The short term effects are all about the slope. And the short term is all that matter to us, because if we don't pass through this bottleneck we won't have a long term (it may well be our "great filter" preventing us from spreading through the stars)
https://en.wikipedia.org/wiki/Holocene_extinction
Life will go on. Humans? Maybe. Human civilization will be disrupted for sure
Also: here's a visualization of how fast the climate changed in the last 20000 years vs today
https://xkcd.com/1732/
The short term effects are all about the slope. And the short term is all that matter to us, because if we don't pass through this bottleneck we won't have a long term (it may well be our "great filter" preventing us from spreading through the stars)