We've been hearing for a couple of decades now that throughout the world, the reefs we've enjoyed as divers will not survive in their relatively healthy states much past 2050 if reckless and irresponsible fishing, drilling, dredging, and waste disposing continues at the rates they've at least maintained since the mid 20th Century. My experience as a diver returning again and again to the same sites every few years over my 26 years underwater, has shown me that there has indeed been a significant deleterious effect upon most reefs in my travels over that time period.
The mind-boggling series "Earth: The Biography" which just recently aired (and most likely will be repeating) on the National Geographic Channel, ends its final installment with the argument that Earth has been through devastation before and will continue to be mighty and renewing. The dinosaurs ruled Earth for 100 million years, and were driven to extinction through their inability to adapt to change. Today, whatever is driven to earlier than desired or expected extinction or radical change, including lifeforms as well as the inorganic (oceans, land masses, climates), will be replaced by other species and geography. There's a good chance that surviving and/or newly evolved lifeforms will not include us, homo sapiens, a term which oddly enough, which in Latin literally means "wise man." Will we be wise enough to adapt? Will we be wise enough to halt our damage?