Carbon credits are a means of reducing the net CO2 in the atmosphere. What matters is not, in the end, who is pumping out what where, but that the net amount stops rising, and falls over time. Releasing CO2 is a reversible form of damage, not a permanent one, and paying someone elsewhere to absorb or mitigate that release is totally legitimate.

The idea of carbon credits, and a market in those credits, is based on the model which was implemented to phase out CFC production, and very successfully at that. By allowing a market in credits, you let the mitigation take place at the point in the economy where it is cheapest per tonne (ie most cost-effective). This reduces the overall economic impact.

Of course such a market must be thoroughly overseen and regulated, unfashionable as such words are in regards to commodity and derivative trading, but otherwise free of artificial distortions and barriers. The fact that GHG emission is free of charge today is a massive market distortion which tilts the playing field towards coal and away from renewables.

I don’t think rape really qualifies as reversible damage. No amount of funding for crisis centers can “mitigate” the cost of the original impact.