[Editor's Note: This article originally appeared on The Huffington Post, and is reprinted with permission.]

Expectations for a climate treaty had been in a dramatic downward spiral until President Obama's meeting with Hu Jintao in Beijing this week, where they agreed to shoot for emissions targets, and press for an agreement at Copenhagen that would "rally the world." Was it was all part of a concerted White House strategy to downplay expectations for a global treaty, then build them up again, so Copenhagen felt like a success?

While I don't go that far, there is an odd disconnect between the pessimistic and optimistic story lines that we have to transcend. Instead of letting our expectations be manipulated one way or the other, we need stay focused. We need to be crystal clear about what can realistically be accomplished at Copenhagen, and unmistakably vocal about demanding that negotiators accomplish it.

President Obama put conditions on his willingness to attend the Copenhagen conference, saying he'd go only "If I am confident that all the countries involved are bargaining in good faith and we are on the brink of a meaningful agreement." There should be no room for hedging on this. There is no excuse for failing to conduct good-faith negotiations that produce a meaningful agreement next month. Copenhagen can and must commit the world leaders to taking bold, ambitious action to seal the deal on a new climate treaty.

According to a current briefing [PDF] from the International Institute for Environment and Development, various outcomes are possible from Copenhagen, including a new legally binding Copenhagen Protocol, an amended Kyoto Protocol, interim decisions on various negotiating tracks, or a combination of all three.

Yes, there is also the possibility of no agreement at Copenhagen at all, or a nonbinding, political "implementing agreement" that punts to the domestic laws of each nation. It's true that there are lots of lingering differences on emissions targets and financing, and yes, it is possible some of them may not get resolved into a legally binding agreement or agreements until June or December 2010. But resolved they must be before then, and many key ones can and must be tackled during the ten negotiating days of the Copenhagen conference.

For example, one critical area in which a deal is likely next month is Reducing Emissions from Deforestation and Degradation in Developing Countries (REDD). Deforestation accounts for 17.4 percent of all global GHG emissions -- more than the whole global transport sector, according to the IPCC. The IPCC also estimated tropical forest loss causes 20 percent of carbon emissions worldwide. We currently lose over 80,000 acres of tropical rainforest (with another 80,000 acres significantly degraded) each day, which is a land area bigger than Alabama (33 million acres) each year, and that process is accelerating.

When trees are cut down, they stop sequestering carbon, then they release more carbon as they decompose or burn, and even more carbon gets emitted from tilling soil and other agricultural activities on cleared forestlands. A deal that would prevent these emissions could potentially take more carbon out of the atmosphere than one that made every car, truck, train, plane and ship on the planet non-polluting. Meanwhile, forests won't wait.

Such a deal is in fact still within reach. The draft proposal language on REDD that emerged from the November Barcelona talks has gaps and weaknesses, but it could and should be strengthened and adopted in Copenhagen. REDD pools funding from developed countries to reduce deforestation in developing countries, where most of the carbon emissions from deforestation occurs. The idea is to give billions of people in the developing world with land-based livelihoods a financial incentive to conserve their forests.

Implementing this won't be easy. There are contentious, unresolved questions of who pays, how much, overseen by whom, for what sort of benefit, causing what sort of impacts on forest communities. Still to be resolved in Copenhagen are critical planks in the draft document concerning transparency and governance, objectives for protecting intact natural forests and the rights of affected communities. Any agreement on REDD must be broad enough to significantly cut emissions, conserve forests and build up forest carbon stocks. It should provide adequate, sustainable and accountable financing, safeguards against conversion of forests to plantations and respect affected communities' and indigenous peoples' rights.

But these issues are resolvable in the weeks ahead. One good sign is that an on-again off-again loophole that would have allowed palm oil plantation monocultures that encroach on tropical forests to qualify for REDD funding got partly closed again in November's Barcelona talks. Copenhagen negotiators can and should close it the rest of the way.

REDD could well be one of the success stories of Copenhagen, but it's also a cautionary tale. We've already had some preliminary commitments to REDD from the 2007 Bali Action Plan [PDF]. Their main benefit was to enshrine the concept and make it more likely REDD would be part of the next treaty. Now, the next treaty is being negotiated, and for countries to actually implement REDD instead of just continuing to talk about it, it has to be part of a wider, legally binding agreement on emissions.

That's Copehagen's Catch-22. The conference can and should advance dialogue, help consolidate the key ideas and positions, raise technical and operational issues of importance. REDD in particular is one of the more achievable ones, though there are still obstacles to overcome. But if negotiators content themselves with focusing on more easily achievable elements of a larger agreement, and holding further dialogue on the rest, it will endanger all elements, lower- and higher-hanging fruits alike. To move forward even on the achievable parts, we now need a binding overall agreement, if not wholly negotiated next month, then substantially negotiated next month and finished in 2010.

Even a 2010 binding agreement will require taking major steps forward on remaining issues now. To encourage delegates to take them, many NGOs, including mine, are going to Copenhagen to make some noise. President Obama should too. He should consider that we are "on the brink of a meaningful agreement," because we have to be. Instead of lowering our expectations of Copenhagen, we must expect and demand more of negotiators, and push them over that brink.                   

Tensie Whelan is executive director of Rainforest Alliance, which works to conserve biodiversity and ensure sustainable livelihoods through the transformation of land-use practices, business practices and consumer behavior.

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