I wrote this note in the hope that some youngsters may benefit from an example of how careers evolve, and in response to questions about the seeming tension between my work on technofixes and my personal links to environmental activism.  

A dyslexic child, I did not learn to read until the end of 4th grade, but then quickly became a bookworm. My parents were intellectually ambitious. Deborah Gorham (mom) was a feminist scholar and activist. Tony Keith (dad) is an environmental scientist who left his graduate work studying DDT in herring gulls to start up toxic chemicals research at the Canadian Wildlife Service, where he built a career doing applied environmental science and management.

I gradually did better at school but was never a star student. In high school I mixed in with three (mostly) non-overlapping crowds: the punks (sex pistols), the nerds (dungeons and dragons), and an outdoors club (camping and natural history). One lucky break in Grade 11 was a teacher, Mr Maris Neimanis, who got a handful of us coding. It was 1979. We started programming Fortran on bubble cards that got sent away to the schoolboard computer and returned with the line printer output. One mistake or a smudged card meant a two day wait. We soon got access to the university computers with punch card machines, and by Grade 12 or 13 we were programing the simplex algorithm in APL on terminals at the university. It was a special time. When I visited school a few years later, programing had become an official subject and a class was writing short basic programs on commodore PETs.

I have been profoundly lucky with mentors. My first big break was getting hired by Paul Corkum to work in his laser physics lab at Canada’s National Research Council for three summers starting in Grade 11. My stepmom was volunteering with Paul’s wife to settle Vietnamese refugees and got me a tour of Paul’s lab. Paul was not overjoyed to be pressed into giving tours, but I asked good questions and got a job. Paul is now a very bright star in the physics universe, but when I joined his lab in the summer of 1980 his group was small, and he had time to mentor an eager summer student. I learned optics, electronics, machining, and much more. Paul introduced me to the Feynman Lectures and to Dyson’s Disturbing the Universe.

My undergraduate experience in physics at U-Toronto was mixed—as was perhaps inevitable after my jump-start with Paul. The intellectual highlight of my undergraduate years was philosophy. I was lured on by amazing teachers, most notably Ian Hacking, and ended up taking many philosophy courses. I dropped out of university at the beginning of my 3rd year, driven by some combination of hormones, an urge to climb, and a need to break with my parents’ expectations. I restarted school later that year and ended on a mixed note: Toronto’s physics department rejected my grad school application, yet I ended up winning Canada’s national physics prize exam.

After undergrad, the outdoors called louder than career. I did odd jobs, climbed, and looked for ways to get paid to be in the wilds. Through my dad’s network I got a job with wildlife biologist Ian Sterling studying walruses at Dundas Island in the high Arctic of Canada. Among other tasks I helped Ian brand walruses for later identification, so with mild exaggeration I can add “professional walrus brander” to my CV. Ian’s unusual combination of warm and effective leadership with scientific rigor remains an inspiration to me. 

Despite reservations, I decided to try for grad school in physics because I knew I was good at it. Paul Corkum’s recommendation was likely decisive in getting me admitted to MIT as Dave Prichard’s student. Tabletop physics of the kind practiced by Corkum and Pritchard is a both a craft and an intellectual discipline. It’s a talent that’s hard to test for, so recommendations count for a lot. I loved the day-to-day work—theory, hands-on skills—in Dave’s lab more than any other job since. Building the first atom interferometer was a thrill, but I was not answering questions that mattered to me, and I was unexcited about practical applications of the work. My research was funded by the Office of Naval Research, and it was possible that an atom interferometer could make an exquisitely sensitive gyro that might improve inertial navigation for submarines. A ballistic missile sub needs to know its position with high accuracy if it is going to hit a missile silo. One need not be accurate to burn a city.  And there is no reason to hit an empty silo. Giving ballistic missile subs better accuracy would help make them “counterforce” or first-strike weapons.

Through grad-school friendship networks, I fell in with students working on interdisciplinary problems of climate change. The group included grad students from meteorology, political science, public policy, and others from MIT and Harvard. All were drawn to work on some aspect of climate change, and all shared the conviction that progress demanded reaching across disciplines.

The group was in the vanguard of climate research—a new generation pushing ahead of our professors. Ted Parson was the convener of the group and has been a friend and collaborator ever since. I joined in 1988 and was soon working on a review of geoengineering as described elsewhere on this site. A few years later, while finishing my doctorate, I met Hadi Dowlatabadi who convinced me to leave physics and join him as a postdoc at Carnegie Mellon’s Department of Engineering and Public Policy (EPP), launching my professional career at the interface of climate science and public policy. I published my first geoengineering review with Hadi in 1992.

Here’s is quick sketch of the following three decades. More than any other person or institution, EPP’s approach to analytical work at the technology-policy interface set the tone for the rest of my career. But I knew I needed more climate science. So I applied for NOAA’s Climate and Global Change Postdoctoral Fellowship and went to work for Phil Rasch at the National Center for Atmospheric Research (NCAR) in Boulder. One day at the NCAR lunch table, Ralph Keeling overheard me mentioning that I was a Prichard student. He took me out to dinner telling me that there was always another physicist coming into do climate modeling, but that there were not enough people with experimental talent developing new measurements.

