Copenhagen failed. It was intended to extend Kyoto's caps to the US, China, India, and other the developing countries. Instead the Copenhagen Accord aborted to the Kyoto approach.

Failure was predicted by those who study cooperation and international treaties. Climate is a public good, and Kyoto failed to recognize the well-studied difficulties of cooperation in a public-goods game. So the attempted agreement contained multiple fatal flaws. Here is the list:

1. Unacceptable Caps

The US asked India to cap itself at half our per-capita emissions level in 1880 (not a typo). Had China accepted a "trend-line" cap in 2000, it would have been forced to buy roughly $100 B of carbon credits in 2010 from other countries.

2. Paid Not to Cooperate

If poor countries became part of the international capping system, as we asked, their profits under the UN's Clean Development Mechanism (CDM) would no longer make sense.  CDM effectively pays them to reject caps.

The EU's cap (and the Waxman-Markey cap) are tough to meet. So, both let companies buy CDM offsets instead. Poor countries demand that industrial nations accept much stricter caps so they can sell more profitable CDM credits. The combination of more demands and no cooperation from developing countries caused the deadlock in Copenhagen.

3. No Enforcement

There is no meaningful penalty for missing a Kyoto emission target. So Canada just announced in the middle of the Copenhagen conference, that it thought it's target no longer made sense, so it was forgetting it. Even the most cooperative countries are missing their Kyoto targets.

Even if Kyoto had specified a real penalty for failure to comply, the target was set 15 years in the future (from 1997 to 2012) and then it take a couple more before the final reporting is in. By then (as happened to Canada and others) emissions can be far off track. This means the penalty will be large and the excuses plentiful. The result will be penalties will be dropped or countries will drop out of the agreement.

4. 100+ Unique Commitments

Differences between countries are large (e.g., India vs. the US). And relevant factors are many: wealth, emission levels, growth, past emissions, etc. There are no agreed principles. So getting 100+ countries to agree on a different commitments is extremely difficult. But besides the complexity there, emission targets actually embody the free-rider problem that the Kyoto and Copenhagen agreements were intended to remedy.

5. A Distant Reward

The ultimate reward for participation is an improved climate. But most improvements occur toward the end of the century and beyond, and they are uncertain. Such distant rewards provide weak motivation. As explained here, more immediate rewards are possible.

Copenhagen's Outcome

Copenhagen demonstrated that the design flaws in the Kyoto approach, listed above, were fatal. The Copenhagen Accord included only five countries because the acrimony created by this approach was so great. The brilliance of Obama's agreement was (1) that it put an end to the discussion of binding caps for poor countries -- these are even mentioned, and (2) it validated the key idea developing countries needed to make their commitments -- something they had refused to accept.

This is a start on a new path, and since the old path was worse than a dead end, this is extremely valuable. Contrary to the previous US negotiating position binding caps are not the only, or even the strongest, form of commitment. Now there is a chance to try for commitments that will foster cooperation, not antagonism. Once cooperation is established (and not before) commitments can grow to be strong in effect not just appearance.