Bangkok, Thailand From nuclear power to reforestation to better toasters, the world now has a game plan from climate experts for fighting global warming, a report their chief scientist says will have a "profound influence" on upcoming negotiations.
American officials questioned the economic cost, and the Chinese questioned whether fast results could be achieved. But a leading expert said there was little choice.
"If we continue doing what we are doing now, we are in deep trouble," said Ogunlade Davidson, co-chairman of the U.N.-sponsored group that produced the report, approved by consensus by more than 120 nations Friday at the end of a weeklong meeting.
A 35-page summary of a 1,000-plus-page study, the report said the world must significantly cut emissions of carbon dioxide and other greenhouse gases by sharply improving energy efficiency in buildings, vehicles and even kitchen appliances; shifting from fossil fuels to nuclear, wind, solar and other renewable energy sources; saving forests as "carbon sinks"; capping agricultural emissions, and taking many other steps.
The document says the world has the technology and wealth now to act decisively in time to avoid a sharp rise in temperatures that scientists say would wipe out species, raise ocean levels, trigger droughts in some places and flooding in others, and wreak economic havoc.
The assessment by the Intergovernmental Panel on Climate Change builds on reports by two other IPCC working groups issued earlier this year, which said unabated emissions from power plants, auto exhausts and other sources could drive global temperatures up as much as 11 degrees Fahrenheit by 2100, and reported that warming was already affecting animal and plant life.
The Working Group III study looks in detail at the most promising technologies for reining in the heat-trapping gases and at policies, such as taxes or quotas on carbon emissions, that might encourage development of those technologies. It also looks at how much that might cost economies.
It estimates the world must stabilize the amount of greenhouse gases in the atmosphere by 2015 at 445 parts per million to keep global temperatures from rising 3.6 degrees Fahrenheit above preindustrial levels. Scientists fear temperatures higher than that might cause severe damage. Current atmospheric concentrations are believed to have passed 400 parts per million.
Delegates hailed this latest assessment, the first by IPCC since 2001, as setting the stage for a strong international agreement to replace the 1997 Kyoto Protocol, with its relatively weak mandated emissions cuts, when it expires in 2012.
"Clearly, the signs that the IPCC assessed will have a direct and profound influence on the discussions that take place and the direction toward (a post-Kyoto) agreement," said the IPCC chairman, climatologist Rajendra Pachauri.