Ocean Forces Threaten Our Climate

This has really set the cat among the climatological pigeons. If Broecker is right, the slowdown in the Antarctic deep current ‚ starting about a century ago ‚ ought to be doing two things. It should make the Antarctic colder, and also encourage the Gulf Stream to make Europe warmer.

The latter result can explain one baffling aspect of global warming. Temperature records - mainly from the northern hemisphere ‚ show that the present phase of global warming actually began in the 1880s, before the man-made greenhouse effect got going. It accelerated in the 1970s, when greenhouse gases started to fill the atmosphere. So what we are seeing now ‚ in the northern hemisphere, anyway - could be a combination of the recent man-made greenhouse effect with a longer-term natural warming trend, powered by changes in the ocean currents.

In Europe, that would mean the climate getting hotter more quickly than the forecasters have predicted. But in the region around Antarctica, the situation is by no means as clear-cut. Here, Broecker's analysis means that man-made warming is fighting against a natural cooling trend - and nobody knows what the consequences of that might be.

But one thing is for certain. As we enter the 21st century, the links between ocean currents and weather are moving from academic analysis into a matter of life and death around the globe.

For more information:

Download 'Artic Meltdown: Rising Seas' TV documentary
http://www.firstscience.com/home/firstscience.tv/arctic-meltdown-rising-seas_4.html

Download 'Meltdown: In the Shadow of Nepal's Lost Glaciers' TV documentary
http://www.firstscience.com/home/firstscience.tv/meltdown-in-the-shadow-of-nepal-s-lost-glaciers_19.html

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