For the many months preceding the appointment of Kelvin Droegemeir to finally fulfill the role of White House Science Advisor, there was a bit of a “will they/won’t they” storyline with retired Princeton physicist William Happer. Happer—who also served at the Department of Energy during the George H.W. Bush administration—is better known these days as a climate contrarian willing to publicly claim that CO 2 emissions are a boon rather than an existential threat.

In the end, Happer was not tapped as Science Advisor by the Trump administration, but E&E News reported Tuesday that he is now a member of the National Security Council.

Happer was previously listed as the director of a group called the “CO 2 Coalition,” which has a website that claims that CO 2 released from fossil fuels is just good news for global plant growth while having no real effect on Earth’s climate. (These claims are false.) He has also taken to referring to the field of climate science as a “cult movement.”

Happer has testified at a number of government hearings on climate change—including one in Minnesota for which he was paid by Peabody Coal. At a 2015 Senate Subcommittee on Space, Science, and Competitiveness hearing, he voiced support for explicitly dedicating funding to scientists who reject the consensus conclusions of climate science. (Any researcher can submit study proposals to the National Science Foundation, where they are judged on scientific merit and funded based on the available budget.)

And when former EPA Administrator Scott Pruitt floated the idea of a public “red team” climate debate pitting contrarian scientists against representatives of the rest of the scientific community, Pruitt’s office turned to Happer for suggestions for people who would argue against the science.

Happer’s exact role on the Natural Security Council is unclear, but he described his role to E&E News as senior director for Emerging Technologies. E&E News writes, “When asked about his new NSC role, Happer said he would do his best to ensure that federal policy decisions ‘are based on sound science and technology.’"