Until recently, it looked like the depleted ozone layer protecting the earth from harmful solar rays was on its way to being healed. Anthony Saldhana, 35, a mechanic at a repair shop in downtown Mumbai, adds air-conditioning refrigerant to a car.

But thanks in part to an explosion of demand for air-conditioners in hot places like India and southern China — mostly relying on refrigerants already banned in Europe and in the process of being phased out in the United States — the ozone layer is proving very hard to repair. Four months ago, scientists discovered that the “hole” created by the world’s use of ozone-depleting gases — in aerosol spray cans, aging refrigerators and old air-conditioners — had expanded again, stretching once more to the record size of 2001.

An unusually cold Antarctic winter, rather than the rise in the use of refrigerants, may have caused the sudden expansion, which covered an area larger than North America. But it has refocused attention on the ozone layer, which protects people and other animals as well as vegetation from the sun’s harmful ultraviolet rays. Now, the world’s atmospheric scientists are concerned that the air-conditioning boom sweeping across Asia could lead to more serious problems in the future.

As it turns out, the fastest-growing threat to the ozone layer can be traced to people like Geeta Vittal, a resident of this hot, thriving metropolis of 18 million, who simply wants to be cooler and can now afford to make that dream a reality. When her husband first proposed buying an air-conditioner eight years ago, Mrs. Vittal opposed it as a wasteful luxury. But he bought it anyway, and she liked it so much that when the Vittals moved last year to a new apartment, Mrs. Vittal insisted that five air-conditioners be installed before they moved in. “All my friends have air-conditioners now,” she said. “Ten years ago, no one did.”

Rising living standards throughout India and China, the world’s two most populous countries and the fastest-growing major economies, have given a lot more people the wherewithal to make their homes more comfortable. The problem is that Mrs. Vittal’s air-conditioners — along with most window units currently sold in the United States — use a refrigerant called HCFC-22, which damages the ozone. “The emissions of things like HCFC-22: we had thought they were sufficiently in control, that we didn’t have to worry about them,” said Joe Farman, the British geophysicist who discovered the ozone hole.

A recent technical study by the World Meteorological Organization and the United Nations Environment Program found that the so-called ozone “hole” over Antarctica — actually an area of unusually low ozone concentrations — was mending more slowly than expected. Scientists mostly blame chlorofluorocarbons, a chemical used in an early form of refrigerant that they now realize was released into the atmosphere in larger quantities than forecast. As a result, the international agencies now say that injury to the Earth’s ozone layer could take a quarter of a century longer to heal than predicted.

The fastest-growing offending gas that scientists say can be better managed is HCFC-22. Nearly 200 diplomats will gather in September in Montreal to determine how to speed the timetable for the elimination of certain gases that threaten the ozone layer, in particular how to manage HCFC-22. A deadline for proposals is March 15. At a meeting in Washington on Feb. 16, Bush administration officials said for the first time that they are considering four possible proposals for a faster phaseout.

Industrial countries currently must phase out production of HCFC-22 by 2020 and are ahead of schedule, with the United States banning domestic production in 2010. The Environmental Protection Agency is studying whether to ban imports of the gas and sales of new products using the gas by then as well. By contrast, the Montreal Protocol, which governs the phaseout of ozone-depleting chemicals, allows developing countries to continue using HCFC-22 through 2040.

China in particular is stepping up exports to the United States of air-conditioners using the chemical, often labeled as R22, especially after the European Union finished phasing out the production and import of such air-conditioners in 2004. Pound for pound, HCFC-22 is only 5 percent as harmful to the ozone layer as the chlorofluorocarbons it replaced. But it still inflicts damage, especially when emitted in enormous quantities by China, now the world’s dominant producer of window air-conditioners, and by India, a fast-growing market and manufacturer.

