Ashes to ashes, dust to dust: theory that Atlantic Ocean is warming due to climate change laid to rest
The North Atlantic is hotting up fast but it's not because of climate change, say scientists in the most recent edition of the journal Science. No, it's because there's less dust around to keep the water cool.
Over the past 30 years, the North Atlantic has been warming up at a rate of a quarter of a degree Celsius per decade. (That's pretty fast for a tropical ocean basin, apparently.)
Like the left-handed man in a Sherlock Holmes novel who limps, smokes Indian cigars and carries a blunt pen-knife in his pocket, suspicion immediately fell upon climate change. But the real culprit, it now emerges, is a drop in the amount of dust and sulphate in the skies above the Atlantic.
Dust blown out of West Africa (the world's largest 'dust superstore') and volcano-belched sulphate, both of which cool the atmosphere by scattering sunlight, are on the decline, say the scientists, which is why the ocean is warming.
Of course, climate change could still get the last laugh, according to the study, a joint project between the US National Oceanic and Atmospheric Administration and the University of Wisconsin.
In fact, the report concludes that rising CO2 concentrations could change wind patterns and reduce sand erosion through 'fertilisation' of desert vegetation, thereby driving the temperature of the Atlantic up by another 0.4° Celsius by 2050. Not cool.
~RS~q~RS~~RS~z~RS~40~RS~)
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An interesting side-effect of the amount of atmospheric dust is that it plays an important role in the number of Hurricanes in the tropical Atlantic; the more dust there is the fewer Hurricanes there are. Conversely the less dust, the greater the number of hurricanes.
So swings and roundabouts as far as good and bad news is concerned for the Caribbean islands and the Gulf Coast of America.
There has been a lot of interest in recent years in the relationship between aerosols and the frequency of hurricanes in the tropical Atlantic; one benefit of this research could be improved annual hurricane forecasts.
See also:
http://www.sciencedaily.com/releases/2009/03/090326141553.htm
http://www.sciencedaily.com/releases/2008/02/080215191428.htm
http://www.sciencedaily.com/releases/2006/07/060726180444.htm
As for warming, the researchers believe that aerosols account for 69% of the warming in the N. Atlantic; this brings its rate of warming more into line with warming in observed in other oceans. Of course the remaining 31% of warming still has to be accounted for; a warming climate would do this.
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Would somebody please help the BBC's Victoria Gill read the blog above, as she was obviously too busy to notice it or the "dust" article on Science, when reporting about disappearing shrimp cocktails
http://news.bbc.co.uk/2/hi/science/nature/8037888.stm
Actually I think the Editors of Science itself should answer a few questions...
http://omniclimate.wordpress.com/2009/05/12/science-magazine-evidence-of-agw-prejudice/
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