Coal to gas: The influence of methane leakage

Gas produces approximately half the amount of CO₂ per unit of primary energy compared with coal. Here we consider a scenario where a fraction of coal usage is replaced by natural gas (i.e., methane, CH₄) over a given time period, and where a percentage of the gas production is assumed to leak into the atmosphere.

The additional CH₄ from leakage adds to the radiative forcing of the climate system, offsetting the reduction in CO₂ forcing that accompanies the transition from coal to gas. We also consider the effects of: methane leakage from coal mining; changes in radiative forcing due to changes in the emissions of sulfur dioxide and carbonaceous aerosols; and differences in the efficiency of electricity production between coal- and gas-fired power generation.