Many years ago, I actively engaged the political discussion surrounding carbon markets, as I thought I might be able to help. I've been directly involved in similar types of international negotiations, albeit at a smaller scale and unrelated to carbon markets. Talking to people involved in the carbon market negotiation made it abundantly clear why there will never be a useful outcome.

Most of the governments involved in negotiating a common international agreements on carbon markets unofficially represent for-profit interests seeking advantage in the structure of the carbon market. There is an enormous amount of profit that can be realized here, and the good faith actors are in the minority. This is quite normal even in small international agreements but it becomes exponentially harder to arrive at an agreement that is minimally corrupted with respect to its nominal purpose as the profit incentive to corrupt the agreement increases. The last time I looked in on the current state of the carbon market negotiations, it had been corrupted beyond redemption. I have no faith that something useful will result.

This is why international agreements are unlikely to have a material impact on climate change. International agreements tend to only be effective when there is minimal profit or advantage to be gained by corrupting the purpose of the agreement. Climate change activities simply involve too much money for an international agreement to produce a credible outcome. It is the wrong tool for the job.