Originally Posted by
73qanda
That would be big news. Do we have some examples?
You will find mass extinctions events on more or less every boundary between geological periods (these are after all pretty much defined by the type of fossils dominantly found). Often the transition is also marked by drastic changes in the Earth's climate and/or atmosphere. Generally speaking, climate, atmosphere, surface geology and living matter are closely coupled, so disturbing one of these will necessarily lead to changes in the others. Depending on magnitude the system might return to the previous status quo, or settle for an entirely different equilibrium.
The famous two degree target is essentially to be understood as a perturbation that is small enough to be safe. That does not mean that birds will fall out of the sky once we are at three degrees, rather it means we might be converted from pilots to passengers at that point.
Obviously this is not really your or my problem, because neither of us will live long enough, it is only a problem for the generations to come..