President Trump on Aug. 15 said that "there's blame on both sides" for the violence that erupted in Charlottesville on Aug. 12. (Bastien Inzaurralde/The Washington Post)

Daniel Kammen, a renewable energy expert appointed last year as a science envoy to the State Department, resigned Wednesday, citing President Trump's response to the violence in Charlottesville as the final straw that led to his departure.

Daniel Kammen (UC-Berkeley)

In a resignation letter posted to Twitter, Kammen wrote that Trump's remarks about the racial violence in Virginia had attacked “core values of the United States” and that it would have “domestic and international ramifications.”

Demonstrations by white supremacist groups on Aug. 12 turned deadly after a neo-Nazi plowed a car into a crowd, killing one counterprotester and injuring at least 19 other people in Charlottesville. Two Virginia state troopers were also killed when their helicopter crashed.

Trump's initial response was widely criticized, even by members of his own political party, for being insufficient and vague. Though the president later condemned the hate groups, he went on to effectively undo his conciliatory remarks by giving an off-the-rails news conference days later in which he once again blamed “both sides” in Charlottesville.

Kammen, who was appointed during Barack Obama's presidency, said it would be unconscionable for him to continue serving the administration after those remarks. He said he stood with “the unequivocal and authoritative statements” of a slew of other public officials, both Democratic and Republican.

“Acts and words matter,” Kammen wrote. “To continue in my role under your administration would be inconsistent with the principles of the United States Oath of Allegiance to which I adhere.”

However, his most biting message may have come in the form of a hidden acrostic: The first letter of each paragraph spelled out I-M-P-E-A-C-H.

The State Department appointed Kammen, an energy professor at the University of California at Berkeley, as one of five U.S. science envoys in February 2016. At the time, Kammen said he would be working on various global energy initiatives, as well as “the wider Paris Accord.”

In his resignation letter, Kammen cited other concerns that predated Trump's Charlottesville comments, including the president's decision to withdraw from the Paris climate accord in June.

“Particularly troubling to me is how your response to Charlottesville is consistent with a broader pattern of behavior that enables sexism and racism, and disregards the welfare of all Americans, the global community and the planet,” Kammen wrote. “Your decision to abdicate the leadership opportunities and the job creation benefits of the Paris climate Accord, and to undermine energy and environmental research are not acceptable to me. … Your actions to date have, sadly, harmed the quality of life in the United States, our standing abroad, and the sustainability of the planet.”

During his approximately 18 months as a science envoy, Kammen said, the United States had “built significant partnerships in North and East Africa, and in the Middle East, around shared visions of national security, job creation in the U.S. and sustainable energy.”

According to his letter, Kammen has also served in various federal roles since 1996, including at the Energy Department and the Environmental Protection Agency.

A State Department representative said: “Today, Dr. Daniel Kammen made a personal decision to resign. We appreciate his dedicated service to U.S. scientific diplomacy during his appointment working on energy efficiency and renewable energy in Africa as a Science Envoy. Margaret Leinen and Tom Lovejoy are current Science Envoys. The State Department’s Science Envoy program supports the establishment, strengthening, and mobilization of regional and global networks of scientists to advance U.S. science and technology priorities and solve real-world problems.”

Kammen did not immediately respond to a request for comment Wednesday.

Kammen wrapped up his resignation letter with something of a warning for Trump, borrowing the words of President Dwight D. Eisenhower: “A people [or person] that values its privileges above principles soon loses both.”

Trump's response to Charlottesville has cost him the support of a slew of business leaders and Hollywood performers who resigned from various presidential advisory groups.

From North Korea threats and Charlottesville blaming to his chief strategist's firing, President Trump packed a lot of headlines into his stay at his New Jersey golf course. Here's a look at what he got up to during his "working vacation." (Jenny Starrs/The Washington Post)

Kenneth C. Frazier, the chief executive of Merck, was the first member to quit the president’s American Manufacturing Council on Aug. 14, citing “a matter of personal conscience” and “a responsibility to take a stand against intolerance and extremism.” Trump quickly rebuked him on Twitter.

Over the next few days, several more executives followed Frazier's lead, prompting Trump to lash out at them as “grandstanders” who could easily be replaced.

Before the end of the week, both the manufacturing council and the president's Strategy & Policy Forum had been disbanded. Though Trump announced publicly it was his decision to end both councils, those close to the process, including JPMorgan Chase chief executive Jamie Dimon, said the groups had already decided to disband.

Last Friday, the members of the President's Committee on the Arts and the Humanities announced in a fiery letter that they were resigning en masse.

“Ignoring your hateful rhetoric would have made us complicit in your words and actions …” the letter stated. “Supremacy, discrimination, and vitriol are not American values. Your values are not American values. We must be better than this. We are better than this. If this is not clear to you, then we call on you to resign your office, too.”

That letter also contained a hidden message. The first letters in each of those paragraphs, taken together, spelled out: “R-E-S-I-S-T.”

Read more:

Trump’s business advisory councils disband as CEOs abandon president over Charlottesville views

Trump celebrates solar eclipse by looking up without special viewing glasses

Trump, first lady to skip Kennedy Center Honors over concerns of ‘political distraction’