What is climate change?

A significant majority of scientists agree that emissions of greenhouse gases from human activities are causing an increase in the average temperature of the earth's surface.

Greenhouses gases trap heat in the earth's atmosphere, and their concentration has increased considerably over the past century. Today's atmosphere contains one third more carbon dioxide (the main greenhouse gas) than at the start of the industrial revolution. Major sources of greenhouse gases include power stations, industrial factories, transport and agriculture.

As the average temperature rises, the risk of extreme weather, flooding and drought increases. Many security analysts forecast that these changes would lead to mass migration and civil and international conflict. To reduce the risk of climate change in the future, significant reductions in human emissions will be required.

Research into human interaction with the climate has grown extensively over the past twenty years. It is now thought that a global cut by 2050 of 80% - 90% below the 1990 level is necessary to reduce climate risk to an acceptable level.