[Symmetry]

I would generally consider the current ecosphere being replaced by something totally different as a variant of "The ecosphere recovering" as long as the successor has as much complexity as the predecessor - and exactly what the GP is talking about.

But of course there are far worse things than that sort of disaster. Earth turned into a snowball several times but geologic processes producing CO2 managed to fix the problem. The Sun is continuously getting brighter so that wouldn't be a problem nowadays. But eventually, in a billion years, the increasing brightness of the sun will cause the oceans to evaporate and complex life on Earth will probably never recover.