National Geographic Society Newsroom

Interview with Polar Bears International Chief Scientist Steven Amstrup

Steven C. Amstrup, a former chairman of the IUCN Polar Bear Specialist Group and a world authority on polar bears, has joined the conservation group Polar Bears International as senior scientist. A long time scientific advisor to PBI, Amstrup was previously wildlife biologist with the United States Geological Surveys’s Alaska Science Center in Anchorage. He...

Steven C. Amstrup, a former chairman of the IUCN Polar Bear Specialist Group and a world authority on polar bears, has joined the conservation group Polar Bears International as senior scientist. A long time scientific advisor to PBI, Amstrup was previously wildlife biologist with the United States Geological Surveys’s Alaska Science Center in Anchorage. He led the team of international researchers that prepared documents used in the decision to list polar bears as a threatened species.

In his new position at PBI, Amstrup will be able to work more directly with the organization’s educators, conservationists and administrators to focus on the most urgently needed research, outreach, and capacity building to help at-risk populations of polar bears in a rapidly warming Arctic. “Attracting the talents of this world-class biologist full-time speaks to the reputation of our organization,” said PBI President Robert Buchanan in a news statement earlier this year. “This solidifies our role as a conservation group based upon science. Governments, other nonprofits, and the public look to PBI as a trustworthy source of information–and inspiration.”

Steven Amstrup.jpg

Photo of Steven Amstrup by Mike Lockhart

Interview with Steven Amstrup by Jordan Schaul

In 1992 you and other colleagues reported that polar bear numbers in Alaska were stable and healthy at about 3,000 to 5,000. The worldwide population was estimated at between 25,000 and 40,000–most of the bears living off the coasts of Canada and Russia.

At the time you were developing a global database on baseline demographic data for the world’s population’s of polar bears in conjunction with other scientists. The goal was to collect baseline data to use for the assessment of a range of stressors.

The primary stressors were: The impact of human activities; resource development (oil exploration, ect.); and possible global environmental changes on polar bear habitat and populations.

Did you project at the time that any observed trends could greatly influence polar bear populations 20 years later or that the synergistic effects of all of these stressors would have created the situation polar bears are facing today?

Polar Bears International.jpg

Ever since the earliest days of polar bear conservation, the main threat with which managers were concerned was human harvest. After all, the polar bear environment was remote and untrammeled, and for the most part it appeared it would remain that way.

Once we came to grips with this threat (through harvest controls and guidance from the International Polar Bear Treaty) there were concerns about industrial developments, and those concerns continue today. But I think that most of us believe the potential threats of industrial development can be managed just as we already have largely been successful in managing the potential threats of hunting.

We were concerned about those things, back then, but did not see the demise of the species ever coming from these other uses of polar bear habitats.

In those days, the now bright bulb of global climate warming was dimly lit, and its potential effects on polar bears and their habitats were poorly understood. James Hansen had given his famous testimony before Congress only a few years before, and as we all know it had not received the attention it deserved.

But, of course, in those days, our understandings were at a pretty low level. The observational record of sea ice change was short, and the causes of observed changes were only beginning to be understood.

The major declines in perennial sea ice that occurred in 1989 and 1990 were thought by many of us to be the result of a coincidence of natural factors, and it has been only with the benefit of our retrospective views and the increasing knowledge base that we can put those losses into proper perspective.

Similarly, climate modeling has improved by leaps and bounds in subsequent years.

The early global models simply did not do very well in explaining observed sea ice patterns (although they did quite well in predicting global mean temperature) and hence it was easy not to focus on their results.

The short story is that back then, our other concerns (hunting and industrial development) overshadowed emerging knowledge of climate change and its potential to change the landscape for polar bears.

Did you ever conceive of the possibility that in a worse case scenario suitable polar bear habitat would be compromised to this degree as it is now?

The real breakthrough for me came in the late 90s when I, and my research team, realized we could no longer do our field research in the autumn.

