New greenhouse gases emitted in making flat-screen televisions or some refrigerants might be capped under a planned UN treaty to combat global warming, delegates at UN talks in Ghana said.
Emissions of the recently developed industrial gases, including nitrogen trifluoride and fluorinated ethers, are estimated at just 0.3 per cent of emissions of conventional greenhouse gases by rich nations. But the emissions are surging.
"I think it's a good idea to add new gases to a group of six already capped by the UN's Kyoto Protocol for slowing global warming," Yvo de Boer, head of the UN Climate Change Secretariat, said.
"It makes sense to address all gases that lead to climate change," he said.
"The more gases you cover, the greater flexibility countries have to work out how best to cut back," he said. He added that it was up to governments to decide.
More than 190 nations have agreed to work out a broad new pact to succeed Kyoto as part of a drive to avert rising temperatures likely to bring more heatwaves, floods, desertification and rising seas.
Mr De Boer said the EU had originally, in negotiations more than a decade ago that led to Kyoto, favoured limiting the treaty to carbon dioxide, emitted by burning fossil fuels in factories, power plants and cars.
But the addition of five other gases, such as industrial nitrous oxide or methane, emitted by livestock or rotting vegetation in landfills, had bolstered Kyoto, he said. Carbon dioxide is the main gas, accounting for 80 per cent of emissions.
Among new gases, nitrogen trifluoride is used in making semiconductors such as in flat-screen televisions. Fluorinated ethers have been used in some refrigerants in recent years as replacements for another group of gases found to damage the earth's protective ozone layer.
Other new gases, such as iodotrifluoromethane or methyl chloroform, are used in the electronics industry or occur as by-products of industry.
"Very little is known about sources, current and future emissions and atmospheric abundance of these gases," according to a technical report presented to delegates.
"Emissions in 1990 are assumed to have been close to zero but are increasing exponentially," it said.
It estimated that current annual emissions were below the equivalent of 50 million tonnes of carbon dioxide - or 0.3 per cent of greenhouse gas emissions from human activities in rich nations.
For carbon markets, the impact of adding new gases was unknown but would "in principle, increase the demand for tradable units under the Kyoto Protocol," it said.
Disadvantages were that it could cost a lot to set up new monitoring and could distract focus from more important gases.
"I'm pushing this issue to get more clarity," said Harald Dovland, a Norwegian official who chairs a group in Accra looking into new commitments by backers of Kyoto.
Kyoto obliges 37 rich nations to cut emissions by five per cent below 1990 levels by 2008-12. "There are not big amounts of these new gases emitted now. But many parties want to ensure that there are no increases," he said.