As my colleague Ryan wrote earlier, the congressional climate change bill no represents the most meaningful path for urbanists, and advocates for clean transportation in general, to make their voices heard in the national debate.

President Obama, accepting the Nobel Peace Prize today. (Photo: AP)

So it bears repeating that the bill is losing momentum, with the Senate environment committee unlikely to take up its version until next month. And that legislative slowdown is already having international consequences:

The U.S. may not agree to cut
greenhouse-gas emissions in a new treaty this year because there
is no domestic law setting a framework, the country’s top
negotiator said at United Nations climate talks in Bangkok.

Without legislation advancing in Congress, it will be
difficult for the world’s biggest economy to pledge an emissions
target for itself, U.S. negotiator Jonathan Pershing told
reporters today as negotiations wound up in the Thai capital.

“It will be extraordinarily difficult for the U.S. to
commit to a specific number in the absence of action from
Congress,” Pershing said. “The question is open as to how much
we can do. It’s not really possible to answer.”

Supporters of the Senate climate bill — including President Obama — have downplayed the significance of passing a Senate climate bill before talks on global emissions reductions begin in Copenhagen in December. Foreign relations committee chairman John Kerry (D-MA), the bill’s chief sponsor, has even suggested that the bill has a stronger chance of winning Senate approval than any treaty signed at Copenhagen, which would have to secure a two-thirds majority in the upper chamber of Congress.

But if the U.S. continues backing away from setting a broad emissions target this year, it could result in a further loss of momentum for the Senate climate bill, setting up a vicious cycle of sorts. And all this on a day when Obama takes the Nobel Peace Prize for helping America "[play] a more constructive role in meeting the great climatic challenges the world is confronting.”