It is perhaps selfish of me to say, but if I or my descendents aren't alive, I don't give a blankety blank if the world survives.
That is just another way of saying that survival is always the first order of business. We may not even take a nanosecond to consider it when making a decision since it is often obvious that survival is not affected, but it should never be subjugated in rank. It is the first rung on maslow's ladder (pyramid). It is the first step on any decision matrix.
I am a firm believer in restating the obvious. Too many times I have overlooked the obvious (cords not plugged in, car out of gas, battery dead) and paid extra for it.