COPENHAGEN – World leaders on Sunday insisted that the climate deal clinched in desperation at the U.N. summit was the best that can be done as they returned home to a lashing from critics.
Newspapers widely called the summit accord a failure and experts such as the head of a Nobel Peace prize-winning climate panel said "urgent" action was now needed.
President Barack Obama acknowledged that all of the world's polluters would quickly have to do more, but German Chancellor Angela Merkel said the critics would only hold up the battle against rising temperatures that threaten devastating floods, storms and drought.
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Obama returned to the White House and said "extremely difficult and complex negotiations" had been needed in Copenhagen.
"This breakthrough lays the foundation for international action in the years to come."
But even the U.S. leader said "we will have to build on the momentum" and get Congress to pass mandatory cuts in greenhouse gases blamed for global warming.
Merkel, who will host a new international meeting in Germany in 2010, hit back at the critics. Related article: Merkel defends climate compromise
"It is a first step toward a new world climate order, nothing more but also nothing less," she told Bild am Sonntag newspaper.
"Those who are only putting Copenhagen down are helping those who want to blockade rather than move forward."
Germany will host a follow-up meeting of environment ministers in Bonn in June, ahead of another summit in Mexico City next December. "We now need to build on Copenhagen," she said.
The Danish chair of the U.N. climate summit, Connie Hedegaard, said Sunday she thought it would be difficult to gather together so many world leaders again for a new conference, though the effort must be made.
"I think it will be very difficult," she told AFP, but added that the world still needed to set binding objectives on reducing carbon emissions, "if not I'm afraid that too much time will pass before the world does what is necessary" to stop global warming.
The Copenhagen Accord, only passed by a procedural motion after two weeks of tense negotiations, has been widely condemned as a backdoor deal that excluded the poor and doomed the world to disastrous climate change.
The agreement was assembled by the leaders of the United States, China, India, Brazil, South Africa and major European nations, after it became clear the 194 nation summit was in danger of failure.
China, the world's top polluter, has given the warmest welcome to a summit that experts say it has benefitted from by making the fewest concessions. Related article: Asian leaders voice hope in climate deal
"With the efforts of all parties, the summit yielded significant and positive results," Foreign Minister Yang Jiechi said in a statement.
At the same time China's foreign ministry spokesman on Sunday hit out at critics of the closed nature of the accord, saying Beijing had always maintained close contact and coordination with all countries during the summit.
"China is a developing nation, we... firmly maintain the development rights of developing countries, and firmly maintain the unity and coordination of emerging nations," Qin Gang said in a statement on the ministry's website.
The summit set a commitment to limit global warming to two degrees Celsius (3.6 Fahrenheit), but did not spell out the important global emissions targets for 2020 or 2050 that are the key to holding down temperatures.
Related article: Top U.N. scientist urges binding pact The summit promised 100 billion dollars for poor nations that risk bearing the brunt of the global warming fallout, but has not given a fixed payout plan.
So far, the United States has promised to contribute 3.6 billion dollars in climate funds for the 2010-2012 period, with Japan contributing a total of 11 billion dollars over the same period, and the European Union 10.6 billion dollars.
Even U.N. chief General Ban Ki-moons admitted the agreement had failed to win global consensus and would disappoint many who demanded stronger action against climate change.
"Many will say that it lacks ambition," Ban told the end of the summit. "Nonetheless, you have achieved much."
Rajendra Pachauri, chairman of the Nobel-winning Intergovernmental Panel on Climate Change (IPCC), said: "Developing countries, certainly Africa, are very concerned and very suspicious of the developed countries on whether they are really genuine in making these offers."
"In the next few weeks and months we will have to work very hard to see that, before the end of 2010 if not earlier, we get a binding agreement that really moves action in the direction we need," he told the Indian NDTV television channel.
"We really have to move on rather quickly to reduce the emissions of greenhouse gases. There is growing evidence of the impacts of climate change and if we delay action these impacts are going to become much worse, far more serious," he warned.
The Wall Street Journal called the Copenhagen deal "a pre-emptive dead letter because countries like China, Brazil and India said they were unwilling to accept anything that depressed their economic growth."