In the opening days of the United Nations Framework Convention on Climate Change (UNFCCC)’s 26^th Conference of the Parties (COP26), more than 100 countries signed the Global Methane Pledge, which aims to significantly reduce global methane emissions by 2030. Meanwhile, the hydropower industry presented the San José Declaration on Sustainable Hydropower, a strategy through which it plans to double global installed capacity by 2050. Both the hydropower and methane pledges claim to align with the goals of the Paris Agreement, yet they are inherently contradictory since hydropower emits considerable quantities of methane.

Inside the COP26 blue zone, the secure area where negotiations occur, a group of Indigenous peoples and river defenders from dam-impacted communities met with a member of the UNFCCC’s observer relations team to address this contradiction. These advocates submitted petitions and letters that call for an end to hydropower, citing the contribution of dams (and their reservoirs) to greenhouse gas emissions (GHG), the detrimental effects of dams on coupled socio-cultural and environmental systems, and the need for the UNFCCC to recognize Indigenous rights during climate policy-making processes. The UNFCCC team member accepted these documents, promising to deliver them to COP26 President Alok Sharma. She reassured everyone that there is a space for Indigenous voices at the UNFCCC and ensured the group that the government considers their concerns in policy-making. However, Alok Sharma had already stated his support of the San José Declaration during the most recent World Hydropower Congress, leaving the group uncertain (but hopeful) in their efforts to stop Indigenous territories from being “sacrifice zones” for extractivist development projects (Middleton Manning 2018; Willow 2018).

While water systems have been managed sustainably for irrigation, flood control, and water security for centuries, the methods and scales of controlling water have expanded exponentially throughout the twentieth century with the advent of new technology and the drive for “development and progress.” There are now an estimated 2.8 million dams worldwide, many of which have caused incalculable social and environmental destruction to communities. According to the World Commission on Dams, at least 80 million people have been displaced by dams, although the numbers are definitively much higher now considering the long term effects are not included and an additional 45,000 large dams (>15 meters in height) have been built since that report was published in 2000. Hydropower projects exacerbate existing land tenure conflicts, separate peoples’ spiritual and cultural connections to place, destroy communities and livelihoods, as well as damage interconnected ecosystems (cf. McCully 1996).

Indigenous peoples are disproportionately affected by hydropower development and face high levels of violence for protecting their lands and waterways (Del Bene, Scheidel, and Temper 2018). In the Térraba community where I work in Costa Rica, the rights of the Brörán peoples have been repeatedly violated while the state attempted to build three hydropower projects in the past 50 years, with the latest being promoted as a pathway to carbon neutrality. International pressures to build hydropower has resulted in a myriad of local socio-political, cultural, and economic struggles, as well as physical confrontations in Térraba.

After a brief global halt in hydropower development in the 1990s over the Indigenous rights violations inflicted during the World Bank’s support of the Sardar Sarovar project in India, the hydropower industry has entered into a public relations offensive to effectively greenwash its image. In so doing, the industry breached the realm of climate governance under the Kyoto Protocol’s Clean Development Mechanism (CDM). As a CDM, hydropower is promoted as a clean, zero emissions, renewable energy source and can therefore be subsidized by carbon credits. This acceptance of hydropower as a sustainable solution to climate change via the CDM program has led to a global resurgence in development. Yet increasingly, research on the amount of GHG released from dams, specifically methane emitted from reservoirs, calls into question hydropower’s green reputation.

Methane production from reservoirs is created through decomposition of organic materials under anoxic (low oxygen) conditions and released into the atmosphere through ebullition (bubbles). Emissions from dam reservoirs have been contested, in part due to variable methodological approaches. However, recent studies emphasize that hydropower reservoirs in the tropics contribute compelling amounts of methane to atmospheric concentrations, in some cases more than coal-fired power plants. The majority of emissions from hydropower projects occur in the first decade of a dam’s lifespan, a time period during which the global warming potential (GWP) of methane is extremely high. The GWP from reservoirs quadruples when calculated on a 20-year time frame as opposed to the 100-year time horizon currently utilized by the IPCC to inform policy. Miscalculating methane via inappropriate temporal scales is a critical error given the urgency for addressing climate change.

Concerned scientists, environmental organizations, and river defenders therefore call for hydropower to be removed from recognition as a Clean Development Mechanism, including more than 300 who signed a petition urging the UNFCCC to rescind its support for hydropower. In Glasgow, an anti-dam activist handed a copy of this petition to Eddie Rich, the president of the International Hydropower Association. Mr. Rich accepted the petition while enthusiastically stating his continued interest in doubling installed capacity via “sustainable” hydropower, although never explicitly stating who or what hydropower is sustainable for.

During their announcement of the Methane Pledge, both President Joseph Biden and EU Commission chief Ursula von der Leyen stated the importance of immediately cutting global methane emissions. But in order to effectively accomplish the goal of reducing methane emissions by 30 percent within the next decade, policy makers have to seriously consider the potency of methane that is being emitted by hydropower projects in the first 10 years of their lifespan. For the UNFCCC to successfully address climate change from the platform of sustainability, they need to reconsider their support for hydropower by accepting the multitude of Indigenous and scientific knowledges that refute hydro’s ability to mitigate climate change equitably. Climate policy makers need to reconcile the incompatible entanglement of these two governance mechanisms, the San José Declaration and the Methane Pledge, while there is still time for everyone to mitigate and adapt to climate change.