> Isn't it just rereleasing CO2 that was in the atmosphere earlier? I don't know the facts here, but I'm pretty sure carbon can slowly be added from other sou

> Isn't it just rereleasing CO2 that was in the atmosphere earlier? I don't know the facts here, but I'm pretty sure carbon can slowly be added from other sources. So sure, that CO2 might have been in the atmosphere before, but then we added more CO2 as well. The point being, the CO2 we're digging up wasn't in our atmosphere before. The atmosphere that we and all the animal and plants have been adapted too. Sure, there's a time when the CO2 concentration (and even O2) was wildly different. But then there were other animals living on earth, that was adapted to those conditions. Slow change is fine, rapid change is disastrous.