Well, yea, it's been a key factor in multiple mass extinctions before. And, pleasantly enough, if we were to somehow survive it getting "too hot" in terms of the carbon cycle, we would then experience rapid global cooling, which has been a key factor for, you guessed it, multiple mass extinctions. And, if we somehow survive Earth freezing over, if global cooling occurs too fast, volcanism will increase greatly, which may or may not have lead to, big surprise here, multiple mass extinctions. Combine this with the fact that Earth gets hit with meteors large enough to cause the equivalent of a nuclear bomb detonation about once a year (almost always in the ocean due to surface area ratios of ocean vs land), and we start to realize that money grubbing over inefficient, dirty fuels is probably the stupidest thing the human race is still doing.