We Are doomed!

A character ion the British comedy 'Dad's Army's' favourite catchphrase was "We are doomed."
And of course in the very long term we all are as all life on Earth will disappear when the sun becomes a red giant. That is millions of years away but I think homo Sapiens will become extinct long before that, perhaps only in three or four thousand years time, or about the same time as recorded history.
This extinction will not happen at a stroke - unless we are hit by a large asteroid- but life on Earth will become increasingly difficult and much of it will be our own doing. Our contribution to climate change, man's propensity to kill one another mostly for irrational reasons means that at some point another world war is very likely notwithstanding the so called 'nuclear deterrent.'  Also man's inherent selfishness, in primitive times a survival mechanism, but now resulting in the world's population being divided into the 'haves' and the 'have nots.' Despite the work of voluntary agencies, some governments, and philanthropy I suspect the affluent will get richer and the poor poorer  until the poor die out from starvation and disease.
The irony is that the rich and powerful, and that includes the resources of governments could do something about this if they really wanted to.  I say this because of man's ingenuity. Scientific knowledge and technical know how has been increasing exponentially.  one has only to look at developments in space technology, genetics, and nanotechnology to name some examples.  Why is the USA spending billions in an effort to get men to Mars and return them safely?
The main reason is curiosity, although the expense is given added justification for other reasons such as advancing scientific knowledge and even creating employment.  Think what could be achieved if the same resources were directed towards earthly problems.  There are those who believe that when the world eventually becomes uninhabitable space ships will be the means of escape to other worlds, but such escape would only be for the privileged few, and anyway who would want to spend a lifetime-perhaps even procreating- in a spacecraft in the hope of finding a habitable planet?  Even on Mars one would have to live in a totally enclosed environment, and a long term experiment in the United States did not bode well for this kind of living.  If this same ingenuity were used towards eliminating Third World disease and poverty the results could be spectacular.
But no, we are far to selfish, ans added to that corrupt governments of former colonies, taking a leaf from their colonial history have learned that lining one's pockets at the expense of the populace is the way to go.
So you see I am far from optimistic about the future.  I don't have any grandchildren but I don't envy babies born today, and as for their grandchildren and great grandchildren well I think they are in for a rough time!