24 September, 2006

Global Warming ! ...

Global warming is essentially caused by the energy that is normally reflected back off the earth's surface being absorbed by the polluted atmosphere rather than passing through unpolluted air back into space. This is due to the recent dramatic increase in carbon dioxide and methane largely caused by the burning of fossil fuel, coal and oil.

On 12 Sept I flew up to a meeting in Pretoria. The following pics are just three of a series that I took as I flew back from Johannesburg to Cape Town. I was hoping to illustrate the improvement in air quality as we flew south, intending to use the pics in a schools presentation on Climate Change that I am preparing. I was not disappointed.



This first picture was taken shortly after we took off from Johannesburg (now Oliver Tambo) International Airport. You can just see the airport through the smog on this fine spring day!



This picture was taken about half way through the two hour flight over the southern Free State, just approaching the Great Karoo. The poluted air mass, left, that covers the northern half of the country where all our coal fired power stations are situated can be clearly seen. The cloudy area on the right of the picture was the extreme northern limit of the cleaner unpolluted southern ocean airmass.



This pic is taken about 18h00, two hours after the first picture. It shows the mountains about 60km north of Cape Town. Compare the great visibility through the atmosphere with the first picture.

Eish, Im glad to live in Cape Town.