"Montreal is the next step on the road," British Environment Minister Margaret Beckett told a gathering of businessmen from around the world to discuss what they could do to help stop catastrophic climate change. "But there are huge sensitivities and it will not be easy."

"No one should be expecting to see an agreement this year on taking Kyoto beyond 2012," she said, adding that time was pressing and it was hoped to get a deal by the end of 2010.

The main -- if not the only -- hoped for outcome from the meeting taking place between Nov. 28 and Dec. 9 is an agreement to find a way of broadening the discussions to bring in key developing nations not currently bound by Kyoto.

But it is an uphill struggle as the world's biggest polluter the United States rejects it and Australia refuses to sign up because it does not cover booming economies like China and India whose coal-fed power stations belch carbon into the atmosphere.

Beckett -- in the environmental chair this year of the Group of Eight industrialised nations who has taken the lead in pushing climate to the top of the international agenda -- said it was now crucial to take decisive action.

"All the signals in 2005 point to a future with ever tighter constraints on CO2 and other greenhouse gases," she told the opening session of the two day meeting in London.

"To avoid catastrophic climate change, global emissions must peak and start to decline in the next couple of decades," she said, adding the longer people and governments delayed taking action the more dire the consequences and the higher the cost.

TEMPERATURE INCREASE

Scientists say the earth's temperature will rise by at least two degrees centigrade this century due to greenhouse gases from burning fossil fuels for transport and electricity, putting millions at risk with extreme weather events and rising oceans.

James Rogers, chief executive officer of giant US power supplier Cinergy Corp which currently burns 30 million tonnes of coal a year, said it was one of the most daunting challenges facing the world today.

Not only had business to change the whole way it worked in order to cut carbon emissions, but it had also to raise awareness among both business and domestic users of power.

And demand was growing exponentially.

One-third of the planet's six billion people were currently without electric power, and not only would they demand access to the living standards of their richer peers, but at the same time the population was estimated to grow to nine billion by 2050.

"The science is clear enough at this time to go to work," he said, adding that there would be no single answer but a vital need to develop long-term perspectives.