It all can be done, and will be done, but when it finally gets done, which is not so far off in universal terms, it might seem like a it took one day short of forever in human comprehension.

  If you look out the window, wherever you are, what you are seeing didn't arise accidentally. There was purpose there. Overlapping purposes, but intertwined. The purpose of Gaia, nature, the whole, and then the overlay upon that, which is humankind. 
Humans are allowed to live here, they didn't come here to run rampant. They were given, of all other creatures, self awareness. Why? Was that so they could find the weaknesses, the blind spots, in the other less crafty creatures and use those against them? Suffice it to say that that's been done. Man has achieved dominion over the earth. But why? 
Again, look out the window wherever you are. Chances are it's not entirely a nature scene. Whatever has not been constructed by nature is of man. 
Does whatever you're looking at look amazing? Or does it look ordinary, perhaps in need of some paint, some repair? Rust might be evident, weeds, there might be wreckage or refuse of some kind around the edges, perhaps. Whatever it is it ain't a perfect scene. Am I right?
Yeah, I've been around. Even the best neighborhoods show their flaws. 
So- is this the view that a dominant species wants to have, or is there room for a better one? If there's room, this species better get to work and not just talk about fixing things. After all, you've got dominion. You should be able to get it done. No other species is stopping you, and the earth cooperates fully, offering the dominant species resources aplenty. Nothing says dominant species more than surveying everything you can see and thinking "It's all there for the taking! A buffet meal bigger than Vegas! How 'bout we call it 'The Garden of Eden'?
(just don't eat the apples)
(Oops. Too late....) 

It's true that the dominant species has come a long way, there's no doubt about that. History, what the dominant species is allowed to know about it, shows a steady progression, though one with quite a few bumps and rough patches. "Best they could do at the time" say the historians, "given the difficulties inherent in people trying to get along". Soooo difficult, that part. 
Problem is, and always has been, that within the dominant species have been those ones who wished to themselves dominate, which hasn't worked out too well, has it? Oh, there have been brief experiences by individuals who stood at the helm of empires but those empires haven't lasted long because it never was too popular, for the people on the other side of their borders, to sit there waiting for the inevitable invasion to arrive. 
You'd think the dominant species would've learned that and more by now because over time comes the common sense realization that with a little cooperation and some stable trust things could get built that last and actually make the populace happy but..... 
.....too much work, those at the top say. 
  Can't figure it out.
     Can ya give us another two thousand or so years?