Melting freshwater icebergs raise critical questions about ocean circulation. However, to find answers to what’s happening on ocean surfaces, some scientists are searching ocean floors for evidence of past environments and clues to the pace of current climate change.
As a fifth-year Ph.D. student at Columbia University’s Lamont-Doherty Earth Observatory, Yuxin Zhou’s research focuses on the factors destabilizing the circulation in the North Atlantic, spanning the past 150,000 years. The majority of his findings are based on new and previously published measurements of long tubes of sediment cores collected from ocean floors in the North Atlantic.
“Model simulations can be a very powerful tool to narrow down the spread off of estimates we have on the freshwater fluxes,” Zhou said.
Prior to the pandemic, he spent long weekdays working at Lamont-Doherty in the Palisades near New York City. However, due to stay-at-home orders, he has been on campus for only three to four weeks in total since March.
When Zhou does travel to the campus, entering the laboratory requires an extensive sanitation protocol. He must change into the appropriate lab attire, which includes long pants, long sleeves, closed-toed shoes, gloves, goggles, a mask, and a lab coat. After stepping onto a sticky mat to remove dust particles from his shoes, Zhou can enter the lab and begin working.
Measuring 18 data points from one sediment core can take up to two weeks but provides key data on specific elements and isotopes within the sediment, and indicates the amount of freshwater released by melting icebergs during a certain period of time.
To begin the measuring process, Zhou begins by removing a small portion of the sediment core and places the solid sediment into a heat-and acid-resistant container. He then uses heat and several types of acids, including hydrofluoric acid, to gradually dissolve the solid sediment into a liquid solution.
While working in the Lamont-Doherty Earth Observatory laboratory, Zhou wears full personal protective equipment including a lab coat, face mask, goggles, and gloves. In the lab, Zhou works on various scientific processes including column chemistry (right). (Yuxin Zhou // Columbia University)
Once a dissolved liquid, it’s time to begin a chemical process called column chemistry, which filters and separates elements in the liquid. The chemical process results in a concentrated liquid containing three primary elements, which Zhou needs to measure the iceberg meltwater: thorium, protactinium, and uranium.
Finally, the concentrated liquid is placed into a machine to test the concentration of each isotope. With conclusive measurements, Zhou can determine the amount and location of freshwater released by icebergs in the North Atlantic.
The remainder of the sediment core is archived in the Lamont-Doherty’s core repository, one of the largest such repositories in the world. With accessibility to decades of core sediments collected from around the world, Zhou hopes his new method will contribute to scientist’s global efforts to predict and mitigate the effects of climate change.
“The best minds in the world have been working on this for a very long time,” Zhou said. “The scientists have nothing other than the best interest of science and the human society when they devote their careers to these questions about climate change.”
For the past few weeks I have been taking photographs of changing food habits, cooking, areas of trash and places that remind me of all three. I wanted to capture food through a colder city setting and kinder home settings – food seen through windows, shuttered restaurants, urban gardens and alley dumpsters. The images found right near my doorstep seemed to highlight either distance or fantasy.
The only image that was taken inside shows CLOROX wipes, which now gives me the feeling of fear and of waste. The rest I took while walking through my neighborhood, especially during quieter times and dimmer days. Montrose Avenue, the main street closest to my apartment, is often alarmingly empty of people now.
These photos both comfort me and leave me feeling closed off. It’s like when I smell my neighbor’s cooking. I am consistently reminded that we are all very near to each other. But, in reality, we are far away, behind brick walls and mirrored windows.
Dollop Café sits empty on Montrose Avenue.Cooking from the outside in.Ordered bulk packaging in the recycling.Cara Larson holds up her bread starter. She’s been baking homemade bread recently.Free cans.CLOROX wipes.Burger trash.Pick-up order.Coffee.Community garden.
Photo at top: Cara Larson holds up her bread starter. She’s been baking homemade bread. We yelled conversation at each other from opposite sides of her window. (Elena Breuss/Medill)
The locked office of the late climate scientist Wallace “Wally” Broecker displays a wooden ship’s wheel, mounted on a window-paneled wall behind his former desk. The wheel overlooks the forested campus of Columbia University’s Lamont-Doherty Earth Observatory, where Broecker conducted research for nearly 70 years. It originated from one of LDEO’s first vessels used for ocean chemistry testing in the 1960s, and the choice of its current home is no accident: The captain’s wheel is symbolic of Broecker’s leadership at the institution, says paleoclimatologist and LDEO professor Jerry McManus.
Wallace Broecker’s former office is on the second floor of the Gary C. Comer Geochemistry Building in Palisades, New York. LDEO administration hopes to re-open its doors for continued use while preserving Broecker’s memory, although it has not yet come to a decision. (Zack Fishman/MEDILL)
Broecker, who died in February at the age of 87, made significant contributions to the scientific understanding of the oceans, climate and climate change during his long academic career, mentoring several generations of students. Born in Oak Park in 1931 as the second of five children, he received his Ph.D. in geology at Columbia and became an assistant professor there in 1959. Since then, he pioneered the use of carbon isotopes and trace compounds to date and map the oceans, as well as introducing the concept of a “global conveyor” that connects the world’s oceans through heat-driven circulation. Broecker also popularized the phrase “global warming” in a 1975 paper and has been deemed the “grandfather of climate science” by many in the field.
More than 200 researchers and family members celebrated his legacy at the Wally Broecker Symposium in late October, with many of the world’s leading earth scientists in attendance. McManus led the organization of the three-day conference, which took place on the LDEO campus, an hour’s drive north of Columbia’s main campus in Manhattan. Dozens of Broecker’s former students and colleagues presented new research based on his findings, as well as heartfelt and entertaining stories about the late scientist.
Princeton geoscientist Michael Bender opened the symposium with a summary of Broecker’s decades-long career, which he said spanned dozens of research topics and many ambitious experiments. Bender said Broecker first visited LDEO for a summer job in a lab and he learned about the new technology of radiocarbon dating, or measuring isotopes of carbon to determine the age of materials. Broecker’s supervisor was impressed enough to arrange the young scientist’s transfer to Columbia from Wheaton College in Wheaton, Illinois, for his senior year and asked the 22-year-old to take over the lab.
An innovative Broecker would go on to use radiocarbon dating in 1958 to measure how glaciers affected the depth of a prehistoric lake in Utah. He also pioneered the use of tracking radioactive particles to study circulation in bodies of water, as he did in the 1980s when he poured radium into lakes in Ontario, Canada — with governmental permission — to follow its motion.
“I tried to look at Wally’s work as a whole, and the scope is just completely overwhelming,” said Bender, one of Broecker’s former students. “We were incredibly lucky to have the opportunity to be associated with this man and his science.”
