Natural causes of global warming include the release of methane gas from arctic tundra and wetlands, climate change, volcanoes etc. Methane, a greenhouse gas which traps the heat within the earth's atmosphere, is let out in large quantities in the arctic tundra and wetlands. In case of volcanoes, when a volcano erupts, tons of ash is let out into the atmosphere. Even though nature contributes to global warming, this contribution is very insignificant when compared to human contribution for this hazard.
Anthropogenic causes for global warming are those which are caused due to human activities. The most prominent cause being man-made pollution. A large part of this pollution can be attributed to the burning of fossil fuels. This includes burning coal to produce electricity as well as burning gasoline to power internal combustion engine vehicles. When these fossil fuels are burnt, they let out carbon dioxide, which is yet another greenhouse gas which traps heat within the atmosphere of the Earth and contributes to global warming. Secondly when the Earth is dug to extract these fossil fuels in the process known as mining, the methane inside the Earth's crust escapes into the atmosphere and adds to other greenhouse gases such as carbon dioxide. If we start investigating the anthropogenic causes of global warming, we zero in on one of the most important cause of global warming - population. More population means more requirements, which includes food, electricity and transport. In order to fulfill these requirements, more fossil fuels are consumed, which eventually leads to global warming. Humans breathe out carbon dioxide, and with an increasing population, the amount of carbon dioxide humans breathe out also increases and leads to global warming. Even agriculture contributes to global warming, owing...