Did you know that when you buy flights with certain airlines you can now pay a bit more to offset your carbon footprint? Or perhaps you've read about big pop groups who plant forests of trees every time they do a tour, again, to offset their carbon footprint? But what exactly is a carbon footprint, how is it measured and where did it come from?
Originally a footprint was exactly what you might imagine - the print made by a foot. In the sixties, space travel transformed the word, using it to mean the landing area for a spacecraft, and it has continued to be common in technical circles, with people talking about the footprint of computers (that's the space they take up on a desk), printers and many other such gadgets. Small footprints are considered to be a positive thing, large ones are generally bad.
Everybody has a carbon footprint - it's the amount of carbon dioxide we produce with any action or activity. As carbon dioxide contributes to 'greenhouse gases', our carbon footprints have a direct impact on the environment. You can estimate your carbon footprint on any number of popular websites: if it's small, then you're probably leading a relatively green lifestyle. But what happens if it's big?
Well, the answer is that you can 'offset' it. This modern answer to the problem is for people to contribute to balancing the negative effects of their actions by using green fuels, recycling, reforestation and a number of other activities which are said to contribute to a lowering of the carbon dioxide.
So, before you print out the lesson plan and transcript of this entry, think about your carbon footprint. Do you really need to use that paper, the ink, the electricity... ?
Transcript (pdf - 31 K)
Lesson plan - Teacher's notes, student worksheets with answers (pdf - 90 K)
Audio - Gavin Dudeney on "Carbon footprint" (mp3 - 677 K)
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