A way forward

Environmental issues have been elevated in the context of the U.S.-China relationship over the past five years, Lewis said.

"It's surprising to think we could have an agreement like this since [China and the United States] seem to have such different positions," she said. "When you look at the bilateral relationship in the broader context, climate change has arisen as the issue where we have far more in common than not. Even though there are fundamental disagreements, we still have the same goal."

While cooperation on climate change is becoming a key foundation of the future between the great powers, significant political obstacles remain. The timing of the announcement and the fact that it is not an enforceable agreement are significant. It would be nearly impossible for Obama to pass a climate change treaty through a hostile Congress, but the high-level, highly public announcement of intentions creates a "momentum" for work that doesn't make headlines, Wang said. This model could be used in other areas of bilateral relations such as terrorism and trade.

"I think the notion that the United States and China—who have been these two big players on opposite sides of the fence and viewed as the biggest antagonists—were able to stand up together, that's a big thing," Todd Stern, U.S. special envoy for climate change, told reporters at a forum held by the Center for American Progress.

The non-binding pledge may also be a model for a global agreement for next year's UN Climate Change Conference in Paris. The objective of the 2015 conference is to achieve, for the first time in over 20 years of UN negotiations, a binding and universal agreement on climate, from all the nations of the world.

"The vision of an international binding agreement is wrong. Countries need to see it's in their own interest and see [emission reduction] as positive," Wang said.

The agreement also makes China a major player in the global climate debate. With a commitment by the world's largest emitters, other countries have run out of excuses. Chinese and American emissions represent 42 percent of main greenhouse gas emissions, and smaller countries and developing economies have feared their emission cuts would be useless unless the major players take action.

"I'm very interested to see if this announcement has some reverberations. China is now in a position where it is clearly the largest emitter. It will be interesting to see if it will influence Brazil, India and South Africa," Lewis said.

The United States, as well, has run out of excuses to take action.

"The argument that the United States cannot act because China won't act has finally begun to fade. A very understandable anxiety—that America cannot cut carbon emissions while our biggest competitor keeps burning dirty energy with no end in sight—can now be put to rest," wrote Fred Krupp, President of the Environmental Defense Fund, in the Wall Street Journal.

The author is a contributing writer to Beijing Review, living in New York City