Ralph convinced me that I should either follow him to Scripps or go to Jim Anderson’s group at Harvard where, as Jim’s postdoc, Ralph had measured the Earth’s respiration oxygen, the perfect complement to his father’s CO2 measurement. I went to Jim’s group where I built an accurate radiometer for NASA’s ER-2 but failed to get it on a satellite. During the years at NCAR and with Jim’s group, I kept the connection to EPP and public policy, and in 1999 I moved back to Pittsburgh to take a faculty job. The work was great, but we had young kids and wanted to move back near family in Alberta. So, in 2004 I moved to U-Calgary which was starting a major energy and environment program. The U-Calgary years were packed. In 2007 Jabe Blumenthal invited me and then Ken Caldeira to brief Bill Gates on climate. That meeting grew to into a long sequence of over twenty meetings on climate and energy that we, along with Karen Fries, ran for Bill over the next fifteen years.

I founded Carbon Engineering in 2009 as described elsewhere on this site. But by 2010 U-Calgary’s program was floundering and Harvard was calling, so I moved back to Cambridge for a third time.

In 2023 after decades of working on geoengineering from the fringes, I moved to U-Chicago to lead the Climate Systems Engineering initiative (CSEi). I was excited by U-Chicago’s commitment to build climate systems engineering as a field. I was turning 60 and change felt good. Rather than focusing on my own research, my goal is now to recruit new faculty and build a broad research community.


One lesson I draw from this is the profound role of chance. A chance connection got me a tour of Paul’s lab which was the best imaginable entrance to physics. A chance conversation with Hadi, my family’s neighbor’s daughter’s boyfriend, got me a postdoc in climate policy which shaped the rest of my career. And finally, a chance meeting with Ralph Keeling got me out of NCAR and into Jim Anderson’s Lab where I learned stratospheric science along with hardware engineering and management skills that gave me the confidence to start Carbon Engineering.

Students coming to me for career advice too often aim to walk a narrow path towards an ideal career. But overfocussing on a narrow path reduces one’s ability to take advantage of random opportunities that might yield a better outcome on a somewhat different path. Inflexibility yields missed opportunities, but excessive flexibility yields an opposite error: Jump around too much and it’s hard to develop the reservoir of skills and contact networks that allow one to get more done with less effort. I like to think of career advancement as a directed random walk in some aptitude-opportunity space, a walk that is directed towards a goal that slowly drifts with accumulating experiences. 

Another lesson is the pivotal role of mentors and their recommendations. Seek out mentors whom you respect. Ask them for advice. I remind myself of the how much I relied on my mentors every time I find myself recoiling at the prospect of having to write another recommendation letter. 


I have avoided the personal in this essay, but a mention of my outdoor life seems appropriate as an influence on my work.

I got the outdoor bug in high school, getting out with friends camping winter and summer. Almost all our trips were self-directed. At about 17 I did a solo hike on the Appalachian Trail from Maine to Vermont. I was getting comfortable traveling on my own. A few years later I skied solo across Algonquin park.

One of my only experiences with organized outdoor education was a hideous month at a wilderness canoe camp in north Ontario. My one friend Mark and I were mocked as nerds (‘the professors’) before we both left on separate multi-week trips. When I returned from my trip, I learned that Mark had been killed in a whitewater accident. This reinforced my inclination towards self-organized trips. Only in the last few years, have I spent a few days with alpine guides and learned to appreciate their deep physiological and technical skills.

In the decades since, I have been lucky to spend a lot of time in deep wilderness including more than 1,000 km of ski expeditions in the High Arctic, several multiweek paddling trips on northern rivers, two long subarctic base-camp trips, solo hiking in the Himalaya, multi-week sea kayak trips in the Philippines and off Canada’s east coast, and innumerable camping trips.

I got the climbing bug in my early 20’s, dropping out of school for a spell with extended stays at the Gunks and Joshua Tree. Climbing lapsed with kids in my 30’s, but I restarted in my late 40’s—mostly sport, but some alpine, and ice. Now at 60 I am learning the new-school art of projecting sport routes and am keen to push beyond the mid 12’s before I get much older, while still being puzzled by how this is remotely doable when 11b felt so hard in the late 80’s. Here’s a screed about Free Solo I wrote for Gripped and a few pix.

The wilds shaped my professional life. As keen as I was to succeed in environmental science, I was always half thinking that I’d should quit academia and get outside. I was confident that cheap living plus contract tech skills could make an outdoor life work. This gave me confidence to take career risks like working on solar geoengineering, because the downside risk of career failure just didn’t scare me much.

Time in the wilds and a friendship network filled with folks who work in conservation or field biology have also shaped my professional judgments about climate and environmental protection.

The urgent need to act on climate too often subsumes all other environmental concerns. And climate’s gross injustice—that accumulated emissions from the rich now threaten the life and livelihood of the poor—can make it seem an affectation of the rich to express concern about any impacts of climate beyond those affecting human welfare.

Justice between rich and poor ought to be central to public policy. But climate is just one of many arenas where policy can alter distributions of wealth and power. One can imagine a world that is far more just without satisfactorily resolving climate; and one can imagine great climate progress without reducing injustice.

But one cannot decouple choices about climate and the natural environment. Other hazards may pose more immediate environmental threats than climate, but industrial civilization cannot hope to spare more of the natural environment without resolving climate. That means developing the capacity to not just halt warming but to restore climate back towards the pre-industrial.