Why HydroPower is not Green
Image by Author - increased need on irrigation takes toll on our ecosystem
The Dark Side of Hydropower: Why It's Not So Green After All
Hydropower has long been touted as a clean, renewable energy source that can help reduce our reliance on fossil fuels and fight climate change. However, a growing body of research shows that hydropower's environmental impacts are more substantial than commonly portrayed. Far from being a green energy panacea, hydropower has a sizable carbon footprint and causes significant ecological damage.
A Major Source of Greenhouse Gases
While hydropower doesn't directly burn fossil fuels, the artificial reservoirs created by dams are a prolific source of greenhouse gas emissions - especially methane. When vegetation and organic matter is flooded and decays in the oxygen-deprived conditions of a reservoir, it creates ideal conditions for methane-producing microbes to thrive.In total, dams and reservoirs are estimated to emit around 1 gigaton of carbon dioxide equivalent annually in the form of methane and CO2 - more than the total emissions of Canada. With methane being 35-86 times more potent than CO2 as a greenhouse gas over different time scales, hydropower's climate impact is staggering.
Ecological Devastation
In addition to its greenhouse gas footprint, hydropower takes an immense toll on river ecosystems and surrounding habitats. Dams block the migration routes of fish species like salmon, often leading to population declines and even extinction for some species. The Three Gorges Dam in China displaced a staggering 1.3 million people to create its reservoir.Dams and reservoirs disrupt the natural flow and temperature patterns of rivers, impacting water quality and aquatic life downstream. Native plants and animals lose their habitats when land is flooded to create reservoirs. In short, hydropower's ecological footprint is severe and irreversible.
Vulnerability to Climate Change
Perhaps most ironically, hydropower's long-term viability as an energy source is threatened by the very climate change it was meant to help mitigate. Shifting rainfall patterns, droughts, and changes in river flows due to global warming make future hydropower generation uncertain and unreliable. Major dams like Hoover Dam have already seen their electricity generation capacity reduced by droughts. The water in the Colorado River has reduced so much that it doesn’t even reach the ocean any longer. Meanwhile, in the PNW the Snake River water levels have drastically dropped in the last decade due to reduced rainfall, increased drought, and growing demand.
As recently as 2023 the Bureau of Reclamation further announced the need to reduce the flow from the dams above the Lower Snake River in order to maintain reservoir levels for irrigation. This announcement raises concerns for all involved in any activity downstream - regardless of what they might feel about keeping the dams. These decisions and needs clearly demonstrate dams are not our best tools to manage water demand or provide the water required to anybody who rely on the four Lower Snake River Dams.
As climate change accelerates, the hydropower industry faces an existential threat from the drying up of the water sources its dams depend on.
The Need for Truly Sustainable Solutions
While hydropower is a renewable source of electricity, the high environmental costs it incurs make it a poor solution for sustainably meeting our energy needs over the long term. Rather than doubling down on hydropower, we need to prioritize energy sources like wind, solar, and next-generation nuclear that have relatively small environmental footprints. Hydropower is not the green energy solution it's often portrayed to be. By recognizing its substantial greenhouse gas emissions, ecological damage, and vulnerability to climate change, we can shift our focus to developing better renewable energy technologies for a truly sustainable future.
The future of our planet depends on prioritizing and correcting our energy choices today.
