I find my mind turning to the timing of my own death at 88 and the death of the biosphere at a few billion years. The key thing is to realize, if they admit of change at all most people assume a linear relation between temperature increase and devastation effects. Most relationships are not linear but messy, For example, if the temperature increases by .01 degrees F the Santa Ana winds in southern California and in all the mountains of the world go through whiplash reversals from strong rain to dry winds.
We are stuck not being able to say accurately when things will get much worse or much better. Well, we can cross off much better. We are left trying to understand when things will get worse, for example, the food supply. I don't see that we know anything that says for sure that a food catastrophe cannot happen within weeks. Not that it's likely but that we just can't tell.
I am going to increase short statements that should enliven your own thinking. and leave it to you to draw conclusions that are important to you. This question about timing is one of those hint environments for you to work out. I do this because I am so unclear about the timing, but am fairly certain that talk of 2-40 or 2050 usually ignores measure flags that we already know. The hobgoblin of Green energy and industrial replacement of the fossil fuel regime with clean energy prevents hanking.