Tuesday 1 April 2008

Climate Change - What is the greenhouse effect?

This sequence of lessons aimed to introduce the concept of global warming and to analyse scientific evidence. Thanks to Miss Gunstone and Miss Hayes for working with all the Year 10 groups to prepare presentations about the key issues.



The earth has warmed by about 1ºF over the past 100 years. But why? And how? Well, scientists are not exactly sure. The Earth could be getting warmer on its own, but many of the world's leading scientists think that things people do are helping to make the Earth warmer.


You need to be aware of several important definitions before we go any further...

Climate is the long-term average of a region's weather events, usually over at least 30 years.

Climate change represents a change in these long-term weather patterns. They can become warmer or colder. Annual amounts of rainfall or snowfall can increase or decrease.

Global warming refers to an average increase in the Earth's temperature, which in turn causes changes in climate. A warmer Earth may lead to changes in rainfall patterns, a rise in sea level, and a wide range of impacts on plants, wildlife, and humans.

When scientists talk about the issue of climate change, their concern is about global warming caused by human activities.

The Greenhouse Effect is the rise in temperature that the Earth experiences because certain gases in the atmosphere (such as water vapour, carbon dioxide, nitrous oxide and methane) trap energy from the sun. Without these gases, heat would escape back into space and Earth’s average temperature would be about 60ºF colder. There would be no life on earth under these circumstances.



The Greenhouse Effect is shown in the diagram above and in the YouTube movie below. The movie won't play at school as the site has been filtered by the LEA. Sorry!


If you are an auditory learner, you might like to listen to the Geocrest Podcast about climate change - Global Warning.

And finally, here is the an official video from the British Government.


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