Tackling climate change is one of the biggest and most urgent challenges faced by this generation, and there are many ways you can make a difference. The first step is to understand exactly what climate change is.

What is climate change?

The climate is not static. Over the millions of years of earth's existence, the climate has changed many times in response to natural causes such as variations in energy received from the sun and volcanic eruptions.

Today, when people talk about 'climate change', they mean the shifts in temperature that have happened over the last 100 years. During this time, the average temperature of the atmosphere near the earth's surface has risen by 0.74 degrees Celsius. 11 of the 12 hottest years on record occurred between 1995 and 2006. And the average sea level around the UK is now about 10 cm higher than it was in 1900.

Most scientists agree that global temperatures could rise between 1.1 and 6.4 degrees Celsius above 1990 levels by the end of the 21st century, depending on future emissions of greenhouse gases. If the rise is high, then changes are likely to be so extreme that it will be difficult to cope with them. There are likely to be more intense and frequent extreme weather events, like floods and hurricanes, and a further rise of up to 59 cm in sea levels.