We also have other things at play. If humanity is going to disappear then there is nothing for the markets to do. The money is only worth something if there are places to spend it and people to spend it on.
So for the markets the best move is to ignore any pending world altering crisis as in the chance the crisis does. It happen or affect the market as much then the best move would have been to capitalize on the movement created by the crisis.
Making moves in the market now creates a very real crisis for a potential one. If everything claimant alarmist or even the more mild climate concerned happens it’s not clear that it would affect the market as a whole.
On top of this climate moves slow. In such any effect it could have on the market will also be slow allowing for it to adjust. Some losses here will turn into wins else where. Think about all the big companies that are no longer on the market because tech changed the world in ways that were arguably just as big as anything we can think of with climate except some big extreme life is all dead event, which in that case see the top paragraph.