President Bill Clinton awards Broecker the National Medal of Science in 1996. He received the award for his research on ocean circulation, the global carbon cycle and climate change. Broecker won several awards in the Earth sciences, including the prestigious Crafoord Prize, the equivalent of the Nobel Prize for his field. (Lamont-Doherty Earth Observatory)
Other researchers from numerous fields credited Broecker’s findings as foundational to their work. Geoscientist Jean Lynch-Stieglitz of the Georgia Institute of Technology said she “found Wally’s fingerprints all over” her research, as she used his model of the ocean “conveyor belt” to track how nutrients and heat circulated in the last 10,000 years. LDEO paleoclimatologist Dorothy Peteet shared the results of her and Broecker’s joint investigation into the causes and timing of glacier retreats during the last ice age.
Presenters also highlighted the scientist’s outspoken views on addressing climate change. Peter Schlosser, an earth scientist at Arizona State University, played a video clip of Broecker’s final address to the scientific community about necessary actions to limit global warming. From his hospital bed in 2018, Broecker said more drastic climate mitigation measures must be considered, such as capturing carbon dioxide from the air or injecting cooling aerosols into the atmosphere. The address was first played at the Planetary Management Symposium, held last year at Arizona State.
“If we are going to prevent the planet from warming up another couple degrees,” Broecker said, “we’re going to have to go to geoengineering.”
Praise of Broecker’s personal character pervaded the symposium with warm testimonies to his values and quirks. He was an “intellectual snow plow” who tackled problems with rigor and confidence, said Princeton geophysicist Daniel Sigman. His passion sometimes overflowed into what LDEO oceanographer Mark Cane called “strategic and effective” tantrums, often digging in his heels against administration and correcting guest speakers in his own class. Broecker was also a lifelong prankster, with stories of his tomfoolery tracing back to high school, when he rarely got caught. More recently, he had a staff member take his place during a video conference and mime the words Broecker was saying off-camera. (He didn’t get away with that one.)
LDEO professor Jerry McManus, who led the organization of the Wally Broecker Symposium, speaks about abrupt climate change that occurred at the end of the last Ice Age. (Zack Fishman/MEDILL)
“He had such a human heart,” McManus said, and fellow LDEO faculty member William Ryan called Broecker a “master of kindness.” Numerous attendees said he was an important influence in determining their career path as someone who often opened doors of opportunity. Ahbijit Sanyal, a director at Johnson & Johnson and another former student, said his teacher was “like a father” to him and once used his influence to help Sanyal’s wife immigrate to the U.S.
Yet more often, Broecker played down his status as a prolific researcher, and one scientist said he didn’t care about “personal wealth” or “glory.” He seemingly disliked his fame for popularizing the phrase “global warming” — he once offered his students $250 to find an example of its use before his landmark 1975 paper, though none were successful.
But Broecker paid a lot of attention to young scientists and their success. Encouragement and affirmation goes a long way for junior scientists, said Mayaan Yehudai, a Ph.D. student at LDEO and previously a teaching assistant for two of Broecker’s classes.
“When you’re a student, you don’t always know when you know that you’re qualified,” Yehudai said. “So, to have somebody like that tell me that I’m qualified or to believe in me is very, very meaningful.”
After the first full day of presentations, the visitors attended a ballroom dinner and listened to several heartfelt speeches from Broecker’s family and friends, including several senior members of LDEO. Filmmaker Anna Keyes presented a video centered around an interview with Broecker, her grandfather. His two younger sisters, Bonnie Chapin and Judy Revekop, told stories of growing up with a high-energy and caring Wally.
Broecker, then 22, poses for his student ID photograph as he joined the Columbia University geology department in 1953. (Lamont-Doherty Earth Observatory)
Broecker didn’t want a memorial, so the symposium was the largest gathering his family has attended in his memory, Revekop said. Nevertheless, she believes he would have appreciated the event.
“I’m sure he would love to be a little something sitting on a corner, watching and enjoying,” she said.
The dinner also featured an outpouring of musical talent. Geophysicist Richard Alley of Pennsylvania State University wrote and performed a song about his colleague’s career on a prerecorded video, drawing laughs from the attendees. Tom Chapin, a brother-in-law of Broecker and Grammy-winning folk singer, also played an original song about the late scientist’s research. His daughters, Abigail and Lily Chapin, later joined him to sing — this time, less about science and more on spiritual unity.
Broecker’s daughter Cynthia Kennedy, who attended the dinner and livestreamed the seminar, said the symposium was “fabulous” and praised the community of scientists it brought together.
“What they did for him was as much as he gave to them, because that’s what kept him going: their curious minds and their youth and their energy,” Kennedy said. “He fed on that, and that’s what made him who he was.”
Read more about Wally Broecker and his partnership with late philanthropist Gary Comer to launch a national initiative of climate research fellowships that Comer funded. The Comer Family Foundation continues to support the climate change research program.
Photo at top: Wallace Broecker in 2018 at Leeward Farms in Casper, Wyoming. (Jasmin Shah/Comer Family Foundation)
Tom Chapin (left) and his daughters Lily Chapin (center) and Abigail Chapin (right) perform during the symposium ballroom dinner. Tom has been performing since the 1970s and won three Grammys for Best Spoken Word Album For Children. Lily and Abigail have created music as the Chapin Sisters since 2005. (Zack Fishman/MEDILL)
Geoengineering professor Juerg Matter, from the University of Southampton in England, speaks about capturing atmospheric carbon dioxide and storing it underground to address climate change. Capturing CO2 directly from the air was one of Broecker's proposed solutions to combat climate change. (Zack Fishman/MEDILL)
Princeton Professor Michael Bender explains the cluttered timeline of the research topics Broecker pursued over his career. (Zack Fishman/MEDILL)
A ballroom of researchers and family members listens to Michael Bender read an old letter written by Broecker's late brother Howard. (Zack Fishman/MEDILL)
Broecker's sisters, Judy Revekop (left) and Bonnie Chapin (right) share memories of growing up with Broecker at the ballroom dinner.
Climate change is rapidly taking the world as we know it into uncharted territory. What we do next and how quickly we do it can shape the degree to which changes are catastrophic – with an escalation in wildfires, drought, flooding, food shortages, and severe storms – or advantageous – with investments in renewable energy and innovation. We are seeing some of both already.
The latest report of the U.N. Intergovernmental Panel on Climate Change, released in October, gives us a time-frame of 12 years to cut global emissions by 45 percent below 2010 levels and stay below the tipping point of 1.5 degrees C (2.7 degrees F) global temperature rise. The report was based on the work of 133 scientists and other authors and more than 6,000 peer-reviewed research articles. The Paris Agreement, from which the Trump administration has withdrawn the U.S., set the 1.5-degree limit as an urgent limit in 2015 with the support of 194 countries.
“Everybody talks about the Paris Convention – we can’t heat the Earth more than 1.5 degrees. So what are you gonna do?” asked Columbia University geochemist Wallace Broecker in an interview during October’s annual Comer Abrupt Climate Change Conference in Wisconsin, “Is there a magic switch you pull? Boom! We stop raising CO2 and the Earth cools and it doesn’t warm anymore? Forget it!” Broecker said.
It’s as if there’s a new apocalyptic blockbuster in theaters, and Joerg Schaefer has a front-row seat.
