BONN, Germany—The U.N. climate chief on Wednesday welcomed President Barack Obama's decision to attend next month's climate conference in Copenhagen, where the Americans will offer their first specific target for slashing U.S. greenhouse gases.
"The world is very much looking to the United States to come forward with an emission reduction target," Yvo de Boer told reporters at the headquarters of the U.N. climate treaty secretariat.
But Obama's timing, coming in the first week and not the crucial second week of the conference, was sure to disappoint the Europeans and U.N. climate officials, who had hoped he would take part in final negotiations to apply top-level political pressure and approval for agreements on key points.
Sixty-five presidents and premiers, including the leaders of Germany, France and Britain, say they will participate in the conference's final days.
The White House said Obama would offer to reduce U.S. carbon dioxide and other global-warming emissions by about 17 percent below 2005 levels by 2020—but that would be provisional, depending on the level set by legislation slowly making its way through the U.S. Congress.
The United States is the last among three dozen industrialized nations to put a "number on the table" for the two weeks of negotiations in the Danish capital, beginning Dec. 7. Others have been more ambitious.
The European Union, for example, has committed to reducing its emissions of gases blamed for global warming by 20 percent by 2020, compared with 1990 levels, a more stringent benchmark year than the Americans' 2005. The new government in Tokyo has pledged to reduce Japan's greenhouse gases by 25 percent by 2020, compared with 1990, if other countries make similar commitments.
Reductions of 17 to 20 percent contemplated in pending U.S. legislation shrink to about 4 percent when compared with 1990, analysts say.
De Boer welcomed word from Washington on Wednesday that Obama would attend the 192-nation conference on Dec. 9, the day before he accepts the Nobel Peace Prize in Oslo, Norway.
"I think it's critical that President Obama attend the climate change summit in Copenhagen," he said. "We have figures from all industrialized countries, with the exception of from the United States. This is the first thing we need, and this is critical."
As for Obama missing the final negotiations, de Boer looked positively on the possibilities.
"We really need a (U.S.) target and financial commitment, the earlier the better. If he (Obama) comes in the first week to announce that, it would be a major boost to the conference," he said.
De Boer acknowledged that industrialized countries' pledges thus far, estimated to total globally a reduction of 16 to 23 percent, fall short of what scientists say is needed to head off serious impacts from global warming—that is, reductions of 25 to 40 percent below 1990 levels.
"Current pledges are insufficient to keep the temperature increase below 2 degrees Celsius (3.6 degrees F)," de Boer said.
Reacting to the news of Obama's attendance, European Union Commission President Jose Manuel Barroso said: "I have made it clear that we need as many world leaders present as possible. I hope that others will follow suit."
Scientists believe a 2-degree-C increase in global temperatures from pre-industrial levels would lead to destructively rising seas and climate shifts that would produce droughts, floods and other severe disruptions.