Interior Secretary David Bernhardt told lawmakers Wednesday that he hasn’t lost sleep over rapidly rising atmospheric carbon dioxide and that he has missed some news regarding concentrations of the greenhouse gas reaching the highest mark in human history.

It was a rather stunning admission from the chief steward of America’s public lands, which are affected by wildfires, drought and other threats exacerbated by human-caused global climate change. He oversees about 500 million acres, or about one-fifth of the United States.

Researchers announced this week that atmospheric CO2 levels have exceeded 415 parts per million (ppm) for the first time in more than 3 million years, before humans walked the Earth. Rep. Matt Cartwright (D-Pa.) questioned the newly confirmed agency chief about the CO2 milestone during a hearing of the House Natural Resources Committee.

“I didn’t see that particular fact,” Bernhardt said with two demonstrators wearing green swamp monster masks seated directly behind him. Bernhardt’s revolving-door experience in lobbying and government has earned him labels such as the “ultimate D.C. swamp creature.”

“I haven’t lost any sleep over it,” the former oil and gas lobbyist said when Cartwright asked him how he would rank his level of concern about this dangerous CO2 spike.