Some of the world’s foremost climate scientists shared their latest field research reports at the annual Comer Climate Conference this past fall in southwestern Wisconsin. None was as jarring as Schaefer’s talk on his work in Greenland and the Himalayas. His data indicating the vastly increased potential for sea level rise and severe water shortages are harrowing.
The renowned Columbia University professor gave two presentations, each on a paper that he published late in 2016. The first described a groundbreaking mission to drill through 2 miles of ice in the center of Greenland. The cosmic ray burn that Schaefer and his team found on the bedrock beneath the glacier indicates that, contrary to conventional wisdom, Greenland was completely ice-free during certain interglacial periods over the past 2.6 million years. The isotopes that were present in the sample – traces of beryllium-10, aluminium-26, and chlorine-36, among others – deliver the telltale clues that appear when cosmic radiation bombards rock uncovered by ice.
Schaefer’s mood was heavy as we sat down to speak in the library of the Comer Family Foundation estate after he had presented his findings. Outside the window to his right, a concrete landing strip gave way to the rolling hills of the Midwest’s Driftless Area. On a shelf to his left sat a leather-bound copy of Darwin’s Origin of Species. But Schaefer seemed weighed down by the subject matter of the day, unable to appreciate the treasures around him. “What I showed you today is another piece of bad news,” he said.
The expedition’s results may mean that Greenland is much more susceptible to climate change than we had thought. As we continue to warm our planet, the Arctic island could deglaciate in a matter of decades. And if it does, it will mean almost 25 feet of sea level rise.
Joerg Schaefer at the Comer Climate Conference last fall. (Adam Cohen/MEDILL)
The second talk Schaefer gave was based on a foray not into the Arctic, but into the archives of the American intelligence community. In a paper he co-authored and published in September 2016, Schaefer compared modern NASA imaging with recently declassified spy satellite data dating back to the early 1970s in order to build a series of digital elevation maps that quantify glacial retreat in the Himalayas.
The study is unprecedented in scope, as it traces the movement of roughly 18,000 individual glaciers over three decades, from 1974 to 2006, and thus isn’t skewed by regional variation for factors such as elevation and precipitation. Additionally, the Cold War-era, school bus-sized satellites, launched into orbit by the U.S. National Reconnaissance Office to keep tabs on the Soviet army, provide a clear picture of objects as small as 2-feet wide. That’s a resolution higher than current Google Earth imagery.
Unlike the Greenland results, the significance of the Himalayan satellite data is unequivocal. The glaciers of the Asian mountain range, which hold the largest quantity of ice outside of the polar regions, are shrinking by 1 percent each year, and that rate is accelerating. Even with a conservative estimate of 1.5 degrees Celsius (roughly 2.5 degrees Farenheit) of warming above preindustrial levels by the end of this century, more than one-third of Himalayan ice mass would be lost.
“But it will be much more, because the warming will be more,” said Schaefer, who has done field research in the Himalayas. “And if you warm the global temperature by 2 degrees, you’re warming more than that in the higher mountains of Asia, because the high altitudes warm more.”
The global community will have to deal with at least a foot of sea level rise as a result of this Himalayan thaw. But more than 1 billion South Asians who rely on glacial melt for agriculture, energy production, and potable water face far more dire consequences.
“Right away,” said Schaefer, “if you are there for the first time, it becomes clear that glaciers are not just some abstract tourist attraction, which they basically are in Switzerland, where I did my Ph.D. There, if you change the glaciers, it’s kind of inconvenient for some skiers. In the Himalayas, it’s a very dominant part of the environment, and as soon as the glacier changes, the entire habitat of the people living in downstream valleys changes.” The water supply is paramount. “At some point, you will be sitting with no water at all outside of the rainy season in the big Indian rivers like the Indus and the Ganges and the Brahmaputra. This will be an epic disaster if it happens.”
Richard Alley, the Penn State geosciences professor who has authored numerous assessment reports for the Intergovernmental Panel on Climate Change, said that, even without taking diminishing water reservoirs into consideration, future heat stress will be enough to make life grim for the people of South Asia and the world’s other tropical regions.
“It is very clear that poor people in hot places get screwed by climate change,” said Alley. “When it gets unexpectedly hot, people die. And that’s not really close yet in Anchorage. But it may be closer in Ankara. And it may be way closer in some of the big cities of India. And it’s miserable long before it’s fatal.”
Toward the end of our interview, Schaefer shifted to a more optimistic call for action. He highlighted the work of Columbia’s Earth Institute, one of many American academic centers making strides in communicating the urgency of the situation by promoting collaboration between earth scientists, economists, political scientists, and other researchers. It is not too late, Schaefer insists, to take concrete action to save humanity from the most catastrophic climate outcomes.
“We are at a point where the message is so clear that we really can transfer something robust to policy makers,” said Schaefer. “We have to do the best we can. Predict and transform – bring this message to the decision makers, and prepare them for what might come.”
Photo at top: Aerial view of Himilayan glaciers in Bhutan. (Included in Joerg Schaefer’s presentation at the Comer Abrupt Climate Change Conference)
Richard Alley smiled widely, beer in hand, as he welcomed a group of student journalists to the annual Comer Climate Conference this fall. “I bet you all have a cell phone on you,” he said. “Don’t throw it on the ground!” The students exchanged sideways glances. “It might break,” Alley continued. “And that’s important. Things break easily.”
Things like the Earth.
Alley, professor of Geosciences at Pennsylvania State University, is a world leader among the contributors to discoveries about global warming and one of the scientific community’s master communicators. He has written five books, testified before various United States senate and house committees, and authored numerous assessment reports for the Intergovernmental Panel on Climate Change. Alley has devoted his career to conveying the fragility of the complex systems that keep our planet in balance. He now feels it is time for “reframing the discussion” to convince people of the urgency surrounding climate change.
In January 2014, C-SPAN broadcast live as Alley testified before Congress. At one point, the panel got on the topic of prehistoric interglacials – eras in which the Earth warmed without human interference. “Why did it happen then if these same factors that you’re blaming it on didn’t exist then?” asked Republican representative Dana Rohrabacher of California.
“The ice ages are caused by features of Earth’s orbit,” Alley responded. As he spoke, he put one finger on the top of his head (the North Pole) and one hand in front of his nose (the equator), illustrating the back-and-forth nodding of the orbit that happens over 41,000-year cycles. “We know what that’s doing right now, and it’s not [happending] fast enough to explain what we’re seeing.”
Richard Alley, a master communicator, being interviewed at the Comer Climate Conference in October. (Morgan Levey/Medill News Service)
That 30-second sound bite is the topic of the 500-page Earth: An Operators’ Manual, which Alley published in 2011. “More and more,” he writes, “the processes that made Earth’s landscape in the past are not the processes that students observe today, because the dominant processes today are ‘us.'”
The majority of the American public has finally gotten the message, thanks to the insistence of scientists such as Alley. A July 2017 survey conducted by the Yale Program on Climate Change Communication shows that 58 percent of Americans “believe climate change is mostly human caused,” while “only 30 percent say it is due mostly to natural changes in the environment.”
