Hydropower dam/reservoir complexes are a global warming (and other) threat


In case anyone on this list has been persuaded that hydropower is “green” and “sustainable,” I’m offering two reality checks (not “fact checks”) on that topic. I hope these will help to disabuse anyone of the notion that voting NO on Question 1 on the CMP Corridor is anything remotely resembling an “environmental” vote.
The first is the following article, which elaborates in some startling ways on some of the “usual” environmental reasons for opposing megadam complexes:
A “Climate solution”? Big Hydro Is Anything But A growing body of peer-reviewed scientific evidence shows that large-scale hydropower generation is a significant source of greenhouse gas emissions By Ana Simeon Watershed Sentinel October 5, 2021 watershedsentinel.ca/articles/a-climate-solution-big-hydro-is-anything-but/
The second is a piece I’ve written summarizing the seldom-if-ever-discussed — but very real — consequences of the manipulation of the normal hydrologic cycle of rivers in the Northern Hemisphere by megadams in Canada and Siberia, in terms of both the death of marine fisheries and the significant contribution to global warming feedback loops. I hope those of you who take the time to read it will find it interesting and sobering, and perhaps move you to go out and vote YES on Question 1:
—————— Hydroelectric is no protection against global warming Dick Atlee, Southwest Harbor, ME
There is a far larger issue concerning Question 1’s NECEC hydropower than those being fought about in dueling advertisements.
There is a serious question about the adjectives “renewable” and “sustainable” and “anti-global warming” generally applied to hydroelectric generation by large dam/reservoir complexes (megadams). Public discussion has focused on the loss of carbon-sink trees, and the methane-generation of rotting vegetation. But are these missing an elephant in the room?
The natural hydrologic cycle of the Northern Hemisphere rivers that flow into the Arctic Ocean and — through Hudson Bay and the Gulf of St. Lawrence — the North Atlantic, consists of rivers locked in ice throughout the winter, followed by a spring rush of cold freshwater into the ocean from mountain snow melt, where it creates complex changes in temperature layering and salinity.
However, for hydroelectric generation to be steadily dependable over time, winter’s minimal flow and spring’s sudden gush has to be evened out — reversing the natural cycle — by means of a controlled water release from a reservoir, water which is heated during the summer. This has profound effects in two vital areas: the marine life on which we depend for food, and the land and ocean temperature which affects global warming.
Northern marine life has adapted its life cycles to this pattern. But the megadams that have been constructed in both Siberia and Eastern Canada since the 1960s have disrupted this by their evened-out flow of heated water. They have produced radical changes in salinity, temperature gradients, and the energy necessary for the life and successful transport of larvae and young fish. This major disruption of a system that has been stable for thousands of years has been extremely stressful or deadly for many native marine species in the marine food chain, such as cod.
This warming has affected not only the ocean, but also the climate of the area through which those rivers flow. It has occurred with the northern Siberian megadams, which have (deliberately) warmed the Arctic Ocean and the Siberian land mass. The melting of the tundra there is well known, with its threat of massive methane release, as is solar-energy feedback loop caused by loss of reflectivity of reduced Arctic Sea ice — a one-two punch of global warming.
Here, it has contributed to the startlingly rapid warming of the Gulf of Maine and connected water masses, which is now understood as a threat to the Atlantic circulation that has kept our climate relatively stable for centuries.
Ground-breaking renowned Canadian marine scientist Dr. Hans Neu took careful measurements of these crucial marine parameters for two decades starting in the early 1960s. His was the seminal work revealing these effects and how far they extended into the ocean. His research led him to predict both the warming of the Gulf of Maine and other coastal waters, and the destruction of the cod fishery.
Valuable parts of Dr. Neu’s work can be found at friendsofsebago.org and in Stephen Kasprzak’s book “Arctic Blue Deserts” (www.arcticbluedeserts.com/). Take a look, and then consider the following question in this seldom-considered frame of reference.
Is hydroelectric power — “green” or not — a sustainable protection against global warming?

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