10 Reasons Why Hydropower Dams Are a False Climate Solution

A river is a spectacular living corridor that feeds forests, fisheries, coastal ecosystems, and farmlands; transports life-sustaining organic matter and nutrients; provides drinking water; fosters cultural connection; and prevents carbon dioxide from entering the atmosphere. A river supports staggeringly rich biodiversity. One major way we negate rivers’ many benefits is by building dams.

Once considered a renewable way to harness the power of rivers, hydroelectric dams are now better known for their adverse impacts: They destroy a river’s biodiverse ecosystems, decimate the food security and livelihoods of local communities, and produce harmful methane that exacerbates climate change. Dams are costly to build, difficult to maintain, and aren’t climate-resilient or competitive against proven clean energy alternatives like solar and wind power.

In 2000, following publication of the seminal World Commission on Dams (WCD) report, many countries and financiers stopped proposing and funding dams, but a remaining few are now using climate change as a pretext to save the declining industry, and calling for scarce climate dollars to be used to keep the industry afloat. Projects are now being pushed in arguably the worst places to build a dam: on rivers flowing through biodiversity hotspots and protected areas in the tropics. With vested interests calling for the doubling of existing hydropower capacity in the coming decades, here are 10 key reasons why dams are a false solution to the climate crisis.

1. Climate Change Is Making Dams Unreliable and Risky

Large hydropower projects are particularly vulnerable to the impacts of climate change. Droughts have crippled hydropower generation all over the world, leading to energy rationing and blackouts from the U.S. to China, and from Brazil to southern Africa. This trend is only expected to increase in the current changing climate scenario being witnessed globally. Meanwhile, increasingly common extreme weather events make large dams dangerous for people living downstream, as they become vulnerable to dam failures.

2. Dams Produce Significant Amounts of Methane

At least 25% of today’s global warming is caused by methane emissions, which have “more than 80 times the warming power of carbon dioxide over the first 20 years after it reaches the atmosphere,” according to a press release from the Environmental Defense Fund (EDF).

As the Intergovernmental Panel on Climate Change (IPCC) report in 2021 showed, cutting methane emissions is the most urgent step we must take to immediately slow the rate of global warming, an observation also made in Nature. Dams generate methane and carbon dioxide when vegetation and organic matter are flooded in the reservoirs and start to decay underwater, as well as when areas are deforested to make way for building the project. Dam reservoirs represent a significant source of methane globally, equivalent to the greenhouse gas footprint of Canada, and scientists have found in some cases that dam reservoirs can cause more warming than coal-fired power plants.

3. Hydropower Climate Calculation Doesn’t Add Up

The dam sector’s industry group, the International Hydropower Association (IHA), along with other vested interests are pushing to more than double the entire amount (850 gigawatts) of hydropower installed in the past 100 years in a bid to mitigate climate change.

The IPCC report is a reminder to all of us that we have less than 10 years to drastically cut emissions if we’re to avoid the worst impacts of climate change. Let’s look at the numbers: The average time it takes to build a dam is approximately 10 years, and dam construction itself causes serious emissions (for example, cement production).

Even if a dam was built in less time, a new dam reservoir actually adds to the climate crisis by emitting most of its methane and CO2 emissions in the first decade after its commissioning. For example, in Brazil, researchers discovered that the Belo Monte Dam caused a threefold increase in greenhouse gas emissions after only two years of operation. Building a vast new fleet of dams as IHA calls for would spike methane emissions at precisely the time we need to reduce them.

4. Hydropower Dams Are Falsely Marketed as a ‘Sustainable’ Climate Solution

The IHA continues to propagate the falsehood of hydropower projects being a viable solution to mitigate the climate crisis, which fails to consider the facts or latest scientific evidence to the contrary. In September 2021, IHA made its pitch for scarce climate dollars to subsidize the hydropower industry, pledging that all new hydropower projects must meet its own “Hydropower Sustainability Standard.”

This commitment to ensuring sustainability for hydropower dam projects, however, falls flat on its face when one considers the fact that all ‘sustainable’ hydropower projects pushed by the IHA members in 2020 did not even meet their definition of sustainability. A report called “Water Yearbook” for 2020 stated that “most of [the] hydropower development in the world is unsustainable and proceeds at the expense of key sustainable development objectives.”

