Posted on 06/13/2002 4:47:26 PM PDT by TheRedSoxWinThePennant
African droughts "triggered by Western pollution"
19:00 12 June 02
Exclusive from New Scientist Print Edition
Emissions spewed out by power stations and factories in North America and Europe may have sparked the severe droughts that have afflicted the Sahel region of Africa. The droughts have been among the worst the world has ever seen, and led to the infamous famines that crippled countries such as Ethiopia in the 1980s.
Sahel dries out The cause appears to be the clouds of sulphur belched out alongside the soot, organic carbon, ammonium and nitrate produced when fossil fuels are burnt, according to researchers in Australia and Canada. As these compounds move through the atmosphere, they create aerosols that affect cloud formation, altering the temperature of the Earth's surface and leading to dramatic shifts in regional weather patterns.
In the past thirty to forty years, the Sahel--a loosely defined band across Africa, just south of the Sahara and including parts of Ethiopia in the east and Guinea in the west--has suffered the most sustained drought seen in any part of the world since records began, with precipitation falling by between 20 and 50 per cent.
Although the droughts have had climate experts scratching their heads, the impacts have been obvious. During the worst years, between 1972 and 1975, and 1984 and 1985, up to a million people starved to death.
Now Leon Rotstayn of the CSIRO, Australia's national research agency, thinks he knows what caused them. Rotstayn and his colleague Ulrike Lohmann of Dalhousie University in Halifax, Nova Scotia, ran a simulation of global climate that included interactions between sulphur dioxide emissions and cloud formation. Sulphur dioxide creates sulphate aerosols that provide condensation nuclei for clouds. With more nuclei, clouds form from smaller droplets than usual, and are more efficient at reflecting solar radiation, cooling the Earth below.
Acid rain
When the researchers included the huge sulphur emissions from the northern hemisphere during the 1980s in their model, the Earth's surface in the north cooled relative to the south, driving the tropical rain belt south and causing droughts in the Sahel. Their results will be reported soon in the Journal of Climate.
"It's still speculative, and the model isn't very refined, but it's very interesting. It's the first time we've seen a connection between pollution in the mid-latitudes and climate in the tropics," says Johann Feichter of the Max Planck Institute for Meteorology in Hamburg. Feichter, who has run similar simulations but cannot talk about the results because the research is being peer-reviewed for a major journal, says the sulphur emissions probably worsen the natural cycle of droughts that would have happened anyway.
During the past few years, the droughts have become less severe, a change that Rotstayn puts down to the "clean air" laws in North America and Europe that reduced sulphur dioxide emissions in response to another environmental crisis, acid rain.
But the problems in Asia may be just beginning. Climate researchers around the world are beginning to study other types of aerosols, such as the clouds of black soot and sulphate being churned out by rapidly industrialising India and China, in the hope that they may shed light on other regional weather anomalies. For instance, northern China has had unusually dry summers in the past few years, while it has been particularly wet in the south.
Rachel Nowak, Melbourne
Pssst... Wrong talking points.
When the environ-communists first went after automobile emissions, the 'fix' was to use catalytic converters which actually produced sulphur dioxide out the tailpipe (that rotten egg smell). When mixed with humidity and moisture produced as a by-product of internal combustion, the result was....sulphuric acid and some plant life dying next to major highways.
I don't trust a single 'fix' ever proposed by these environmentalist fools.
From Hillary to Castro, all the little commies hate the USA.
Expect more fallout and more whining just like the above thanks to the EPA report on "global warming"
Oh, so that is what it was. Feeling bad now for all the times I beat the kids for breaking wind in the car. (JUST KIDDING)
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