CHANGE IN COPENHAGEN PLANS…. President Obama was scheduled to travel to Copenhagen this upcoming week, to appear at the international summit on climate change. It was going to be convenient — the president will pick up his Nobel Peace Prize on Thursday — but the timing was odd, because the climate change meeting would just be getting underway.

Yesterday afternoon, the White House announced a change of plans. Obama will be in Norway on the 10th, but he’s delaying the Copenhagen trip a week.

President Obama will attend the high-level portion of international climate talks in Copenhagen on Dec. 18, the White House announced Friday, ratcheting up expectations that the United Nations-sponsored negotiations could produce a significant deal on global warming.

Obama had planned to stop in Copenhagen on Wednesday, on his way to Oslo to receive the Nobel Peace Prize. Instead, the president will be there during the critical period when more than 80 heads of government convene to try to finalize an agreement.

In a statement, White House spokesman Robert Gibbs said Obama has determined that “there is progress being made towards a meaningful Copenhagen accord” now that both China and India have announced nationwide energy-efficiency targets in the last week.

Indian announced Thursday that it will lower its carbon emissions relative to the size of its economy by 20 percent by 2020, and China announced a week earlier that it would lower its emissions relative to its economy’s size by up to 45 percent over the same period.

Alden Meyer, director of strategy and policy for the Union of Concerned Scientists, said Obama’s decision to go suggests that “he’ll be [in Copenhagen] at the end to help seal the deal.” AEI’s Kenneth Green, a conservative White House detractor, added that the schedule switch “changes the game.”

David Roberts, who called the announcement a “last-minute stunner,” had a very good piece summarizing the significance of the schedule shift. Roberts explained, “If he’s willing to stick his neck out like this, Obama must be pretty confident that he can get a deal…. Momentum is finally on the side of an international agreement.”

One other angle to keep in mind: with the president making two transatlantic trips over the course of just nine days, Obama may also make some unexpected overseas stops. Keep an eye on the possibility of a new arms treaty with Russia, replacing START, which may be complete by the 18th.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.