Emissions from tropical hydropower and the IPCC

•Tropical dams emit greenhouse gases, which are undercounted in IPCC guidelines.•IPCC comparisons with other energy sources undercount hydroelectric emissions.•GHG inventories must fully count emissions as a basis for negotiating national quotas.•The IPCC needs to reassess emissions from dams independent of the hydropower industry. Tropical hydroelectric emissions are undercounted in national inventories of greenhouse gases under the United Nations Framework Convention on Climate Change (UNFCCC), giving them a role in undermining the effectiveness of as-yet undecided emission limits. These emissions are also largely left out of the Intergovernmental Panel on Climate Change (IPCC) Special Report on Renewable Energy Sources and Climate Change Mitigation, and have been excluded from a revision of the IPCC guidelines on wetlands. The role of hydroelectric dams in emissions inventories and in mitigation has been systematically ignored.