There are two main types of external sources leading to climate change. One type of external factors such as solar radiation and volcanism occurring naturally. The other external factor leading to climate change began with the Industrial Revolution, and is directly the result of human activities.
There have been previous periods of climate change but the current changes are distinctly more rapid and not due to natural causes. Instead, they are caused by the emission of greenhouse gases, mostly carbon dioxide (CO2) and methane. Burning fossil fuels for energy production creates most of these emissions. Greenhouse gases are transparent to sunlight allowing it to warm the Earth’s surface. When the earth emits this heat as infrared radiation, it is absorbed by the gases, trapping the heat near the earth’s surface and causing global warming and climate change.
Human activities are estimated to have caused approximately 1.0°C of global warming above pre-industrial levels, with a likely range of 0.8°C to 1.2°C. Global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate.
