Suppose you take some schmoe, give him a whiteboard, a marker, and a video camera.
What's the worst that could happen?
This. This is the worst that could happen.
Note that if you take out global climate change, and put "asteroid strike" or "killer virus" or "nuclear holocaust" or ANY OTHER doomsday scenario, his "argument" leads to the same "inescapable conclusion."
The problem with expected value is that you need probabilities. Bozo here appears to believe that we should spend an infinite amount of resources on multiple problems. If you multiply infinity by an integer, where the integer is determined by the number of "problems" that at least one bedwetter is worried about, then you get.... well, you get Al Gore winning a Nobel Prize.
And that, my children, is the worst that could happen. Good night, and sleep well.