I'm one of the annoyingly upbeat people saying things like "We don't actually know that. We don't actually have as much hard data on historical climate as we pretend we do. If you think we know what's going on here, you have much more faith in human mental models than I have."
Actual temperature recordings by humans go back to about 1850 and we were delayed in discovering the hole in the ozone because our computers were told to disregard "zero" as an error in the data.
https://en.m.wikipedia.org/wiki/Global_temperature_record
We have mental models for the climate based on things like ice cores and inference but, no, we don't actually know and Jurassic Park is silly not because of the genetics but because the atmosphere was thicker back then. We know that because dragonflies and the like were huge, with two foot wingspans and our current atmosphere would not support them in terms of respiration and probably not let them fly, as a guess.
The respiratory system of dinosaurs likely would be insufficient to support them in this day and age because the atmosphere is too thin. They would gasp for air like a fish out of water.
This detail is generally overlooked and typically mocked and dismissed if you bring it up.
General understanding of past climate on earth is not as sure fire "We know this for a fact" as humans like to imagine. There is a lot we don't know and one of the truisms about actual science is that real science is open to learning "We were wrong. It doesn't actually work that way."
Science is our current best understanding of reality and it is full of incomplete info, erroneous ideas, etc and anyone who is actually rational actually knows that.
And anyone who actually knows anything about people and getting things done in this world -- like businessmen -- knows that if you don't bother to try to fix it, it doesn't get fixed. If you run around screaming "The sky is falling!" and trying to prove that and convince everyone you are right, that tends to be self fulfilling prophecy.
So if one is actually concerned about the future, one focuses on solutions, not on hand wringing.
The world has been on the brink before and survived it. What humans broke they can sometimes unbreak. But that doesn't happen if your only goal is to convince everyone "We broke it and it can't be fixed."