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Just over a century ago, a Swedish scientist, Svante Arrhenius, showed that gases like carbon dioxide can trap heat. We need natural levels of carbon dioxide in the air to trap heat from the Sun and prevent the Earth from being a cold, lifeless rock floating in space.
The problem now is that the level of carbon dioxide emissions worldwide are now around 12 times higher than in 1900 as the world burns increasing quantities of coal, oil and gas for energy. Levels of greenhouse gases in the atmosphere are higher now than at any time in the past 420,000 years, according to samples extracted from deep in the Antarctic ice.
By burning fossil fuels humans are adding carbon dioxide and other heat-trapping greenhouse gases to the atmosphere at a perilous rate and the earth is heating up. The 1990s was the hottest decade of the 20th century and probably of the last 1,000 years. If the warming continues as scientists expect, we face the possibility of record heatwaves, drought, rising sea levels, flooding and the northward migration of insect-borne tropical diseases. The increases in atmospheric concentrations of greehouse gases are seriously disrupting the natural balance of the world's climate.
Some areas are warming much more than others. Scientists were stunned when a huge ice shelf fell apart in Antarctica. An area of ice thought to weigh almost 500 billion tonnes has broken off the Antarctic continent and shattered into thousands of icebergs in one of the most dramatic examples yet of the effects of climate change.
Read this news article and find out how many metres the sea levels are predicted to rise if temperatures across Antarctica continue to rise.
Although we still have much to learn about climate change, the threat is so serious that we cannot delay acting. Greenhouse gas emissions can be reduced by:
