THE humble air-conditioner, quietly purring away in millions of homes and cars this summer, has become the unknown player in Australia's growing contribution to global warming.
The refrigerant gases in every air-conditioner and fridge have the potential to be far more devastating than car emissions, yet they barely rated a mention at the UN climate conference in Bali earlier this month.
So hidden is the problem to the public that, unknown to most NSW MPs, even State Parliament runs an ageing air-conditioning plant beneath Macquarie Street using nearly a tonne of hydrochlorofluorocarbons.
HCFCs, the refrigerant gases used to replace ozone-depleting CFCs in the 1990s, have a ferocious global warming impact out of all proportion to the often small amount of gas involved.
The air-conditioning system under Macquarie Street, which keeps things cool in the NSW Parliament and the adjacent State Library, contains HCFC gases equivalent to the annual greenhouse gas emissions of about 2500 four-wheel-drives. The gas used there is now being rapidly phased out around the country and can no longer be imported because it is deemed to be too damaging.
Parliament is not alone - the cooling systems in many large, older buildings still rely on bulk synthetic refrigerant gases, although the Federal Government plans to phase out HCFC use in Australia altogether by 2030.
A growing proportion of HCFCs and the less damaging hydrofluorocarbons, or HFCs, are captured and either recycled or destroyed by a plasma treatment process that turns them into salt water.
But of the 7000 tonnes of refrigerant gases imported annually, about 4000 tonnes remain unaccounted for, and leakages are endemic.
"We need to dispel the myth that refrigerant gases are somehow safe," said Michael Bland, an environmental consultant who has been involved in the problem of refrigerant gas capture and storage for two decades. "They are very dangerous and a growing part of our greenhouse problem."
Car air-conditioners, now fitted as standard in new models, are among the most leaky and dangerous. On average 15 per cent of the kilogram or two of refrigerant gases used to run a vehicle air-conditioner seep out into the atmosphere every 12 months.
Michael Bennett, the general manager of Refrigerant Reclaim Australia, said that figure is distorted because, compared to many other developed nations, Australians tend to drive older-model cars with less robust air-conditioning. "We are aiming to get it up world best practice, which would be about
7 or 8 per cent per annum," Mr Bennett said.
Refrigerant Reclaim Australia, an organisation funded by the main refrigerant gas importation companies, is destroying gases in old air-conditioners, fridges and fire extinguishers at an increasing rate, rendering about 440 tonnes safe at a national reprocessing plant in Melbourne in the 12 months to June.
Leaking refrigerant gases make up between 1 and 2 per cent of total Australian emissions. But they account for about 12 per cent of
the "radiative forcing" of the atmosphere, which can reduce heat loss and add to global warming.
And when the energy used to keep the machinery running is taken into account, the refrigeration and air-conditioning industry creates about 7 per cent of total Australian emissions, according to a report published in 2005 and jointly funded by the main industry players and the Federal Department of Environment.
But even that proportion is rising rapidly, as Australia becomes one of the world's most air-conditioned nations and households now run an average of just over two cars. And there are roughly 14 million fridges and cold stores across the country, each with their load of refrigerant gas.
The Department of Environment and Climate Change maintains that the damage from leaks is minimal, as long as air-conditioners are serviced regularly and disposed of by an engineer licensed to recapture the gas when they break down.
"The estimated emissions from refrigerant leakage is a small proportion - around 20 per cent - of the total lifetime emissions from a piece of refrigeration or air-conditioning equipment," said a Department of Environment spokeswoman, Heike Phillips. "While HFCs have a high global warming potential, they are a very efficient refrigerant."
The department is urging Australians to cease the habit of simply putting old whitegoods out on the pavement, and have the gas professionally removed. It issued guidelines last week pointing out that it is illegal to tamper with refrigerant gases.
"If you just pull that old air-conditioner off the wall and let its two kilograms of refrigerant escape or leave it to slowly leak away at the tip, you will have emitted the equivalent of four tonnes of carbon dioxide - the same as six months of driving your car," it said.