5. Dam Projects Often Violate Human Rights

Large hydropower projects have serious impacts on local communities’ rights. According to the 2000 WCD report, dams had displaced at least 40-80 million people and have negatively affected an estimated 472 million people living downstream over the years. Hydropower companies often violate the rights of Indigenous peoples to their lands, territories, resources, governance, cultural integrity and right to free, prior and informed consent (FPIC).

Last year’s guilty verdict in the assassination of Indigenous leader Berta Cáceres by the former head of a dam company in Honduras highlights the danger faced by people opposing hydropower dams. The impact of dams on Indigenous populations continues unimpeded despite the key role that Indigenous peoples play in protecting 80 percent of global biodiversity and leading the world in preventing carbon emissions in their territories.

6. New Hydropower Is Expensive and Ill-Suited to Deliver Energy Access

Another considerable mark against large hydropower projects is their enormous expense. Due to planning errors, technical problems and corruption, dams experience average delays of 44 percent and cost overruns of 96 percent. Sooner or later, silt tends to build up in reservoirs over the years, and the cost of maintaining dams far outweighs their benefits. Meanwhile, the energy produced by large dams is generally inaccessible to local communities, either because it is too expensive, monopolized by the industry, or exported to distant cities or neighboring countries.

7. Free-Flowing Rivers Help Mitigate the Climate, Biodiversity and Water Crises—Dams Do Not

Rivers, when unfettered and healthy, help regulate an increasingly volatile global carbon cycle by drawing an estimated 200 million tons of carbon out of the atmosphere each year. This is just one of the dozens of essential services provided by free-flowing freshwater ecosystems, which range from provision of food to flood mitigation and access to water supply. Dams do a poor job of storing water; “it’s estimated at least 7 percent of the total amount of fresh water needed for human activities evaporates from the world’s reservoirs every year,” according to an article in Deutsche Welle.

8. Alternatives Are More Affordable and Driving the Energy Revolution

Truly renewable, clean energy sources are readily available and financially competitive and have overtaken large hydropower projects as the preferred choice for energy generation and access. Utility-scale renewable energy technologies such as wind, solar, and geothermal have the potential to provide environmentally and socially sustainable energy and are also increasingly cost-effective for consumers.

Given the plunging costs of alternative energy sources and improved storage technologies—as well as significant advances in energy efficiency and grid management—it is now possible to expand energy generation while drastically reducing greenhouse gas emissions and preserving our free-flowing rivers.

9. Expanding Hydropower Is Incompatible With Efforts to Address the Looming Biodiversity Crisis

While they account for less than 1% of the Earth’s surface, freshwater ecosystems are home to more than 10% of all species. Hydropower dams are a key culprit in the rapid 84% decline in the populations of freshwater species experienced since 1970.

This year, the second phase of the 15th Convention on Biological Diversity (CBD) is expected to begin in August, and the participants of the convention will discuss and agree on the UN biodiversity framework, and with freshwater ecosystems being the “most degraded ecosystems in the world,” urgent global action is required to turn this around.

10. The Destruction of Nature Is at the Root Cause of Multiple Crises

We’re facing multiple challenges: climate change, massive biodiversity loss, and a global pandemic, among other challenges of human rights, equity, and poverty. We must tackle the root systems and drivers of our major global challenges. The future depends on us to make the right decisions at this critical moment.

Hydropower dams are a false climate solution and should not be prioritized in future energy or climate plans. A new paradigm in river stewardship and protections is critical, particularly in the wake of COVID-19, to safeguard the water sources that are indispensable to life and public health, help prevent countries from taking on calamitous new debt, ensure a just energy transition that centres people and human rights, and effectively confront our climate and water crises and biodiversity loss.

We have less than 10 years to halve our greenhouse gas emissions to stave off catastrophic climate change, and we must also address the interlinked water and biodiversity crises. As Bob Watson, former chair of the IPCC and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, said, “If we fail to act now, future generations will ask, why did we not act to save the Earth given all of the scientific evidence we have?” It is past time to put to rest these false notions of hydropower being a sustainable climate solution and instead invest in energy pathways that can both address climate change and deliver electricity to those who lack it.

Josh Klemm is the co-executive director of International Rivers, a non-profit at the heart of the global struggle to protect rivers and the rights of communities that depend on them. He previously led the Africa Program at the Bank Information Center. Find him on Twitter @JoshKlemm.

Eugene Simonov is the international coordinator of the Rivers without Boundaries Coalition (RwB), which unites local communities and activists to protect transboundary rivers of the Eurasian continent.

This article was produced by Earth | Food | Life, a project of the Independent Media Institute.