Monday, 12 January 2009

Global warming – yes or no?

Global dimming
Fossil fuel use, as well as producing greenhouse gases, creates other by-products. These by-products are also pollutants, such as sulphur dioxide, soot, and ash. These pollutants however, also change the properties of clouds.
Clouds are formed when water droplets are seeded by air-borne particles, such as pollen. Polluted air results in clouds with larger number of droplets than unpolluted clouds. This then makes those clouds more reflective. More of the sun’s heat and energy is therefore reflected back into space.
This reduction of heat reaching the earth is known as Global Dimming.
Impacts of global dimming: millions already killed by it?
Global warming results from the greenhouse effect caused by, amongst other things, excessive amounts of greenhouse gases in the earth’s atmosphere from fossil fuel burning. It would seem then, that the other by-products which cause global dimming may be an ironic savior.
A deeper look at this, however, shows that unfortunately this is not the case.
Health and environmental effects
The pollutants that lead to global dimming also lead to various human and environmental problems, such as smog, respiratory problems, and acid rain.
The impacts of global dimming itself, however, can be devastating.
Global dimming can be dealt with by cleaning up emissions.
However, if global dimming problems are only addressed, then the effects of global warming will increase even more.
Horizon Video on this topic here. –beware folks it is 48 minutes long!
If this is too long then here’s a shorter one

Climate change from the BBC
Good for the new additional section to Higher Geography on the impact of global warming this year.

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