Owen Brian Toon

2011 Roger Revelle Medal Winner

Owen Brian Toon was awarded the 2011 Roger Revelle Medal at the AGU Fall Meeting Honors Ceremony, held on 7 December 2011 in San Francisco, Calif. The medal is for “outstanding contributions in atmospheric sciences, atmosphere-ocean coupling, atmosphere-land coupling, biogeochemical cycles, climate, or related aspects of the Earth system.”


Brian Toon studies the most difficult problems in atmospheric sciences, often dreaming up new ones. His work in atmospheric physics and chemistry as applied to clouds and aerosols on Earth and the planets includes seminal contributions in global climate change and ozone depletion, development of community microphysical models, leadership of ­high-​­profile NASA airborne missions, mentoring of junior colleagues, and contributions to public awareness of global environmental issues. Virtually all superlatives apply to his many accomplishments.

Brian began as a planetary scientist, honing his skills as a theoretician and applying detailed and computationally efficient radiative transfer codes to problems ranging from Martian dust storms to the extinction of the dinosaurs. While on a trajectory that would make him a world leader in planetary sciences, his work on nuclear winter (a term first used in his 1982 “TTAPS” paper, named for R. P. Turco, O. B. Toon, T. P. Ackerman, J. B. Pollack, and C. E. Sagan) introduced him to the world of geopolitics. Brian soon adapted his codes to address sulfate aerosols and the marine sulfur cycle, and with such an effective tool, it wasn’t long before he was drawn into the vortex of stratospheric ozone. His seminal study of the thermodynamics explained the appearance of polar stratospheric clouds responsible for the “ozone hole” over Antarctica (Geophysical Research Letters, 1986). His work and service ever since have remained at the intersection of science and policy.

Brian has remained a visionary in both worlds—Earth sciences and planetary sciences. His scientific achievements continue to illuminate and advance. He posited the importance of absorption of sunlight by ­sulfate-​­coated soot particles; defined the critical roles of cirrus clouds, subvisible cirrus, and dust on atmospheric water and energy balance; and showed how air pollution can reduce cloudiness (in contrast to the opposite but better known “indirect effect”). His concurrent work on the atmospheres of Mars and Saturn’s moon Titan motivated some of the most innovative planetary missions, including those that use direct observations of those worlds to understand the causes of climate change back here on Earth.

Through his service, Brian is dedicated to increasing knowledge and improving the human condition. His early leadership skills were honed when he served as deputy project scientist for NASA’s first airborne polar ozone campaign (Airborne Antarctic Ozone Experiment (AAOE)). Results from that mission and the many that followed sealed the scientific case linking chlorofluorocarbons to polar ozone depletion and solidified negotiations that produced the international agreements now successfully protecting the ozone layer. His unselfish leadership and ­consensus-​­building approach to these large-scale, multi-investigator science campaigns set a high standard for subsequent generations of mission scientists.

Brian continues to provide expert advice on the effective use of suborbital vehicles in atmospheric research. His lasting impact on science also includes his mentoring of outstanding postdocs and students too numerous to list; development of accurate and numerically efficient models that he generously shares with others; and, as chair for a decade, guidance of our young program at the University of Colorado into a top-tier department as recognized by the National Research Council.

It is my great honor to introduce Brian Toon, the 2011 recipient of the AGU Roger Revelle Medal.


—Darin Toohey, University of Colorado at Boulder


Thank you so much for the Roger Revelle Medal. I am surprised to be in the company of Roger Revelle and the previous winners of this award, and very pleased. Of course, this is the sort of event that makes you think back.

My first thought was, Why am I doing this? Few of us do science just to put food on the table. Some have suggested that science is a contact sport and we seem to thrive on the competition. However, I have been driven since childhood to understand everything around me and to puzzle out the great mysteries of the day. What causes the climate to change? How do Earth and the planets compare? How did we get here, and where are we going? Science is a giant treasure hunt with shiny prizes hidden all around. I have had great fun with my colleagues, students, and postdocs digging up little clues to big problems. My greatest blessing has been the wonderful people who have gone along with me on this adventure, and of course they did all the digging. I especially thank Maggie Tolbert, my most valued colleague in science and in life.

My second thought was a conversation I had 30 years ago with Steve Schneider.  Steve suggested that you aren’t doing anything important unless everyone is complaining about you. Ever since, I have been happy about the many people complaining about me. I recommend this attitude to you next time you get a paper reviewed or read the latest attacks on climate science. Many think we have not told our story well enough, not presented the facts clearly enough, and that is why there is such intense scrutiny of our field. While communication is important, and hard to do, I think the basic facts about climate change have been heard very clearly, and because they are so important people are challenging them, trying to figure out how to get around them, and aiming to intimidate us so we will stop digging up any more facts. Keep digging.

My final thought is that no matter how bad things seem at the moment, they are getting better over the long run. Look back to insurmountable obstacles in your past and see how they were overcome. It once seemed that China and India would forever be unable to feed their populations, but now, because of agricultural technology, both are challenging for world leadership. Dictators and totalitarian regimes once controlled much of humanity. The political world is still not perfect, but because of communications technology, the voices of individuals have led to the near-global spread of free societies.  Population growth drives climate change and extinctions. Fortunately, through education, improved health care, and expanding opportunities, the population growth rate is declining, and one can see a distant future where population stabilizes.

The good guys do win, nice people don’t finish last, the world is becoming a better place, and there are still lots of science treasures waiting to be found.

—Owen Brian Toon, University of Colorado at Boulder