Brazil leads ranking of planned dams in protected areas that may intensify climate crisis

In total, 1,249 hydroelectric plants around the world are built and another 509 are planned in preservation areas. This week, when government representatives meet at COP 26 in Glasglow, Scotland, to discuss the climate future of the planet, one of the issues that may be on the agenda is the controversial carbon credit currently granted for the construction of these hydroelectric plants, which have several social and environmental impacts in protected areas, in addition to emitting methane, a very potent greenhouse gas.

The incentive is currently granted through the so-called Clean Development Mechanism (CDM) of the United Nations, which was defined in the Kyoto Protocol. The premise is that hydroelectric plants – as well as wind and solar – would avoid the release of carbon dioxide into the atmosphere at the expense of thermal plants, thus contributing to slowing global warming.

 The supposed benefits related to hydroelectric plants that justify this mechanism, however, are disputed in several scientific studies. In 2019, the Conservation Letters Magazine published an article that demonstrates impacts of dams such as the forced displacement of traditional populations, the emission of methane gas and the great risk to freshwater biodiversity. These impacts are even more serious when dams are built in preserved areas.

In dark blue – dams built within existing protected areas, in light blue – new proposed dams in protected areas, in pink – dams built before the creation of protected areas, in light green – protected areas.

According to the study, the majority of projects are located in Brazil, especially in the Amazon. When the study was published, at least 158 dams were operating or under construction in the Amazon basin and another 351 had been proposed with the potential to affect more than 37,000 km² of protected areas.

“Conservation units, especially indigenous lands in Brazil and around the world currently play the role of protectors of our socio-biodiversity and our forests, responsible for a good part of the relationship between climate and rain”, assesses the coordinator of the Movement of People Affected by Dams, Francisco Kelvim commenting on the threat posed by hydroelectric dams.

Francisco remembers that any impact on the river environment causes long-term changes in the forest as well. “The problems we have seen in hydroelectric plants in the Amazon, such as the loss of important species of fauna, flora and ichthyofauna, changes in the water table and increase in lake temperatures, happen not only until these reservoirs are stabilized, but in a permanent and cumulative manner ”.

Dams and the greenhouse effect

These projects represent not only a major social and environmental risk for the territory, but also for the global climate. This is what the scientist Philip Fearnside emphasizes, in an exclusive interview to MAB. Phillip is an American biologist and scientist linked to the Brazilian National Institute for Space Research (INPE), who settled in Brazil and gained wide international notoriety through studies on Brazilian hydroelectric plants and their effects on the climate.

The flooding of forest areas due to the creation of hydroelectric power plants in tropical areas not only impacts local biodiversity but also causes the emission of methane, a highly potent greenhouse gas. In the image lake created in the Xingu River. Photo: Lilo Clareto

“Dams emit a lot of greenhouse gases, especially methane, a very potent gas for global warming. In fact, the latest IPCC (Intergovernmental Panel on Climate Change) report published in August dedicates an entire chapter to the effects of this type of gas on climate change”, explains the scientist. As a result of these studies, this Tuesday, Novermber 2, during the COP, Brazil and more than 100 countries joined the Global Commitment on Methane in a collective effort to reduce methane emissions by 30% by 2030 compared to 2020 levels.

Methane is produced in the digestive tract of cattle and in other natural processes such as the decomposition of organic matter. According to Philip, the decomposition of the flooded forest in the hydroelectric lakes is very expressive for the generation of the pollutant. “This gas is emitted in the first few years after the construction of dams. It lasts less time than carbon in the atmosphere, but it has a much greater impact on global warming”, he emphasizes. Studies show that methane is 80 times more potent in raising the Earth’s temperatures than carbon dioxide (CO2).

Philip points out that the methane emissions in the short term are very serious due to the urgent need to control the emission that will occur in the coming years. “This is critical for us to avoid a climate collapse situation, which is called a ‘point of no return’.

In this context, the scientist claims that encouraging the construction of hydroelectric plants as a clean energy alternative does not make sense because they do not collaborate to prevent climate change.

“So it is also very important that it is simply prohibited in COP decisions to give carbon credits to dams. Nobody is building a dam to fight global warming, they are doing it to make profits from the sale of energy. And it is worth remembering that the hydroelectric plants are already built with public financing and have several subsidies. In the case of the Madeira River, its two dams still have carbon credits and, instead of helping to combat the greenhouse effect, they are causing more damage. In addition to emitting methane, they allow rich countries that are going to buy these carbon credits to emit more greenhouse gases”, evaluates the researcher.

Kelvim recalls that in addition to the effect on the climate, hydroelectric dams have many other potential impacts that were not foreseen. “The rivers in the Amazon basin, due to the influence of the Andes and the regime of floods, high flows, among other factors, are constantly changing. The environmental licensing of hydroelectric projects in the Amazon did not consider this and the impact of the formation of these reservoirs in the long term”, explains the coordinator.