Lee Zeldin, the administrator of the US Environmental Protection Agency (EPA), gave the keynote speech at a conference on Wednesday morning, one which was hosted by a prominent climate-denying think tank that previously compared those concerned about the climate crisis to the Unabomber on billboard posters in 2012.

“No longer are we going to rely on bad, flawed assumptions instead of accurate, present-day facts, without apology or regret,” Zeldin said at the Heartland Institute’s conference on climate change in Washington, DC, referring to well-established climate science.

Zeldin has been widely criticized by climate experts. Last month, more than 160 environmental and public health organizations called for him to resign or be fired, saying no EPA administrator in history “has so brazenly betrayed the agency’s core mission.”

In his speech, Zeldin poked fun at the media for calling him “controversial” for not “following blind obedience to whatever the dire, doom and gloom position of the day is from John Kerry or Al Gore or AOC”—referring to the congresswoman Alexandria Ocasio-Cortez. “It’s controversial that we won’t sign up for the script that the world is imminently about to end,” he said.