The latest estimate from technical experts is that the chemical’s output in developing countries is rising 20 percent to 35 percent each year and could continue at that pace for years: slightly over 2 percent of Indian households currently have air-conditioners, according to LG Electronics of South Korea, a giant maker of air-conditioners.

HCFC-22 is cheaper to install than the latest ozone-safe chemicals, which are harder and more expensive to manufacture. Lambert Kuijpers, one of three co-chairmen of the Technology and Economic Assessment Panel of the Montreal Protocol, said that production of the ozone-damaging gas in the developing world is on track to increase more than fivefold in the current decade. An accelerated phaseout of HCFC-22 “is the most important” item on the agenda, he said.

But the trend in the developing world is working against an early phaseout. India used to impose a 32 percent luxury tax on air-conditioners but cut the tax in half over the last three years as demand from the middle class rose. Competition has also shaved prices, making air-conditioners much more affordable. “There is a lot of pent-up demand,” said Prasanna Pahade, the senior manager for corporate planning at Voltas Limited, the biggest Indian manufacturer of air-conditioners.

In China, ownership soared to 87.2 air-conditioners per 100 urban households in September, from 24.4 seven years earlier. The countryside, home to two-thirds of the nation’s population, is poised for even greater growth. In 2005, there were 6.4 air-conditioners per 100 rural households, a 35-fold increase from a decade earlier. Developing countries like China and India enjoy exemptions from global environmental standards. The Kyoto Protocol, which governs emissions of global-warming gases, is also lenient toward them, on the grounds that industrialized countries have released the great bulk of the offending gases and poorer countries should be allowed to catch up economically before taking on additional environmental costs.

Some, like the Carrier Corporation, are calling for more equal standards. But Carrier has already invested in the technology to use newer chemicals and could profit from a faster phaseout of HCFC-22, which would impose greater costs on rivals in developing countries.

A multilateral fund under the Montreal Protocol helps developing countries convert to newer chemicals. The United States and Europe must decide if they want to increase their contributions to that fund. Indian and Chinese refrigerant companies are also eligible for hundreds of millions of dollars a year under a relatively obscure United Nations program, the Clean Development Mechanism. Manufacturers receive credits for destroying a rare waste gas, produced while making HCFC-22, that is among the most powerful global-warming gases known.

In many cases, the payments, aimed at encouraging reduction in gases that contribute to climate change, are actually worth considerably more than the cost of the HCFC-22 being produced. The manufacture of more modern refrigerants does not qualify countries for global-warming credits. So HCFC-22 producers in developing countries have little incentive to switch to making newer refrigerants.

There is some progress in sight. The State Environmental Protection Administration of China said last September that it planned to halt all production and consumption of the more damaging chlorofluorocarbons by July this year. Haier, a big Chinese manufacturer of air-conditioners, said in a statement that it had voluntarily begun shipping to the United States only models that use more advanced refrigerants, which do not damage the ozone layer.

But huge challenges remain. The global auto industry has moved directly from the use of chlorofluorocarbons to gases that do not hurt the ozone layer, although they are powerful global-warming gases. Here in India, car factories now install air-conditioning systems that use these modern refrigerants.

But owners of older cars, as well as people who buy new cars without air-conditioning and then decide they need it, still go to repair shops to install air-conditioners that use the worst of the chlorofluorocarbons. Nilesh Bothelo, the manager of a repair shop in downtown Mumbai, said that a chlorofluorocarbon-based system was so much simpler and easier to install that he charges just $600 for it. He charges twice as much for a system using the modern refrigerant.

Indian chemical companies are happy to ship as much chlorofluorocarbons as needed, Mr. Bothelo said. When asked what the chemical looks like, he abruptly had a mechanic pour a little out of a battered metal tank onto the oil-stained ground. The milky gas flowed toward the dirt, bounced and then faded away, vanishing into the air. “If it were something so bad,” Mr. Bothelo said, “they would not legally sell it.”
(Por Keith Bradsher, The N.Y.Times, 23/02/2007)