Terry L. Root

Terry L. Root is a senior fellow emerita at the Woods Institute for the Environment at Stanford University and a professor, by courtesy, in the Biology Department. She researches how wild animals and plants are changing with climate change, with a current focus on the possible mass extinction of species with warming. She has been a lead author for the Third (2001) and Fourth (2007) Assessment Reports of the Intergovernmental Panel for Climate Change (IPCC) and a review editor for the Fifth (2014) Assessment Report. The IPCC shared the Nobel Peace Prize in 2007 with Vice President Al Gore.  She holds a Ph.D. in biology from Princeton University.


Born and raised in Albuquerque, New Mexico, Terry Root has always loved the desert, especially the birds. As a teenager, she recalls, “I got really hardcore into bird watching.” For Root, though, bird watching was more than an adolescent hobby. It became her professional passion. Today, as a scientist, she tries to understand what birds and other species are telling us about the human impacts on our ecosystem. She also believes, however, that her responsibilities are not limited to gathering and interpreting data. “I always felt,” she explains, “that science has an obligation to try and provide information to policymakers and the general public in order to try and make the world a better place.”

From bird watcher to biologist via computer science

Despite her early love of birds, Root’s career did not begin with them. Hesitant to mix work and play, she majored in math and statistics in college. Although keenly interested in these subjects, she did not love them quite as much as birds. “I didn’t want to couple my career with my hobby, because I was afraid that would make my hobby not as much fun,” she said.

After college, Root was employed as a scientific programmer—that is, a computer programmer specializing in developing scientific software—when unexpectedly her interests converged. While programming ways to analyze cosmic ray data from the Voyager spacecrafts at the Jet Propulsion Laboratory at the University of Colorado, Root took an ecology class for fun and “fell in love with it.” As she was completing a project for the class, she stumbled onto a professor’s stash of old “magtapes” (i.e., reels of magnetic tape once commonly used the way we use USB flash drives today—except they were too big to store in your pocket). These magtapes contained Audubon Society Christmas Bird Count Data, but the professor, lacking computer expertise, had no idea what to do with them. With her advanced programming skills, Root began processing the data and became so enthralled with what she was learning that she went on to earn her master’s degree in biology and then her doctorate in biogeography and physiological ecology.

The evidence for climate change

As a biogeographer, Root began studying birds on a continent-wide scale while most others were looking at quite small study areas. Discovering that environmental factors were affecting bird ranges, not just competition and predation, Root focused her research on temperature. She found that birds only migrate as far north as their metabolism will allow them to compensate for heat lost overnight.

She explains, “Birds feed all day and when they go to sleep at night they shiver their muscles in order to stay warm. When they wake up the next day, they’re skinny and have to go out and feed again. If the nights are too long or if it’s too cold, they’re not going to make it.” She calculated that “they have the capability of shivering their muscles for as long as the night is long at a rate that is roughly 2.5 times their basil metabolic rate.”

In her next major study, Root wanted to learn if and how birds are affected by temperature fluctuations related to climate change. Her research established that species have been moving their ranges over time. “They’re coming north earlier in the spring,” she says, “and some are leaving later in the fall. And they’re moving their ranges up in elevation and up in latitude (toward the poles). That’s probably my most famous study.”

Root’s third major project provided evidence that humans are contributing to the rising temperatures driving the changes in bird ranges. Utilizing temperature data on migration routes, she developed computer models to analyze bird responses to human and natural causes for the rising temperatures. While the models showed birds were being more affected by temperature rises due to human causes, “they fit the pattern best when I used the modeling for human influences plus natural influences,” she asserts, “So that was telling us that indeed humans are changing the climate.”

Speaking up and taking action

“I think that as people realize that we’ve got to be working on real world problems,” Root reflects, “we have to … ask extra questions that are real world questions.”

Although she has at times faced pushback from academic scientists who valued basic research over applied research, Root has maintained her dedication to enhancing communications between scientists, policy makers, industry, and the general public throughout her career. During her time as a graduate student in Colorado, she took a job with Mobil Oil to pay the bills. As a member of the company’s environmental group, she discovered how important it was for scientists to collaborate with industry to save species. She was impressed with how Mobil was trying to do this—at least in her division—and the experience has motivated her ever since to use her research to address actionable problems related to maintaining an ecologically vibrant earth.

Of her contributions to the IPCC reports, Root concedes, “It’s a lot of work. You don’t get paid for it. It’s really tough.” However, standing up for the policy relevance of science is something she embraces. “I’ve always worked with politicians and groups that work with politicians, decision makers, and policy makers,” she says, “I’ve worked with fish and wildlife managers extensively on how species are being affected and how these impacts should be handled. I’ve testified in front of Congress many times, and I’m on the board of many organizations that are trying to link science and policy. That’s just what I do.”

Making a difference

Root remains troubled about the future of our planet and the predicted massive species extinctions related to climate change. “As I look out my window right now I wonder, will the planet look the same if I were sitting here in a hundred years? No. It’s not even going to be close,” she surmises.

Despite these apprehensions, Root remains hopeful because of her students. “The energy and optimism that the students bring is refreshing and gives me immense hope,” she says. “When you have students around that come up to me and say, ‘I want to make a difference in the world,’ that gives me hope.”

Last revised date: June 13, 2016

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