As if it needed one, here’s another dilemma for the Obama administration: How to move aggressively to tackle climate change without getting China on board?

With or without you (AP)

During the campaign, Obama officials said it would be politically all but impossible for the U.S. to impose curbs on greenhouse-gas emissions unless big emitters like China also play ball; China already emits more greenhouse gases than the U.S. and its fast-growing economy means that lead will grow wider in coming years.

But last week, President-elect Obama said he’d make climate-change legislation the starting point of his energy revolution, reaffirming his campagn pledge to cut emissions by 80%, and that the U.S. should reclaim global leadership in fighting climate change.

What would that mean in practical terms? This summer, the Center for American Progress put together a primer for the next administration’s approach to China. In it, CAP fellow Robert Sussman said:

Early in the next administration, the new president should announce that the United States is committed to substantial, mandatory reductions in U.S. greenhouse gas emissions that are not conditioned on the actions of China or other countries.

He said the U.S. should instead urge China to expand upon recent improvements in energy efficiency, renewables, and the like, and open the door to accepting binding emissions limits under the next version of the global Kyoto treaty.

But getting both China and the U.S. Congress to agree to such a deal won’t be easy, Mr. Sussman argued: “We can expect negotiating such a package will be challenging because of China’s misgivings about adopting even nonbinding goals, and due to the risk of U.S. domestic political backlash against an agreement that is perceived as imposing unequal burdens on the two countries.”

That isn’t just idle policy-shop speculation: Robert Sussman, a former Deputy Administrator at the Environmental Protection Agency, is Team Obama’s point man for the EPA transition. The EPA would be responsible for implementing whatever climate policy the administration and Congress come up with.

The tricky point for President-elect Obama: Taking steps to protect U.S. industry left at a disadvantage from unencumbered Chinese rivals could run afoul of World Trade Organization rules as well as Bejing. And Chinese goodwill, as Fareed Zakaria noted today, is crucial to financing Mr. Obama’s ambitious stimulus plans.

Maybe it won’t matter, anyway. Monday, a pair of researchers from the Intergovernmental Panel on Climate Change said slow government response makes it “almost unfeasible” to cut global emissions as much as needed by 2020 to avoid the worst effects of climate change.