Peter J. Huybers

2009 James B. Macelwane Medal Winner

Harvard University

Peter J. Huybers, Miaki Ishii, and Benjamin P. Weiss were awarded the 2009 James B. Macelwane Medal at the AGU Fall Meeting Honors Ceremony, held on 16 December 2009 in San Francisco, Calif. The medal is for “significant contributions to the geophysical sciences by a young scientist of outstanding ability.”


It is my great honor to introduce Peter Huybers to receive the AGU Macelwane Medal. Peter is an extraordinary climate scientist who has made fundamental contributions to understanding past and future climate change. Peter was an undergraduate at West Point Military Academy. Following several years of military service, he was trained in oceanography and climate dynamics at Massachusetts Institute of Technology (MIT) under the supervision of Carl Wunsch. His thesis work focused on understanding the periodic nature of Pleistocene glaciations. Specifically, he used statistical methods to develop better age models to test some of the different hypotheses about connections between changes in the Earth’s orbital variations and the record of glaciations from deep-sea sediments, emphasizing the role that stochastic processes might have in creating variability in the climate system. During his postdoctoral research with Bill Curry at Woods Hole Oceanographic Institution (WHOI), Peter developed a theory to explain why the 40,000-year period of changes in the Earth’s tilt rather than the more powerful 20,000-year changes in the Earth’s precession of the equinoxes appears most prominently in climate records over the past 2 million years. His explanation—reminding us that the duration of the seasons may be as important to the growth or demise of ice sheets as the peak summer insolation—is both simple and elegant (indeed, so obvious once stated that many of us have wondered why we did not see it for so many years). It is certainly one of the most important contributions to understanding the mystery of the ice ages over the past 2 decades.

Peter’s approach to studying past and future climates is somewhat untraditional in that most of the paleoclimate community focuses on the production of new records of ancient climate, or developing new tools, often with geochemical approaches, to produce those records. Peter brings a very different perspective. Peter knows the paleoclimate and modern climate records in great detail, but he is not a geochemist or a meteorologist; he is trained in climate dynamics, but he is not a dynamicist; he uses statistics and other data analysis techniques, but he is not a statistician. Quite simply, Peter is an Earth scientist. He combines a deep appreciation for geologic and geochemical problems, along with a sophisticated understanding of the physics of the climate system, wrapped together with a sharp and insightful ability to take disparate data sets and interpret them in a statistically rigorous manner. He is also a gentle and kind spirit, engaging students and colleagues in a way that makes collaborations blossom, even with scientists from vastly different disciplines—quite unexpected from a former tank commander. His research interests continue to broaden with his new friendships, exploring provocative new ideas like the role of volcanic emissions of carbon dioxide (CO2) in glacial cycles or the impact that future climate will have on agriculture. He is greatly deserving of this medal not only for the important contributions he has made but even more so for the discoveries that lie ahead.

—DANIEL P. SCHRAG, Harvard University, Cambridge, Mass.


Thank you for the kind introduction, Dan. It is an honor to receive the Macelwane Medal. It is also an interesting coincidence. More than a decade ago I pondered whether to study science or become a Jesuit priest. I don’t regret my choice, but there is some fulfillment in receiving a medal named after an Earth scientist and a Jesuit. Even better, this medal gives me an opportunity to acknowledge the tremendous support I have received over the years.

First, I thank my thesis adviser, Carl Wunsch. He taught me the standards of scientific work through good advice, diligent editing, and an unwavering personal example. I am glad we continue to collaborate. Kerry Emanuel, Ed Boyle, John Marshall, Dick Lindzen, and others at MIT provided a vibrant and challenging education. After graduate school at MIT, I went 70 miles southeast to WHOI as a National Oceanic and Atmospheric Administration postdoctoral fellow and was hosted there by Bill Curry. Bill, Delia Oppo, Jerry McManus, Konrad Hughen, Olivier Marchall, and others at Woods Hole deepened my understanding and appreciation of the climate record.

After Woods Hole, I moved two T stops northwest from MIT to Harvard, initially as an environmental fellow working with Eli Tziperman, which was great fun. Harvard has been warmly welcoming and wonderfully stimulating. Dan Schrag has broadened my understanding of climate, environment, and energy. Charlie Langmuir alerted me to interactions between the solid Earth and climate. Andy Knoll helped me to better teach undergraduate Earth history. Rick O’Connell, Jim Anderson, Miaki Ishii, and Francis MacDonald are wonderful colleagues. I share a floor with Zhiming Kuang, Steven Wofsy, Brian Farrell, Jerry Mitrovica, and Eli Tziperman and could not ask for better neighbors, although I wish Paul Hoffman had postponed retirement. This community of scientists and friends is one of the major reasons I have not strayed far from the Boston area.

Along the way I have benefited from interacting with a range of other idiosyncratically great scientists. Wally Broecker, George Denton, and Richard Alley have lent much inspiration. I thank Mark Cane, Peter Molnar, David Lea, Ray Pierrehumburt, Maureen Raymo, Adam Maloof, David Battisti, Michael Bender, Taylor Perron, Oded Aharonson, and Gerard Roe for many interesting conversations. Jake Gebbie and Zan Stine have been good friends in graduate school and beyond. Cristian Proistosescu, Ethan Butler, Andrew Rhines, Nathan Arnold, Eddie Haam, and Martin Tingley have been wonderful students and postdocs. It has been a great privilege to interact with the Earth science community.

My gratitude would be incomplete if I did not also count my family. My wife, Downing Lu—the proximate cause of why I did not become a Jesuit—has been a source of inspiration and love. I have grown together with her beyond what I would have dreamed of alone. Our son, Pax, is a joy. My parents, Peter and Noreen, have been wonderful parents to me and wonderful grandparents to Pax. My sister, Kat, is a great friend.

Thanks to you and the many more who have made for such good company along the way.

—PETER J. HUYBERS, Department of Earth and Planetary Sciences, Harvard University, Cambridge, Mass.