Do we owe them anything? There are probably a lot of answers to that question. Personal opinion varies, and sadly, is more valued than actually useful responses.
Do we owe ourselves a simpler lifestyle so that our children have a fighting chance of surviving the environmental apocalypse we are creating? Yep. And if it helps others survive as well, that's a frickin' bonus.
But apparently what humans are best at is being selfish, and what we're worst at is giving a flying f**k about strangers. Neither of these traits bodes well for any sort of future, no matter which of us survive long enough to get there. It is typically egocentric of us to assume that since we drive SUV's and all the poor people in the world are stuck with riding donkeys that we will naturally be the ones that survive. And while our Magic 8-ball sometimes says "Signs point to yes", there is every possibility that the presumably carcinogenic filling inside said toy is biasing the answers.
Civilizations built on greed, and busy assuming that the suffering of others is irrelevant, cannot last another 100 years. We do not have the financial structure necessary to calmly watch Manhattan and other metropolitan areas drown amidst rising sea waters. We do not have the ability to prevent ourselves from creating super-bugs and unintentionally icky GMO's. We don't the the capacity to handle huge the calamity of fires racing through new drought regions or to live near oceans once all the fish are dead.
So the question is not the one asked by the OP. The question is this: What could we have done different long ago that might have allowed us to actually be human instead of this parody of a living, breathing being that most of us have become.The best most of us will do is die curious about how different it could have been had we all cared about important stuff.
Important Notice: Don't ever catch me in a bad mood again. It could get ugly.