By Lakshmi Chandrasekaran/Video by Kelly Calagna –

“Don’t get old if you can help it,” climatologist George Denton joked at the Comer Abrupt Climate Change Conference in Wisconsin this fall. But he must have been proud. As one of the earliest and premiere veterans of climate change research, the University of Maine professor had three generations of students in the room.

Denton has devoted a better part of his life to studying and quantifying ice sheets across the globe. He does this by gleaning the geological history going back across more than 2.5 million years of ice ages. He studies smaller mountain glaciers to understand what causes abrupt ocean and atmospheric changes that lead to the warming spells, changes that our contemporary world may be triggering at an ever faster pace.

“We as humans have reached 7 billion and we are living in a world where the climate is changing rapidly. Understanding how ice age climate works will help us understand what is going on now,” said Denton.

One of the biggest questions for climate change now is to understand what caused the Ice Ages – and what caused rapid shifts out of them, he said. Equally important is that “during the Ice Age, humans spread around the planet as a result of climate shift,” said Denton. About 60,000 years ago, humans spread out from Africa to Europe and then to Australia and even Siberia, he noted. With hundreds of feet of water gripped in the glaciers, a land bridge opened between Siberia and Alaska and humans followed the great mammals such as the mammoths into the Americas at least 15,000 years ago.

With human activities altering climate along with natural forces, “It’s to our benefit to understand the whole system that we are fooling with. So I think the studies of Ice Age that happened in the past will provide us with a foundation as to how the climate system is working now,” remarked Denton

George Denton explores the important clues about abrupt climate changes revealed by the end of the ice ages. (Abigail Foerstner/MEDILL)
George Denton explores the important clues about abrupt climate changes revealed by the end of the ice ages. (Abigail Foerstner/MEDILL)

“The biggest question in modern geology is what causes ice ages. George Denton’s research in New Zealand focuses on mountain glacier fluctuations during the last ice age cycle” that ended some 18,000 years ago, said Alice Doughty, a former student of Denton’s who is currently a post-doctoral fellow at the Department of Earth Sciences of Dartmouth College. “Calculating the timing of glacier change is KEY to solving the question of cause and that this would help us predict future change,” she said.

“George Denton is well-known for several decades of research concerning the role of the Southern Hemisphere in climate change. This work, has led to fundamental insights into the cause of ice-age terminations and of abrupt climate change,” said Brenda Hall, another former student and now a research collaborator and associate professor at the Climate Change Institute of the University of Maine where Denton teaches.

Denton’s results from several expeditions to Southern Chile show a rather unusual observation that past climate change events occurred in both the hemispheres at the same time. Denton and his colleagues tested and supported the idea that atmospheric influences link both the hemispheres in controlling climate during the last ice age meltdown and “this has gotten the community closer to understanding how the climate system works,” said Peter Strand, a graduate student at the Climate Change Institute. In other words, they showed that climate change is global.

But Denton is involved in trying to resolve the many yet unsolved mysteries of the sprawling ice ages. “Ice ages are enormous events. They caused sea levels to go up and down 300-400 feet, caused huge ice masses to break off the northern tier of Canada and United States. They changed temperature around the world by six degree Celsius which is a lot and then the Ice Age went away for reasons we don’t understand,” said Denton, during an interview.

Denton has dozens of publications to his credit. He has been elected to the prestigious National Academy of Sciences and the Royal Swedish Academy of Sciences – among his plethora of awards and honors.

The glaciers shrouded the entire Great Lakes region in since during the during the last great ice age some 20,000 years ago.

The Advisory Committee on Antarctic Names commemorated his contributions to research on glaciers in Antarctica by naming Denton Hills after him. His colleague, Robert Nichols named a small hanging glacier in Victoria Land in Antarctica the Denton Glacier in his honor as well.

Much of climate change research, as we know it today, began gaining momentum in the 1950s. Talking about his initial foray into climate research, Denton reminisced fondly about his days as a graduate student at Yale in the 1960s – a time when there were few grants and even fewer role models for research in the field. But Denton’s Ph.D. thesis advisor just set him out in the world to find his own thesis problem.

