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Global warming

Carbon dioxide from burning fuels causes global warming, a process capable of changing the world’s climate significantly.

The percentage of carbon dioxide in the atmosphere has risen from 0.028 in 1700 to 0.035 in 1990.

Carbon dioxide in the atmosphere has risen at a higher rate since the 19th century

The earth's global average temperature has risen from  13.5º C in 1860 to 14.4º C in 1995 (temperatures over a 5 year average).

The temperature of the earth has risen over the years

As you can see from the graphs, the amount of carbon dioxide in the atmosphere has increased steadily over the past 150 years, and so has the average global temperature.

Carbon dioxide is a greenhouse gas. It absorbs heat energy and prevents it escaping from the Earth’s surface into space. The greater the amount of carbon dioxide in the atmosphere, the more heat energy is absorbed and the hotter the Earth becomes.

Greenhouse effect

Earth absorbing and reflecting some solar radiation
  1. Sun’s rays enter the Earth’s atmosphere
  2. Heat is reflected back from the Earth’s surface
  3. Heat is absorbed by carbon dioxide (greenhouse gas) and as a result becomes trapped in the Earth’s atmosphere
  4. The Earth becomes hotter as a result

Results of global warming

A rise of just a few degrees in world temperatures will have a dramatic impact on the climate:

  • Global weather patterns will change, causing drought in some places and flooding in others.
  • Melting of polar ice caps will raise sea levels, causing increased coastal erosion and flooding of low-lying land – including land where major cities lie.

The Triftgletscher glacier, Switzerland, 2002

The Triftgletscher glacier, Switzerland, 2003. As the glacier melts further, the lake's water level rises.

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