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Sweating Man


An interesting exchange recently took place here in Brazil regarding emissions of greenhouse gases, including methane from hydroelectric dams. Roberto Smeraldi, director of the NGO Friends of the Earth, Brazilian Amazon published an op-ed in the country's principal daily, the Folha de São Paulo, entitled "Free Lunches End up Being Costly". In the article, Smeraldi criticized the lack of analysis of energy alternatives in the government's latest 10-Year Energy Plan, which projects the construction of 71 new dams. Smeraldi also observed that both the government and critics of the plan have decried the impacts of new thermoelectric plants and their greenhouse gas emissions, while ignoring the emissions of new dams planned for the Amazon.

Smeraldi mentions three cases of Amazon dams – Balbina, Curuá-Una, and Samuel where emissions exceed those of coal-fired power stations generating the same amount of energy, and the case of Tucuruí, where emissions certainly exceed those of a natural gas generating plant, and could exceed those of a coal generator if all emissions are factored in.

Brazil's proud electric sector was quick to respond. Luis Pinguelli Rosa, physicist and former president of the state holding company Eletrobrás wrote the Folha, saying it was "incorrect to say that many Brazilian dams emit more greenhouse gases than thermoelectric plants powered by fossil fuels." According to Pinguelli Rosa, Balbina is an exception, while "97 % of the installed capacity of the dams studied (by the Coppe institute of the University of Rio de Janeiro) including Tucuruí…contribute much less (greenhouse gases) – in some cases one percent of what a thermoelectric contributes".

Not permitting the public to be hoodwinked by "the official story", Smeraldi responded — "My data for Samuel and Tucuruí dams comes from the National Emissions Inventory of the Science and Technology Ministry, coordinated by Pinguelli Rosa. In the two cases not covered in the inventory, and for the additional data on emissions from spillways, turbines, and cement used in construction, I used data published by researchers of official agencies of the government, including Pinguelli and Coppe." Touché!

For the Brazilian government, the issue of greenhouse gas emissions from the dozens of large dams being planned for construction in the Amazon over the next two decades is like Uncle Izzie passing gas at the dinner table – better not to even talk about it. As the IPCC discusses the role of renewables in addressing climate change, Brazil arrogantly touts its "clean energy matrix" and argues that calculations of methane emissions from dams are based on flawed assumptions. José Gonzalez Miguez, a Brazilian government official on the Clean Development Mechanism's Executive Board, says Brazil aims to influence how IPCC deals with methane emissions from hydroelectric dams. Saying the question has been "poorly analyzed in the scientific literature" and that "there's a lot of confusion", Miguez theorizes that "there are natural emissions of vegetation which get pulled downstream (by the river), and there is also sewage…being dumped". As a result, according to Miguez, methane emissions of dams are being exaggerated.

Is hydroelectricity clean or dirty energy? Perhaps this determination will in the end depend on whether scientists or politicians decide.