Denton began reconstructing ice sheets in the glaciers of the Saint Elias Mountains of the Southwestern Yukon territory and set his field of research rolling with this expedition.

Soon, his research led to several successful odysseys to glaciers in South America, New Zealand and elsewhere across the globe. When philanthropist Gary Comer became concerned about climate change, he began to work with Denton and brought him together with other pioneers in the climate change field such as Richard Alley of Pennsylvania State University and Wally Broecker of Columbia University.

Comer, the founder of Lands’ End, sailed the Northwest Passage in his yacht “Turmoil” in 2001 and noticed that the notorious shipwreck alley of icebergs seemed ominously ice free. The “successful” completion of his expedition, stoked Comer’s interest in what was different about ocean water conditions and why they had changed drastically. He approached Broecker – one of the earliest scientists to coin the term “global warming.” And Broecker brought in Alley and Denton to investigate the causes of “abrupt” climate change. With Comer’s substantial funding for climate research and fellowships, the triumvirate brought together top climate scientists from across the country as mentors for a new generation of researchers who studied with them.

As a prominent scientist at the Climate Change Institute, Denton has successfully collaborated with many other researchers worldwide throughout his career. Denton emphasized the importance of interdisciplinary research in the field of climate change research. “Staff members in the institute, spread through a number of departments such as earth sciences, soil sciences, agriculture, biology, anthropology work on climate research,” said Denton, adding that climate change was important to all these fields and in particular to agriculture in Maine.

The Gulf of Maine is the fastest warming body of water on Earth and the fishing industry on this coast provides livelihoods to a lot of people. “So the University of Maine has decided, since climate change is very important to the state, they better try and understand it. They set up the Climate Change Institute, which is interdisciplinary,” Denton said.

Denton has passed on his scientific legacy to numerous climate change researchers of today. Many of his former students are professors who mentor their own research team of students and postdocs. And that brought the generations of students from the Denton era to this conference in Wisconsin.

“These students at the Comer Conference, are largely from the Earth Sciences School and Climate Change Institute at the University of Maine. Under the auspices of the Comer Foundation, they travel all over the world. They go to Mongolia, China, Western US, Europe, South America, New Zealand, and to the southernmost landmass on Earth. They are trying to piece together climate change all over the world,” said Denton.

Denton’s contribution to climate change is outstanding, his colleagues agree. “We are all embarked together on a great adventure. And that is to unravel the mystery of ice ages. That is one of the greatest mysteries of Earth sciences and we are lucky to be involved in that pursuit,” said Denton concluding his talk and not his work.

Photo at top: Glaciers shrouded the entire Great Lakes region during the last great ice age some 20,000 years ago. Thick walls of ice covered the areas shown in white (USGS image).



By Lakshmi Chandrasekaran –

Glaciers and forests show jagged retreats in Jill Pelto’s paintings while the sky above heats up. Pelto, a graduate student studying climate science at the University of Maine, uses her art to convey the impacts of climate change on world environments.

She overlays climate change research data with striking colors and vivid imagery to depict our living world amid rising temperatures. Her watercolor paintings convey multiple layers of information, all the while visualizing the problems of climate change. Jill calls her works “glaciogenic art.”

Jill combined both her passions for art and climate science during her undergraduate studies at the University of Maine where she graduated last year with a double major in studio art and earth science. Through the dual media of painting and data she strives to convey the impact of our unsustainable practices on climate and environment. A tiger clings to a disrupted, shrinking ecosystem in one painting. Using data that shows the decline in forest area from 1970-2010, Jill’s painting on habitat degradation depicts why tigers are an endangered species today due to human impact on their environments worldwide. Another painting shows the annual decrease in the size of glaciers worldwide, global sea level rise and global temperature increases, all incorporating climate change data.


By Lakshmi Chandrasekaran –

Peter Strand busy drilling quartz samples from at the Altai Mountains, Mongolia. (Kevin Stark/MEDILL)

Cosmic rays, hurling across the galaxy near light-speed, generate a time machine on Earth for us to measure the retreat of the glaciers and the pace of climate change.