Though he will continue to try to popularize the science – his lesson in plate tectonics set to the tune of Johnny Cash’s Ring of Fire and posted on YouTube may be his biggest hit to date – Alley believes we should now devote more of our collective energy to convincing those who already understand the urgency of anthropogenic climate change to take action. Some have an ethical problem with “rich people in cold places burning fossil fuels and hurting poor people in hot places.” Others prioritize issues like national security and job creation, both of which would be positively impacted by good climate policy. Alley wants to consider each group separately and use targeted messaging to unite, rather than polarize. “Anything you can think of on this topic – all of them point the same direction,” he says.
Alley served as MC, as he does every year, at the conference held by the Comer Family Foundation in early October. He was a good friend of the late Gary Comer, founder of Lands’ End. Now, as one of the foundation’s science advisors, he helps make recommendations on awarding climate field research grant money from the foundation.
Moving around the airplane hangar where conference sessions are held on the Comers’ sprawling southwestern Wisconsin estate in a blue checkered button-down and wool slippers, Alley led the forum with his characteristically unyielding ebullience. “Grab your coffee, grab your chair – we have exciting science to do!” he said between talks on beryllium-10 moraine dating. (Beryllium-10 collects in the quartiz of ice-free rocks struck by cosmic rays once the glaciers have tossed them aside as they lumber away, offering a time machine for pacing the retreat of glaciers.)
At the end of day two, it came time for Alley’s closing remarks. He choked up as he wished his fellow scientists a fruitful year of discovery. “I love these meetings,” he said, his voice trailing off. “You have a voice because you’ve done the science.”
Photo at Top: Richard Alley in the field. (Photo by Karen Alley for the PBS series “Earth the Operators’ Manual) Related story: Richard Alley talks about how fixing climate will be good for the economy.
Note: Adam Cohen is a Comer Scholar, a Medill scholarship program supported by the Comer Family Foundation to promote graduate studies in environmental journalism.
“You can’t open a McDonald’s ketchup packet without the little notch. Try it, okay?” noted climatologist Richard Alley.
Without the little notches, plastic ketchup packets are almost impossible to open no matter how much you pull or tear. Cracks in the world’s ice sheets are like those little notches, Alley said. Once these cracks appear in ice sheets, the stress concentrates there and eventually can lead to large sections of ice falling off and melting quickly.
The 2016 Comer Abrupt Climate Change Conference brings together some of the world’s top climate scientists to discuss their most recent research. (Photo courtesy of the Comer Family Foundation)
Alley, professor of geosciences at Pennsylvania State University, used the analogy to describe how ice sheets can rapidly break apart due to preexisting “cracks” or “notches” in the ice produced when meltwater opens small crevices and then makes them big ones, he said. “When you make these cracks bigger, it makes [the ice sheet] break way faster,” Alley said in his presentation at this year’s Comer Abrupt Climate Change Conference.
Alley and a gathering of some of the world’s top geologists, paleoclimatologists, engineers and climate modelers meet each fall in southwestern Wisconsin to discuss their most recent discoveries on the origins and consequences of abrupt climate change.
“We know what nature can do, so we know that climate change is a big deal, and we know that what humans are doing now is not natural,” Alley said. “Across almost anything that we look at, the first degree of warming had very small costs, but we’ve done that. The second degree of warming will have larger costs. We’re mostly committed to that. The third degree of warming will have even larger costs.”
Alley emphasized the fact that the Pentagon prioritizes climate change as a national security issue and that adapting to a sustainable energy system will be beneficial for the economy.
The key question the scientists addressed at this year’s conference was urgent – “not whether or not global warming and climate change are happening, but how fast,” said Philip Conkling, a sustainability consultant and author. “To understand that, we have to understand the dynamics of the past.”
Field research took many of the scientists around the world and deep into the history of Earth’s climate in order to better understand the sensitivities and “switches” that triggered abrupt changes thousands and even millions of years ago. Piecing together these discoveries provides a progression of natural events to compare to the changes occurring today at an accelerating rate as a result of human impacts.
Joerg Schaefer, a geochemist at Columbia University, presented the latest findings on the threat to the stability of the melting Greenland ice sheet, which holds an equivalent of about 7 meters of sea level rise (about 23 feet), enough to inundate many coastal cities.
“The Greenland Ice Sheet was most certainly gone during natural forcing [in the past] and of course this is also worrisome because what we are doing in the moment will almost certainly at one point, and maybe soon, deglaciate Greenland. So it’s really pressing that we understand these processes quickly,” Schaefer said.
The problem is that human use of fossil fuels is moving global climate much faster than nature does, several scientists said.
Richard Alley showed how rapid sea level increases can occur as a result of cracks in the Earth’s ice sheets. (Janice Cantieri/MEDILL).The Greenland Ice Sheet was deglaciated in the past due to natural processes, which is worrisome, Joerg Schaefer said, because current carbon emissions from human use of fossil fuels could likely force a modern deglaciation. (Image: NASA)
In order to avoid significant sea level rise, droughts, food shortages, disease, and international conflicts, the world must cut carbon dioxide emissions by more than a factor of 10, said pioneering climate scientist Wallace Broecker of Columbia University.
“Every ounce of CO2 we put in the atmosphere makes it a little bit worse. We see things happening already and obviously. As we warm the planet up more those things are going to get bigger and extend further,” he said. “We’ll start to see whether sea level will start to rise at a bad pace. It’s going to move ecology everywhere.”
Levels of carbon dioxide in the atmosphere remained below 300 parts per million (ppm) for at least 800,000 years prior to the Industrial Revolution, even during the warm spells between the ice ages. Carbon dioxide levels are now rising above 400 ppm as the greenhouse gas traps heat and is rapidly warming the planet.
Pioneering climate scientist Wallace Broecker says the world must reduce our carbon emissions by a factor of 10 to avoid some of the worst damages from warming. (Abigail Foerstner/MEDILL)
“The biggest hope is to get rid of using fossil fuels, but, you know, I can’t see that happening in less than 50 years,” he said. And because of the role of the ocean in absorbing CO2, there is a high chance that the world is already committed to significant temperature rise, likely well above the 2 degrees Celsius cap set out in the 2015 Paris Agreement, Broecker said.
While many researchers painted a bleak future for the planet if no action is taken now, some promising innovations could provide solutions, or at least prevent the scale of the worst damages caused by warming. Physicist and engineer Klaus Lackner is developing a technology to capture carbon dioxide directly from the air. It could help “close the loop” of carbon emissions, he said at the conference.
A prototype of Lackner’s “artificial tree” has been successfully operating on the roof at Arizona State University’s Center for Negative Carbon Emissions for the past year. About 100 million of the units, each built to remove one metric ton (2,204 pounds) of CO2 a day, could offset the 36 billion metric tons of carbon dioxide emitted by the people of earth each year, he said.
