Emissions from tropical hydropower and the IPCC
Section snippets
Emissions from tropical dams
Amazonian dams produce greenhouse gases, especially during their first 10 years of operation (e.g., Abril et al., 2005, Delmas et al., 2005, Fearnside, 2002a, Fearnside, 2005a, Fearnside, 2008a, Fearnside, 2009, Fearnside, 2013, Fearnside and Pueyo, 2012, Galy-Lacaux et al., 1997, Galy-Lacaux et al., 1999, Guérin et al., 2006, Gunkel, 2009, Kemenes et al., 2007, Kemenes et al., 2008, Kemenes et al., 2011, Pueyo and Fearnside, 2011). Published numbers for emissions from hydroelectric dams vary
Special report on renewable energy
The IPCC special report on renewable energy sources and climate change mitigation (IPCC, 2012) summarized its findings on emissions from hydroelectric dams as: “there is currently no consensus on whether reservoirs are net emitters or net sinks” (Arvizu et al., 2012, p. 84). The report classified hydropower as having half or less impact per kWh of electricity generated as compared to any other source, including wind and solar (Moomaw et al., 2012, p. 982) (Fig. 1). One factor that may, in part,
Turbines ignored
When water is released from the turbines it is under considerable pressure—for example, in the case of Brazil's Tucuruí Dam the pressure is approximately four atmospheres from the weight of the water at the level of the turbine intakes (currently at 40 m depth), plus one atmosphere from the air above the reservoir. This pressure is suddenly reduced to one atmosphere as the water emerges from the turbines, causing an immediate emission of gases. Much of this emission will occur almost
The sociology of science and dam emissions
Both scientific research and its interpretation for policy are done by human beings who act within the context of their social and institutional environments. The journal Climatic Change hosted a debate over this issue between this author (Fearnside, 2004, Fearnside, 2006) and the then-head of Eletrobrás (Rosa et al., 2004, Rosa et al., 2006b). The debate was refereed by Cullenward and Victor (2006), who pointed out that “A large proportion of the published work in this field comes directly
Conclusions
The Intergovernmental Panel on Climate Change (IPCC) guidelines for national inventories of greenhouse-gas emissions need to be revised such that the required level of reporting on dams reflects the full extent of their emissions of all greenhouse gases. The IPCC also needs to conduct a thorough review of the subject independent of the hydropower industry.
Acknowledgements
The author's research is supported exclusively by academic sources: Conselho Nacional do Desenvolvimento Científico e Tecnológico (CNPq: Proc. 305880/2007-1; 304020/2010-9; 573810/2008-7; 575853/2008-5), Fundação de Amparo à Pesquisa do Estado do Amazonas—FAPEAM (Proc. 708565) and Instituto Nacional de Pesquisas da Amazônia (INPA: PRJ15.125). Marcelo A. dos Santos Júnior drafted the figures. Simone Athayde supplied bibliographic material. Reviewer comments were very helpful.
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