Black-and-white answers to motley puzzle

By Fiona Harvey in London
Published: May 18 2009 22:08

Tackling climate change rarely looks like a black-and-white problem, but scientists are now proposing deceptively simple solutions involving white paint and soot.
A traditional stove in Mumbai. The smoke and soot triggers respiratory illness and blackens the atmosphere, adding to the greenhouse effectWhite paint reflects heat back into space, so changing the colour of roofs and pavements could make a big ­difference
Meanwhile, soot produced by traditional methods of cooking, such as burning wood, straw and animal dung, is causing an increase in the amount of heat the earth absorbs by blackening the atmosphere. When it falls on snow, the soot contributes to melting. About half of the Arctic ice melting can be attributed to this “black carbon”, according to research by the US space agency Nasa and Columbia University in New York.
Cutting pollution from cooking fires – for instance, by replacing them with more efficient stoves, or even “solar cookers” using the sun’s energy – would also help to remove one of the leading causes of death for women and children in the developing world. Smoke inhalation and burns claim many victims.

That can be achieved comparatively easily, compared with other ways of tackling climate change. Efforts to fight global warming have so far centred on grinding negotiations, which have continued for two decades without producing an accepted international framework to carve up our common responsibility to cut greenhouse gas emissions. Scientists have stated, ahead of crucial talks in Copenhagen in December, that we are fast running out of time.
But look outside the limitations of the current policy framework and there are more options available, says Durwood Zaelke, president of the Institute for Governance and Sustainable Development in Washington.
“The time has come to explore these other options,” he says. Tackling soot, which comes from poorly protected factory chimneys and coal-fired power plants as well as cooking fires, is one challenge, along with seemingly exotic actions such as painting roofs white. “These could be big, short-term wins,” says Mr Zaelke.
Al Gore, the former US vice-president who has helped to lead the climate change battle, warned political leaders last month: “Black carbon is settling in the Himalayas. The air pollution levels in the upper Himalayas are now similar to those in Los Angeles.”
Another option for cutting greenhouse gases is to expand the remit of the world’s most successful environmental treaty to date.
The Montreal protocol is largely forgotten, as is the problem it was drawn up to solve: the hole in the earth’s ozone layer, which in the 1980s and 1990s was the most serious example of human activity damaging natural systems. The accord, requiring countries and industries to phase out substances that deplete ozone in the atmosphere, has been so effective that the ozone layer is on the road to recovery by the middle of this century.
Climate change is a separate problem, with different causes. But the two issues are linked, and the Montreal protocol has brought about a significant fringe benefit: many ozone-depleting substances covered by the treaty are also powerful greenhouse gases.
As a result, the protocol has had more than five times the effect in reducing climate change than the Kyoto protocol – designed to limit greenhouse gas emissions – has had to date.
Later this year, the United Nations will discuss extending the Montreal protocol further, in order to cover gases known as hydrofluorocarbons (HFCs), which are more than 11,000 times as powerful a greenhouse gas as carbon dioxide. If successful, this move could cut greenhouse gases by as much as a tenth.
However, doubts remain on whether the White House is supportive of such a move. The US missed a deadline in early May for expressing an interest in participating in negotiations.
Pursuing these options alone will not be enough to halt climate change, Mr Zaelke says. An agreed framework for cutting greenhouse emissions will also be needed. The Copenhagen talks will decide whether the world can achieve that. But, he adds, the pursuit of other efforts could help to make success more likely.
Copyright The Financial Times Limited 2009