The agreement sparked controversy because the world leaders who hammered out its text in the final hours of the UN climate talks last months, known as COP 15, essentially ignored the ongoing battles among 192 countries that had been playing out during two weeks of negotiations.

But Stern argued that this is precisely why the accord should carry weight.

“It was the product of a hands-on agreement by a set of representative world leaders,” Stern said in his speech at the left-leaning Washington-based think tank.

Stern said that countries should formally enact all its provisions without being allowed to simply “cherry pick” parts that they like.

“The accord by its terms is an operational agreement, and we think it ought to be operationalized,” he said.

In Washington and elsewhere, the Accord has been criticized because it was not legally binding; it set no date for achieving an international treaty and set no global targets for reducing emissions. Stern said the United States would like to see a legally binding international treaty –  a statement that has been welcomed by many.

But he also said that the treaty would need to enforce commitments from developing countries like China and India. Here in Washington, environment policy analysts have been downplaying the need for countries to sign a new treaty by the next United Nations Framework Convention on Climate Change (UNFCCC) summit – or COP 16 – to be held in Cancun, Mexico in December.

Stern agreed with this view and called for a pragmatic approach.

“We cannot allow ourselves to get tied up in the ideological knots,” Stern said. On getting an agreement in Mexico, he said, “I’m not going to fall into the trap of saying if not that, we’ve got a failure, because I don’t believe it.”

Stern also took the opportunity to urge the Senate to pass cap-and-trade legislation, something that is looking less likely with each passing week. Getting that done, he said, would give the United States “a foundation for both leverage and credibility” internationally. As to whether the United States will have any room to negotiate with other countries if Congress chooses not to act, he said, “I’m not going to speculate about what happens if not.”

In a meeting in late January at Washington DC’s ***Center for Strategic and International Studies, Stern’s deputy, Jonathan Pershing, gave his view on what happened at COP 15. The meeting in Copenhagen had been the culmination of a series of events. Everyone knew that a deal was not in the cards months before. Meanwhile, the problem of climate change gets progressively worse Pershing said.

Looking forward, he said that a new international climate agreement needed to be all encompassing and verifiable; it needed to promote new technologies – especially energy efficiency and fossil energy –  and above all the process needed to be flexible.

As for COP 15 outcomes, Pershing highlighted the progress made in Copenhagen on linking poverty alleviation to economic development and environmental improvement. COP 15 was also notable for the statements of commitment from developing countries. But, like Stern, Pershing concluded with the observation that it was imperative for Congress to pass climate legislation to give the United States more biting teeth in future UN climate negotiations.

Most commentators here have concluded that COP 15 was evidently important, confusing, but definitely not a failure. One hundred and thirty heads of state participated, which was a much higher level of commitment than at previous COPs. And never before have developing countries been involved. Copenhagen was, at least, a signal for multilateralism with the active participation of Brazil, South Africa, China and India.

In 2010, Bellona would like to see the Senate pass climate change legislation and to do so, the bill will need the support of some Republicans. The political landscape is difficult for the Democrats and the economy, jobs, healthcare reform and national security tend to dominate the political debate on Capitol Hill.

Jonathan Temple is the director of Bellona USA.