[taylodl]

> Many species are supposed to go extinct, all the time.

True, but what are called "mass extinction events" actually took place over tens of thousands of years, which is "quick" when talking about geological time. We're potentially talking about a mass extinction event taking place over hundreds of years. The problem is that's a long time compared to a human lifespan, but an extremely short time from a geological standpoint. We have nothing from the past to analyze what the effects of this exceedingly fast extinction event will be - including whether it will lead to such ecological collapse that complex land animals such as humans can continue to exist. We simply don't know. One would think we should proceed with caution, but instead we're hitting the accelerator.