Perhaps it is not so sad. The thing about futuristic and apocalyptic tales is that they remind us of how important it is to preserve our environment. It is my hope and belief that efforts underway now can help to thwart this reality from coming true.
Well, in the story, that reality already came true, that's why it's quite sad, imo.
And yeah, I quite agree with the rest :D.
Hopefully, realities like the one in the story, can be prevented from coming true.
I hope so too!