"The earth is really warming, and this warming needs to be mitigated," said Narasimhan Sundararaman, secretary of the Intergovernmental Panel on Climate Change.
"Fortunately, the options are there."
"It's out there, it's just a matter of liberating it, giving incentives to companies, removing the barriers to rolling out new technologies and changes in the system to make it all work" , said another U.N. source in Accra.
The report listed a number of technical advances that are helping reduce greenhouse gas emissions, including the rapid elimination of industrial byproduct gases, and the introduction of more environmentally friendly wind turbines and hybrid engines.
Greenhouse gases primarily carbon dioxide produced by burning fossil fuels like coal and oil are widely believed to trap heat in the atmosphere, resulting in rising temperatures that have shrunk glaciers, caused sea levels to rise and hurt plant and animal life.
The 17-page document, a summary of a 1,000-page study called Climate Change 2001: Mitigation, written by about 200 scientists, and reviewed by about 400 independent experts was the third in a series by the climate-change panel. The fourth, due in September, will summarize all three.
It was adopted late Sunday by 140 delegates from 85 countries, after four days of discussions in Accra, Ghana's capital.
Most of the research indicated that already existing technologies could stabilize atmospheric carbon dioxide levels over the next 100 years or more. But success will depend on overcoming a range of technical, economic, political, cultural, social and institutional barriers, the panel said.
In the panel's first report, released in January in Shanghai, China, it said global temperatures could rise by as much as 10.5 degrees Fahrenheit over the next century. It said the increase was much higher than previously expected and there was clear evidence that car exhaust and other industrial pollution was to blame.
The likely effects included tropical diseases spreading into the United States, deserts expanding across Africa and glaciers melting in Europe, according to the panel's second report, released in February in Geneva, Switzerland.
However, the use of energy sources involving low levels of carbon emission could make an "important contribution" to combating the problem, the panel said in Monday's report.
Among the examples cited were forestry and agricultural byproducts, municipal and industrial waste, wind energy, hydropower and nuclear power, which is widely opposed by environmental groups.
Half of the potential emision reductions could be achieved by 2020, with the benefits in terms of energy saved exceeding the costs, the panel concluded.
Some ways of fighting global warming could have broader benefits as well, including reducing health problems, increasing employment and protecting forests.
The report concedes, however, that at least until 2020, energy supply is likely to be dominated by relatively cheap and abundant fossil fuels.
The panel also noted that the poor people around the world have limited possibilities to adopt new technologies or change their practices.
The report followed a meeting Sunday in Trieste, Italy, at which environment ministers from the world's seven most industrialized countries plus Russia renewed their commitment to fight global warming and promised to work towards an agreement over gas emission reductions.
American and European environmental officials have been at odds over the implementation of a 1997 Kyoto accord that calls for gas emission cuts to reduce global warming, and a conference in The Hague last year failed to reach an agreement.
The key issue blocking the negotiations was whether and to what extent countries should be allowed to count carbon dioxide absorbed by forests and farmlands toward their emissions reduction targets. The United States supports such credits, while the European Union opposes them.
Negotiations will resume at a conference scheduled in July in Bonn.
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