Faculty Q&A: Sean Solomon on Lamont-Doherty, Earth Science and Space

Bridget O'Brian
March 15, 2019

As a scientist, Sean Solomon has studied Mercury, Venus and Mars. Now he heads Columbia’s Lamont-Doherty Earth Observatory, whose researchers study planet Earth, from its deepest ocean to its highest peak.

Solomon arrives at Columbia from the Carnegie Institute, where he was its principal investigator for research with NASA’s Astrobiology Institute. Astrobiology is an interdisciplinary approach to understanding the origin of life on Earth and its potential for existing elsewhere.

“The four inner planets of our solar system are nature’s experiments in how a planet like the Earth became the planet it is today, and they had four extraordinarily different outcomes,” he said. “To understand our own planet, we must understand how all Earth-like planets formed and evolved.”

Despite its breadth, the discipline of Earth sciences is sometimes a small world. Solomon has known G. Michael Purdy, his predecessor at Lamont, for more than 40 years. They have co-authored 15 papers and worked on five oceanographic cruises together. When Solomon was at MIT and Purdy at Woods Hole Oceanographic Institute, they supervised students in a joint Ph.D. program.

“One of the important perspectives Sean brings is his knowledge of the other planets,” said Purdy, who is now the university’s executive vice president for research. “The mapping of other planets has helped in our understanding of this planet’s evolution and vice versa.”

Returning to Earth sciences brings Solomon full circle. “It’s an extraordinarily interesting time in the Earth sciences because of the growing awareness of all the changes going on and the opportunity to make a difference in the ways that we as a society address them," he said.

Sean Solomon

Q. What is it about Lamont that makes it such a unique part of the University? 

We’re a very large organization addressing the planet Earth from all the scientific perspectives from which we can study our environment: oceans and atmosphere, and how they work together to form climate; how life evolved on this planet and modified its environment as it did so; how the environment affects life, and how the history of the planet’s change is recorded in the geological history of the continents and the sea floor. We have people who travel the globe, sail on every sea, trek deep into the hearts of all the continents, and work in the Arctic and the Antarctic.

Q. Can you talk about some of the research directions under way?

We’ve identified several areas that cross-scientific disciplines where Lamont is very well positioned to make an impact. One is called Climate and Life; it’s looking at both the history and the future of the impact of climate on all the things that have to do with life. We’ve got an initiative on changes in ice and the coastlines that recognizes that climate change is having an impact on sea level through loss of ice at the poles. We’ve got a group on earthquakes designing an initiative to understand how and when large earthquakes occur. We’ve got a new initiative that we’re calling Real-time Earth, which involves continuous observations with instruments, such as a video system on the sea floor. The idea is that if we make continuous observations of a variety of phenomena, we will see things on new timescales and interactions that hadn’t before been appreciated.

Q. Can you talk in more detail about some of the University’s interdisciplinary initiatives?

One of the reasons I came here, beyond the enormous appeal of Lamont-Doherty, is that Columbia had the vision to set up the Earth Institute. That vision, now about 15 years old, was to combine a deep scientific understanding of the planet with all the other ways of addressing changes to our environment. The Earth Institute integrates economics, law, urban planning, social sciences, public health and agriculture with basic Earth science in a way that feeds into better mechanisms for identifying the processes that govern change and solutions to the problems that society faces as this change occurs. As our climate varies – and there’s both a natural and an anthropogenic contribution to this variation – we’re trying to study how that overall change in temperature and other characteristics such as wind and precipitation patterns, droughts and susceptibility to wildfires feeds into issues such as planning for coastal communities – a vital issue in the aftermath of last year’s Hurricane Sandy.

Q. Columbia’s new Institute for Data Sciences and Engineering is focused on the transformative effects of big data at the University and in the world. How is big data affecting the science at Lamont?

Earth science by its very nature has huge datasets. Some of the NASA satellites observing the Earth are producing petabytes (1,000 terabytes) of data per day. Lamont is taking a leadership role in integrating many large datasets that heretofore hadn’t been generally accessible. We’ve got a large group that is making global datasets accessible to the community in geochemistry, petrology, and marine geology and geophysics. We’re always wrestling with questions of computational capability and data volumes, and it’s driving our science. We’re delighted that Columbia is pioneering some new directions in big data. We feel that Earth science has a critical role to play, and we’re eager to contribute.

