I also share this kind of existential angst. The future is unknown - yes, such a scenario might come true. As might nuclear war, a truly deadly pandemic etc. And yes, there is too little done to mitigate the potential impact. And lots of unknowns.

However - don't let it drag you down. Think about what you can do, personally, as a person that has agency, to mitigate the potential effects for you, for your family, for your community.

And the answer for me, personally, is the same as for many other of these issues - stay in good health both physically and mentally, keep in touch with the people around you, have a buffer (financially, resources, time), raise awareness of the potential impact. And don't be a doomer, acknowledge that you might be wrong - because you would have been (up to now).