If that were an even remotely-likely outcome, it would have happened. Life is extraordinarily good at surviving and evolving new equilibria.
That was merely an illustration that stable does not mean desirable, not a suggestion that such an outcome is likely.
Meh, the history of life on this planet is one long series of massive, unexpected perturbations, ranging from ice ages so severe that the equatorial seas are covered with several meters of ice, to massive volcanic eruptions that block most global insolation for years, to massive meteor strikes. In addition, the ice core records show that the planet has undergone radical climate change (much faster and more extreme than what we're currently seeing) without any cause at all as far as we can detect, as recent as 60K years ago.
Sure, and the history of life on earth is one of massive, unexpected mass extinctions, which often followed those massive, unexpected perturbations, because those aren't the kind of perturbations that natural systems can be robust against (hence my qualifier that the perturbations occur "regularly for a time"; you know, things like winter and summer, hurricanes, etc). It's certainly inevitable, but I'd rather not induce that on my own species any sooner than necessary.
Equally, we shouldn't ignore the fact that doing nothing at all (assuming we could) will also have disastrous consequences on our own habitat. Earth changes all the time, in all sorts of ways. If we want stability we need to learn to actively engineer the planet.
Yeah, I'm all for that. In the meantime, however, I'll continue to be a bit pissed off when some arrogant prick on slashdot trivializes all environmental concerns because he's apparently taken "higher-level math or engineering courses" and thinks he understands "how dynamic systems function". The nerve of that dumbass...
if threats are judged from the perspective of a reasonable recipient, rather than the intent of the sender, then the "oh, everyone makes death threats online, they'd never follow through" defense fizzles away.
Uh, you mean the opposite? If you can demonstrate that there really is an internet subculture where "everyone makes death threats", then surely you have demonstrated that at least in that subculture no reasonable recipient would interpret them literally? Assuming the "threat" is made within the context of that subculture, that is. Reasonableness has to be context dependent, after all.
the US seems to be trailing the UK by a small margin.
Eh, only in some ways. The UK might have more surveillance cameras and official domestic spying, but the US has probably more unofficial domestic spying, and, from what I've heard, generally in the UK your hair don't stand on end when you're near a cop.