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Sunday, March 13, 2011

The Ozone Layer

I'll be posting about the Ozone Layer because I think a lot of people have slight misunderstandings of the Ozone Layer with regards to the greenhouse effect. 

To recap, the ozone layer is in the stratosphere. 
image taken from: http://www.cec.org/ods/en/module01/cec_odspolicy_m01t01p01_e.asp?print=1
The ozone layer is made up of ozone molecules, O3. The ozone layer is extremely important to us because it absorbs the very harmful UV rays from the sun, preventing them from coming down to Earth's surface, thereby protecting us. These harmful rays can cause skin cancer and many other forms of genetic problems in living organisms. 
Ozone is a greenhouse gas. Greenhouse gases absorbs heat reflected back by Earth's surface. The ozone layer absorbs heat as well. In the recent years, the increased use of chlorofluorocarbons, CFCs, has led to an increased depletion of the ozone layer. CFCs are broken into free radicals by UVt light in the stratosphere. These free radicals then break down more than ten thousand ozone molecules. Thus there are holes in the ozone layer. 
These holes allow more harmful UV rays to reach Earth's surface, dramatically increasing skin cancer/disease rates, especially in Australia which is near the hole above Antarctica. 
Although there are more UV rays entering, it does not affect the heat budget. This is because UV rays aren't considered "heat". The heat budget is dependent on the insolation (incoming solar radiation), in other words, infrared radiation, which doesn't require a medium to travel. So, with or without the hole in the ozone layer, the heat absorbed by Earth from the Sun remains the same. 

Greenhouse gases include Methane, Nitrous Oxide, Water vapor, Carbon Dioxide and Ozone. 
image taken from: http://eo.ucar.edu/kids/green/warming4.htm
The greenhouse effect refers to the greenhouse gases absorbing heat and warming up Earth, sustaining the temperature at which we can all survive in. Without the greenhouse effect, Earth would be too cold to live in. You may have heard of people saying that greenhouse effect is a bad thing, but it is not. It is just that people are concerned about the increasing amount of Carbon Dioxide, which leads to global warming. 
Global warming is the increase of Earth's temperature, mainly due to the increase in the amount of carbon dioxide. With more greenhouse gases, more incoming radiation from the Sun would be absorbed, warming Earth up even more. Thus affecting the heat budget. 
Please correct me if i made a mistake, coz i wrote these from what i understand.

1 comment:

  1. Short and informatively written.The greenhouse effects caused by Ozone layer depletion is not just affecting to environment but also to human health.