While I am against pollution, carbon credits (and similar schemes) seem unlikely to do more than create more corruption.
In general terms, carbon credits work like this (there are many possible variations): a government decides that it will allow X amount of carbon production and then breaks X up into units that can be purchased. Those producing carbon on a large scale (such as oil companies) need to buy these units so they can produce carbon. Under some plans, each company that produces carbon is also given Y units of carbon it can produce. If it produces less, it can then sell these carbon credits to other businesses. In general terms, it makes pollution “rights” a commodity that can be bought and sold.
Europe has created a market in which carbon can be traded. The result, as anyone with knowledge of how the world actually works expected, was that politically powerful companies were able to make new profits by exploiting the situation. To use one example, the German government gave credits to coal burning plants and these companies charged their customers for the the carbon costs. Since the companies paid nothing for these credits, they made a nice profit on this little trick. The carbon trade market also allows for some clever profiteering in other ways-such as getting carbon credits and then selling them at a vastly inflated rate.
Thus, the main result of the carbon credit system has been what one would expect: corruption, profiteering and business as usual. Perhaps it has helped cut down on carbon emissions, but it seems unlikely it has had a major impact.
Does this mean that efforts to combat pollution should be abandoned? Of course not. The negative effects of pollution are well established and these harms, like any harms, should be countered. The trick, perhaps the impossible trick, is finding a way to do this without creating more corruption and profiteering.