Climate change is when there is a big difference in normal climate patterns over a long amount of time. More than 100 years ago, people around the world started burning large amounts of coal, oil and natural gas for domestic and industrial purposes. Burning fossil fuels releases carbon dioxide (CO2), a heat-trapping gas, into the atmosphere, which is the main reason why the climate is changing. Heat trapping gases are also called 'Greenhouse gases'. They exist naturally in the atmosphere, where they help to keep the Earth warm. But people are adding extra greenhouse gases to the atmosphere. These extra gases are causing the Earth to get warmer, setting off all sorts of other changes around the world-on land, in the oceans, and in the atmosphere and these changes affect all th eliving things including people, plants, and animals in many ways.