The Brown Cloud Haunting Asia  

Another article from a week or so ago, this one from The Independent - Haunting Asia, a brown cloud blots out sun.

A noxious cocktail of soot, smog and toxic chemicals is blotting out the sun, fouling the lungs of millions of people and altering weather patterns in large parts of Asia, according to a report released Thursday by the United Nations.

The byproduct of automobiles, slash-and-burn agriculture, wood-burning kitchen stoves and coal-fired power plants, these plumes of carbon dust rise over southern Africa, the Amazon basin and North America but are most pronounced in Asia, where so-called atmospheric brown clouds are dramatically reducing sunlight in many Chinese cities and leading to decreased crop yields in swaths of rural India, says a team of more than a dozen scientists who have been studying the problem since 2002.

Combined with evidence that greenhouse gases are leading to a rise in global temperatures, the report's authors called on governments rich and poor to address carbon emissions.

"The imperative to act has never been clearer," Achim Steiner, executive director of the United Nations Environment Program, said in Beijing, where the report, "Atmospheric Brown Clouds: Regional Assessment Report With Focus on Asia," was released.

The brownish haze, sometimes more than a mile, or 1.6 kilometers, thick and clearly visible from airplanes, stretches from the Arabian Peninsula to the Yellow Sea.

In the spring it sweeps past North and South Korea and Japan. Sometimes the cloud drifts as far west as California. The report identifies 13 cities as brown-cloud hotspots, among them Bangkok, Cairo, New Delhi, Seoul and Tehran. In some Chinese cities, the smog has reduced sunlight by as much as 20 percent since the 1970s, the report says.

Rain can cleanse the skies, but some of the black grime that falls to earth ends up on the surface of the Himalayan glaciers that are the source of water for billions of people in China, India and Pakistan.

The result: The glaciers that feed into the Yangtze, Ganges, Indus and Yellow rivers are absorbing more sunlight and melting quicker, researchers say.

According to the Chinese Academy of Sciences, those glaciers have shrunk 5 percent since the 1950s and at the current rate of retreat could shrink by an additional 75 percent by 2050.