FIRST came the ozone hole, then global warming. Now there鈥檚 a new phrase on environmentalists鈥� lips: brown haze (see 鈥淔orest fires fuel pollution crisis鈥�).
It is no accident, of course, that the United Nations Environment Programme and its scientists have chosen the eve of the World Summit on Sustainable Development to publicise the growing problem of air pollution in Asia. The dismal sight of smog hanging above the Himalayas is precisely the sort of mind-concentrating image that delegates ought to carry with them to Johannesburg. Provided, that is, that they don鈥檛 get the wrong end of the stick, because handled badly, the notion of this giant smoggy cloud could confuse and even hinder efforts to curb pollution.
Air pollution in Asia is nothing new. In the past, the smogs and hazes of the region tended to be seen as a set of local phenomena tied to cities and towns, or whipped up by particularly intense forest fires. This week鈥檚 report confirms the limitations of that view. 杏吧原创s have been sampling air quality above the Indian Ocean and finding evidence that in the dry season emissions of gases, soot and other particles from disparate parts of Asia spread and mix so fast that they produce vast pollution plumes that transcend city and national boundaries. This, the UN argues, instantly turns Asian air pollution into one of those big transnational problems that, like ozone depletion, can only be tackled by international cooperation and political agreements.
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But this view is only partly true, and taken to extremes it could backfire. It鈥檚 true that more than a million people in South Asia are thought to die every year from pollution-linked respiratory illnesses. But many of these are victims of the terrible home-grown smogs that afflict the region鈥檚 megacities, not giant hazes drifting in from afar. Air pollutants are 100 times as concentrated in the smog above Bombay as in the haze above the Indian Ocean. And what pollution is reckoned to kill half a million women and children in India every year? Not a menacing transnational haze, but cooking fumes.
If countries and cities in Asia think air pollution is regional and that their neighbours are carrying on in their old dirty ways, they may become wary of implementing expensive pollution controls. Such fatalism would be tragic.
There is another reason for keeping a clear head. How much of the brown cloud is down to biomass burning and how much to fossil fuels remains unclear. A crackdown on forest fires and dung burning might not achieve much if the key culprit turns out to be, say, the sulphurous coal that China burns in vast quantities. Without more research it is hard to assess priorities.
By contrast, the origins of many localised smogs are obvious. The number of cars, trucks and two-wheelers on the roads of Delhi, for example, has risen tenfold in two decades and is now thought to account for 60 per cent of that city鈥檚 particulate pollution. India does not need to wait for an international convention on the brown cloud to sort this out.
Yet the world cannot afford to shrug its shoulders over the brown cloud. Its persistence and size make its potential threat to the climate too serious to overlook. Asian air pollution is simultaneously global and local in nature. Neither dimension can be safely ignored.