Estimation of water-atmosphere carbon balance in the coastal zone of Lake Baikal based on the CO2/CH4 fluxes

Long-term observation series of carbon dioxide and methane fluxes in the water-atmosphere system in the coastal zone of Lake Baikal are analyzed. It is shown that the total sink of carbon dioxide from the atmosphere to the water surface is 5.9 gСО2 m-2 year-1, while the methane emission from water is estimated as 80 mgСН4 m-2 year-1. For comparative estimation of the radiative forcing, it is taken that the contribution of the atmospheric methane molecule to global warming is 27 times greater than that of the СО2 molecule. Then, the coastal area of Lake Baikal contributes to global warming due to the methane emission 8-20% more than to the cooling due to absorption of carbon dioxide by the water.