The End Of The World

 Human beings are not evolved to understand a slow-moving disaster.  

We (human beings) are, however, well-evolved to respond to immediate.

That is why humanity cannot seriously respond to a comming ubiquitous climate catastrophe.

On the other hand, it seems likely that likely that human being would seriously respond to the threat of an asteroid that will destroy the earth in 75 years unless a  united response could be mounted.