Campus energy professor Daniel Kammen announced his resignation from his position as science envoy in President Donald Trump’s administration with a written letter Wednesday.

As science envoy, Kammen coordinated with the U.S. Department of State headquarters and built partnerships using United States embassies in Africa and the Middle East, according to Kammen. He worked in this unpaid position for less than a year, starting October 2016.

As first reported by SFGate, Kammen released his resignation letter publicly via a tweet Wednesday morning. In his tweet, he wrote, “Mr. President, I am resigning as Science Envoy. Your response to Charlottesville enables racism, sexism, & harms our country and planet.”

“Herein, with regret, I resign,” Kammen said, in the letter released Wednesday. “Your actions to date have, sadly, harmed the quality of life in the United States, our standing abroad, and the sustainability of the planet.”

A White House administration official could not be reached for comment.

Kammen said in an email that he began to consider resignation as an option after Trump pulled out of the Paris Climate Accord, adding that before Trump became president, Kammen and his team made strides in various fields, including clean energy education and STEM education for girls.

Kammen is teaching a course called “Energy and Society” this semester at the College of Natural Resources and Goldman School of Public Policy. He also doubles as an adviser to doctoral candidates, including energy and resources doctoral students Juan Pablo Carvallo and Nikky Avila.

Avila said in an email that Kammen encourages students to engage in forward-thinking research and that his work has “contributed to policy changes that promote a just and sustainable society.”

Carvallo has worked with Kammen for five years as a part of Kammen’s lab, the Renewable and Appropriate Energy Laboratory. Carvallo said he believes the resignation is consistent with Kammen’s principles.

“I think it got to a point where the views of the administration were clashing with (Kammen’s) own values, so I think he had to go,” Carvallo said. “The commitment he has to policy making and science-based policy making is what kept him inside for so long.”

Kammen’s tweet received more than 115,000 likes on Twitter and more than 42,000 retweets. The first letter of each paragraph in the statement collectively spelled out the word “impeach.” Kammen stated in the letter that Trump has led with a “destructive pattern” that has affected his duties as science envoy. Kammen also noted that he cannot accept Trump’s decision to “undermine energy and environmental research.”

“I do not see (Trump’s) actions at present working in the best interests of the US and the global community on a range of issues,” Kammen said in an email.

Malini Ramaiyer is an assistant news editor. Contact her at [email protected] and follow her on Twitter at @malinisramaiyer.