"A lot of sensible decisions would naturally flow from this long-term objective," said Stephen Byers, former British transport minister and a close ally of British Prime Minister Tony Blair, as he unveiled the report. Byers co-chaired the international task force that produced the report with the US Republican Senator Olympia Snowe.

The ceiling of two degrees Celsius is likely to be reached in the next 10 years without major changes in energy and transport policy, according to the study, entitled "Meeting the Climate Challenge".

The report has been timed to coincide with Blair's promised efforts to advance climate change policy this year as head of both the Group of Eight (G8) group of richest nations and the European Union.

The report was complied by three leading think tanks, the Institute for Public Policy Research in Britain, the Centre for American Progress in the United States and The Australia Institute.

Global warming, also known as climate change, is caused by the build-up of greenhouse gases in the Earth's atmosphere from the burning of coal, oil and gas in power stations and motor vehicles which began with the Industrial Revolution in 1750.

The global average temperature has already risen by 0.8 degrees since 1750, so the world has little more than a single degree of temperature latitude before the crucial point is reached, the report said.

The consequences of such a rise could include widespread agricultural failure, water shortages and major droughts, increased disease, sea-level rise and the death of forests, it said.

The report urges all G8 countries to agree to generate a quarter of their electricity from renewable sources by 2025, and to double research spending on low-carbon energy technologies by 2010.

It also proposes the adoption of a framework which would allow the United States to join global efforts to reduce greenhouse gas emissions. Washington has refused to sign the existing international agreement, the Kyoto Protocol, to cut greenhouse gas emissions.

Blair is expected to highlight the challenge posed by climate change in his address to the world economic forum in Davos, Switzerland, on Wednesday.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.