Scientists say toxic cloud impacting economies, world health.
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"Early warning" on Asia’s toxic haze
[This true-color image released by NASA in January shows most of southeastern China covered by a thick, greyish shroud of aerosol pollution.]
LONDON, Aug. 12 : The toxic haze hovering over southern Asia much of the year is threatening the lives of millions of people in the region and could have an impact much farther afield, according to a U.N.-sponsored study.
THE WORLD BODY said the haze, a toxic cocktail of ash, acids, aerosols and other particles, is damaging agriculture from Afghanistan to Sri Lanka.
The lives of millions of people are at risk from drought and flooding, partly because rainfall patterns have been radically altered, with dire implications for economic growth and health, according to the study.
"We have an early warning. We have clear information, and we already have some impact. But we need much, much more information," U.N. Environment Program chief Klaus Toepfer told a news conference.
"There are also global implications, not least because a pollution parcel like this, which stretches three kilometers [about two miles] high, can travel halfway round the globe in a week."
VARIED SOURCES
Toepfer said the haze was the result of forest fires; the burning of agricultural wastes; dramatic increases in the burning of fossil fuels in vehicles, industries and power stations; and emissions from millions of inefficient cookers.
He said the U.N.’s preliminary report on what it dubbed the "Asian Brown Cloud" was a timely reminder to the coming Earth Summit in Johannesburg, South Africa, that action, not words, was vital to the future of the planet.
"The huge pollution problem emerging in Asia encapsulates the threats and challenges that the summit needs to urgently address," he said.
"We have the initial findings and the technological and financial resources available. Let’s now develop the science and find the political and moral will to achieve this for the sake of Asia, for the sake of the world," he added.
GLOBAL RANGE
Scientists say it’s too early to draw definite conclusions about the impact of the haze, and of similar hazes over East Asia, South America and Africa.
"We need much more basic scientific data to be able to establish what are the consequences for human health and the environment," said co-author Paul Crutzen, co-winner of the 1995 Nobel chemistry prize for his work on the ozone layer.
But they warn the impact could be global.
For many years, scientists believed only lighter "greenhouse gases" -- such as carbon dioxide that is produced from burning fossil fuels such as gasoline and oil -- were global in reach and effect.
They now say microscopic, suspended particles of pollutants -- generically called aerosols by atmospheric scientists -- also travel the globe.
WARMING TIES?
It’s unclear what the haze’s relationship is to global warming, which many scientists believe is fueled by the manmade emission of greenhouse gases that trap the Earth’s heat.
The haze appears to block sunlight, creating some cooling effect on the ground, but its heat-absorbing properties are thought to be warming the lower parts of the atmosphere considerably.
The combination of surface cooling and lower atmosphere heating could be altering the winter monsoon, sharply reducing rainfall over northwestern Asia and increasing it along the eastern coast.
Toepfer said scientists and policy-makers "should avoid making premature final assessments," but should start trying to cut pollution by introducing more efficient heating stoves in developing countries and turning to solar power and other clean sources of energy.
Professor Victor Ramanathan, one of the more than 200 scientists involved in the study, said the haze was cutting the amount of solar energy hitting Earth’s surface beneath it by up to 15 percent.
"We had expected a drop in sunlight hitting the earth and sea, but not one of this magnitude," he said.
The report calculated that the haze -- 80 percent of which was manmade -- could cut rainfall over northwest Pakistan, Afghanistan, western China and western central Asia by up to 40 percent.
Apart from drastically altering rainfall patterns, the haze was also making the rain acid, damaging crops and trees, and threatening hundreds of thousands of people with respiratory disease.
HOW MANY MORE SURPRISES?
Crutzen said atmospheric pollution could be contributing to up to 2 million premature deaths a year in India alone.
"If present trends as they are continue, then we have a very serious problem," he said.
The report called for special monitoring stations to be set up watch the behavior of the cloud, and its impact on people and the environment.
"The concern is that the regional and global impacts of the haze are set to intensify over the next 30 years as the population of the Asian region rises to an estimated 5 billion people," the report said.
Ramanathan, a scientist at the Scripps Institution of Oceanography in La Jolla, Calif., said the surprises found by the study will drive researchers to keep studying human impact on the environment.
"We’ve been looking at environmental issues for the last several decades, yet the Asian haze came as a major surprise to us," he said. "We don’t know how many more surprises we will find."
The report is online at www.rrcap.unep.org/abc/impactstudy.
The Associated Press and Reuters contributed to this report. |
