I think the most cut and dry situations is which they capture concentrated emissions from something like an O&G refinery or a cement plant, since it's an effort which ONLY exists for the sake of reducing emissions.

Even some of these, hilariously enough, despite how insanely quantifiable their benefits are, you see phenomenon like phantom credits like where Alberta, Canada gave Shell double credit for each tonne of Co2 they actually reduced.

I'm sure subsidies for green energy projects do reduce emissions, I just think the accounting is BS.