Meanwhile, the global research continues. A team of researchers and graduate students led by Aaron Putnam from the University of Maine presented findings from field work in the remote Potanin Glacier Valley of Mongolia’s Altai Mountains. During the six-week expedition, the team trekked through the mountains and collected boulder samples that map the retreat of the glaciers, revealing clues about why, when, and how quickly the last ice age ended.
Kevin Stark of the Medill News Service showed drone footage and photos from his experience as an embedded reporter with Putnam’s team in Mongolia, and his story was published in Pacific Standard Magazine in October.
The conference closed with warm memories of the late Gary Comer, who created the Comer Family Foundation to support initiatives in healthcare, education and the environment. Comer, the founder of the Land’s End retail company and a Chicago native, became concerned about warming global temperatures after completing a 2001 sailing expedition through the Northwest Passage. The Arctic passage connects the Atlantic and Pacific Oceans and warming temperatures had melted many of the icebergs in this famed “shipwreck alley” of the passage, creating a clear pathway for his ship.
After returning, Comer sought out Broecker, credited with coining the term “global warming” in 1975. Together with Alley and glaciologist George Denton, of the University of Maine, they created a fellowship program to support research on the causes and consequences of abrupt climate change. Since 2003, more than. 300 papers have been published by Comer Fellows in peer-reviewed journals.
Philip Conkling closed the conference by reading a note he wrote for Gary Comer in 2005, after one of their final sailing expeditions together:
To be brave and cheerful – to be brave and cheerful is no easy thing. Staring in the face in the morning’s mirror, where the skin fits more loosely now. Like a favorite sweater, gone soft with age. Surely, the news cannot be all bad. The images the eyes dissolve are no longer cut with the sharpest knife, but we have already seen much of the world. And anyway, what we need now is vision, not sight. Inner vision too, and insight, if it’s not too much to ask. To be brave and cheerful is no easy thing. Be calm, and live with light in a slowly freezing sea. Should it be surprising that those who have given so much find it hard to drink from an overflowing cup? August 12, 2005.
Animation: Scripted by Janice Cantieri/Produced by Next Media Animation. Photo at top: NASA. Original caption: NASA’s IceBridge mission observes the effects of summer melt on Greenland Ice Sheet.
Aaron Putnam of the Climate Change Institute at the University of Maine is searching for the switches that caused the Earth to lurch out of the last Ice Age. Climate levers are not yet well understood, and “just what the heck” causes them is still a mystery he’s hoping to solve in Mongolia this summer. To weave together the clues, Putnam is trying to find data in a remote ice field in Mongolia’s Altai Mountains. Putnam was awarded an Early Career Award by the National Science Foundation to pursue this work. Medill Comer Scholar Kevin Stark and Destiny Washington, a 17-year old student at Chicago’s Gary Comer College Prep are embedded with Putnam and the research team for the length of the field season and blogging about the experience in these pages.
The final days of a Mongolian odyssey in search of climate clues
By Kevin Stark
The Potanin Glacier in the Mongolian Altai (Kevin Stark / Medill).
Wednesday, Aug. 3. Our journey ends in a science laboratory at the Mongolian University of Science and Technology (MUST) in Ulan Bator.
Three long rows of work benches, science posters tacked to the wall, and rocks piled around the room fill the geology lab, lit by four chandeliers hanging from the ceiling. More than 120 of the rock samples collected by the University of Maine team are piled onto these tables, each in individual canvas bags, information carefully written in black permanent marker on the sides. Clues to climate change lie within, a time machine that traces the retreat of the glaciers with each rock.
Oyungerel Sambuu, a professor at the university, will be helping the team ready all of the documents for exporting the samples. Her students, Ninjin Tsolmon, or Ninjin, and Purevdorj Purev-Ochir, Oochko, accompanied us for the entire field season. They are surveying their own samples—roughly 60 rocks.
Ninjin Tsolmon (right) and Purevdorj Purev-Ochir (left) are geology students at the Mongolian University of Science and Technology (Kevin Stark / Medill).
Ninjin and Oochko are geology students at MUST, and while their summer project dovetails with the work of our team, led by Aaron Putnam of the University of Maine, the intention of their work is different.
They are collecting many different types of rocks—bedrock, sandstone, pyrite, malachite, quartz veins, manganese oxide and others. Now that the rocks are back at MUST, they will examine them under a microscope. “Maybe we can find some geologic minerals from inside the samples,” Ninjin said.
Ninjin and Oochko are learning how to find and identify metals embedded in bedrock, a useful skill for research or professional work in Mongolia’s mining sector. They are looking for metals like copper, iron, and zinc. “This was a very successful field season,” Ninjin said. They will also create a map of the bedrock from information they gathered around the Potanin Glacier site.
Oochko and Ninjin will record all of their information and complete a report. Next spring, they present their findings at a competition with other Mongolian geology students from surrounding universities. I ask them if they will be the winner, and they smile. “I don’t know,” Ninjin said.
I am certain they will have a competitive project, and Aaron agrees. “They did very well, and they are very strong,” he said, “It was a hard trip. They did much more than was expected, beyond just the geology, they helped translate, helped with camp. It was great.”
Ninjin Tsolmon drilling into a granite boulder (Kevin Stark / Medill).
Midday, we break for a lunch at Los Banditos, a Mexican restaurant that also serves Indian food. I order a banana lassi and chicken tacos. After a month of eating mostly boiled mutton, the food in UB is a welcomed change for the whole group—even if it’s a strange fusion of dishes.
Peter Strand, a Ph.D student at University of Maine, is wearing a blue colored shirt, shorts and sandals. He has scrubbed off the thick layer of sunscreen, bug spray, and mountain grit that accumulated over the month-long field season. He has shaved, but he kept a mustache for several days.
Back at the university, Pete is directing the team, readying the rock samples for shipment to the United States. The group is inventorying and weighing the rocks. Pete needs a bill from MUST certifying that the rocks have no commercial value, and then he’ll pack up the samples in big blue barrels.
They need the weight of every sample for an official inventory list to give to the Mongolian shipping company. They also must estimate the value of non-rock items. Aaron told me some nightmare stories of other earth scientists whose precious samples were lost or didn’t arrive for over a year.
“That’s the nice thing about rocks,” Pete said. “They have been sitting on the landscape for thousands of years, a little time banging around in a bag isn’t going to hurt anything.” But if the samples get mixed or contaminated, they would be useless.
The samples will be sent to the airport in New York, where Pete will hire a person to pick them up a drive them to University of Maine.
The entire research team gathered at the Potanin Glacier (Kevin Stark / Medill).
One remaining question is what happened to our GPS base station. The most expensive piece of our equipment never arrived in Mongolia from our flight out of the Beijing airport. Today, Aaron went to the airport to see if it had arrived while we were in the field.
“Low and behold, I did not find our base station,” he said. “We left today with no resolution to the problem.” So that means that it’s either in the airport in Beijing, it was sent back to Maine, or it is lost to the ether of the world. “Any one of those three possibilities,” Aaron said. “I’m wondering if the latter option is the closest to being correct.”
