I can't help thinking that, if the Earth's environment were really this unstable, life could never have survived so long here, or at least it never could have e

I can't help thinking that, if the Earth's environment were really this unstable, life could never have survived so long here, or at least it never could have evolved to be as complex as it has. It's not like this is the warmest the planet has even been. That methane has to come from somewhere, and if it's coming loose now, then certainly during warmer periods with less glaciation, it would not have been bound to sea beds then, either. So at some point in the past, rather many times in the past, some recent enough that humans walked the Earth, this stuff was not bound to sea beds. Yet nothing 'spiraled out of control'. A new equilibrium was reached, that's all. Of course, relatively harmless changes that occur over tens of thousands, or millions or years, i.e. time enough for life to adapt, can be catastrophic if they take place over a few hundred. We may end up rendering the planet uninhabitable for a great many existing species, and mostly the larger ones, too, perhaps including even ourselves, but the idea that we're going to end up with a planet that is like Venus or something, I can't take seriously. We're still using, exclusively, raw materials that have been on Earth from the start - so methane released, hydrocarbons burned, etc., all the energy we use, has been in play before, and it did not destroy life.