What is climate change?

'Climate change' means changes in long term weather patterns across the world

Rising temperatures (also known as 'global warming') will cause sea levels to rise, changes in weather patterns and more extreme and intense weather conditions, such as cyclones.

In the UK, we have already seen heatwaves, heavy rain and flooding becoming more common - the 1990s were the hottest and wettest decade since records began over 350 years ago.

Across the world, climate change will lead to more droughts and flooding, causing crops to fail, homelessness and more people dying.

Why is the climate changing?

Scientists from across the world agree that changes in the climate are mainly caused by human behaviour.

Over the past 150 years, people have been burning more fossil fuels, such as coal, oil and gas. This has caused a build up of carbon dioxide (CO2) in the atmosphere. We have also been cutting down more and more trees, as rainforests have been cleared to make way for farmland. Trees absorb CO2, so even more of the gas builds up.

How does CO2 affect the planet?

CO2 is a 'greenhouse gas' because it acts like a blanket around the Earth, causing it to warm up. There is now more CO2 in the Earth's atmosphere than there has been for tens of thousands of years.

This page was last updated on 3 October 2009