As a responsible nation supposedly concerned with the future generations as Americans, Yes, we do have an obligation. The problem is that in the minds of the old school folks, say anyone over sixty-ish, they could care less about the future because they can only worry about today. That was the response one elderly man gave when a reporter asked what he thought about rising sea levels in the east and the fact that his shore home was going to be half underwater in twenty years or so. When I worked with an elderly gentleman in my early twenties doing lawn Maintenance that was his attitude as well. He would even suggest we go back in the woods and dump our leaves ad grass clippings rather than taking them back to the shop! That is exactly what the old generations thought of future generations, not at all!!!
They had no thought about longterm consequences, and before anyone can argue or protest, who do you think dumped all the radioactive waste and chemical leavings in all the popular lakes and waterholes here in New Jersey? Yep, our pappies and grandpappies were irresponsible jerk offs who refuse even today to be held accountable for their actions. Another example is in Gloucester City where an inordinate number of folks were getting cancer, MS and other odd conditions. Everyone's basement was choked with Radon! They did some research and digging and found that many deadly chemicals had been buried beneath the ground and then houses were built right on top of them! I transported an elderly woman who explained she worked at one chemical light bulb plant which was shut down because the chemical they used was deadly. Rather than spending the money to dispose of said chemicals they had remaining in volumes they buried them underground and then sold the land to developers who had no idea.
All this presented as proof that past generations caused most of the health and environmental issues we have today, I submit that provided with this example of stupidity and irresponsibility all following generations need to learn from these errors in judgement. Every action you take will echo throughout time long after you are gone. Take every action you can today to make this a better place for future generations and maybe, just maybe they wont be forced to leave this world in search of another.