Shocked =

tlw
Modern humans haven’t been around for “millions of years”.

And it’s only over the last couple of hundred that we’ve been able to start make huge cumulative changes in things like the climate.

The ability to pretty much wipe ourselves out in an afternoon has only been around for around 50 years.

Modern humans have been around for 200,000 years or more.  But humans have been around for millions of years and there's no reason to believe greed and stupidity are exclusively recent features of modern humans.  I remain unimpressed with insights that suppose a sudden effect by a constant feature.  In Stephen's defense, I'm sure he had more to say on the subject than the meme posted above.  
 
Arrogance is far more dangerous to humans than greed, in my little opinion.  Greed is observable and can be managed, but arrogance has to be inferred, which requires self reflection, humility and skepticism - all of which are in ever shorter supply. 
 
Stupidity can't really be helped.  That word is just a reference to intellectual limitation. Too much stupidity and you don't have the intelligence to build a nuclear weapon or burn million year old organic matter for energy.  One could argue humans aren't stupid enough to not kill themselves.  
 

JohnKenn
We are too low on the evolutionary totem pole to comprehend anything in a broader extent regarding cosmology, no matter how advanced our primate level physicists and mathematicians are.
 

 
Right on.  Was it Robert Anton Wilson who said something to the effect...'every model we make tells us how our mind works, as much as it tells us about the universe..these are just human symbolic games'?