Lower Snake River dams are greenhouse gas factories, new study finds

Annually, the LSR dams produce as much greenhouse gasses as burning 2 billion pounds of coal
little goose dam
Little Goose Dam, one of the Lower Snake River dams (photo: Matt Stoecker).

The four lower Snake River dams that produce, on average, about 1,000 megawatts of electric power every year are really “climate catastrophes,” according to the chief scientist for a non-profit that hopes to expose dams as significant greenhouse gas producers and not the generators of clean, green energy they’re often billed to be.

A new report from Tell the Dam Truth estimates that the four lower Snake River dams produce as much heat-trapping greenhouse gasses annually as 400,000 cars or burning 2 billion pounds of coal.

“Contrary to popular belief, hydropower is not a carbon-neutral source of energy,” said Mark Easter, chief scientist for Tell The Dam Truth and a former senior research associate at Colorado State University’s Natural Resource Ecology Laboratory. “The concept of how methane gets produced by dams and reservoirs is not widely understood. And that’s the source of the problem here—the Lower Snake River dams and reservoirs are giant methane factories, and the science proves it.”

The report, titled, “Estimate of Greenhouse Gas Emissions for the Lower Snake River Dams and Reservoirs using the All-Res Modeling Tool,” estimates that the dams in Washington state emit about 1.8 million metric tons of carbon dioxide each year. The All-Res modeling tool estimates emissions using a lifecycle analysis framework and includes the known greenhouse gasses emitted by dams and reservoirs through their entire lifespan.

The modeling tool was built using funding from Patagonia’s Holdfast Collective, which has donated $1.5 million in grant funding to a host of grassroots non-profit organizations that are working to remove the four dams on the lower Snake River. The dams are the final four “passable” obstacles that salmon and steelhead face on their way home to the Snake River basin from the sea, and the first four obstacles they face as smolts migrating to the Pacific.

Without drastic measures that would likely have to include the removal of the four dams on the Snake, salmon and steelhead runs to the Snake River basin in Idaho and eastern Oregon are forecast to continue their steady decline. According to the National Oceanic and Atmospheric Administration, Snake River salmon and steelhead could be extinct as early as the 2060s thanks to a deadly cocktail of migration barriers and a warming ocean.

The report, TDT claims, provides more evidence that the dams should be removed. Not only do they provide difficult obstacles for migrating anadromous fish, but they also produce greenhouse gasses that trap heat and contribute to global climate change.

According to TDT, the reservoirs behind the dams are greenhouse gas factories that emit methane and other gasses thanks to artificially trapped organic matter that decomposes as the reservoirs warm each year. This decomposition, the report says, creates greenhouse gasses that are the equivalent to burning 2 billion pounds of coal every year.

In December 2023, the Biden administration inked a 10-year partnership with Indigenous tribes and Pacific Northwest states to restore wild salmon and steelhead runs and to expand clean energy production in the region. And that clean energy production can’t be expanded without first eliminating the dams that contribute to the global climate crisis, TDT says.

“Only by removing these dams, can we begin to restore the magnificent Columbia and Snake river watershed, save numerous species from extinction, honor treaty rights and build climate resiliency,” said Patagonia CEO Ryan Gellert. “We applaud investments in true clean-energy solutions and programs that recover wild, self-sustaining fish populations that tribes and other local communities depend on. We’re hopeful Congress will finally recognize that hydropower harms ecosystems and the climate, and that they must authorize removing the dams to free the Snake River.”


This makes me rethink the purchase of Patagonia products.

I agree.

What a crock of you know what. You people dont want hydro, you dont want coal, gas, or oil. Windmills kill birds, solar panels destroy the ground beneath them, yet you still drive your vehicles, you still heat your homes, and you still electrify your homes. You have absolutely no solutions. Go ahead take out the dams. How do you intend to replace 1000 Megawatts? Your models are created to give you the result you desire. CO2 is essential to life. All plantlife needs CO2 to life and then create O2 that we need.
I'm 72 years old and you climate changers have predicted disasters all of my life. NOT ONE HAS COME TRUE! The climate has changed one way or the other since the beginning of time. Why arent you over in China and India where they are building hundreds of coalfired plants. You know why? Because they would tell you where to go.
I have lived off the grid for almost 30 years. Your "carbon footprint" cant hold a candle to mine. When are you going to complain that 8 billion people exhale CO2 with every breath.

