Some of the more pessimistic people I've talked to in the run-up to the meetings in Copenhagen speak as if these talks are a foregone conclusion. To me it seems a little silly to predict what's going to happen. What the heck are an estimate 50,000 advocates doing flocking to the city if they don't think they can actually impact the procedings? (Though I guess you could've said that about the Democratic National Convention in Denver last year. And, yes, guilty as charged, I was there.) There are obviously plenty of directions that these talks could go, and where it winds up, nobody really knows. Perhaps most interesting, wherever it winds up, there won't be any clear consensus about whether COP15 was a success, a failure, or something in between.

While the devil really is in the details for a treaty like this--any line of text could make all the difference in the world for some country or continent or business or tribe-the Copenhagen talks will be most immediately evaluated in a broader sense, by the structure, ambition and scope of whatever agreement, if any, is produced. So let's explore how a couple of these possible meta-outcomes would be received, and the likelihood (my amateur opinion only) of it happening. I see four realistic possibilities, and one not-so-realistic one that many climate action advocates are still pushing for.

No deal

Obviously nobody would be happy, with the exception of some extremely hardline radical activist groups who are fighting for deeper, more wholesale systemic change (the end of capitalism, for instance). Also, curiously, the revered NASA scientist James Hanses who made his contempt for the UNFCCC process public in a recent statement, would celebrate a failed COP15. For the negotiators, this would essentially mean that they'd failed at their jobs. NGOs who have spent the better part of the decade-and every working hour of the past few years-working to secure a fair, ambitious and binding deal would be outraged. Heads of state who put significant political capital on the line to attend the talks would be left with a lot of explaining to do to their citizens and constituencies back home.

Likelihood: don't rule it out. Many developing countries are feeling bullied by the industrialized world to agree to a deal that they feel would threaten their future and, in some cases, their very existence. It's entirely possible that rich countries won't offer ambitious enough emissions cuts and financial support, and developing countries would feel the need to take a stand, make a loud and powerful point, and try their luck next year.

Weak but final non-binding deal

This could take a number of forms, none of which are exclusive: a ministerial-level decision, a Heads of State handshake, a written document with no enforcement or compliance measures, and no intention of strengthening the decision with legal language in the future. NGOs would be predictably (and rightly) outraged, but leaders from the industrialized world would do their best to spin this as a positive outcome.

Likelihood: I'm guessing that most developing countries would rather have no deal at all than such a hollow gesture. But it's possible that they'll feel compelled to play along, probably for diplomatic reasons totally outside of the climate change realm like trade or aid.

To be continued deal

Negotiators find that their respective positions-mostly between the developed and developing world-are still way too far apart to be reconciled, but nobody wants to give up. Enough progress is made through the two weeks to give some hope for a future deal, but nothing that's immediately ready to present, let alone act on. Again, developed world leaders would publicly celebrate the progress made, promising better things in the year ahead. The European Union and some other rich nations might show some impatience, and could possibly call out the United States for holding things up, but in the interest of international relations they'd probably keep mum. Much of the developing world would go public with their frustration, calling much attention to the fact that every passing year of inaction dooms the planet's most vulnerable to dangerous impacts and miserable fates.

Likelihood: Way too likely. It feels like there's an enormous amount yet to be resolved and, knowing the pace of these UN talks, far too little time to work it out.

Strong, complete, but not-yet-legal deal

Picture an agreement that covers all the essential issues, has specific mitigation and finance commitment numbers for respective countries, includes comprehensive and effective language about all the key tools (like REDD, tech transfer, and so on), but doesn't yet have the legal details in place, and so isn't yet a ratifiable treaty. Yet being the most important condition. This deal would have to assure, in the strongest language possible, that the legal language about compliance and enforcement would be worked out as soon as possible in 2010. Ideally with a hard deadline in place (possibly in Bonn in June, or in Mexico City at COP16 in December). The Danish government has called publicly for a weakish version of this outcome, a 6-8 page "politically-binding" text that covers all key issues and sets a deadline for legal completion. Ideally the final document would be longer and more thorough, and best if, as the United States has mentioned, it's "immediately actionable," and countries are politically (if not yet legally) committed to start living up to the word of the agreement right away.

Most countries would celebrate this as an enormous triumph. Certainly some grumbles of discontent would be heard from particularly vulnerable nations that will categorically condemn any deal that isn't immediately legally-binding. Similarly, a good number of international NGOs and civil society orgs (particularly those working on development and the Global South) would call this out as being too weak.

Likelihood: I see this as the most likely outcome. And, in my opinion, the most desirable. It'll take incredible effort, remarkable concessions from both the developing and developed world, a boatload of trust, and the confidence amongst all parties that moving to a low-carbon, climate resilient future will prove easier than all the economic naysayers threaten. In other words, it'll take real, true diplomacy and an international spirit of cooperation that's only been seen a handful of times in human history.

A final, legally-binding deal

In a perfect world, a strong, fair, ambitious, and legally-binding treaty would be signed on December 19th by heads of state. In it, developed countries would agree to significant emissions cuts and major commitments of public funds to finance mitigation and adaptation efforts in developing countries. It would be immediately actionable, and enforceable.

Likelihood: It's too late. I've spent the last couple of months talking to international policy experts, law professors, veterans of international legal processes, and former diplomats and negotiators. The general consensus is that it's simply too late to make this happen. One law professor told me that the worst possible outcome from Copenhagen would be a legally-binding deal, as it'd be so rife with loopholes because of the rush that countries would be wiggling out of their "commitments" for decades. "Any lawyer will tell you that the last thing you want to do is rush the legal language." As badly as the NGOs and everyone who cares a lick about climate change wants it, it is simply not a realistic possibility for this to get done. The public pressure for a legally-binding deal in Copenhagen is coming probably 6-12 months too late. It's not going to happen, and if it by some miracle did, we'd all regret the rush job for a very long time.