Sure, everyone reading and responding to this did profit from CO2 emissions for sure, but reducing emissions without going back to the stone-age is perfectly possible and this should be clear to anyone:
We could simply start taxing Co2 emissions, which would boost renewable energy buildout INSTANTLY:
One example: Right now, electricity (and concrete) are DIRT cheap-- my electricity bill is a complete joke compared to e.g. groceries (or mobile data, even).
Significant electricity costs (like 1$/kwh) would definitely help reduce emissions, and this could easily be done in a way that would not completely ruin the poorer half of the population by moving other taxes correspondingly.
This is just not done because people (and their governments) simply don't care enough (still!).