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Global Change | Atmosphere

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Atmosphere [

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The atmosphere in which we live is extremely thin compared to the overall size of the Earth. We live in the lowest (8 km) layer. Most people live in a smaller zone still - just 0-500 metres above sea level (m.s.l.). Relatively few people are living higher than this and very few can be encountered above 4000m above sea level. At 5000m, the air pressure is only half that at sea level. People cannot survive for long above 8000m altitude. If we see the Earth as a 100 centimetre (cm) diameter balloon, the atmosphere layer where life is possible is only 0.5 mm thick.

The stratosphere is essential to our survival. It is situated at 50 km above the surface (how thick is this layer using the 100cm diameter balloon analogy?). In the stratosphere, a special layer called the Ozone layer prevents UV rays penetrating the atmosphere. No life would exist without such an important barrier.

But as a result of scientific studies and measurements it seems that the Ozone layer is getting thinner due to excessive man-made gas emissions.

Such a serious condition requires careful daily monitoring, using all the advanced, technical tools available today.

Do you wish to be involved in this type of work? Thanks to the ESA Earth observation satellites, such as ERS, you can monitor the situation every hour. Using this web site, you will be trained on how to apply space data to this specific problem. You will also learn more about this subject - so critical to life on Earth.

	Resources
	General information about the Ozone
	GOME Catalogue (includes UV Index)

	Projects
	Avoid getting sunburnt Get the UV values of the day! [ ]
	The OZONE Hole Warning ! [ ]