…I was fortunate to be promoted to Assistant Professor, and I took great pleasure measuring previously inaccessible properties of excited atoms with my graduate students and post docs. Although I tried to ignore the Vietnam war, it was becoming an increasingly divisive factor in American life. Keeping up an old family tradition, my brother Ian served as a US army doctor in South Vietnam.

After the 1970 US invasion of Cambodia, our physics building was seized by protesters. With other physics faculty and students, I was held captive for several days. The pretext was that several senior physics professors, notably Mal Ruderman and Henry Foley, were members of JASON, a group that did classified and unclassified studies for the US government. Having had several sleepless nights becoming acquainted with the protesters, while defending our cherished equipment with other young faculty members, I decided that JASON must be a pretty good organization if it had enemies like these. So, when Henry Foley asked me to join JASON a few years later, I was honored to do so. JASON continues to do valuable work for the USA, and I am still a member.

During a JASON summer study in 1982, some senior technical people from the US Air Force and DARPA asked the JASONs if they could think of any way to help ameliorate the distortion of laser beams by atmospheric turbulence. This is the same phenomenon that limits “seeing” of large, ground-based telescopes. After passing through parcels of warm and cool air, an initially flat optical wave from a laser or a distant star is “wrinkled.” If you are trying to use a high-power laser to shoot down an attacking missile, the wavefront distortion prevents you from focusing all of the laser power on target. And the image of a star at the focal plane of a big telescope is splattered into hundreds of speckles, instead of a sharp point. This seriously limits the angular resolution, which is one of the main rationales for a big telescope. At that time, it was known that for sufficiently bright stars, you could use the starlight itself to measure the wavefront distortion. This information could be used to control a deformable (“rubber”) mirror in such a way that when the distorted wavefront reflected on it, most of the wrinkles were removed.

But you can’t see many bright stars in the sky at night, and none at all during the day. So, Air Force defenders were going to have a hard time unless their targets were obliging enough to be backlighted by bright stars like Sirius or Vega. By luck, I thought I knew the answer to the problem. It turns out there is a layer of sodium atoms at an altitude of about 100 km above the earth’s surface. The atoms are released when micrometeorites burn up in the atmosphere. I knew from my work at Columbia that sodium atoms had huge scattering cross sections for yellow resonant light — the same as the light you see if you happen to spill salty water into the flame of a gas cooking stove. So, I proposed that the Air Force invest in a big sodium laser and use it to create an artificial “sodium guide star” just in front of their desired target.

After some initial skepticism, the Air Force gambled that the idea would work. A brilliant team of scientists and engineers led by Bob Fugate soon built and successfully tested a sodium guide star at the secret Starfire Optical Range in the desert near Albuquerque. Some ten years later, after the collapse of the Soviet Union, and the independent proposal by astronomers to build a sodium guide star, the Air Force work was declassified, largely due to the persistence of my JASON colleague and friend, Claire Max, then at the Livermore National Laboratory. Finally getting a little public recognition for my work, I was elected to various scientific societies, including the National Academy of Sciences. More details can be found in The Adaptive Optics Revolution: A History, by Robert W. Duffner (University of New Mexico Press, 2009).

I learned a lot about the atmosphere at JASON. I was involved in the analysis of “thermal blooming” of high-power lasers when they are weakly absorbed by H₂O and CO₂molecules in the atmosphere. The physics is closely related to that of greenhouse warming. I learned about the physics of the tropopause, where much of the wavefront distortion of starlight or defensive laser beams takes place. I was one of 14 JASON coauthors of one the first books on global warming, with the nerdy title, The Long-Term Impacts of Increasing Atmospheric Carbon Dioxide Levels, edited by Gordon J. MacDonald (Ballinger Publishing Co., 1982). We over-predicted the warming from more CO₂ as badly as later establishment models, a topic to which I will return below.

My invention of the sodium guide star gave me some credibility in parts of the US government, but since the work was highly classified in the first few years, only a few scientists knew about it. I scrupulously avoided working on related areas with my university students. But based on this classified notoriety, I was elected to be Chair of the JASON steering committee in 1987, and in 1990 I was appointed Director of the Office of Energy Research at the US Department of Energy (DOE) by President George H. W. Bush, where I served under Secretary of Energy, James Watkins, until the election of President Bill Clinton and Vice-President Al Gore in the 1992 election. I served for three more months under Secretary Hazel O’Leary in the spring of 1993. I was fortunate that both Secretaries of Energy were supportive of basic science, the responsibility of my office.

The DOE Office of Science had an annual budget of over $3 billion at that time, more than the National Science Foundation. It funded almost all of DOE’s non-weapons basic research, including a great deal of environmental science and climate science. This was my first encounter with the climate establishment, and I was surprised to find environmental science so different from high-energy physics, nuclear physics, materials science, the human genome, and the many other areas we had responsibility for. I insisted that my assistant directors arrange for regular seminars, given by principal investigators of grants we supported. In most fields, principal investigators were delighted that government bureaucrats were actually interested in their research. They enjoyed being questioned during their talks, since this allowed them to show off their erudition. But, with honorable exceptions, principal investigators working on environmental issues were reluctant to come to our Washington offices, and evasive about answering the questions that were so welcome to briefers from other fields.

About three months after the beginning of the Clinton administration, Hazel O’Leary called me into her office to ask, “What have you done to Al Gore? I am told I have to fire you.” I assume that the main thing that upset Al Gore (left) was my questioning of blatant propaganda about stratospheric ozone that was his focus at the time: “ozone holes over Kennebunkport” and similar nonsense. Although Secretary O’Leary offered to find a way to keep me at DOE as a civil servant, I was glad to have an excuse to get back to doing real science at Princeton University, which was kind enough to offer me a professorship again.

For the next few years after my return to Princeton in 1993, I was very busy working on an exciting new project on magnetic resonance imaging with laser polarized nuclei that my young colleague, Professor Gordon Cates, and his students had pioneered while I was at DOE. But watching the evening news, I would often be outraged by the distortions about CO₂ and climate that were being intoned by hapless, scientifically-illiterate newscasters. My wife Barbara, who patiently sat through my outbursts, finally said, “Why don’t you speak up?” At Barbara’s urging, I began to speak up and I have never stopped.

I often hear that since I am not a card-carrying climate scientist — that I, and many other scientists with views similar to mine, have no right to criticize the climate establishment. But as I have outlined above, few have a deeper understanding of the basic science of climate than I. Almost all big modern telescopes use my sodium guidestar to correct for atmospheric turbulence. It works. As we will see below, most climate models do not work. The history of science shows many examples of fields that needed outside criticism. A famous example is Andrei Sakharov’s leadership of opposition to Trofim Lysenko’s politicized biology in the Soviet Union. We will have more to say about Lysenko (right) later in the interview, but one of Lysenko’s main defenses was that Sakharov, a physicist who invented the Soviet hydrogen bomb, was not a “Michurinian” biologist.

The need for outside criticism was well articulated by James Madison, arguably the first graduate student at Princeton University, and the principal architect of the US Constitution. In the “Federalist X,” Madison wrote: