It is generally understood that the shift from coal to gas has helped, at least in the short run, to reduce emissions of greenhouse gases. It is certainly true that combustion of natural gas releases less CO2 per unit of energy than combustion of coal. Unfortunately, that’s not the entire answer. A recent study published in Science Advances indicates that 3.7% of natural gas produced in the Permian Basin ends up in the atmosphere. Given methane’s global warming potential, that’s a significant number.
I don’t know whether further investigation will confirm that number, and methane losses in the Permian Basin may be higher than elsewhere due to the lack of sufficient infrastructure to move the gas to markets. Regardless, though, the study reminds us that what matters are cumulative impacts, both direct and indirect. The cost of coal includes the GHG emissions – and other environmental degradation – from mining, as well as from combustion. Even beneficial technologies aren’t exempt. Comparisons of electric vehicles to internal combustion vehicles have to include the costs associated with the mining and production of rare earth metals used in electric vehicles.
In other words, it’s all about the life cycle, stupid. Unfortunately, our environmental protection regulatory system is not organized to provide life cycle analyses. Impacts are cabined by media-based regulatory requirements. NEPA and its state analogs are the closest we have to a method to incorporate life cycle assessments. Unfortunately, anyone who has followed recent litigation to require BOEM and FERC to assess indirect impacts of mineral leases, pipelines, and the like, knows what a blunt instrument NEPA is, even if it’s better than nothing.
I wish I had a solution. For now, all I can say is that we have to keep doing the science while continuing to work to make government legislation and regulation reflect the knowledge that science provides. That would be, one might say, a breath of fresh air.