased frequency and intensity of extreme precipitation events such as hurricanes. These storms can destroy homes and infrastructure, and kill people.
Climate changes can also disrupt ecosystems and food webs. For instance, animals that rely on snow and ice in the arctic are struggling as temperatures rise. Salmon populations are dwindling as the ocean warms, and their decline is affecting species like orcas and grizzly bears that eat them.
Human-caused climate change can make it harder for people to escape poverty, by increasing the risks they face. Floods can wreak havoc in urban slums, and heat and drought can cause farmers to lose crops and suffer health problems. And when armed conflict or natural disasters occur, they can push millions of people to flee their homes. To help people survive and thrive, we need to address the root causes of climate change.