Well, indulgences are basically fraud and CO2 offsets that do not materialize are also fraud.

The problem isn't on the buyer side. It's that the seller is inherently going to break his promises and defraud you for a penny.

Sure, but CO2 removal can be funded otherwise than by CO2 offsets or carbon credits -- by a tax on fossil fuels, for example. It is even possible that research can be targeted at using the carbon removed from the atmosphere for fuel or for production of plastic. Burning the carbon (again) as fuel results in no net reduction in atmospheric CO2 of course, but it would probably replace fossil fuels (just as any other renewable source of energy would) and if it ever looks to become profitable, then that would tend to cause increases in the efficiency of CO2-removal tech at no expense to the taxpayer with the result that any CO2-removal efforts not funded by profit-motivated fuel production (e.g., taxpayer funded CO2 removal) become more efficient.

But my main point is that global warming is eminently amenable to technical solutions similar to how for example putting humans on the moon was eminently amenable. Not all societal concerns are so amenable, but for those that are, it seems to me very suboptimal to resort to analogies with religious concepts in public discussions of the concern.

My first comment has a score of -4 now by the way.

Funnily it works both ways as indulgences were supposed to "wash away the sin".

Also, I would have hoped that we could have managed to solve the pollution issue in a rational way, but hope is getting thin. And religion comes with the power of strong taboos that might succeed where we previously failed. Or maybe what is blocking us is how progress has been given the status of a new religion, and while we can appreciate where it got us, we also have to consider whether the costs aren't going to outweigh the benefits in the future...