The three-dimensional global climatic model is employed as a tracer transport model to the study of atmospheric distributions of methane. Methane is input at appropriate surface grid points. The 4-year model experiment was run using sparse observed data at 19 sampling sites for the period 1984-1987, by which time a stable north-south gradient in the atmospheric methane and seasonal variations are obtained in the model. Verification of the climatic model as a tracer transport model indicates good agreement in the northern mid-latitudes with the known experiments of the 3D model synthesis of the global methane cycle.