Methane coming into the atmosphere from natural and anthropogenic sources plays the important role in greenhouse warming. Atmospheric methane content is increasing by similar to 0.6-0.8 % per year, especially in high and temperate latitudes of Northern Hemisphere. Therefore the quantitative study of injection and destruction mechanisms of atmospheric methane is important for estimation of observed climate changes. The wetlands in common with the large oil- and gas deposits located in Siberia and in Russian Arctic are among the main methane sources in the Northern Hemisphere. The measurements of methane concentrations carried out in the vicinity of gas fields in spring of 2000 in common with specially developed for this region 3-D regional transport model are used for correction of estimates describing the methane leakage from gas deposits. The obtained results allow to make more accurate assessment of the regional sources input into the natural and anthropogenic components of global atmospheric methane budget.