The thing about peak oil is that it's not about quantity, but rate. We're gonna be pumping a ton of oil out of the ground for an extremely long time, we just won't be able to ramp production up much beyond what it's at to meet demand. Peak oil is about the supply/demand dynamic, not reserves

Even without oil, coal will be overall responsible for way more damage

Even without any fossil, mass livestock and logging will still get the job done all on their own. Hell, I bet logging without replanting is worse than burning coal. Gotta keep in mind that high degrees of global warming have happened before without any fossil release