A three-kilometre deep blanket of sooty pollution stretching across southern Asia threatens to inflict untold economic damage on the region and put hundreds of thousands of people at risk, scientists in London said on Monday.
The toxic cloud, dubbed the ”Asian Brown Haze”, is a mass of ash, acids, chemical droplets and other particles.
The scientists, working with the United Nations Environment Programme (UNEP), say the haze is already disrupting weather systems, triggering droughts in some areas and floods in others.
They are worried that its impact will intensify over the next 30 years as southern Asia’s population rises to an estimated five billion.
The pollution forming the haze could be leading to ”several hundreds of thousands” of premature deaths due to respiratory disease, it was claimed.
”The haze is 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 burning wood, cow dung, and other bio-fuels,” UNEP executive director Klaus Toepfer said in London.
”There are also global implications, not least because a pollution parcel like this, which stretches three kilometres high, can travel half way round the globe in a week,” he said.
The findings, which come on the eve of the World Summit on Sustainable Development which opens in Johannesburg on August 24, are the result of observations by 200 scientists working on the Indian Ocean Experiment.
The researchers found the pollution blanket was reducing the amount of sunlight or solar energy hitting the Earth’s surface by up to 15%.
A combination of surface cooling and lower atmosphere heating had altered the winter monsoon, leading to a sharp decrease in rainfall over north-western areas and producing more rain along eastern coastline.
Pakistan and north-western India were hit by droughts in 1999 and 2000 while areas such as Bangladesh, Nepal and north-east India had suffered severe flooding in recent years, they said.
During the 1998 flood in Bangladesh, as much as two thirds of the land area was inundated and nearly 1,6-million hectares of cropland damaged.
Rainfall could be reduced by 20 to 40% over north-west India, Pakistan, Afghanistan, western China and neighbouring regions, the scientist’s report said.
Results from seven Indian cities alone, including Delhi and Mumbai, suggested that by the mid-1990s some kinds of air pollution were responsible for an estimated 37 000 premature deaths each year. – Sapa-DPA