A new study by University of East Anglia researchers confirms what Indigenous communities have long charged: gigantic hydroelectric dam construction projects are not environmentally friendly, as proponents claim, but in fact pose a profound threat to biodiversity and life in the Amazon.
As long as we demand energy there are always better ways to get it. The trend is for smaller dams that provide power locally.
Seems to me there has been a study like this about every ten years...since the '60s.
The dumbing down of America includes memory loss.
Also, and directly to the point of big hydro being no better than fossil fuels as an "alternative" energy against climate chaos:
It's been known for years that hydroelectric dams contribute directly to increased greenhouse gases released into the atmosphere: http://www.reuk.co.uk/Hydro-Contributes-to-Global-Warming.htm
Organic matter in the dammed river is blocked by the dam, and decomposes anaerobically underwater, releasing the much more potent greenhouse gases methane and nitrous oxide, rather than CO2.
The initial flooding when the dam is first built also causes a large methane release when all the organic material in the newly-created lake decomposes: http://www.newscientist.com/article/dn7046#.VZgJpLeprsk
The Doc "Damnation" is a pretty good story of the problems with dams and the value to the environment/ecosystems by removing them. It's available on Netflix.
So people should leave and go back where they came from?
See also 20 years or so worth of essays by Arundhati Roy on dams and other environmental depredations in the rain forests of India. It's one of the threads in her best known work, the novel "The God of Small Things" as well.