Two years ago, an incendiary study was published with a (seemingly) outlandish claim: it said that the United States could completely phase out the use of fossil fuels by 2055, and that it could do so without the use of carbon capture technologies or nuclear power.
That was an extraordinary claim back then, and the study’s lead author, Stanford University civil and environmental engineering professor Mark Jacobsen, defended his work after its release from skeptical analysts and scientists. This week he’s digging in even harder after a new study was released in the Proceedings of the National Academy of Sciences—the same place that published the original report—that claims that the Jacobsen study “used invalid modeling tools, contained modeling errors, and made implausible and inadequately supported assumptions.” The MIT Technology Review has a good run-down of this scientist spate:
In the original paper, Jacobson and his coauthors heralded a “low-cost solution to the grid reliability problem.” It concluded that U.S. energy systems could convert almost entirely to wind, solar, and hydroelectric sources by, among other things, tightly integrating regional electricity grids and relying heavily on storage sources like hydrogen and underground thermal systems. Moreover, the paper argued, the system could be achieved without the use of natural gas, nuclear power, biofuels, and stationary batteries.
But among other criticisms, the rebuttal released Monday argues that Jacobson and his coauthors dramatically miscalculated the amount of hydroelectric power available and seriously underestimated the cost of installing and integrating large-scale underground thermal energy storage systems.
“They do bizarre things,” says Daniel Kammen, director of the Renewable and Appropriate Energy Laboratory at the University of California, Berkeley, and coauthor of the rebuttal. “They treat U.S. hydropower as an entirely fungible resource. Like the amount [of power] coming from a river in Washington state is available in Georgia, instantaneously.”
Both the original study and the rebuttal rely on models and other research, and both sides are refusing to back down. Responding to the rebuttal, Jacobsen said that there was “not a single error in our paper.” In a letter he co-signed with three other Stanford professors, he called this newest critical study “demonstrably false.” One of the rebuttal’s co-authors, former associate director at Lawrence Livermore National Laboratory Jane Long, explained that “[energy] issues are complex and hard to understand, and Mark’s simple solution attracts many who really have no way to understand the complexity,” explaining that “[it’s] consequently important to call him out.”
Judging by all the heated rhetoric, it seems that this disagreement is getting a little personal. That said, all this still well within the bounds of how good science should be vetted: in public arenas, with researchers seeking out the opinions of their peers. It may take some time for the dust to settle, but the simple fact that so many highly qualified scientists are taking the issue seriously bodes well for our chances of gleaning a better understanding of the underlying truth.
But with the caveat that dust is still in the air, Jacobsen’s original study still seems wildly optimistic to us, to put it kindly. If it were somehow possible to put the United States, with the currently available suite of renewable technologies, on a (cost-effective) path towards completely phasing out fossil fuels, we’d already be well on our way. The fact is, we’re not, because oil, coal, and especially natural gas still have major roles to play in our country’s energy future.
We’ll let the scientific method do what it does best. In the meantime, we reserve the right to be deeply skeptical of a sanguine study that doesn’t pass the sniff test.