At the end of the day, our blue barrels are filled, and all the paperwork has been prepared. I see Ninjin and Oochko walking outside with wide smiles, two accomplished students ready to enjoy the last weeks of summer.
For the Comer Foundation’s Scott Travis, the trip ending seems to be settling in. “It all worked,” he said.
“We are almost 40 days in and everybody is still talking and walking and that’s all we could have asked for,” he said, laughing. While the science expedition has been successful, our group survived a challenging field season without any major injuries or real emergencies.
“It’s one thing getting them here, it’s another getting them home safe and everyone having a good experience and we have all accomplished that and that’s pretty fantastic,” Scott said.
University of Maine researchers return to a valley of climate clues:
By Kevin Stark
Aaron Putnam and Peter Strand, both of University of Maine, hiking along a glacial moraine on the last day in the field. (Kevin Stark / Medill).
Wednesday, July 27. A steep decline and a long hike through boggy terrain swamped with mosquitos took us from the Takhilt Valley into the Khoton Nuur tributary valley of the Altai Mountains. The trip’s lead scientist Aaron Putnam has explored this valley for clues to climate trigger over the past three summers. Last year, he came with Peter Strand, his graduate student from University of Maine, and together, they sampled granite moraines dating back to the last Ice Age when the glaciers dumped them here and retreated. The climate clues are in the rocks. “This is an important part of the valley,” Pete said.
We camped here for several days, primarily flying the drone to collect images for producing high resolution maps. At the University of Maine lab, Aaron and Pete have rock samples waiting to be processed and dated, but “we didn’t have a good map, until now,” Pete said.
The campsite is quiet and near a thin section of the a tributary river. In the evenings, group members fish for Mongolian grayling. It’s delicious, and eating it reminds me of the trout from the alpine lakes in the Sierra Nevadas. There is a climate story even with this fish, as they are usually only found in the Arctic Ocean and waterways that are connected to it. That makes their presence another mystery. “They are completely isolated here, totally landlocked, and we have no idea why.” Aaron said.
The drone work in this valley completed, we drove down the dirt valley roads lined with larch trees, the white water of the river rumbling like a train. Soon, we see the Khoton Nuur Lake, an expansive, thin body of water, sharp valley walls rising high in both directions.
From that vantage point, granite boulders are spread out across the ground without any organization. “Where do you sample?” Aaron said. “You could get a date every meter for the entire length.” Near the lake, the bedrock is granite, not greywacke like other parts of the Altai Tavand Bogd National Park that we have been.
We reach a series of moraines looking over a collection of biluuts, sections of bedrock terrain that have been molded by glaciers. Pete sampled in this area last year, on rounded, grass covered moraines. He is here to complete the sampling set of the huge ridge of boulders left behind as the glacier melted.
Last year, he was unable to access a high set of moraines because of a rocky pathway. We stopped to inquire about a road at a local ger, the traditional Mongolian home made of felt and wood. Thankfully, there is a road, and we are pointed in the right direction. Had driving not been possible, we might have had to rent camels or horses again.
We drove to the top of the hill and camped near a thin stream. After preparing our camp, we hiked over the moraine ridges that spread out from the mountains like the ripples of the lake. Our intention is to explore and plan for a few days of sampling.
At this new location, local children kept coming to visit us, sometimes in pairs—the braver ones leading the way. We gave them candy, sweets, pens and pencils that change color when you hold them in your hand. Aaron packed them with the kids in mind.
The hike up to the Potanin Glacier and back is a well-traveled backpacking route for international tourists, so our crew carrying rock drills and drones was not that exciting. “We are off the beaten path, and back in the land of curiosity,” Aaron said.
University of Maine’s Mariah Radue and Gary Comer College Prep’s Destiny Washington measure a granite boulder at the group’s last field site. (Kevin Stark / Medill)
Early in our stay here, we walked to the highest moraine in this area, and a new landscape emerged. It’s filled with glacial debris, a ground moraine with a terrain that reminds me of the terminus of the Potanin Glacier.
From this vantage point, it’s a chaotic morphological feature, but from the satellite images that Pete and Aaron studied before the trip, this was completely indiscernible—another reason it is so important that our team will be capturing drone footage.
The sampling was easy and, for the most part, so did the drone work. At one point, the mapping application crashed when the drone was more than a kilometer away from our camp.
Fortunately, the Comer Foundation’s Scott Travis landed it, and the drone was found after a short search.
We left the Khoton Nuur tributary valley in cars, stopping in a small town to eat dumplings and drink milk tea. From here, it was a several hour drive back to what Aaron and Pete believe is the last glacial maximum of the Potanin Glacier, or the Potanin LGM, as we fondly call it. It had stormed the night before and our caravan stopped several times when trucks stuck in the thick gray muck.
At the beginning of the trip, we stopped here for a short time, so it’s full circle for us now. From our make-shift breakfast table, we could look down the valley framed by towering red rock hills. In the evening, the light here is silver, the hills seem soft, and what little vegetation there is will almost glow. The red of the mountains is similar to places in the American West, Utah, Nevada. “This is Asia’s West,” Aaron said.
Gary Comer College Prep’s Destiny Washington and climate researcher Aaron Putnam prepare their tents at the last field site. (Kevin Stark / Medill)
Over the next four days, University of Maine graduate student Mariah Radue will be leading the team, mapping all of the moraines and getting samples from the most prominent ones. Before the trip, she identified what is likely a major glacial advance and a major recessional—she wants samples from both. Also, outboard of the prominent moraine, there are ears from previous advances. “It would be great to pin down the dates,” she said.
These days mark the last leg of our field season, and the crew is looking a bit wild. Aaron’s blue eyes seem to gleam brighter, everyone’s skin is hard and covered in mosquito bites, dry from the sun. I have sun spots on my fingers – bumps resulting from many days in the hot sun. Our food supply runs low, and we are eating sardines and dry bread, along with our coffee and tea. But everyone is happy and healthy, looking forward to a hot shower at a hotel in the city of Ölgii, before our five-day drive back to Ulan Bator.
The 10-mile hike to 10,000 feet test us humans and our camels
By Kevin Stark
Wednesday, July 20. The group gathers around a granite boulder that will be sampled above the Takhilt Valley (Kevin Stark/Medill).
It’s a chilly morning when we leave our campsite at the Potanin Glacier and hike back into the Tsagaan Gol Valley. My tent is coated in a thick layer of frost. I eat some bread and jam and drink coffee and let the tent dry out before packing up.
Mentally, the group is preparing for our trek over the Takhilt Pass or, at least, very near it. It’s unclear if we will hike the pass or another route. Our imagery of this part of the Altai Mountains is poor. This stretch of our trip will be a physical test for us – humans and camels.
It’s approximately a 10-mile hike over the pass, and we’ll climb grueling switchbacks to altitudes higher than 3,000 meters (nearly 10,000 feet)—higher even than the glacier.
