Is natural gas a “bridge fuel”? A dead end? Or something else?

He states his priors before arguing, because the topic is polarizing. He takes net-zero by roughly mid-century seriously and has little patience for favoritism toward particular fuels; the pathway that is most affordable, reliable, safe and secure may well still include fossil fuel, and he is fairly confident it will. He also insists on a distinction the rest of the piece rests on: natural gas the fossil fuel and gaseous fuel infrastructure are closely related today but are not the same thing, because one always arrives with a carbon atom that has to be dealt with and the other does not.

He then builds the two reigning metaphors in their strongest form, on their advocates’ behalf rather than his own, and grants both a good deal. The bridge case runs that methane carries more energy per carbon atom than coal or oil, so the North American shift from coal-fired to gas-fired power has arguably made a bigger carbon impact than any other abatement strategy anywhere in the world to date; that the hard-to-decarbonize long tail will take decades and can often be fueled by gas in the meantime; that fracking left the continent with cheap domestic supply and a pipeline network already built; and that gas is an instrument of national security as well as a cheap abatement measure. Its last step, and only its last step, is that bridges end, so gas has to fall sharply, probably from the 2030s, toward zero. The dead-end case turns on leakage: methane is a far stronger greenhouse gas than carbon dioxide over the horizons that matter, enough that at the measured average leak rate many gas uses are no better than coal on a twenty-year view. It adds that new gas assets lock in decades of amortization, careers and local tax revenue, so a gas bridge will probably extend itself, and that adequate substitutes already exist in power, industrial heat and building heat and need not be perfect to start deploying.

His own metaphor keeps almost all of the bridge case and deletes its final step. A backstop is agnostic about how much gas and for how long, which he thinks trains the mind better than a structure with a fixed far end. He gives it three jobs. The first is macro: if transmission constrains renewables and nuclear deploys slowly, gas with carbon capture is one of few remaining options for zero-carbon primary energy. The second is a reserve for stretches of unusually high demand or low renewable output, where he expects storage to handle most intermittency but some periods in some regions to be exorbitantly expensive to cover without a little gas. The third, the most important in his opinion, is heating buildings in cold climates through extended freezes; he calls himself a big believer in heat pumps and expects them to carry the large majority of building heat, while allowing that in some regions the remainder could be punishingly expensive to electrify.

The whole structure is conditional on the methane problem being solvable cheaply, and that is where he puts his strongest evidence. He cites the International Energy Agency to the effect that near-zero emissions from oil and gas production would be roughly cost-neutral over time, that the up-front investment is small against the industry’s own earnings, and that a large minority of the measures pay for themselves because the retained gas is worth more than the equipment. None of it requires new technology, only replacing worn pipes, fittings and pneumatics, with new solutions useful mainly for finding and quantifying leaks. He adds a regulatory stick in the form of the Inflation Reduction Act’s more rigorous emissions quantification and steep fines for large emitters. Residual combustion emissions then get handled by carbon capture at large point sources and, for household furnaces and office boilers where capture is implausible, by buying enough offsets from large carbon removal projects, a route he says opens only if gas use in those applications is substantially reduced first. He concedes the weakest link immediately: carbon capture has never been demonstrated at scale on any power generation, the serious early attempts on coal failed, and gas is the harder target of the two.