Global is happening. Some people say that the rise in temperature is a natural thing. Many more say that the burning of fuels is the main reason for this.

[?] fuels burn to give carbon dioxide and . Both these are greenhouse gases. They trap infra-red , keeping the planet at a higher temperature than it would otherwise be. If there were no greenhouse gases, the planet would be very .

There is a fear that if the perma-frost in Siberia were to thaw, lots of would be released. Methane is a very powerful greenhouse gas, and would make the effect worse.

Glaciers are , and sea-levels are rising all the time. Some countries will be flooded.

Carbon doxide can be by plants. [?] is a good way of reducing carbon dioxide levels.