(Updated below, 21st June 2018.)
Zeke Hausfather published “Climate Impacts of Coal and Natural Gas” on the BEST project site. He makes a close analysis of the relative benefits of coal and natural gas, considering the subtleties and pitfalls of “global warming potential” as a measure, and fully considering various ranges for fugitive methane emissions. He concludes that natural gas has a role as a “bridge fuel”, but, in doing so, fails to consider the inevitable products of natural gas combustion or natural breakdown of its methane in the environment, and, that is, carbon dioxide. It’s all about the carbon dioxide. It’s always all about the CO2. See, for instance,
- “Short-Lived Climate Pollution“
- “Disentangling the effects of CO2 and short-lived
climate forcer mitigation“
- “To address climate change, nothing substitutes for reducing carbon dioxide emissions“
Present recommendations place a zero Carbon emissions target for clamping average global surface temperature, not average global land surface temperature mind, to +2° C over preindustrial. Now some, including me, suggest +2° C is a bit much, but it looks like that’s (unfortunately) an almost academic argument, given that getting to a +2° C limit will be challenging.
But the point of the Hausfather argument has been heard before, event if the details of rhetoric differ a bit. The key problem I see with it is that natural gas infrastructure, whether fracking, pipeline, or distribution, is being installed as if its lifetime were infinite or, at least, the standard depreciation period of 50 years, and that’s WAY too long for it to be a good and valid tool for greenhouse gas reduction. This is not because it’s better or worse than coal, but simply because it contributes to carbon dioxide emissions and, to reach the goal we need to reach, these need to be zero by 2050.
“So what?” you say.
The “what” is that if indeed all this natural gas infrastructure needs to be abandoned by 2050, or 2080, or 2100, the financial burden of paying it off is accordingly higher. That means that the per unit delivery cost of natural gas to the end customer, whether residential, or a utility burning natural gas to obtain “clean electricity” is grossly understated compared to what it ought to be if that were properly reflected. That means that natural gas is competing unfairly in the marketplace compared with, oh, I don’t know, wind and solar, because the accounting procedure does not reflect the reality of what needs to be done.
Natural gas companies are getting a break on their pricing because no one in the federal government is seriously considering the need to curtail greenhouse gas emissions on a schedule. That’s messing up the transition to zero Carbon.
It’s about time someone really started thinking this through.
Update: 2018-06-21 17:51 EDT
The current issue of Science features:
R. A. Alvarez, D. Zavala-Araiza, D. R. Lyon, D. T. Allen, Z. R. Barkley, A. R. Brandt, K. J. Davis, S. C. Herndon, Daniel J. Jacob, A. Karion, E. A. Kort, B.n K. Lamb, T. Lauvaux, J. D. Maasakkers, A. J. Marchese, M. Omara, S. W. Pacala, J. Peischl, A. L. Robinson, P. B. Shepson, C. Sweeney, A. Townsend-Small, S. C. Wofsy, S. P. Hamburg, “Assessment of methane emissions from the U.S. oil and gas supply chain”, Science, 21st Jun 2018: eaar7204,
Methane emissions from the U.S. oil and natural gas supply chain were estimated using ground-based, facility-scale measurements and validated with aircraft observations in areas accounting for ~30% of U.S. gas production. When scaled up nationally, our facility-based estimate of 2015 supply chain emissions is 13 ± 2 Tg/y, equivalent to 2.3% of gross U.S. gas production. This value is ~60% higher than the U.S. EPA inventory estimate, likely because existing inventory methods miss emissions released during abnormal operating conditions. Methane emissions of this magnitude, per unit of natural gas consumed, produce radiative forcing over a 20-year time horizon comparable to the CO2 from natural gas combustion. Significant emission reductions are feasible through rapid detection of the root causes of high emissions and deployment of less failure-prone systems.