Between 1980, when I began polar bear research in Alaska, and the late 90s, we had been able to go out on the new sea ice of autumn to capture polar bears just as we did and continue to do in the late winter and spring. However, by the late 90s we realized that it was not possible to do autumn research because sea ice freeze-up was occurring so much later in the year that by the time we had solid enough sea ice to work safely, the daylight was so limited we could not effectively fly out in our helicopters to look for bears.

It is hard to find polar bears even in good light. Finding them in the dark…well.

We came to the realization that the “abnormal” winter of 1989-90 was becoming the norm. Of course, by then we were much more aware of global trends because of the improving data availability and better models. But, it was the realization that sea ice had changed so much we could no longer do our autumn work that generated the real epiphany.

There are many imperiled carnivoran mammals from Ethiopian wolves to Iberian lynx that are in real danger of becoming extinct in the near future. A host of species are critically endangered because of a host of factors, and similar to polar bears a common concern is available habitat.

The difference for polar and particularly arctic fauna that rely on sea ice to live on, is that it is virtually impossible for us to restore their habitat. We can restore a variety of habitats to make them more suitable for species recovery programs, but we can’t really restore ice or the potential for seasonal formation of ice. Is this an accurate assertion?

I think you must be careful in suggesting we cannot restore polar bear habitat.

The data are increasingly clear that preserving polar bear habitat is “all about temperature.” That is, to preserve the sea ice upon which polar bears depend we need to reduce the greenhouse gas [GHG] radiative forcing that controls temperatures on Earth. We do that by reducing atmospheric concentrations of those gases.

In that sense, the solution is conceptually simple. In practice, because the principal GHG of concern (CO2) is so tightly linked to our economy, the challenges are difficult, but it is not correct to suggest we cannot solve this.

In fact, it is counter productive to make such a suggestion. It is clear that if people and policy makers believe there is nothing they can do, they will do nothing.

Therefore it is important that all media outlets present this situation in its proper light and emphasize that the loss of polar bear habitat is not unavoidable.

We can change this, and I am confident that we will do so.

Can you elaborate on the magnitude of this crisis–receding ic–has on polar bears. It’s a direct impedement to polar bears reaching their prey base, right? What are some of the more significant, but perhaps more indirect effects of a warming Arctic on polar bear survival and reproductive potential?

We tend to focus on the fact that without sea ice polar bears cannot effectively forage. There are other important issues as well. For example rougher sea ice with more open water interspersed in it will be increasingly difficult for young cubs to negotiate. Adults may be able to work with it, but cubs are not equipped for prolonged immersion in cold water and can become hypothermic.

Also, delayed autumn freeze-up could prevent females from reaching denning areas in autumn.

At the same time the sea ice is becoming less and less suitable as a substrate for denning, it is also changing in ways that may prevent access to land denning areas.

Also, as the sea ice is becoming increasingly difficult for polar bears, we can anticipate it is also becoming less suitable for seal (particularly ringed seals which are the polar bear’s main prey species) reproduction. This is much more difficult to quantify, but is undoubtedly going on.

This may be the tip of the iceberg with regard to ecosystem changes. With sea ice less predominant in the system, both spatially and temporally, other species will invade the system. How fast this occurs and which species might prevail in the new ecosystem is subject of much conjecture at this point. But we know that changes are occurring and will continue.

Those changes are really what will determine the fate of polar bears. That is, will prey be not only sufficiently abundant, but will they be “available” to polar bear hunting strategies?

We must not lose sight, however, that the changes in ecosystem composition are driven by the ice disappearance. Therefore, it is difficult to get away from the conclusion that as the sea ice goes, so goes the polar bear.

Beyond those sorts of obvious changes we have little understanding of how increasing ocean acidification may change the under-ice ecosystem and how those changes may translate upwards. Changing ocean chemistry, however, is a potentially very dark side of human increases in CO2, and something about which we just don’t know much at this point.

You have served as a member and past chair of the IUCN (SSC) Polar Bear Specialist Group. We know through media outlets in the U.S. and esteemed organizations like PBI how alarmed polar bear biologists and climate ecologists are as we face dramatic environmental changes. Is the same concern and message aimed at reducing our carbon foot print disseminated by your colleagues in Greenland and Norway, for example? Do they reach a larger European audience? Is the message about polar bears reaching people everywhere?

