Lee Zeldin, the administrator of the US Environmental Protection Agency (EPA), delivered a keynote address at the Heartland Institute's climate conference in Washington, D.C. on Wednesday. In his speech, Zeldin dismissed established climate science, stating, “No longer are we going to rely on bad, flawed assumptions.” His participation drew criticism from over 160 environmental and public health organizations, which have called for his resignation, claiming he has betrayed the EPA’s core mission. The Heartland Institute, which hosted the event, has a history of climate skepticism, previously likening climate activists to the Unabomber. Zeldin's remarks included derision for previous administrations that followed climate scientists' warnings and emphasized the benefits of carbon dioxide. He also defended significant rollbacks of environmental regulations, including the controversial repeal of the “endangerment finding,” a key legal basis for climate regulations in the U.S. The conference featured other speakers who echoed Zeldin’s sentiments, reinforcing a narrative that challenges the scientific consensus on climate change. Zeldin's comments and the overall tone of the conference highlight a significant divide in U.S. climate policy and the ongoing debate over environmental regulations.