nothing - the world isn't ending, atleast anytime in the next BILLION or so years.
conditions on earth for HUMANS, otoh, may get worse with wars, famines, global climate change, nuclear proliferation.
the US was once in the forefront of working to better living conditions for all; now the US is a pariah for bush's BREAKING treaties on arms control, ignoring the geneva conventions, agressively invading and bombing other countries, etc. while the rest of the world is finding ways to act on climate change, many americans refuse to even admit it's happening.
in the US we're wasting our talented youth by funneling them into financialzation and other parasitic but profitable ventures, instead of training them to do research that might actually produce a better world.