Energy used in LNG liquefaction and transport equal ~20% of the energy content of the shipped LNG itself. Fugitive methane leaks from wellhead to end user add substantially to the GHG footprint of this energy source, since CH4 has ~30 times the global warming potential of an equivalent volume of CO2, averaged over 100 years from its emission.

Natural gas can be burned cleaner and more efficiently than coal, but CH4 and CO2 are greenhouse gases and there is no escaping that fundamental fact.