Actual Carbon Emissions vs. IPCC Scenarios - how far away is safety?

[AverageJoe90]

25. Well, I'm now convinced that more research is needed re: Toba at any rate.

The second is that there is some serious question as to whether there was even a bottleneck. Some paleontologists assert that our population was very low to begin with, was not reduced much if at all by the event, and simply underwent a bit of a population explosion in the tens of millennia afterwards:

Well, they'd be dead wrong as most paleontologists agree that there was a bottleneck(although Toba may not have been the only cause, according to some.), according to most evidence we have right now(not to mention that small populations breeding amongst almost always lead to humongous genetic issues down the road, so human populations can't have been as low as 3,000, either, it just isn't doable. Some species have would have trouble thriving at all with greater numbers.)

If very few other species died out, it's no great miracle that we survived.

Somehow it seems that more research is likely needed in this area; Yellowstone is a volcanic complex of similar potential and the majority of scientists I've heard talk about this say that there's a damn good chance it's eruption very well could cause a mass extinction. And if Toba really, truly didn't cause a significant extinction, which can be plausibly argued is pretty doubtful, given the research done on the possible effects of a future eruption of the Wyoming complex, then Earth miraculously dodged one hell of a bullet, and the next time a supervolcano erupts, this planet may not be so fortunate; after all, it was a supervolcano in today's Siberia that was (likely) the primary (though not only, recent research seems to suggest.) cause of a mass extinction which wiped out ~90% of marine species and about 2/3rds of terrestrial life.

If we were to actually trigger a true extinction event like PETM, we should expect humans to be as subject to it as any other species.

I'm not terribly convinced methane releases on the level of PETM would be possible, either. Could it happen? Yes. Could it lead to devastation of much life on Earth were this to happen? Yes, I think so. But so far, I've seen no convincing evidence of any plausible event quite on the scale of PETM.