As a result of human activity, the amount of greenhouse gasses, particularly carbon dioxide, in the atmosphere is increasing. Greenhouse gases exacerbate the greenhouse effect, which causes the warming of our planet, leading to global warming. Global warming causes changes in rainfall patterns. This, in turn, increases and intensifies extreme weather phenomena, such as heatwaves, drought, flooding, hurricanes and forest fires. As a result of global warming, the amount of snow and ice decreases while the sea levels rise, altering the geographical distribution of plant and animal species. In addition, the changes in rainfall and meltwaters reflect on the quantity and quality of fresh water reserves.