Over the last two years, I've written four articles about the massive problem with methane emissions from hydropower dams and reservoirs. Finally, the mainstream media covered this story Thursday after an international team of scientists released a new study that synthesizes more than 100 scholarly articles on the topic.


The Seattle Times headline read, "Hydropower Isn't Carbon Neutral After All" and the Washington Post headline read, "Oh Great—Scientists Have Confirmed A Key New Source Of Greenhouse Gases"

The scientific study featured in these news articles will appear next week in the journal Bioscience and is co-authored by 10 international researchers including scientists at the U.S. Environmental Protection Agency. As reported in the Seattle Times and Washington Post, key findings in the scientific study include:

  • Methane emissions from dams and reservoirs across the planet, including hydropower, are estimated to be significantly larger than previously thought, approximately equal to 1 gigaton per year.
  • The international boom in the construction of hydropower projects is rapidly accelerating this increase in methane emissions.
  • Reservoirs in mid-latitude areas of the planet, including in the U.S., can have as high of methane emissions as those in tropical countries which have been measured to emit as much greenhouse gases as coal-fired power plants.
  • The United Nation's Intergovernmental Panel on Climate Change (IPCC) should now better account for these massive methane emissions and include them in climate change scenarios.

In the four articles I wrote:

  1. Why Hydropower Is Not Clean Or Cheap
  2. Hydropower Will Undermine COP21 As False Solution To Climate Change
  3. The Hydropower Methane Bomb No One Wants To Talk About
  4. Dams Cause Climate Change, They Are Not Clean Energy

I laid out the science behind why dams and reservoirs cause methane emissions. I explained how there are hundreds of dams under construction right now and thousands in the planning process, and I described how the U.S. government and the IPCC need to address this issue because countries around the world are sweeping it under the rug.

Now I'm taking it a step farther. I'm calling for a global moratorium on the construction and permitting of all hydropower projects.

Hydropower is being pushed forward as "clean" and "carbon free" by an industry that is making hundreds of billions of dollars per year building dams. Countries, including the U.S., are in denial about how hydropower is contributing to climate change. Corruption in developing countries is undermining democracy and endangering the lives of local people who are fighting these projects. The murder of dam-fighter Berta Cáceres in Honduras got widespread international attention, but it is only the tip of the iceberg for the human rights abuses faced by local people fighting hydropower across the planet.

A moratorium on hydropower is the only just path forward.