Source on this? Climate crisis could quite possibly lead to extinction of humans and most life on Earth [0].
Now I do want to emphasized the word could. Extinction events are certainly "on the table", but certainly not a certainty.
However this is the true essence of the reason why we'll never stop climate change. The immediate cost of stopping or even slowing is high, and certain. The cost of not stopping it, is often considered higher, but is always probabilistic and less certain in nature.
Compounding this is that the more we rely on non-renewable hydro-carbons, the more painful it is to reverse or even slow our march towards catastrophic climate change, while at the same time the cost of not stopping it becomes less uncertain.
For example in 1900 it would have been incredibly easy to slow economic progress in order to prevent climate change, but the uncertainty around the cost of not slowing progress was very high, so the perceived expected value of stopping our march toward climate change was much lower than the present time expected cost.
It is strange to see calls for moderate pragmatism when our current state has been accelerating CO2 emissions. We're, quite literally, stepping on the gas to meet whatever future awaits us.
0. See Peter D. Ward's "Under a Green Sky" for one example scenario.