Over 200 nations have agreed at a UN meeting in Montreal to accelerate the phase-out of refrigerants that destroy the ozone layer. But some experts are warning that the revised agreement may spur developing countries - especially China - to churn out more ozone-depleting hydrochlorofluorocarbons (HCFCs) in the short term.

The deal updates a timetable agreed in Montreal 20 years ago, which allowed developing countries to increase their HCFC production until 2016, and maintain that level until 2040.

But that timetable is now seen as too lenient. Demand for air conditioning in China and India is booming and matters have not been helped by the US  accepting HCFCs in Chinese imports until 2010 despite phasing out domestic production. 

Now, under the new agreement, developing countries must freeze production by 2013, at the average 2009-10 production levels. They must then phase out HCFC use by 2030 - a 10 year advance on the previous target. Developed countries have also agreed to push forward their target by 10 years - phasing out HCFCs by 2020. 

HCFCs are used as blowing agents in insulating foams as well as coolants in air conditioning and refrigerating systems. They replaced the older and even more ozone-damaging chlorofluorocarbons (CFCs) in the 1990s, but were never meant to be permanent substitutes. 

In developed countries, they are already being replaced by blends of hydrofluorocarbons (HFCs) or hydrocarbons which are kinder to the ozone layer. Many of the HFCs are potent greenhouse gases, but improved technology - reducing leaks and meaning less coolant is used in air conditioning systems - has already cut down on their climate impact.

Carbon dioxide is an even more friendly replacement. If its use became widespread, then phasing out HCFCs would make the Montreal Protocol more effective than the Kyoto Protocol at cutting greenhouse gas emissions.

But it is unlikely that the deal will stop China building new refrigerant plants to meet demand, said Lambert Kuijpers, co-chair of the Montreal protocol’s Technical and economic assessment panel. Instead, he thought, China would look to push its baseline rate for the HCFC production freeze as high as possible. 

It’s not clear how much converting to non-HCFC-based replacements afterwards will cost: developed countries have spent over $2 billion so far helping developing countries cut production of their ozone-depleting chemicals. A study reporting back in early 2008 will estimate how much more they have to give to fund the acceleration.

Meanwhile, attention is focusing on UN climate talks in Bali, Indonesia, in December. This week, preliminary talks in New York are paving the way for Bali’s climate change discussions, which it’s hoped will establish a successor to the Kyoto Protocol on reducing greenhouse gas emissions - due to end in 2012. US president George Bush is also holding his own climate summit in Washington, DC, at the end of this week. 

Richard Van Noorden