By Alister Doyle, Environment Correspondent
OSLO (Reuters) - Rich nations have converged on targets of around 15 percent for cutting greenhouse gases by 2020, but recession across much of the world could impede efforts to agree a new U.N. climate pact by the end of the year.
Cuts of 15 percent from current levels would fall far short of reductions advised by U.N.-backed scientists, but the recession is limiting government ambitions, analysts say.
"We're beginning to see a rough alignment for the numbers for developed countries," said Elliot Diringer of the Pew Center on Global Climate Change in Washington, of proposals for cuts of around 15 percent.
The United Nations said deeper cuts were needed.
"A 15 percent cut by industrialized countries in 2020 is not enough if you look at what the science is saying," said Yvo de Boer, head of the U.N. Climate Change Secretariat.
Scientists in the U.N. Climate Panel have advised rich nations to cut by 25 to 40 percent below 1990 levels by 2020 to avert the worst of droughts, heatwaves, flood and rising seas.
A U.N. agreement from 2007 demands that developed nations make "comparable" efforts to fight warming, stoked by gases released from burning fossil fuels.
"The important thing now is finally to get all the industrialized country numbers on the table and then begin to compare the efforts of different countries and see if greater ambition can be achieved," de Boer told Reuters.
COMPARABLE?
Analysts predict huge arguments about the meaning of "comparable" efforts in the run-up to a meeting in Copenhagen in December to agree a new treaty to succeed the Kyoto Protocol.
But some say the costs of cuts may not be as high as feared by many countries.
"Within certain limits, the measures will pay for themselves," said Markus Amman of the International Institute for Applied Systems Analysis (IIASA) in Vienna. Policies such as more building insulation could save money by cutting energy use.
An IIASA calculator (http://gains.iiasa.ac.at/MEC/) shows that a 15 percent cut from 2005 levels would have negligible impact on most rich nations' gross domestic product (GDP).
Among national goals, U.S. President Barack Obama wants to return U.S. emissions to 1990 levels by 2020 -- a cut of 14.3 percent from 2007. China and the United States are top emitters.
The European Union, which has done more to cut emissions than the United States since 1990, plans to cut by 20 percent below 1990 levels by 2020. That works out as a 14.2 percent reduction from 2005, according to the EU Commission.
Among 2020 goals, Australia aims to cut by between five and 15 percent below 2000 levels and Canada by 20 below 2006.
Japan says it will unveil a mid-term target by June. Former Prime Minister Yasuo Fukuda said last year a 14 percent cut was possible by 2020. Russia has yet to set a number.
Such cuts fall short of demands on the richer countries by developing nations, led by China and India. Developing nations are expected only to slow their own increases in emissions by 2020, rather than make absolute cuts.
The European Commission said last month four factors should be taken into account to ensure "comparable" effort -- GDP per capita, emissions per euro of economic output, population trends since 1990 and past efforts in combating warming.
-- For Reuters latest environment blogs click on: http://blogs.reuters.com/environment/
(With extra reporting by Gerard Wynn in London; editing by Andrew Roche)
