Producing a ton of coal typically emits 0.19T of CO2, equivalent to 50kg/boe. The numbers comprise mining, methane leaks and transportation. Hence domestic coal production will tend to emit 2x more CO2 than gas production, plus c2x more CO2 in combustion.

However, numbers vary widely based on input assumptions, such as methane lakage rates, btu content and transportation distances, which can be flexed in the model.