This data-file quantifies and disaggregate the CO2 emissions from a typical coal mining operation, across mining processes, coal-processing, methane emissions and freight/transportation.
We estimate that producing a ton of coal emits 0.19T of CO2, equivalent to 50kg/boe. The data are based on USGS technical papers, EPA disclosures from US coal mines and EIA disclosures on mine sizes and coal heat contents.
The conclusion is that domestic coal production will tend to emit 2x more CO2 than domestic natural gas production, in addition to coal combustion emitting around 2x more CO2 than gas 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.