15 October 2009

The Meltdown: What Happened To Global Warming?

Here is a section of an article from a BBC Climate Correspondent Paul Hudson:
For the last 11 years we have not observed any increase in global temperatures. And our climate models did not forecast it, even though man-made carbon dioxide, the gas thought to be responsible for warming our planet, has continued to rise. So what on Earth is going on?

And:

According to research conducted by Professor Don Easterbrook from Western Washington University last November, the oceans and global temperatures are correlated.

The oceans, he says, have a cycle in which they warm and cool cyclically. The most important one is the Pacific decadal oscillation (PDO).

For much of the 1980’s and 1990’s, it was in a positive cycle; that means warmer than average. And observations have revealed that global temperatures were warm too. But in the last few years it has been losing its warmth and has recently started to cool down. These cycles in the past have lasted for nearly 30 years.

So could global temperatures follow? The global cooling from 1945 to 1977 coincided with one of these cold Pacific cycles. Professor Easterbrook says: “The PDO cool mode has replaced the warm mode in the Pacific Ocean, virtually assuring us of about 30 years of global cooling.”

So what does it all mean? Climate change sceptics argue that this is evidence that they have been right all along. They say there are so many other natural causes for warming and cooling, that even if man is warming the planet, it is a small part compared with nature.

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