Polar Bears International sees a benefit to reaching out to zoos and their patrons. They can reach millions of people. What other roles do you see that zoos, and captive wildlife facilities holding bears, play in species conservation in general, and to polar bears in particular?

The PBI is doing its best to make relevant information available to the public and policy makers around the world. But your question unfortunately raises the bigger issue that scientists have not done a good job in delivering the messages regarding the threats of global warming. And they have done poorly in relating to the media on this topic.

On top of that, the general media have not accurately portrayed the issue of climate change and continue to portray it as a debate between two scientific factions. In fact it is a debate between opinion and science (data and the laws of physics on the one hand versus simply not believing humans can affect the climate on the other hand). This is an issue that scientists and educators need to resolve.

An important part of that resolution can be the transformation of zoos and aquaria from places of entertainment to places of education and interpretation. Particularly in the case of polar bears on public display, there is a huge opportunity to convey the message that the principal threat to their continued existence is anthropogenic global warming and the sea ice loss it is creating.

Because polar bears are sentinels of the welfare of their ecosystem, and because of the influence of Arctic sea ice on world climate, the ramifications of the loss of the polar bear’s sea ice habitat extend throughout and beyond the Arctic. The most effective interpretive messages, which can be framed around polar bears, also should carefully explain these worldwide relationships.

Indeed, solving the threats to continued existence of polar bears will preserve species and habitats in almost every ecosystem.

Can you describe somewhat specifically what your new role as Senior Scientist for Polar Bears International will involve. How will your involvment differ from your previous role as an advisor to the organization?

Because PBI has only recently moved from a totally volunteer organization to one that has a few actual employees, it is difficult to know exactly what roles I may play. As senior scientist for the organization, I will play the lead role in providing scientific guidance to the organization.

This means in part that I will do more of what I was doing as a volunteer for the organization while I was employed by the USGS.

I will be drafting positions for the organization to take as well as verifying the scientific accuracy of positions or statements drafted by others. I will play a lead role in assuring that research supported by PBI is scientifically appropriate and that findings will be relevant to conservation issues, that proposals are well formed and presented and that goals and objectives are indeed plausible as well as relevant.

I should emphasize here that other members of the scientific advisory council will continue to provide this kind of quality assurance as well.

I will also assure the scientific accuracy of education and outreach efforts and I will perform an increased number of personal outreach efforts compared to when I was a volunteer. These will include writing things for the PBI website, giving guest lectures and talks around the country, and participating in our ongoing education programs.

Other things are bound to come along the way as the organization matures.

As a research scientist for the federal agency USGS, your role was lead polar bear biologist and, I suspect, you were used to working with esteemed federal biologists like yourself, very focused on applied science and management of apex predators.

I’m sure that you worked with many policy makers during your career with interests in legislation protecting marine mammals. Polar Bears International is comprised of an eclectic group of marketing specialists, science writers, educators, zoo keepers, curators, zoo clinicians and an assortment of other people.

Will this be a big change for you? Will your job require that you involve yourself in non-science related endeavors, on behalf of polar bear conservation?

This certainly will be a change. The biggest change is that at the USGS, it was beyond my purview to provide management and policy recommendations. Whereas PBI is not an advocacy organization, from the standpoint of performing lobbying efforts, it is an organization that advocates, with all of its efforts, for the welfare of polar bears.

At the USGS, I could provide scientific findings that I then hoped would be used by managers and policy makers, but I had to stop short of providing actual management recommendations. At PBI, I will be free to comment on specific management and policy recommendations. This will be a big change.

At the same time, I will do far less research myself. Although an important part of my job will be to keep up with the scientific literature and research progress, my role in conducting research will be diminished. I will still conceptualize projects and try to find funding for them, but I will, most of the time, not be in the lead in actually performing such research.

Some government biologists choose to move from one agency to another after they have “put in so much time.” I don’t know what positions would have interested you at other agencies, but you chose PBI. It sounds like a natural fit, but can you elaborate on how you and PBI will benefit from this new role you have assumed.

