By Hannah Magnuson, Dec. 16, 2018 –
Climate scientists veterans Richard Alley, Wally Broecker and George Denton have witnessed immense changes during their decades-spanning careers. They’re buoyed by scientific advances, but also see critical mitigation needs amid public apathy – and a policy gridlock.
Despite political stagnation, the scientists persist with pioneering research to map the way to firm predictions for what will happen to our changing climate and how it can be addressed.
Between the three of them, they have studied ice sheets and oceans around the globe in sites such as New Zealand and Antarctica, testified in front of U.S. Congressional committees, won top awards for scientific achievement and fostered the next wave of geoscientists. They convened colleagues active in research across the globe to discuss their latest findings at the annual Comer Climate Conference this fall, a climate change conference in Southeastern Wisconsin for scientists funded by the Comer Family Foundation.
Broecker, a geochemist and the longtime Newberry Professor of Geology at Columbia University, played a critical role in discovering the global ocean circulatory system. He has been studying climate change for over 60 years and is credited with coining the term “global warming” in a 1975 research paper. Alley launched the PBS series Earth: The Operators’ Manual, helped author the massive assessments of the Intergovernmental Panel on Climate Change (IPCC), and teaches geosciences at Penn State. Denton follows the tracks of past glaciers across continents and is a distinguished professor for the University of Maine’s School of Earth and Climate Sciences and Climate Change Institute.
All three men delve thousands of years into the past to better understand where human-generated climate changes may be taking us now. They study the changes Earth’s climate underwent during previous periods of warming to identify what to expect as greenhouse gases continue to heat up our planet.
On the Changing Field of Climate Change
Over the course of Alley, Broecker and Denton’s careers, climate change captured the public’s awareness and transformed into a buzzword in a polarized political landscape.
“At one point in my life I would brag that what I was doing was interesting enough that I might get a job in it and I might get a little research funding, but it wasn’t so interesting that anyone would yell at me about it,” Alley said.
In his 41 years studying ice fields, he’s seen climate change wax and wane in the public’s interest as other issues have at times dominated the national conversation. Right now, he doesn’t think major media outlets are covering the issue enough, or in the manner it deserves, he said.
“There’s more he said, she said, they said. We jump up and down and yell at each other instead of the big discussion of ‘this is what the science says, how do we respond to that in a way that respects our values and respects our economy and our employment and our environment?’”
Despite the gridlock in the public sphere, Denton cited several significant advances within the scientific community’s study of climate change over the course of his career.
He thinks the biggest progress started with CLIMAP, a project that intertwined climate change field work with modeling. The project was first published in 1981, when numerical models were becoming more sophisticated and was run by the World Data Center for Paleoclimatology. The project’s emphasis on modeling forever altered the course of climate change research, Denton explained.
“We don’t do anything anymore without a climate model,” he said. “That was a big, big change there. It brought this sort of thing into the modern world.”
The second big advancement, according to Denton, came from developing methods to determine the absolute chronology of particles, and then testing the results through modeling runs. By using accelerators and mass spectrometers, which measure the mass of charged particles to analyze their molecular composition, the scientists can determine the ages of the particles within the ice sheets they’re studying to provide insight on glacial retreat and warming behaviors.
“Wally Broecker here was instrumental in that,” Denton said.
On the Future of Climate Change Research
Looking forward, the geoscientists anticipate large research projects and systemic policy shifts as essential measures for combating the changing climate.
Denton believes the next step for advancing climate science lies in understanding the Southern Ocean. Oceans play a crucial role in climate change, because they absorb and store much of the excess carbon emitted from greenhouse gases—resulting in ocean acidification and sea level rise.
Starting about 18 years ago, a collaborative group of researchers administered by Princeton University’s Environmental Institute distributed a series of floats all over the Southern Ocean. The floats automatically dropped to a depth that allows them to take the ocean’s measurements—a move that will enable “a new understanding of the Southern Ocean and how it affects climate,” according to Denton.
Alley advocated for the continued scientific investigation of possible climate change mitigation and adaptation efforts. “We need to know what is possible,” he said.
As an example, he cited seeding the Southern Ocean with iron—an idea discussed by researchers at the conference as a potential way to grow more plants and displace carbon dioxide so that it’s buried in the mud of the ocean’s floor. He explained that while it might help a little bit, this method might also deplete the ocean of oxygen in some areas, causing an outpouring of nitrous oxide.
To avoid the risk negative side effects, he predicts research will favor the implementation of a renewable energy system.
“My gut feeling is that if we do the research and we find out the whole picture including how [climate change] would feed into human societies, then we’re going to find that it’s easier by a good bit to switch to a renewable energy system,” Alley explained.
Broecker foresees a worldwide carbon tax as a necessary measure for minimizing fossil fuel consumption. He also thinks scientists should explore geoengineering—which involves practices that directly address climate change such as removing CO2 from the air or reducing the Earth’s exposure to the sun.
“That’s our only out right now,” Broecker said, explaining that geoengineering is “a Band-Aid that [helps control] bleeding immediately but, if you take the Band-Aid back off again it’s going to start to bleed just as bad again. So that means it has to be a long-term commitment.”
On The Next Generation of Climate Scientists
In addition to their own research, Alley, Broecker and Denton have each mentored a host of Ph.D. students and post-docs at their respective institutions. Many of their former students are now mentors themselves and expand their old teachers’ reach to countless more students.
At the Comer Conference, many scientists attending were students of Broecker or Denton, or students of their students. Together, they spanned four generations of Ph.D. scientists.
Graduate student Allie Balter was one of many scientists in attendance from the University of Maine, where Denton has long served on the faculty.
“To be able to come home [from field trips] and show [Denton] photos and hear his stories about the time he went there and what he found and his perspective and everything is really great,” Balter said.
“They’re our future, these pretty sharp people,” Denton said of the young scientists in attendance at the conference. He lamented the difficulty the new generation of climate scientists will have in securing funding for their research given the current federal administration that is reluctant to accept the reality of climate change.
“Many [scientists] are removing the word ‘climate’ from their proposals. They call it ‘environmental change,’” Denton explained. “It’s pretty sad.”
Broecker estimated that he’s mentored about 50 Ph.D. students and worked with about 50 post docs over the years. He explained that much of his motivation behind mentoring was “selfish enjoyment” since he loves science and had fun sharing his knowledge and forging relationships with his students.
“You can’t use your students like slaves. You’ve got to inspire them and let them go out on their own,” Broecker said. He cited his former student Jeff Severinghaus, now a professor at Scripps Institution of Oceanography as an example: Severinghaus decided to study California’s sand dunes for his thesis without asking for Broecker’s permission, and he went through with it.
“You have to respect that and honor it because that means you’ve got a really good student,” Broecker said. He wants his legacy to center around his love of science and fostering of new scientists, rather than on him being the “father of global warming.”
“Science is fun. Science is important. And one should be generous,” Broecker said.
Photo at top: Antarctica’s ice fields serve as research hotbeds for climate scientists studying climate changes from past eras to better understand future implications. (Photo courtesy of Jasmine Nears.)
