Correct, when there is very little, life on earth would die out. If we were back in the 3000-8000 ppm range, life would likely explode again.

This is actually the sort of thing I'm talking about, you feel the need to have some caveat here, when there is absolutely no evidence that CO2 is bad for anything in any levels that are even practically achievable or have ever existed since there has been life on the planet at all. Every reasonable piece of evidence we have says that more CO2 means more life.

https://primal.net/e/nevent1qqsve5gl5ufrfhw6y8wtwu0qumj8cesmclxxcvttem2t70k7mkfwnmczp2k5z