Princeton University professor emeritus William Happer is a distinguished atomic physicist. But he is also a climate skeptic whose scientific reputation will be forever tarnished by his participation in the Trump administration.

An internationally recognized expert on the interaction of laser light with matter, his seminal idea of laser “guide stars” permits ground-based telescopes using “adaptive optics” to compete with orbital facilities like the Hubble Space Telescope. In effect, this technique takes the atmospheric twinkle out of stars and other celestial objects, allowing earthbound telescopes to achieve the high spatial resolution needed to observe their fine structural features.

Since the mid-1990s, however, Happer has been a leading member of a small group of scientists disputing widely held conclusions of anthropogenic climate change. A member of the National Academy of Sciences, he made arguments that were a major factor in my own reservations on the subject until the evidence became—in my judgment—overwhelming during the early 2000s.

At first Happer argued that the infrared absorption length of atmospheric carbon dioxide—the distance through which infrared radiation falls by almost two thirds—is only about 25 meters and thus that doubling its concentration would make little difference by cutting this length in half.

But that argument, which had been advanced by others, has been thoroughly debunked by climate scientists for several reasons, including because it ignores the convective churning of the atmosphere that helps transport heat upwards. This specious argument had me fooled for years. The experience has colored my appreciation of Happer’s climate skepticism.

More recently, he has focused his skepticism around the claim that carbon dioxide is not a pollutant at all and that more of it will be beneficial, enhancing plant growth. But for every positive impact like this, one can easily cite a dozen adverse ones—such as arctic and permafrost melting, sea-level rise, ocean acidification, the raging wildfires experienced in western states, and the more intense hurricanes hitting Caribbean islands and Gulf Coast states. This is another weak, specious argument.

In a way, Happer’s behavior reminds me of that of another eminent but aging physicist, 1956 Nobel laureate William Shockley, whose work I have examined. Honored for his leadership role in the invention of the transistor, he turned in the 1960s to the subject of race and intelligence—fields in which he had no particular scientific expertise. Despite widespread public condemnation and scientific ridicule, he persisted in this quixotic effort for the remainder of his life.

In addition to his impressive scientific credentials, Happer is no stranger to the federal government. A political appointee of President George H. W. Bush, he served as the director of the Department of Energy’s Office of Energy Research from 1991 to 1993, when it was building the Superconducting Super Collider, a gigantic particle accelerator in Texas. He’d planned to continue in that position under Bill Clinton but left after disagreements with Al Gore about the ozone hole over Antarctica.

Nearing 80 years of age, Happer entertained the possibility of joining the Trump administration as director of the Office of Science and Technology Policy. But the invitation never came, and he instead joined the National Security Council staff in 2018 as senior director for emerging technologies.

Now we learn that he will lead a federal working group reexamining climate change and its implications for national security, a subject that has been thoroughly studied by the Defense Department and intelligence agencies. It remains to be seen who else will join this group or what it might conclude, but it’s not difficult to guess.

Any report produced will most likely not be read by this president, who has evinced a profound disinterest in the recommendations of scientists, academics and other experts. But if the report minimizes or denies human-caused climate change, which will most likely happen given its provenance, the president will surely trumpet it as evidence for his wholesale rejection of this conclusion.

For Happer to lend his name to such a biased, unscientific process will only tarnish his reputation further among the global scientific community. For this endeavor will likely help buttress the president’s continuing attempts to sow confusion among the general citizenry about what constitutes “truth” and whom to trust in attaining it. Like other noteworthy autocrats, he would much prefer that we just accept whatever he says as true.

Science has achieved its widely respected standing by accepting empirical evidence and reasoned argument as lodestars to the truth. Flawed evidence and biased reasoning can and do creep into the process but are eventually weeded out by skeptical scientists repeatedly subjecting results to further examination. Any accepted theories are therefore conditional, subject to continued testing.

Happer might claim that this is his purpose in questioning the current scientific understanding of climate change. But he has shown his fellow scientists great disrespect, calling climate science a “crusade,” dismissing its conclusions out of hand, and disparaging much of the peer-reviewed literature published on the subject for decades. Essentially all major scientific organizations—including the American Association for the Advancement of Science and National Academy of Sciences—have endorsed the broad conclusion that human activities in burning fossil fuels are the principal cause of climate change. His is the word of one man against hundreds, if not thousands, of equally respected voices.

What I find so objectionable about Happer’s troublesome initiative is his attempt to use a blatantly political process—of a president and an administration demonstrably disdainful of science and wedded to “alternative facts”—to subvert well-established science.

Happer’s leadership of this administration’s attempted end run around climate science therefore deserves the censure of the U.S. scientific community.