Delegates at UN climate talks on Tuesday targeted more than a dozen new industrial chemicals for inclusion in the successor to the Kyoto Protocol climate treaty, which runs out in 2012.

The synthetic compounds are potent greenhouse gases that could, if produced in large quantities, contribute significantly to global warming, scientists warn.

"In terms of the impact these new gases will have over the next decade, it is not that significant," said Steve Sawyer, executive director of the Global Wind Energy Council, an industry lobbying group.

"What is important is the political message it sends to the chemical industry: 'stop inventing gases with a high global warming potential'," he told AFP.

Most are not yet widely used, but at least one -- nitrogen trifluoride (NF3) -- is a standard component in the manufacture of computers and LCD flat-screen televisions.

NF3 is about 17,000 times more potent as a greenhouse gas than carbon dioxide (CO2).

By 2010, world production of NF3 is projected to reach 8,000 tonnes a year, the equivalent of 130 million tonnes of CO2, according to a study published last year in Geophysical Research Letters.

Lead researcher Michael Prather of the University of California at Irvine dubbed the chemical the "missing greenhouse gas."

Ironically, it was developed to replace another family of chemicals, perfluorocarbons (PFCs), covered by the 1997 Kyoto agreement.

Under Kyoto, 37 industrialised countries agreed to cut their overall emissions by five percent, compared to 1990 levels, by 2012. The United States never signed on to these commitments.

Beside CO2 and PFCs, the Protocol includes four other man-made gases that heat up the atmosphere: methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), and sulphur hexafluoride (SF6).

More than 190 nations party to UN Convention Framework on Climate Change (UNFCCC) are tasked with crafted a successor treaty by year's end, and began debate today in Bonn on whether to include the new basket of chemicals.

"This tells the chemical industry it should find substitutes or be sure these gases don't escape" into the atmosphere, said Brice Lalonde, France's top climate negotiator.

The time to act is now, before these chemicals are woven into industrial infrastructure, he said.

"We are talking about less than one percent of all greenhouse gases, but the principle here is to keep them under control," said Jose Romero, a climate negotiator from Switzerland.

All the delegates interviewed thought that the new basket of chemicals would eventually be covered in a new climate deal.

"I think we will be able to find a solution that is fair and effective," said a foreign affairs expert at the US State Department, adding that the United States was still developing a position on the issue.

"The most important thing is CO2, and you would not want to distract from that. But we want to make sure they do not grow to become an even larger component of the greenhouse gas picture," he said by phone.

The new chemicals under review include new types of PFCs and hydrofluorocarbons (HFCs), trifluoromethyl sulphur pentafluoride (SF5CF3), fluorinated ethers, perfluoropolyethers and hydrocarbons.

Other compounds are dimethylether (CH3OCH3), methyl chloroform (CH3CCl3), methylene chloride (CH2Cl2), methyl chloride (CH3Cl), dibromomethane (CH2Br2), bromodifluoromethane (CHBrF2) and trifluoroiodomethane (CF3I).