Global warming is a long-term shift in Earth’s average temperatures and weather conditions. It’s caused by human activities, including the burning of fossil fuels, which adds heat-trapping gases to the atmosphere. The gases warm the atmosphere and lower the amount of sunlight it reflects. Some natural processes can also cause climate change, such as cyclical ocean patterns like El Nino and La Nina and variations in the Sun’s energy output and changes in Earth’s orbit.
In recent years, average global temperatures have risen faster than ever before. According to the Intergovernmental Panel on Climate Change’s Sixth Assessment Report (IPCC Sixth Report) published in 2021, the global temperature has risen by about 2 degrees Fahrenheit (1 degree Celsius) since 1850. The global surface temperature is expected to rise even further if the current rate of emissions continues.
As temperatures rise, many species may find it harder to live in their current habitats. This can force them to move or become extinct. In addition, climate change can increase the frequency and severity of extreme weather events, such as floods, droughts and hurricanes.
Another effect of climate change is the melting of glaciers and ice sheets. This raises sea level, which threatens low-lying coastal areas and islands. It can also submerge landforms and alter ecosystems. For example, the loss of Arctic sea ice can affect polar bears and other animals that depend on it for hunting.