The causes behind global warming are divided in two groups. Man made causes and natural causes. While little can be done in case of natural causes, man made causes are controllable. The burning of fossil fuel results in production of a green house gas called CO₂. This pollution is among the major causes of global warming. Growing population is also a cause of global warming. Increase in population results in a stress on the scarce resources of earth as more people need more food and more means of transportation. Increase in population also increases the global warming directly as we breathe out CO₂.