Tropical rainforests have a double-cooling effect on the climate. Standing forests, without any intervention by man, sequester vast quantities of carbon dioxide (CO2) out of the atmosphere acting as a ‘carbon sink’. This service removes about 15% of human CO2 emissions from the atmosphere every year, equivalent to around 1 tonne of carbon dioxide (tCO2) per hectare per year. Instead of rewarding this service, however, we are destroying it: tropical deforestation, including peatland loss, accounts for around 15% of our global CO2 emissions – more than the entire global transport sector combined – and reduces the ability of tropical forests to sequester CO2. Tropical forests also evaporate huge volumes of water that cool the earth’s surface and create clouds that reflect sunlight back out to space. Besides helping us to mitigate the effects of climate change rainforests also increase our ability to adapt to its impacts.
Climate change is likely to increase the frequency of extreme events such as droughts and floods. Forests can reduce the incidence of flood events at local scales by slowing down the passage of water over the land surface. Forests also provide an essential buffer for local weather patterns since removing tree cover can result in greater extremes of temperature and rainfall thereby increasing the local impacts of climate change.