Originally Posted by Yakk

Ignoring for now the problem with some kinds of carbon credits (it is far harder to measure "carbon reductions" than "carbon emissions"), emitting carbon isn't a sin.

It is a cost.

The amount of the cost is not perfectly clear (the impact of CO2 emissions, and what can be done to fix it, has not been exactly determined), but it is a cost.

Currently, the cost is dumped on the entire world. You produce the CO2, and everyone in the entire world pays for it.

Your "they didn't really do anything to change the way they lived" seems to be talking about carbon emissions as a sin -- something that, once done, cannot be fixed. But that isn't what carbon emissions are!

Carbon emissions are just a cost -- a resource, even. If you pay the price for a resource, or pay the world for the cost of what you did, or do something that undoes the damage done by your actions (quite perfectly, I might add -- the world doesn't care that much if you emit 1 kg of CO2, then sequester 1 kg of CO2) -- there is no harm done.

This does not match up with the "emitting carbon is a sin" position -- because emitting carbon is a sin is a religious-style viewpoint on the problem.

Having a religious-style objection to carbon emissions can be useful -- it can make people feel good and virtuous about reducing their carbon emissions, which motivates them to reduce carbon emissions without being otherwise compensated for it. But it brings with it that baggage: that people who find a way to eliminate the damage they are doing in CO2 emissions without "sacrifice" are bad people.

Originally Posted by Yakk

Going back to the original issue: we do know that humanity is emitting CO2 at levels that are a detectable fraction of global carbon exchange. World wide CO2 production is at about 1% of the current atmosphere's carbon levels, and about 2% of the 'natural' carbon in-out of the global chemosystem (I think that is a good name for it -- more than just life, but all of the myraid chemical reactions that move stuff around).

...

I mentioned the "other fixes". It is within the GDP of a relatively small nation to launch sulphur particles into the upper atmosphere, and produce a short-term global cooling effect. This is apparently a huge source of the short-medium term cooling caused by large volcanic eruptions.

It might turn out to be way cheaper to cool the world using this technique than to control CO2 emissions. Of course, doing global climate engineering is something that many won't want to risk, in the case someone uses ft/second and someone else reads it as meters/second. . .