Climate change caused by the emission of greenhouse gases from human activities affects global temperature and precipitation. Records from the Intergovernmental Panel on Climate Change indicate that the global average temperature has increased by at least 0.4 degrees Celsius (0.72 degrees Fahrenheit) since the 1970s, and that by 2100, it could increase to around 4 degrees Celsius (7.2 degrees Fahrenheit) above preindustrial temperatures.
While the global effects of climate change may seem too small to be noticed by people living around the world, we have already experienced the effects of climate change through severe weather events, including forest fires, hurricanes, droughts, heat waves, floods, and storms. Computer modelling of real data has shown that the frequency and intensity of these events are influenced by climate change.