Anyway, my point was that we are better off avoiding such hyperbole and overstating the case; it biases people towards inaction, especially when the worst case is consistently promoted and consistently fails to occur.
We could (theoretically) end global warming this instant by turning off every electrical appliance and not burning a single molecule of fossil fuel. How many people would die in an hour, without life saving medical equipment or heat in their homes? A day? A year?
When you discuss the morality of avoiding the worst case scenario, you still have to weigh the consequences of the actions (or inactions).
If the doom-and-gloom worst case scenario is consistently wrong, and that is the one that gets talked about most frequently, then people are going to avoid the most serious consequences that would occur by drastic action to head off the worst case scenario- especially when that means putting off personal sacrifices.