This section explains climate change in simple terms. It tells you what changes have been observed and why such change is occurring. It also presents future climate change scenarios for the UK, showing changes in climate that may occur over the 21st century.

The Earth's climate has been relatively stable since the end of the last ice age, about 10,000 years ago, but it is now changing.

The average global temperature is rising. The 20th century was probably the warmest century in the last 1,000 years: there was about 0.6°C of warming, with land warming more than the sea. The 1990s were the warmest decade in the last 100 years.

There is also evidence that rainfall patterns are changing, sea levels are rising, glaciers are retreating, arctic sea-ice is thinning and the incidence of extreme weather is increasing in some parts of the world.