Estimation of the anthropogenic component of greenhouse gas fluxes from the surface of energy reservoirs in the Russian Federation

The paper assesses anthropogenic emissions and absorptions of greenhouse gases from energy reservoirs in the Russian Federation based on the results of field measurements in 2021–2023. Measurements of methane fluxes from the surface of reservoirs were carried out by employees of the Institute of Atmospheric Physics of the Russian Academy of Sciences in the shallow and deep-water parts of the basins of nine reservoirs (Kolymskoye, Bureiskoye, Volgogradskoye, Boguchanskoye, Zeyskoye, Kuibyshevskoye, Rybinskoe, Chirkeyskoe, Sayano-Shushenskoe). Based on these measurements and modeling data, we analyzed and compared the obtained results with the methane emission factors presented in the methodological documents of the Intergovernmental Panel on Climate Change (IPCC). We have developed adjusted coefficients using Tiers 1 and 2 methods according to the IPCC. The results show that the revised national factors are on average 63% lower than the default IPCC factors. A methodology for assessing the anthropogenic component of the greenhouse gas balance due to reservoir construction using Tier 3 method has been developed based on carbon balance calculations and the difference between the parameters of the reservoir water and the river before it. Using the example of the Rybinsk Reservoir, we assessed the anthropogenic component of the greenhouse gas flow, corresponding to a net absorption of 0.18 kg CO2-eq/m2/year. A conclusion has been made about the possibility of a negative carbon footprint of electricity from large hydroelectric power plants.