Now what do the Copenhagen climate talks mean?

By acknowledging over the weekend that the world would have to wait at least until next year for a legally binding treaty to curb global warming, President Obama and fellow Pacific Rim leaders dramatically lowered expectations for next month’s climate negotiations in Copenhagen.

Yet, in the process, White House officials and many environmentalists say, the leaders may have boosted the chances for the U.S. Congress to pass landmark limits on greenhouse gas emissions -- and for the world to act in time to stave off the worst projected effects of rising temperatures.

It’s a paradoxical approach that has raised questions, including:

What did Obama and his counterparts agree to?

Meeting in Singapore, the group -- including the United States and China, the world’s two largest emitters of greenhouse gases -- threw its support behind a plan by Danish Prime Minister Lars Lokke Rasmussen to leave the final details and signing of a climate treaty for next year, abandoning hopes of finishing by the end of the December talks. The nations will instead focus their Copenhagen efforts on an executive summary of sorts.

Does that mean they’re putting off the big issues?

Not necessarily. Rasmussen’s scaled-back plan would still aim to include agreements on the most important features of any treaty.

It calls for specific pledges by individual countries, developed and developing, to reduce their emissions of the heat-trapping gases scientists blame for global warming, along with financial commitments from richer countries to help poorer ones adapt to climate change and transition to low-emission energy sources. It would set deadlines, presumably next year, to fill in the blanks, including how to enforce the various commitments and how to structure the money flow from the richer to the poorer countries.

So where would that leave the long-term prospects for a full climate treaty?

Critics say it could drain the pressure from the United States and China to agree to legally binding action any time soon. But Obama administration officials and many environmentalists say it could do the opposite, sending dominoes tumbling in Washington and around the world toward an agreement.

Here’s their logic: The House has already passed a climate bill. Scaled-back action in Copenhagen could help push a Senate bill over the top by securing pledges for emissions reductions from China and India, and thereby reassuring moderate Rust Belt Democrats. Moreover, by coming to some sort of agreement in Copenhagen, negotiators could continue building momentum toward a final agreement, rather than deflating the ongoing talks.

“It allows us to solidify the commitments to action from major emerging economies that we have seen over the past year,” said Jake Schmidt, the international climate policy director at the Natural Resources Defense Council, “and provide a clear signal that other countries really are taking steps to address their global warming and so the U.S. isn’t going it alone.”

If the United States passes a climate bill, most analysts agree, it greatly boosts the chances of a binding treaty.

How could this plan fail?

The United States could refuse to agree to any specific reduction targets in Copenhagen. China and India could also refuse or they could set targets that U.S. senators find unacceptable. It’s still possible that negotiators might not agree on even a scaled-back declaration in Copenhagen -- and that could set treaty talks back considerably.