Peter Strand, a University of Maine Ph.D. student, will be leading the next part of the expedition. We are taking this route so that he can sample boulders in the Takhilt Valley, building on his work in the nearby tributary of Khoton Nuur.
Last year, Pete and his advisor, University of Maine’s Aaron Putnam, were able to sample moraines in this tributary, which they believe date back to the last glacial maximum. The melting glaciers dropped the mammoth trails of rock that make up the moraines like so many pebbles. In the nearby, Tsagaan-Sol valley, they were also able to sample rock deposited by glaciers that is different than the local bedrock.
Putting these pieces together, Pete and Aaron can track the retreat of the glacier from the last maximum to the modern day. In most glacial valleys of the world, this would never be possible, and it’s why our group has traveled so far. “It’s particularly interesting and it’s why we are taking the time to drone this area,” Pete said. Tracing climate change in the past can give clues to what we may be facing with climate change today.
This year, in the Takhilt Valley, Pete is hoping to sample what he believes is a young Holocene moraine. The Holocene marks “modern” times aross the last 10,000 years. With new information from this area, he can compare the climate signals.
Before we hike the pass, we walk the same route down from the glacier into the White River Valley that we traveled a week before. From here, we catch a ride into an adjacent valley, where Gantuaga lives with his family in a ger.
Gantuaga (our group calls him by his given name, Ganna) is the owner of our rented pack camels. Traditionally here in Mongolia, individuals do not often have family names. People are addressed by their given name, and a person’s full name consists of the name of the person’s father and then their given name, in that order.
Ganna has a wide smile. At Potanin, he took an interest in our drone work, helping us with landings. He even rode his horse in circles around our camp as the Comer Foundation’s Scott Travis practiced using the tracking and video functions.
Ganna (second from left) and his family gather in their home, a traditional ger made of felt and wood. They are clothed in deels, wool garments common in pastoralist communities here.
The day before our hike over the Takhilt Pass, Ganna invites us to his home for a small feast. His ger is large enough to fit our entire group. We eat fresh cheeses—one is like a hard provolone, one like a fried farmer’s cheese—and rolls. I play a game with four small bones and a felt board.
Manaljav—or as he is called by the group, Manlai—our camp chef, and Ganna’s daughter take turns playing a horse head fiddle. It’s a beautiful sounding instrument, pitches can be easily manipulated.
Ganna passes around bowls of fermented milk and a clear, distilled liquid that translates to the phrase “horse wine.” It’s somewhere within the parentheses of sake or vodka. After a few sips the room seems to take on a new brightness. “It was priceless to be able to share that moment with Ganna and his family,” Scott said. “It was one of my highlights so far.”
We retire, stealing strength for the morning hike over the pass. The next day, we leave mid-morning and walk through a small community of gers—Ganna’s neighbors. Herds of goats, yaks and some horses separate as we move through the foothills. Soon, we are winding up a camel trail surrounded by dwarf birch shrubs.
Ganna leads our hike with the team of camels, packed down with our sampling gear and food. After a short walk, the shrubs are replaced with craggy bedrock. Hours later, we reach a bowl at the base of the summit pass. The trail is a white line in the black bedrock, snaking up to the peak in sharp cuts back and forth.
Before ascending, we break for a lunch of pickles, potatoes, carrots, rice and fresh mutton. The meat is juicy and more flavorful than what we have been eating.
Ganna is already halfway up the switchbacks by the time we finish lunch, whistling and kicking the reluctant camels along. “This reminds me of the Himalaya’s,” Aaron said. “Having to prod the horses up the hill.”
It takes us a slow hour of hiking to reach the peak. Down the backside, we descend into a valley of wild flowers—small onions with purple straw blossoms and chives.
Manlai encourages me to chew on one grass; it’s savory, like a salty celery stick, and it has a flavor similar to the sour grass that’s common in Northern California, citric and sweet. I realize later that it was wild sorrel.
The valley floor is bright with yellow, purple and blue flowers. I recognize more poppies, but these are taller and with different colored petals than the ones I saw on the moraines near Potanin.
And the rock in this valley are darker and more weathered, with thick layers of lichen; Pete tells me there are several reasons for that. The bedrock here is a type of rhyolite, and, as soon as we came over the Takhilt pass, we entered a new climate regime; it’s wet.
“The grasses change,” he said. “There are juniper bushes and other shrubs, and the flowers are a lot bigger.”
The day after hiking the pass, the group separates. Pete leads the science group to sample boulders in an adjacent Takhilt Valley, while others stay back to rest sore knees and wash clothes. I stick around camp to type up my notes and organize my photos.
It rains for most of the day, and I work from my sleeping bag in my tent, taking breaks to eat warm soup and drink hot chocolate. Pete and his team are up higher in the valley, struggling. The boulders are not right for sampling. “The morphology is beautiful,” Aaron said. “But the glacier just wasn’t good to us. It didn’t leave anything of use behind.”
University of Maine’s Peter Strand recording information about a boulder. He is writing on a canvas sample bag with a permanent marker—if digital records fail, this information will be important.
At that elevation, it’s sleeting and starting to snow. “It’s the most dangerous condition,” Aaron would tell me later. “It’s the perfect condition for someone to become hypothermic.” If the temperature were a few degrees cooler, it would snow and the group wouldn’t be so wet, though.
Fortunately, no one freezes. We eat a dinner of slow boiled lamb and rice, flavored with barbecue sauce. The next morning, the rain comes in waves. Pete finds a glacial moraine close to our camp and we sample for near the entire day—breaking only when the rain is coming down in thick sheets.
“We did pretty well,” Pete said. With the samples he collected on our last day in this valley, “we will be able to tell when the snow-line rose to roughly the Little Ice Age (1300-1850 A.D.) and we found a moraine ridge.” Samples from the ridge will illuminate when the glacier’s ablation zone equaled the accumulation zone—when it was at a state of equilibrium.
Soon, we’ll be leaving the area around the Takhilt Valley, so beautiful with it’s wildflowers. Still, I’m looking forward to entering the Khoton Nuur tributary, where the landscape is wide open. We will also find the Tsagaan-Sol Gol, a different river that flows white with glacial silt. Aaron tells me that the rivers are teaming with Mongolian Grayling, which make a nice meal and an alternative to boiled lamb.
I can tell that Aaron is looking forward to this valley, for the fishing, but also for the science. Peter sampled the moraines in this tributary valley extensively last year, but he would like better images to produce quality maps. We’ll spend several days collecting images with the drone.
“This holds the secret to abrupt climate change,” Aaron said, only half joking. This tributary valley is important, and it could hold a key piece of information. Information that could help solve the mystery of the demise of the last great Ice Age.
I learned these important life lessons in the Altai Mountains
By Destiny Washington
The group leaves camp early in the morning just as rain is descending down the valley (Kevin Stark/Medill).
Over the past weeks in the Altai mountains of Western Mongolia, I have been camped at the Potanin Glacier and the Khoton Nuur Valley. I have learned some very important life lessons. They include:
–Avoid stepping on wet stones in rivers. You will slip and fall.
