A member of the State Department's science envoy program resigned Wednesday and took a parting shot at the president on his way out.
Daniel Kammen, a professor of energy at the University of California, Berkeley, tweeted early Wednesday morning he would be departing from his role as a science envoy to the State Department.
In his accompanying resignation letter, several sharp-eyed Twitter users spotted a curious acrostic from the first letter in each paragraph that seemed to spell out a message about Donald Trump: "IMPEACH."
Kammen has served in various roles for the Department of Energy, the Environmental Protection Agency and the State Department since 1996.
The science envoy program website notes Kammen's work in renewable energies. Reviving the coal industry was a major campaign issue for Trump. In late March, he signed an executive order reversing the Obama Administration's Clean Power Plan, which would have closed coal-fired power plants and frozen construction on new ones while replacing them with wind and solar farms.
Last week, a business council advising Trump was disbanded by the president after a string of high-profile resignations, starting with Merck CEO Kenneth Frazier.
Several business council members also cited Trump's response to the racist violence in Charlottesville as the catalyst for their resignation.
The State Department's website lists six other science envoys and as of this writing had yet to reflect Kammen's resignation.