Couldn’t agree more with the above sentiment

Dude. Not Hatch's model. Not Patagonia's model. Read the article carefully. Plants will be fine. CO2 never a problem in my 54 years and now at 3 million year high. Have you researched what Earth was like 3MYA? You might not like it so much. BTW, have you even seen or studied the model? Asked to speak to anyone about it? The economic and social impacts of the changes we are facing will be astronomical, more than anything anyone living has ever experienced and much more expensive than trying to reverse the current trend. You guys were previously buying Patagonia products but now you won't because the did a press release about the findings of a 3rd party scientific study? This seems mighty reactionary. Did you not understand the mission of Patagonia over the last 50 years? Did you call up the non-profit that did the study to seek information or challenge their findings in a respectful way, or you just wanna shout angry words from behind your computer. Only about 3% of scientists, maybe less now, still think the current warming trend is natural. Those are pretty bad odds on which to run the countries, states and towns of the world, let alone your own life. You might want to rethink that. Who else is offering a model on dam reservoir carbon footprints? Let me guess...not the dam operators. Or maybe just like Big Oil, operators like PG&E do have the models and data but hid them for the sake of profits. Big Oil has admitted as much AND they've admitted that the scientists are and always have been correct about human influenced climate warming. Look it up. Speaking of which, US oil and gas production is currently--yes, under Joe Biden--the highest it has EVER been. Surprising, no? MAGA world sure likes to perpetrate lies about that, too. I don't like oil, but both of my cars and my house are heated by it. It's a necessary evil at this point cuz I don't have the dollars to replace them. Still, I'm not cavalier and aggressively ignorant about what is going on. Are you really saying that everyone at Hatch, Patagonia and the non-profit or everyone that wants to develop clean energy is SO STUPID that they don't recognize that gasoline and heating oil and other oil products have been the main energy source for the last 150 years. Is that the claim that you're making? That doesn't seem like a rational claim, dude. I'm always looking for ways to reduce my use, both for the planet and for my wallet. Speaking of solutions...what are yours? Or does your pre-determined conclusion about global warming mean that you don't need to think about it? Windmill bird strikes? Really? You do know house cats kill ~500-1000x times more birds than windmills, right? Building window bird strikes are next in order. Look it up. You gonna go around the neighborhood killing cats? And what's the deal with the whataboutism on India and China? This old saw is really, really tired. Never heard that two wrongs don't make a right? You knew that China surpassed US renewable energy production more than a decade ago and produced a whopping 31% of the globe's renewable energy in 2022, right? They may burn coal, too. And renewable doesn't always equal "green". But they are trying and the question you might ask is why would they do that?Moreover, how can we catch up? Replacing the 1000 MW would be simple: nuclear. Perhaps you should stop embracing the points of view that confirm your obvious bias. Stop being so dismissive of the tree-huggers and start reading what they are producing and learn what's really happening out there. The tree-huggers are usually just local who love the places they grew up in or currently live, places threatened by industry, who need to band together to fight those threats. They don't have money to buy off politicians and lobbyists so they use science to defend what they love. Get your head out of the sand.

Gee, at least I sign in with my name. Thanks for the liberal insults. I happen to be a Weatherman who has studied climatological data. I' sure you were here 3 million years ago. I'm sure you were there when core samples beneath the North Pole showed Ferns. It wasnt me that complained about windmills. It was your tree hugging buddies in California.
I didnt even say dont take the dams out. I said you better find a way to replace the loss of 1000 Megawatts. But you didnt want Nuclear power, and wind and solar are not efficient solutions. You speak of necessay evils. . I went off the grid 27 years ago. You libs always have an excuse fir not doing something. My head has been out of the sand for 72 years when I was taught to think for myself. Obviously you are still drinking the coolaid. You never touched on all the previous climate change predictions that never happened. I never said dont do something. I have contributed to numerous environmentally responsible groups. I have provide scientists with weather data that has showed the earth heats and cools and has wet periods and dry periods. Before you attack and insult another person it might behoove you to learn a little about them, but thats not what liberals do. They are always right even when they are wrong. I was taught to keep my eyes and ears open and my mouth shut until I had something intelligent to say.
Have a wonderful day. I'm praying for you.

Not sure about this article, burning fossil fuels releases carbon at a rate faster than its naturally recaptured, which is the problem. Methane from decaying biological metter behind dams doesn't seem like a problem, as it would have decayed somewhere else had the dam not been there. I would have to read the full study, but this article comes across as disingenuous.