[dredmorbius]

A principle source of methane leakage is from gas wells themselves, as well as the extensive infrastructure involved in processing and transporting gas from its point of extraction to usage.

<https://www.epa.gov/natural-gas-star-program/primary-sources...>

In situ / on-prem methane production, storage, and usage would tend to minimise much of that.

Further, I don't see methane synthesis as a likely option for synfuel storage applications as described here, as heavier fuels (~C-12 -- C-15 chain-length kerosene) is liquid (far easier to handle than a gas), nonvolatile (as contrasted with petroleum or lighter hydrocarbon distillates), and can be stored in simple, unpressurised, unrefrigerated tanks virtually indefinitely. You're creating a problem which needn't exist.