“The rivers of Chilean Patagonia cascade from snow-capped mountains through sheer rock facades and rolling hills, radiating bright turquoise, deep blues and vivid greens. The Puelo. The Pascua. The Futaleufú. Each is as breathtaking and unique as the landscape it quenches.
But these rivers, like many worldwide, have been threatened by dam projects that aim to provide power for distant cities and mining operations. Only one-third of the world’s 177 longest rivers remain free flowing, and just 21 rivers longer than 1,000 kilometers (621 miles) retain a direct connection to the sea.
If we are to arrest global climate change, prevent the toxifying of freshwater sources and do right by all those who depend on rivers for survival, we must return more rivers to their natural state.
For decades, rivers have been an afterthought in global climate talks, like the ones that concluded in Madrid this month. New streams of climate finance, like the Climate Bonds Initiative, may soon be available to large-scale hydropower projects. While renewable energy and its financing are an important part of climate solutions, hydropower dams are not the answer.
Hydropower is not a clean, green technology. Rivers help regulate an increasingly volatile global carbon cycle by transporting decaying organic material from land to sea, where it settles on the ocean floor. This draws an estimated 200 million tons of carbon out of the air each year.
As an Intergovernmental Panel on Climate Change scientist, Philip Fearnside, has documented, large dams, especially on tropical rivers like the Amazon, are “methane factories,” emitting in some cases more greenhouse gases than coal-fired power plants. This month in Madrid, 276 civil society groups attending the United Nations climate talks called on the Climate Bonds Initiative to exclude hydropower from climate financing.
Hydroelectric dams, when they are built, flood large areas of vegetation. This fuels decomposition and releases carbon dioxide, methane and nitrous oxide. Considered as a whole, hydroelectric dams emit a billion tons of greenhouse gases per year. This is comparable to the aviation industry, which emitted over 900 million tons of greenhouse gases in 2018.”