Environmental Protection Agency (EPA) Administrator Michael Regan will leave the Biden administration at the end of this year — about a month before the presidency changes hands. While Regan could serve until Trump’s inauguration, he notified staff on Friday he will leave a few weeks early. “Today, I am writing to let you know that my last day as your Administrator will be Dec. 31,” he wrote in a note to EPA staff. “I am so proud to be part of the EPA family,” he wrote, touting the agency’s regulations over the past four years aimed at mitigating climate change and pollution. Jane Nishida, head of the agency’s Office of International and Tribal Affairs, will serve as acting administrator in Regan’s absence. The message said Regan would “return home” to North Carolina, but gave no other information on his next steps. President-elect Trump has already said he would nominate former Rep. Lee Zeldin (R-N.Y.) to helm the agency during the incoming administration.