Q. Can you talk a bit about your own research beyond the planet Earth?

I continue to serve as principal investigator of the MESSENGER mission, which sent the first spacecraft to orbit the innermost planet, Mercury. Mercury, the smallest of the Earthlike planets, had been comparatively unstudied before our mission. We knew from one spacecraft that flew by Mercury three times in the 1970s that it was made of much denser materials than the other terrestrial planets, had its own magnetic field and had a heavily cratered surface. That led to a number of theories about how Mercury was formed and what it was made of. With the MESSENGER mission, we set out to image the whole planet in high resolution, measure the magnetic field and the shape of the planet, and determine the composition of the surface. And we learned that all of the ideas for how Mercury was assembled were wrong. We had to throw out 30 years of textbooks and go back to the beginning for ideas about how all the inner planets were assembled, including Earth.

Q. Many Columbia scientists are involved in the study of climate change. What role do they play in society’s ongoing and sometimes contentious debate about global warming?

I think Earth scientists have a responsibility to do the best science they can and also to communicate as objectively as possible the results of their work. It’s a subject where the story has been muddled by the diversity of strongly held opinions, mostly related to how society should deal with this kind of information. There’s a very impressive and growing record about the history of climate change and eras in the Earth’s past when the climate was even warmer than now, sea level was higher and carbon dioxide levels in the atmosphere were higher. Therefore it behooves us to learn as much as we can about those changes in the past, and try to understand the combination of circumstances that led to them.

Q. When something like the government shutdown occurs, or the sequester, how does that affect science at universities in general and specifically at Columbia?

A very large fraction of Lamont-Doherty’s budget comes from federal science agencies, particularly the National Science Foundation. The health of our scientific enterprise depends on our ability to persuade the science agencies that our projects are worthy and are likely to return results of high importance. When the federal government goes through constrictions in its budget, as we saw last year with the sequestration, that puts strong pressures on the federal science agencies, and we feel those pressures here – in delayed grants, awards that are not made, and the dribbling out of research funds that makes it hard to plan. This interview is taking place in October during a time when the federal government is shut down, and we’re already starting to see the impacts of that shutdown on our research. We run the risk that the entire field season for studying south polar phenomena – from the ice and polar oceans to krill and penguins – won’t be available this year. We also run the risk that the spacecraft we have launched that have cost billions of dollars of taxpayer money will be collecting unique once-only data that they cannot transmit to Earth. Our investment in the exploration of our environment could be in jeopardy simply because we have a government that’s shut down and a Congress that can’t seem to agree on how to move forward. [Editor's note: One Lamont project was cancelled when ice measurement instruments couldn't be flown to Antarctica in time for its start. A related project was scaled back by half.]

Q. Can you talk about Lamont’s growing teaching mission at Columbia?

We work with faculty from the Department of Earth and Environmental Sciences in Columbia College and the Graduate School of Arts and Sciences, and all of the offices and labs of those faculty are here at Lamont. We have more than 75 graduate students who come through that department and earn their degrees by working at Lamont. Classes in Earth and Environmental Sciences for undergraduates are taught at Morningside, but the students have research opportunities here that are unmatched anywhere else on campus. We have a summer research program that draws students from Columbia, Barnard and other universities around the country and immerses them in an intensive, 10-week research experience mentored by our scientists. Many of the undergraduates who participate in that program continue to come back during the school year; they might do a senior thesis, and many of them give scientific papers at national and even international scientific meetings on the work they’ve done here.

Q. Columbia now offers several degrees in sustainability studies. Can you describe Lamont’s role in those programs?

The question of sustainability is one of the core issues for the Earth Institute: human sustainability and the sustainability of agriculture, lifestyle and economics. Lamont scientists teach these courses at the undergraduate, master’s and Ph.D. levels. They partner with other components of the Earth Institute in programs that address sustainability, and they are involved in the sustainable solutions network that [Earth Institute Director Jeffrey D.] Sachs is leading on behalf of the United Nations and the Earth Institute. It’s very much a theme that brings all of us together within the Earth Institute, and it is critical to Columbia’s ability to make a difference in the way that sustainability is viewed globally.

Q. In what ways, if any, does Lamont-Doherty’s special location 15 miles north of Morningside Heights affect its mission?

In contrast to the very urban setting of Morningside, Lamont is on a former country estate. It’s forested, there’s wildlife, and we have a wonderful view of the Hudson looking out from the Palisades, which are themselves a wonderful geological record of what happened to this continent 200 million years ago. Yet our scientists go back and forth on an hourly basis and continue to expand their engagement with other components of the University – Arts and Sciences, the medical and law schools, the School of International and Public Affairs. Increasingly our students are motivated not only by a desire to understand the scientific underpinnings of our planet but to make a difference in how those scientific results are applied in the future.