TreeHugger: "When it comes to human-caused global warming, news of the long-term effects is mixed. On the one hand, the planet will indeed recover from the damage we've done -- the only downside is that it will take 100,000 years, and chances are it will come at the expense of many species along the way. If humanity continues to emit greenhouse gases at the rate it has been, says one scientist, it could take millennia for the Earth to get back to good health, but only after a series of mass extinctions the likes of which have not been seen for millions of years."