Despite the gloom of potential catastrophe that we mast face, there is no reason to give up. If we think about catastrophes with the sober scientific speculation of A Choice of Catastrophes, we must conclude that:
1) Some catastrophes are high-probability and even in evitable, but will take place so far in the future that it makes no sense to worry about them now,
2) Some catastrophes may take place in the near future, even tomorrow, but are so extremely low-probability that it makes no sense to worry about them excessively.
3) Some catastrophes are high-probability and may take place in the near-future, even tomorrow. It is only these which must concern us now.
In every case, however, the catastrophes that are both high-probability and near-future are human-caused: nuclear war, overpopulation, overpollution, resource depletion, and so on. And if they are human-caused, they could, conceivably, be human-cured.
As Isaac Asimov stated in A Choice of Catastrophes, the most significant meaning of the title is that "We can deliberately choose to have no catastrophes at all."