The legal fallout from an academic dispute over clean energy strategy came to an end last week.
Mark Jacobson dropped his $10 million defamation suit against the journal Proceedings of the National Academy of Sciences and Christopher Clack, the lead author of a paper critical of his work.
Jacobson argued that the peer-reviewed critique of his roadmap to power the U.S. entirely with wind, water and solar power contained factual errors that damaged his professional reputation. He previously said that he would drop the suit if the journal published a correction of three key points, but called it off on his own accord.
“After weighing the pros and cons, I find that I have no more reason to fight this battle,” he wrote in a detailed explanation of his decision. “I believe it is better use of my time continuing to help solving pressing climate and air pollution problems.”
While Jacobson insisted that his lawsuit had nothing to do with academic disagreement, observers condemned the tactics as retribution against scientists for engaging in the scientific process. The case deepened a rupture within the community of clean energy researchers over long-term efforts to decarbonize the economy.
Jacobson publicly condemned the 21 authors of the critique as agents of fossil fuel and nuclear interests, but the group included prominent clean energy scholars from numerous respected institutions. At its core, the debate revolved around whether a purely renewable pathway makes the most sense for decarbonizing society, as opposed to a mostly renewable strategy that doesn't lock out other types of resources.
As the author of intricately detailed climate models, Jacobson brought a similarly detail-oriented approach to his rebuttal of the critiques. He issued point-by-point close readings of the critical paper, offering responses that he believed invalidated the criticism. He explicated his decision to drop the lawsuit with a 28-page fact sheet.
All that granularity may have missed the point of the core scientific disagreement.
Jacobson's 100 percent renewables plan uses hydropower as a clean, flexible resource to backstop the days when wind and solar don’t produce enough to run the country. The system fails or succeeds on the ability of U.S. hydropower resources to step in and fill any shortfalls.
In the text of his article, Jacobson describes no significant alteration to U.S. hydropower assets to make his system work. That’s important, because new hydro construction has essentially disappeared in recent decades due to environmental protections, cost of labor and other factors. Reliance on major hydro construction would render the roadmap considerably more difficult to achieve.
The authors of the critique noticed that a graphic in Jacobson’s article depicted instantaneous hydropower discharge at roughly 15 times the capacity listed in the study’s documentation.
This unexplained discrepancy, they argued, unraveled the entire premise. If Jacobson can’t balance the grid without an inconceivable and unexplained multiplication of installed hydro capacity, then one can no longer accept the conclusion that the 100 percent renewable grid is a realistic goal.
This isn’t simply theoretical. The research has migrated into the policy realm. Hawaii has legally committed to 100 percent renewable energy; California tried to last year. Solar executives and Hollywood stars have taken up the 100 percent renewables rallying cry, and they tend not to include a footnote about the hydropower question.
With an army of supporters rallying behind his work, Jacobson had good reason to push back when a prestigious journal and 21 big-name researchers called it into question.
His core defense: That massive, unexplained increase in hydropower capacity wasn’t a modeling error; it was a modeling assumption. He assumed that the U.S. could simply add turbines on existing dams such that they could deliver 15 times more instantaneous capacity, even though total flows for a year would remain constant.
Never mind that this “assumption” was unwritten and implausible. For the critics to call it an error, Jacobson argued, amounted to an unfounded attack on his professional capabilities. He said he would drop his case if the journal published a few points of correction to the critical paper.
That never happened, but Jacobson decided to drop it anyway, two days after his opponents asked the D.C. Superior Court to dismiss the suit.
He cited two reasons in his 28-page explainer. “It became clear” that the lawsuit could last for years and cost a lot of money, perhaps even leading to things like discovery, deposition and a trial. Second, though he did not succeed in changing the scientific record, Jacobson believes he has "brought the false claims to light.”
Now that some of the nation’s leading clean energy researchers have spent an unknown quantity of hours and dollars preparing for a legal showdown, they can reallocate their full attention to their scientific endeavors.
The reverberations of the lawsuit will linger in the community. The case did not create a precedent that libel lawsuits are a good method of resolving disputes between academics. It did, however, drag the clean energy research community into the headlines as a seemingly litigious bunch riven by internal disagreements.
The dispute did not stop advocates from heralding the 100 percent renewable vision. For the sake of scientific completeness, any such pronouncements should include a disclaimer that the vision relies on a massive expansion of hydropower capacity without any practical mechanisms to deliver it. That adjustment, however, would threaten the snappiness of the slogan.
Call it a modeling error, call it an unspoken assumption -- either way, a technical barrier is a more formidable challenge to a purely renewable future than a peer-reviewed critique.