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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. 

• The causes of climate change
• More on climate change from the UK Climate Impacts Programme Opens new window

Early discoveries about climate change

The first research that helped explain climate change dates back to 1753, when Joseph Black discovered carbon dioxide.

In 1827, Jean-Baptiste Fourier suggested that an atmospheric effect existed that kept the earth warmer than it would otherwise be. He used the analogy of a greenhouse.

A Swedish chemist called Arrhenius suggested in 1896 that carbon dioxide emissions from the burning of coal would enhance the earth's greenhouse effect and lead to global warming.

• The causes of climate change

First warnings about climate change

In 1967, a computer simulation calculated that average global temperatures might increase by more than four degrees Fahrenheit, depending on carbon dioxide levels.

In 1979, 12 years later, the world held its first climate conference. The conference called on governments “to foresee and prevent potential man-made changes in climate”.

In 1987, an ice core from Antarctica revealed an extremely close link between carbon dioxide levels and temperature going back more than 100,000 years.

The world’s response to climate change

United Nations takes action
In 1988, the United Nations set up the Intergovernmental Panel on Climate Change (IPCC) to analyse and report on scientific findings. The IPCC’s first report found that the planet had warmed by 0.5 degrees Celsius in the past century. It warned that only strong measures to halt rising greenhouse gas emissions would prevent serious global warming.

Global targets for reducing emissions
In 1992, the Earth Summit took place in Rio de Janeiro. Here, the United Nations Framework Convention on Climate Change (UNFCCC) was signed by 154 nations. It agreed to prevent 'dangerous' warming from greenhouse gases and set voluntary targets for reducing emissions.

Kyoto: legally binding cuts in emissions
In 1997, the Kyoto Protocol was agreed. Where the UNFCCC agreed voluntary targets, Kyoto was the first international treaty to set legally binding emissions cuts for industrialised nations. It was signed by 178 countries and came into force in 2005.

• The Intergovernmental Panel on Climate Change Opens new window
• More on the United Nations Framework Convention on Climate Change Opens new window
• More on the Kyoto protocol - the European Environment Agency Opens new window

The UK’s reaction to climate change

The UK signed both the UN Framework Convention on Climate Change and the Kyoto Protocol, and is on track to surpass its Kyoto target for reducing greenhouse gas emissions.

In 2006, the Stern report was published in the UK by HM Treasury. It was the first report of its kind into the economic impact of climate change, and found that the costs of inaction far outweighed the costs of action.

In 2007, the UK government published the draft Climate Change Bill. The Bill aims to set legally binding targets for reducing emissions by 80 per cent on 1990 levels by 2050.

• Read the Stern Report from HM Treasury Opens new window
• The draft Climate Change Bill Opens new window

The latest on climate change

In 2007, the IPCC confirmed that there is a greater than 90 per cent chance that global warming over the last 50 years is due to human activity. It said that the planet had warmed 0.74 degrees Celsius since the beginning of the 20th century.

At the UN climate change conference in Bali, also in 2007, all the world’s nations agreed to negotiate on a deal to tackle dangerous climate change. The details are expected in the next two years.

• More on the Bali conference Opens new window

What you can do about climate change

Some changes to the climate are inevitable, but there is still time to positively influence the future. You can help minimise further changes and adapt to the new situation through decisions and actions which are often quick and easy to put into practice.

• Greener living: a quick guide to what you can do

More useful links

• Information on climate from the Met Office Opens new window
• More on climate change from the United Nations Framework Convention on Climate Change Opens new window
• A detailed history of climate change - the American Institute of Physics Opens new window
• A detailed history of climate change from the Greenhouse Network Opens new window