Ph.D. student Peter Strand, at the University of Maine, drilled samples of quartz from boulders in Mongolia’s Altai Mountains this summer to tap this time machine. Cosmic rays strike the atmosphere and release showers of subatomic particles such as neutrons that collide with the rocks, creating a variant of the element beryllium that builds up once the ice retreats from the rock and leaves it exposed to the air. Scientists call this variant a cosmogenic nuclide – beryllium-10 (10Be). The surfaces of rocks and boulders contain 10Be and, what’s fascinating is that the 10Be can be used as a measure of when the glacial retreat began, anywhere from a hundred to tens of millions of years ago!


By Lakshmi Chandrasekaran

Lights across the U.S. at night as viewed by satellite. (NASA.gov)

“Green city planning to create green roofs, green parks and deployment of green assets in places where we are worried about heat effects is necessary,” said Jessica Hellmann, director of the Institute on Environment from the University of Minnesota. At stake is keeping climate change at controllable levels.

Jessica Hellmann called for more parks, roof gardens and green space to pull down temperatures in urban areas. (Lakshmi Chandrasekaran/MEDILL)
Jessica Hellmann called for more parks, roof gardens and green space to pull down temperatures in urban areas. (Lakshmi Chandrasekaran/MEDILL)

She stressed in no uncertain terms the need to uphold the international Paris climate agreement to limit global warming to 2 degrees centigrade  (3.6 degrees Fahrenheit). “We just wrote a paper recently about using weather models in the Chicago land area and what would happen if you could turn 25 percent to even 100 percent of all roofs and make them green. How much would it reduce downtown temperatures in the event of extreme temperature scenario?” said Hellmann, adding that their study revealed how temperature plummeted by several degrees Fahrenheit.

Hellmann and other climate experts addressed local, national and global impacts of the “Water-Energy-Climate Nexus” at Northwestern University’s recent Climate Change Symposium. The Institute for Sustainability and Energy at Northwestern anchored the symposium to water and energy resources, keys to climate change solutions.

A meeting of minds

ISEN Executive Director Michael Wasielewski said in an interview that this symposium brought together policy-makers and students as well as scientists and so it serves to benefit researchers both from Northwestern University and other institutions tremendously. Wasielewski said he hopes that the conference is a conversation starter that allows individual researchers to get together and make connections. “This will ultimately lead to new projects and new solutions to address these problems,” he remarked, highlighting the fact that technology curbing climate change may come from seemingly unrelated areas of science and engineering.

The event hosted multiple speakers from universities and agencies across the country. Diana Bauer, director of the Office of Energy Systems Analysis, at the Department of Energy (DOE) said water is essential for power generation and advocated accurate power/water models as critical to energy policy and decision-making. “The DOE has about 18 departments that focus on water and so we are focused on energy and it’s connection to water, “ said Bauer.

Mark Johnson, director of the Office of Advanced Manufacturing of the Department of Energy said,” What our department focuses on is that if the scientists develop new technologies such as applications for clean energy, how do we get them out of the labs to the marketplaces?” He spoke about DOE initiatives, to support partnerships between universities and industries, emphasizing the need for basic and applied sciences to collaborate and come up with energy efficiency solutions.

Lowering our carbon footprint

Energy efficiency and alternative energy are part of the quest by scientists worldwide to lower fossil fuel emissions of carbon dioxide, a greenhouse gas responsible for warming our planet.  As a chemistry professor, Wasielewski and his research group explore producing renewable energy sources such as solar fuels. In particular, his research focuses on artificial photosynthesis that  uses solar energy directly to produce solar fuel.

“The way we do that is by targeting solar energy to catalytically split water to generate oxygen and hydrogen,” he said. Wasielewski’s team also experiments with the use of solar energy to catalytically reduce carbon dioxide to liquid fuels, which could be easily stored. “It is an instance of worldwide effort in that area because the idea of directly using solar energy to drive carbon dioxide reduction to liquid fuel that can be used for transportation is a long-term goal of many researchers,” he said.