To be the most effective advocate for polar bears, PBI needed to have its own polar bear expert. After almost 40 years as a researcher and 30 years studying polar bears, I wanted a pulpit from which I could effectively share and interpret the wisdom I have gained during that time. This seemed a very good fit.

What do you hope to accomplish during your tenure with PBI?

I hope to take a lead role in interpreting, for the public and policy makers, the threats of anthropogenic global warming to polar bears and indeed to much of life on earth as we know it.

I have seen wild polar bears in Barrow only, and of course have worked with several in captivity. When do I get to go out in the field with you? I imagine there is long waiting list.

When I was at the USGS, I had the policy that taking visitors out on the research project would only be done if doing so resulted in a clearly demonstrable benefit to the project or to the polar bears. There is only so much room in a project helicopter and often to make room for a guest one of the regular crew had to stay back in camp. This invariably results in reduced efficiency.

I am no longer calling the shots at USGS, but I would adopt the same philosophy at PBI. PBI’s mission is to advance conservation through research, stewardship, and education. Hence, when hosting visitors provides a clear gain for PBI’s programs that benefit polar bears either through enhancing data-gathering or improving the quality and effectiveness of interpretation efforts, so those efforts more effectively reach the public or policy makers, we will try to make that happen.

Related: Polar Bears International to Open Rescue and Rehabilitation Center


Jordan Schaul is a conservation biologist and a collection curator with the Alaska Wildlife Conservation Center. He received his PhD in conservation/veterinary preventive medicine from Ohio State University and a master’s degree in zoology. He is a council member (ex officio) of the International Association for Bear Research and Management (IBA), a member and coordinator for education and outreach for the Bear Specialist Group of the International Union for the Conservation of Nature, an advisor to the Bear Taxon Advisory Group of the Association of Zoos and Aquariums, correspondent editor and captive bear news correspondent for International Bear News, and member of the advisory council of the National Wildlife Humane Society, which promotes high standards for wild carnivore care and welfare among private sanctuaries in North America. He is the creator of the Zoo Peeps brand which hosts a blog for the global zoo and aquarium community and two wildlife conservation oriented radio programs. He enrolled in clinical degree programs in veterinary medicine and has been on leave to pursue interests in animal management/husbandry science and conservation education.

Read more blog posts by Jordan Schaul.

Join Nat Geo News Watch community

Readers are encouraged to comment on this and other posts–and to share similar stories, photos and links–on the Nat Geo News Watch Facebook page. You must sign up to be a member of Facebook and a fan of the blog page to do this.

Leave a comment on this page

You may also email David Braun ( if you have a comment that you would like to be considered for adding to this page. You are welcome to comment anonymously under a pseudonym. 

About National Geographic Society

The National Geographic Society is a global nonprofit organization that uses the power of science, exploration, education and storytelling to illuminate and protect the wonder of our world. Since 1888, National Geographic has pushed the boundaries of exploration, investing in bold people and transformative ideas, providing more than 14,000 grants for work across all seven continents, reaching 3 million students each year through education offerings, and engaging audiences around the globe through signature experiences, stories and content. To learn more, visit or follow us on Instagram, Twitter and Facebook.

Meet the Author

Author Photo David Max Braun
More than forty years in U.S., UK, and South African media gives David Max Braun global perspective and experience across multiple storytelling platforms. His coverage of science, nature, politics, and technology has been published/broadcast by the BBC, CNN, NPR, AP, UPI, National Geographic, TechWeb, De Telegraaf, Travel World, and Argus South African Newspapers. He has published two books and won several journalism awards. In his 22-year career at National Geographic he was VP and editor in chief of National Geographic Digital Media, and the founding editor of the National Geographic Society blog, hosting a global discussion on issues resonating with the Society's mission and initiatives. He also directed the Society side of the Fulbright-National Geographic Digital Storytelling Fellowship, awarded to Americans seeking the opportunity to spend nine months abroad, engaging local communities and sharing stories from the field with a global audience. A regular expert on National Geographic Expeditions, David also lectures on storytelling for impact. He has 120,000 followers on social media: Facebook  Twitter  LinkedIn