What does the trading work in emissions trading?

http://www.youtube.com/watch?v=pA6FSy6EKrM

10 minutes and a pretty good explanation.

It is really a last ditch method of not doing anything.

What is needed is a reduction, NOW of 100% in the production of carbon dioxide gas. If that were to happen then experts estimate that the earth would continue to warm for the rest of this century, but a turn around would then occur and cooling to some pre 1900 value would commence.

The trading schemes put a dollar value on CO2 and basically license the production of CO2.

At best those schemes might result in a small decrease.

But what is needed is a large decrease. That will entail a rethink across the board of how we live.

That just is not happening.

I'm not sure if I understand what you mean by "what does the trading work." If you're asking what parties participate in the trading, the emitters do. In a cap and trade system, permits to emit are distributed to emitters who then trade amongst themselves to efficiently allocate where they end up. The price of the permits would be, ideally, determined by aggregate demand and the supply of the permits in the market.