WASHINGTON - U.S. President Barack Obama will attend the end of the Copenhagen climate change summit, a late change of plan the White House attributed on Friday to growing momentum toward a new global accord.

Obama was originally scheduled to attend the December 7-18 summit in Denmark on Wednesday before traveling to nearby Oslo to collect his Nobel Peace Prize.

Some European officials and environmentalists had expressed surprise at the initial decision, pointing out most of the hard bargaining on cutting greenhouse gas emissions would likely take place at the climax of the summit, when dozens of other world leaders are also due to attend.

After months of diplomatic activity, there is progress being made toward a meaningful Copenhagen accord in which all countries pledge to take action against the global threat of climate change, the White House said in a statement.

Danish officials say more than 100 world leaders have confirmed they will attend the conference, which Denmark hopes will help lay the foundation for a successor to the 1997 Kyoto Protocol on curbing global warming gases.

Based on his conversations with other leaders and the progress that has already been made to give momentum to negotiations, the president believes that continued U.S. leadership can be most productive through his participation at the end of the Copenhagen conference on December 18th rather than on December 9th, the White House said.

GROWING CONSENSUS

The Obama administration has been encouraged by recent announcements by China and India, two other major carbon emitters, to set targets to rein in emissions and the growing consensus on raising cash to help poor nations cope with global warming, seen as a stumbling block to a new U.N. deal.

Danish Prime Minister Lars Lokke Rasmussen swiftly welcomed Obama's decision, saying his attendance was an expression of the growing political momentum toward sealing an ambitious climate deal in Copenhagen.

In London, a spokesman for British Prime Minister Gordon Brown said Obama's presence would give huge impetus to the negotiations.

The United States will pledge in Copenhagen to cut its greenhouse gas emissions roughly 17 percent below 2005 levels by 2020.

It was the last major industrialized country to offer a target for cutting greenhouse gases in a U.N.-led drive to slow rising world temperatures that could bring more heatwaves, expanding deserts, floods and rising sea levels.

Experts expect the Copenhagen gathering to reach a political agreement that includes targets for cuts in greenhouse gases by rich nations by 2020. Agreement on a successor to Kyoto will be put off until 2010.

The White House said Obama had discussed the status of negotiations with Australian Prime Minister Kevin Rudd, German Chancellor Angela Merkel, French President Nicolas Sarkozy and Britain's Brown.

There appeared to be a growing consensus that a core element of the Copenhagen accord should be to seek pledges totaling $10 billion a year by 2012 to help developing countries cope with climate change, the White House said.

The United States will pay its fair share of that amount and other countries will make substantial commitments as well, it said.

Environmentalists welcomed Obama's move and some called for him to shift his administration's target for cutting emissions at the same time.

After a global outcry, President Obama has listened to the people and other world leaders; he has come to his senses and accepted the importance of this potentially historic meeting, Martin Kaiser, Greenpeace International's political climate coordinator, said in a statement.

Now that he has moved the date, he needs to move his targets and his financial contribution to be in line with what climate science demands, he said. (Reporting by Ross Colvin, additional reporting by Caren Bohan and Jeff Mason in Washington and David Milliken in London; Editing by Peter Cooney)

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