Trump's election was just the nail in the coffin. If humanity is still around in a few hundred years, we'll likely be scattered tribes around the Arctic Circle, Patagonia, maybe along the coasts of a thawed, greening Antarctica. If we're lucky, a few bastions of technological society will be in there somewhere. Anywhere within 500 miles of the equator will be scorched earch, 140F days cooking the land to baked dirt hard as stone, or massive sandstorms where forests once stood.
I just read something this morning, where a climatologist pointed out that the Permian Mass Extinction, which wiped out 90% of all life on Earth, was caused by a 6-10C temp increase over a span of 500,000 years. It was the most devastating mass extinction in the planet's history.
We're already at 1.5C after only 200 years, and will likely breach 3-4C by the end of this century. With the forests burning off, the permafrost venting methane, and the oceans unable to take in any more carbon, positive feedbacks will probably push the planet past 6C within a few hundred years. We'll do in 500 years what it took the Permian event 500,000 to do.
The temperature increases are horrifying, but it's the SPEED of the change that's truly astonishing. The only faster would be a meteorite impact, but that's a cooling event measured in decades, not a warming one that will last for 100,000 years or more. Life simply can't evolve or migrate fast enough to cope with what we're doing.
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