He said global warming should be recast as a security issue, such as war or terrorism, to help mobilise support for tougher global action to cut emissions of greenhouse gases from burning fossil fuels.

"The Cold War was the last big problem the world faced on so many fronts -- economic, political, industrial," he said.

Other experts at the talks, in an Arctic scientific research base, also said there was too much focus on costs of cutting emissions of greenhouse gases, rather than on risks of rising seas, droughts or floods projected by UN studies.

Global warming "should be looked at as a totally different type of challenge instead of asking 'what does it cost?'," said Joergen Randers, a leading Norwegian economist. Casting global warming as a security issue could make it easier to confront.

Most said that costs of fighting global warming were likely to be manageable. A report by the UN climate panel this year said that even the most stringent measures would mean a loss by 2030 of just three percent of global gross domestic product.

But the experts said it was hard to persuade millions of individuals to cut energy use or to get businesses to invest in new technologies to avert long-term damage from global warming.

SWEATER POLICE

Randers said that the cheapest way to cut greenhouse gas emissions in cooler climates would be to get everyone to turn down the temperature at home by a degree Celsius (2 Fahrenheit) and wear a sweater if needed to keep warm.

"This can be done with no loss of comfort," he said, adding jokingly that it might be have to be enforced by "sweater police". Another solution would be to charge higher prices for heating homes beyond about 18C (64F).

Researchers noted that people often act without weighing up long-term consequences -- many smoke cigarettes or eat too much without rationally reviewing risks of lung cancer or obesity.

In a similar way "most people don't see the benefit of switching to a more expensive bulb that will last longer," said Nebojsa Nakicenovic, of Vienna University of Technology.

Still, in some areas, behaviour is changing.

Labelling of electricity appliances in Europe on a scale of A to G according to their energy efficiency meant that shops no longer sell machines less efficient than a C, said Christoper Rapley, director of the British Antarctic Survey.