Relief in Every Window, but Global Worry Too

Kuni Takahashi for The New York Times

Growing demand for air-conditioning in developing nations, as here in Mumbai, India, has raised concerns about global warming.

Click here to read the full article from Elizabeth Rosenthan and Andrew W. Lehren in the New York Times

In the ramshackle apartment blocks and sooty concrete homes that line the dusty roads of urban India, there is a new status symbol on proud display. An air-conditioner has become a sign of middle-class status in developing nations, a must-have dowry item.

It is cheaper than a car, and arguably more life-changing in steamy regions, where cooling can make it easier for a child to study or a worker to sleep.

But as air-conditioners sprout from windows and storefronts across the world, scientists are becoming increasingly alarmed about the impact of the gases on which they run. All are potent agents of global warming.

Air-conditioning sales are growing 20 percent a year in China and India, as middle classes grow, units become more affordable and temperatures rise with climate change. The potential cooling demands of upwardly mobile Mumbai, India, alone have been estimated to be a quarter of those of the United States.

Air-conditioning gases are regulated primarily though a 1987 treaty called the Montreal Protocol, created to protect the ozone layer. It has reduced damage to that vital shield, which blocks cancer-causing ultraviolet rays, by mandating the use of progressively more benign gases. The oldest CFC coolants, which are highly damaging to the ozone layer, have been largely eliminated from use; and the newest ones, used widely in industrialized nations, have little or no effect on it.

But these gases have an impact the ozone treaty largely ignores. Pound for pound, they contribute to global warming thousands of times more than does carbon dioxide, the standard greenhouse gas.