Kammen runs the Renewable and Applied Energy Laboratory at the University of California, Berkeley. As a science envoy, his role is to “leverage [his] expertise and networks to forge connections and identify opportunities for sustained international cooperation,” according to the state department website. Kammen’s role, specifically, is “building capacity for renewable energies.”

In his letter, Kammen lists his decision to resign specifically as the President’s “attacks on core values of the United States,” including his “failure to condemn white supremacists and neo-Nazis,” which has “domestic and international ramifications. He lists the Charlottesville response as “particularly troubling,” as part of a “broader pattern of behavior that enables sexism and racism.”

The resignation comes in the wake of tons of others in response to the President’s post-Charlottesville behavior. CEOs began stepping down from the President’s manufacturing council before he disbanded it. All of the members from the White House Arts Committee also resigned this week. And the assault on science continues—the NOAA under the president disbanded the National Climate Assessment Advisory Committee, also last week.

I’ve reached out to Kammen and the White House for further comment.

Update 8/24/17 8:30AM: A White House spokesperson told Gizmodo that Kammen was appointed by Barack Obama, and that his one-year term would have ended in late September, which Kammen confirmed.