U.S. District Court Judge William Alsup is presiding over climate liability cases by San Francisco and OaklandJudge William Alsup will preside over a hearing to discuss the state of climate science in the San Francisco and Oakland liability cases. Photo credit: Michael Thielen via Flickr

By Amy Westervelt

Perhaps the most surprising part of the ruling that the San Francisco and Oakland climate liability cases should remain in federal court was the subsequent hearing ordered by U.S. District Judge William Alsup. He scheduled a climate science tutorial, a five-hour hearing during which lawyers for both the plaintiffs and the defendants will present information on the current state of climate science.

Alsup also presented eight questions he wants both sides to answer on March 21, including the mechanisms that trap carbon dioxide in the atmosphere and the sources of that CO2.  

“His questions are fairly idiosyncratic, but in general I think this shows an interest in wanting to understand the scientific information underlying these lawsuits, and a tutorial is a good way to do it because then it becomes a public education tool as well,” said Peter Frumhoff, director of science and policy and chief climate scientist at the Union of Concerned Scientists.

Alsup, 72, has a history of digging into the details on cases he’s adjudicating. He learned to code in Java for a case between Google and Oracle and ordered a tutorial on self-driving cars for a recent case between Waymo and Uber.

One aspect of the science missing from his list of questions is any mention of attribution science, particularly recent advancements that connect anthropogenic climate change to the exacerbation of extreme weather events and research that links historic emissions to individual fossil fuel producers.. Frumhoff said he hopes lawyers for San Francisco and Oakland will get a chance to brief Alsup on attribution. “We can now look at total global emissions and ask about the sources of those emissions,” he said. “Scientists have recently quantified how much rise in global sea level can be attributed to particular global fossil fuel companies. That’s relevant to the specific cases before this judge.”

Frumhoff said he doesn’t expect attorneys for the fossil fuel companies to take an adversarial approach. Several fossil fuel companies, most notably Exxon, currently embroiled in multiple climate lawsuits, have recently made clear statements about the risks posed by climate change and the need to address those risks.

Gavin Schmidt, a climate modeller at the NASA Goddard Institute for Space Studies and Earth Institute at Columbia University, has been crowd-sourcing answers to Alsup’s questions from the climate science community, and said he also can’t imagine the defendants’ attorneys attempting to refute the climate science presented.

“There are of course nonsense statements that have been made concerning each of the questions—how many times have we heard that CO2 can’t be a problem because we exhale it?— but I doubt that full-on denialism is what the defendants will go for,” he said.

The defendants, however, could try to emphasize uncertainty in the science in the past.

Some companies may “want to characterize, in the context of questions about climate, that there’s a range of uncertainty over how much change in temperature we might see from CO2 emissions,” Frumhoff said. “They may want to make the argument that there has been historic uncertainty that’s in keeping with the muted policy response that they have advocated for.”

Alsup’s hearing will be video-taped, so whether the legal teams get into a science debate, their presentations will be widely debated online. In the meantime, Judge Vince Chhabria, another judge in the U.S. District Court for the District of Northern California, will decide soon whether the other California climate litigation cases (brought by the counties of Marin and San Mateo and the city of Imperial Beach) should be remanded back to state court, which many predict he will do, making the jurisdictional issues in these cases even more intriguing.