what possible basis do you have to say this? Humans on earth right now have the best quality of life ever enjoyed in our entire history as a species. Every year more and more millions of people around the world have been lifted out of poverty, and are now being educated, while being given access to clean water and healthy food. The future of this planet is extremely bright, as technology continues to advance and quality of life continues to get better. Only 40 years ago, if you had bad kidneys or a bad heart, you were given a death sentence. Now you can just get a new heart, and keep on living. How cool is that!
The biggest disservice we can do for the next generation is tell them that their future is "grim". This is just silly. All the trends say otherwise.