Fracking and the risks of water contamination

The symposium featured talks on essential policies and reforms to target energy challenges. “Hydraulic fracturing is one energy field that requires more regulation,” said Joseph Ryan, a professor of Civil, Environmental and Architectural Engineering at the University of Colorado, Boulder.

Joe Ryan’s research in Colorado shows the need to control toxic chemicals in fracking fluids that could contaminate groundwater. (Lakshmi Chandrasekaran/MEDILL)
Joe Ryan’s research in Colorado shows the need to control toxic chemicals in fracking fluids that could contaminate groundwater. (Lakshmi Chandrasekaran/MEDILL)

Ryan’s research, funded by the National Science Foundation, is studying the impact of hydraulic fracturing on water pollution locally in Colorado. He said he believes that regulators can use this information as a decision analysis tool since water pollution isn’t the only problem related to fracking as climate change threatens increased water shortages in parts of the U.S.

Ryan’s research team looked at water acquisition practices for oil and gas fracking in two Colorado counties – Weld and Garfield. He showed that at least in Weld County, not all of the hydraulic fracturing fluid injected to drill oil and release hydrocarbons, flowed back up and continued to stay underground.

But why would this be a problem? Ryan and his team analyzed the chemical compounds used in the fracturing fluid at high pressure to break up or “fracture” rock and extract oil. They focused on organic compounds in the fluid and found a large number of them –  a total of 659 including guar gum, methanol, ethylene glycol among others. Many are toxic and some are also mobile and persistent, a subset of the 659 compounds that do pose a risk if they are released, Ryan said.  “We should be worried about those” due to potential contamination of groundwater supplies, he said. The additional risk here is that a few of the compounds are not monitored. As a result, Ryan and his colleagues suggested two major recommendations to  Colorado regulators.

First, monitor these compounds that are not commonly measured and “could be regarded as smoking guns that could implicate some contamination episodes,” said Ryan. Second, remove the hazardous compounds and increase the efficiency of fracking. “Unfortunately the oil and gas companies have not put a lot of effort into making a ‘greener’ fluid since it’s expensive and they do a lot of experimentation on the field. There’s no work on how these compounds might affect things from a laboratory perspective,”  Ryan said.

From local to global

Acknowledging the limitations of his study, Ryan said that not all geological considerations are transferable. However, the work on improving air quality and the treatment of wastewater coming out of these oil and gas wells are widely applicable, said Ryan – adding that each state is better off forming their own regulations.

A controversial EPA report released in 2015 on the assessment of potential impacts of hydraulic fracturing for oil and gas concluded: “We did not find evidence that these mechanisms have led to widespread systemic impacts on drinking water resources in the United States.” Scientific studies, such as the one from the University of Colorado, albeit alarming, are limited to a local scale affecting a smaller percentage of people. Should government regulatory agencies take action or dismiss local studies for not being  ‘widespread’ and ‘systemic’ enough? Is there a magic number of people impacted that should prompt us to take action? “This is something we as a society and regulators have to decide,” said Ryan.

As for instituting climate change regulations, Chicago Congressman Michael Quigley (D-5th), the keynote speaker at the symposium, enumerated some of the hurdles he faces. “I serve with [some] people who don’t believe in climate change and evolution,” he said, citing his lack of a necessary quorum at times to carry out policy reforms.

In the face of this opposition, Quigley lamented that despite being served by one of the most progressive presidents on environmental issues, not much has been accomplished in addressing the problems. “The frustrating part is that you are not even seeing climate change issues being addressed in the debates at all, since debates have become reality TV,” he commented.

As a ranking member of the Sustainable Energy and Environment Coalition (SEEC) at the House of Representatives, he strongly advocates policies for regulating environmental issues, limiting the threat to our climate.

Quigley urged the scientists to synthesize their results and communicate to lay audience in an accessible manner so that it could be translated through our political system back through an active Congress.

”Change comes when the base core of the constituency say otherwise,” remarked Quigley, as part of his closing statements.

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