President Donald Trump is on the look-out for a chief science adviser, but who to choose?

If his most recent appointments are any indication of the future, then, on climate change at least, Americans should expect the president to tap a climate science denier.

So it is little surprise then that one person reportedly in the running is 77-year-old Princeton atomic physicist William Happer.

Happer has for more than a decade rejected all the credible evidence on the risks of human-caused climate change. He is often described as an “expert” on climate change, yet his record of publishing research on the issue in peer-reviewed scientific journals is almost non-existent.

So who is he?

Happer’s expertise is in atomic physics. He served in the George H.W. Bush administration as a science director.

But since the late 90s, Happer has become known for his outspoken and often offensive views on climate change and climate scientists, whom he has described as being “more like a cult.”

“They’re glassy-eyed and they chant. It will potentially harm the image of all science,” he told The Guardian.

He has also claimed that the “demonization” of carbon dioxide is like the “demonization of poor Jews under Hitler.”

In recent times Happer has been associating with conspiracy theorists and other oddballs as he rolls out the same talking points that have been his staple for years.

Since the mid-2000s, Happer was involved with the George C. Marshall Institute, a think tank that concentrated heavily on pushing claims that global warming concerns had been over-hyped. Happer was a former chair of the institute — one of many to take cash from oil giant ExxonMobil.

Happer is now the president of the CO2 Coalition — a group created after the Marshall Institute folded — with the tagline that carbon dioxide (CO2) is “vital for life.”

In 2015 Happer was caught in a sting by Greenpeace activists when he offered to write a report on the benefits of carbon dioxide for a fake fossil fuel client. He offered to find a way to hide the funder of the report by asking for the payment to go to the CO2 Coalition.

Happer’s position is shown to be wrong by all the credible evidence and scientific institutions across the world. His claims can also be easily checked.

So what are his claims?

In December 2016, Happer repeated his long-debunked talking points in an interview with Stefan Molyneux (himself an odd character who has had to fend off accusations that he is running a cult-like group through his FreeDomainRadio enterprise).

In the interview, Happer talks about a geological period known as the Phanerozoic eon which started about 540 million years ago and stretches to the present.

Happer says that over this period CO2 has been much higher, suggesting that everything was all fine and, by implication, it would be fine again if levels of carbon dioxide in the air got up to 1,000 parts per million or more.

Dr. Nerilie Abram, a climate scientist at Australian National University specializing in understanding the ancient past, told me:

The Phanerozoic covers an enormous amount of Earth’s history — the last 541 million years. If we were to think about that time period as a single day, complex life first evolved at midnight and the age of the dinosaurs (252-66 million years ago) lasted from just after midday (12:49 p.m.) through to 9:04 p.m. Modern humans only evolved at 11:59 p.m. (0.2 million years ago). So even though the Earth was able to support the slow evolution of life when it had carbon dioxide in the parts per thousand level, sea levels more than 100 meters higher than today, and land masses that were completely different to the countries we currently live in, that planet was certainly nothing like the one that humans have ever lived upon.

Happer also tells Molyneux: “There was no danger from ocean acidification … all of the other scare stories you read about. They just didn’t happen.”

That depends if, when you say there was “no danger from ocean acidification,” you don’t think the extinction of 90 percent of all marine species is anything to write home about.

Research published in the journal Science in 2015 found that ocean acidification from massive injections of carbon into the atmosphere was the cause of a “mass dying” about 250 million years ago which, according to Happer, “just didn’t happen.”

Happer also ignores how warmer conditions in the ancient past have generally coincided with the melting and collapse of ice sheets at the poles, pushing sea levels roughly 30 feet (ten meters) or more higher than they are today.

Many of Happer’s arguments ignore how quickly the climate is changing now compared to the past.

“The speed of current climate change doesn’t have an analogue in Earth’s past,” says Abram.

“We are able to directly measure the carbon dioxide level of Earth’s atmosphere over the last 800,000 years because of the bubbles of ancient air trapped within Antarctic ice cores. The fastest natural changes in the past occurred as the world warmed out of the ice ages, and saw CO2 levels increase by around 35 parts per million over 1,000 years. So far this century we have added an equivalent amount of CO2 to Earth’s atmosphere — 35 parts per million — in just the last 17 years.”

What else does Happer get wrong?

He claims a well-established climate mechanism, known as the water vapor feedback, “does not seem to work” and that this means future warming might not be so bad. Water vapor feedback is the mechanism where adding extra carbon dioxide causes warming, which then enables the atmosphere to hold more water vapor — another key greenhouse gas — that in turn causes more warming.

“There’s time enough [gone by] to see if it works and it doesn’t seem to work,” says Happer.

Unfortunately for Happer, the opposite seems to be true. As challenging as it is to measure, scientists have been using instruments on satellites, weather balloons, and aircraft and have found that water vapor is indeed increasing.

Perhaps Happer would know this if he had been hanging out with leading scientists at genuine academic gatherings, rather than spending time with some genuine oddballs.

As I wrote on The Guardian, in December 2016 Happer was a speaker at a gathering in Arizona organized by G. Edward Griffin and his Freedom Force International organization.

Griffin is a serial conspiracy theorist who thinks the HIV virus is not real, that there is some sort of international plot to spray the planet with chemicals (that’s right, he’s a chemtrailer), and that climate change is a hoax.

Will any of this convince Donald Trump to look elsewhere for his advice on science?

Given Trump is reportedly taking tips from another conspiracy theorist, Alex Jones, the likely answer to that question would be “no.”

Main image: Will Happer at the 2016 FreedomFest in Las Vegas, Nevada. Credit: Gage Skidmore, CC BY-SA 2.0