IMO, many authors, who creates sci-fi novels, showing us future which is being actualy worse than present, like overpoluted air, hunger, fierce desies, or something like that, want to tell us about, what could happen if we wont owercome our drawbacks and fail to solve some problems. Like greed, passivity, hate, fear, imprudence e.t.c.
Like, to what can lead greed-to everything. Support it with foolishnes, and huge war could happen. Not war, alright. Inventions. Which could lead to disasters. Someone held button too long...and life on earth could never be live we used to see.
Gigant cities, castles of steel and concrete, growing more more and more. And less space for nature. Less trees, grass, not even talking about animals. After few generations, our descendants could ever seen nature, like we could see now freely, only on pictures. Possible? Eh, more than we can imagen.
So, may be this could be one of author's goals, that when someone read novel, or watch moovie based on his work, he would say to himself: Nope, I want better future for those, who shall live after me.