Nations also agreed at the U.N. climate talks in Copenhagen to set a goal of limiting global warming to 2 degrees Celsius (3.6 degrees Fahrenheit). But because of inaction, Figueras said, the world is now on "somewhere between a 4 and 6 degree (Celsius) trajectory."
"But the door is not closed," she quickly added. "We have the technology, we have the capital. We have the possibility."
U.N. Secretary-General Ban Ki-moon says one of his top hopes for 2013 is to reach a new agreement on climate change.
"Slowly but steadily, we are coming to realize the risks of a carbon-based economy," he told the forum Thursday. "Those supposedly longer-term issues are actually silent crises with us today: the death of children from preventable diseases; the melting of the polar ice caps because of climate change. ... Let not our inaction today lead to harsh judgment tomorrow."
Prince Albert II of Monaco, whose foundation focuses on climate change and other environmental issues, said Obama's inauguration speech gave a welcome lift toward collective action.
"That can only be positive, because we need to have the U.S. on board," he told the AP.
But Thomas Donohue, president of the U.S. Chamber of Commerce, said despite Obama's speech there would still be resistance.
"While the president and his colleagues will pursue what we believe is an aggressive climate change policy, they're not going to get it through the Congress," Donahoe predicted. "It's going to be done on a regulatory basis ... and that's going to create a different approach to dealing with this very important but controversial subject."
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