We assemble a longitudinal data set for analyzing methane-emitting activities within the MIT Integrated Global System Model (IGSM). It is an earth system model of intermediate complexity that, for forward simulations, is driven by anthropogenic emissions as projected by the Emissions Prediction and Policy Analysis (EPPA) model. We develop initial estimates of emissions coefficients for each of the main methane-emitting activities along with corresponding uncertainty estimates to be utilized as "priors" in inverse calculations. In addition, baseline maps for the spatial distribution of methane emissions by individual activities are coded to EPPA regions for later use with emissions coefficient estimates produced by these inverse calculations.