[dylan604]

The point is that if humans would change, the Earth would change quickly. The way the first comment was worded made it sound like the Earth would need that time and not that humans will drag it out that long. That's a given. The Earth will snap back fairly quickly if the pesky humans would just get their shit together.

[otherme123]

There are some positive feedbacks that once triggered could not be reverted for millenia. For example a potential stop of the AMOC https://en.wikipedia.org/wiki/Atlantic_meridional_overturnin...

[holowoodman]

Melting glaciers and ice caps is another such thing. As soon as the polar albedo changes because there is no more snow and ice, temperatures will stay elevated for a far longer time than it took to melt those caps.