–The best way to prevent blisters is to bandage them as they first form.
But I have also learned how the location of the rock can tell us about the movement of the glacier. University of Maine’s Aaron Putnam is the head scientist for our trip and he explained this to me in great detail.
Some granite rocks contain quartz and that is needed to perform the surface exposure dating. Some rocks fall off the glacier earlier than the glacier can form a moraine, the ridge of rocks left behind as the glacier retreats. The boulders that fell away from the moraine are erratic and raise the question of whether they are older or younger than the moraine.
It would be impossible to tell by physically examining the rock because boulders change over time., Some develop lichen while others don’t develop as much lichen. The development of these features don’t define the age, but it defines the activity of the boulder. Lichen develops on inactive rocks – the ones that stay in place. The only way that we can determine the age is by taking samples of the quartz in the boulders and in the moraines.
I’ve made progress on my part of the expedition by successfully completing my GPS mapping. I was given a trimble—a device for finding GPS coordinates—and Mariah Radue, a graduate student at the University of Maine, taught me how to use it. We collected points as we walked in five meter intervals. We did that along the visible part of the moraine at the on the unit the Potanin Glacier.
For sampling, we examined the boulder first. We had to see if it had the important qualities for sampling. Did it have a smooth polished surface? Did it have a quartz vein? That’s what we looked for. Then we took a rock hammer drill, and I would drill a few holes at an angle in order to take the sample using a hammer, wedges, and shims. I’d hammer the wedges in until the rock came loose. If you hit it the right way, the boulder made a nice cracking noise, like you are breaking a stick. It was oddly satisfying.
What I find most interesting is the process by which the boulders came to rest in their current location, due to the glacier. A boulder can be dropped off by a glacier, and the glacier could stop melting around the time it drops the boulder. This can change the landscape. When the glacier drops the boulder, the timing can determine if the boulder falls on the moraine or off the moraine. And we can use this information to determine the age of both the boulder and the moraine. It’s interesting to think about how the landscape changed.
All of these lessons will stick with me for a very long time, and I think they’ll make it easier to explain my results in my presentation. Now, the idea of what we are doing is really sticking to my head. I can explain why the boulder might have a different age from the moraine. Also, the the next time I go to the wilderness, I’ll know not to step on wet stones or other places that could accidently hurt me.
My adventurous student can tackle the glaciers – but please hold the dried curd
By Jessica Stevens
Gary Comer College Prep’s Destiny Washington (yellow jacket) was chosen by her environmental science teacher Jessica Stevens (purple jacket) to participate in the Mongolian expedition. University of Maine’s Nathan Norris cleans pulverized dust from a granite boulder after drilling holes to extract a sample. (Kevin Stark/Medill)
Destiny Washington knows how to handle a trip to Mongolia. She is a 17-year old student at Gary Comer College Prep where I’m an environmental science teacher. I was asked last spring to choose a junior to accompany me on a research trip to Mongolia. She’s been eating new foods without complaint — sour cabbage, yogurt, even lamb’s tongue, cheek and ear. She said no to the dried curd (“My stomach didn’t want to eat dried curd,” she said) and a few other foods. She made the most hysterical faces and politely said, “I don’t think that’s for me.”
Taking this trip with a resilient and adventurous student of mine has made the journey so much more enjoyable for me. The most difficult challenge that we have put to Destiny is a 10-mile hike — at an elevation of 10,000 feet — at the site of the Potanin Glacier. We learned how to check for blisters and breathe at high altitude—the Comer Foundation’s Scott Travis told us to exhale deeply, to exit all of the carbon dioxide from our lungs and create space for more oxygen. I knew that this was hard on Destiny. “It was terribly long,” she said “I didn’t know where anything was.” Still, she seemed to have fun with it.
How did we end up here? Last March, I had a meeting with the principal of our high school, Estee Kelly, about my position for the next year. I would have been happy to know that I was teaching environmental science for another year, but Ms. Kelly asked me if I would take a Comer Student to do climate change research in the Altai Mountains in Western Mongolia.
Destiny Washington has been drawing glacial landscapes as part of her field work (Kevin Stark/Medill).
I knew that this experience would change one scholar’s life for the better—I know from experience that traveling encourages personal growth, and getting to perform scientific research in high school could provide a student with the drive to pursue science as a profession, to do great things. I picked Destiny Washington. She has great potential and was interested in completing her own project—she will investigate the differences in the amount of time it took a glacier to retreat in the Altai Mountains in Western Mongolia during different periods in history. She will test the role that increased levels of CO2 in the atmosphere have played on the melting glaciers.
The trip leader and head scientist Aaron Putnam has been helping Destiny with this project. I first met Aaron a month after I learned about the Mongolia trip. The administration asked if I would allow a guest speaker. I was hesitant, considering my fourth-period class had a lot of big personalities, but I agreed.
Teachers at Gary Comer College Prep are busy, and so no one told me exactly who the speaker would be. It was Aaron, the leader for our Mongolia trip, as I found out in my meeting with him after class. My class was so caught up by Aaron’s enthusiasm. He had them pass around a 24,000-year-old piece of wood and talked about glaciers. My class asked questions that made me proud.
Aaron’s been great with Destiny on this trip, too. He asked her questions about the formation of the landscape and helped her form well-crafted scientific answers. She had the opportunity to ride a horse for the first time. We were crossing a stream and she tasted fresh meltwater from a glacial stream. “It was fun,” she said.
The proud smile on Destiny’s face when we finally made it to the glacier made the trip more than worth it for me. “I definitely felt a sense of accomplishment,” Destiny said.
She did all of this with good humor and without complaint; well except about the flies. Destiny really hates the flies.
Coming face-to-face with the Potanin Glacier
By Kevin Stark
Lead scientist Aaron Putnam guides a drone in for a safe landing. The Comer Foundation’s Scott Travis documents the event in a photo. (Kevin Stark / Medill)
July 13, 2016. It’s a day’s hike up the Tsagaan Gol Valley to the Potanin Glacier, journeying roughly 10 miles along a horse trail. Our guides ride horses, along with Mariah Radue, a graduate student at the University of Maine. She is comfortable on horseback from years of riding. “The horses are sure-footed,” she said.
The camels are loaded with drones, drills, bags of potatoes and rice, and backpacks. Camels can carry twice as much weight as a horse, up to 660 pounds. But it’s slow hiking—the trail is steep and we are adjusting to a higher elevation—even with the camels carrying most of the gear. We stop for a lunch of sardines, tuna and bread by a stream.
Mariah will be leading the field expedition for the next week. She will be analyzing the granite samples collected from this part of the trip for her graduate work. “The Tsagaan Gol Valley gives us another example of deglaciation from the last glacial maximum (18,500 years ago) to pre-industrial times,” she says.
After hiking most of the day, we reach a pass between two mountains and come face to face with Potanin. From the perspective of Mariah and glacial geologist Aaron Putnam, her advisor, this is a rare opportunity. The valley is a nexus of geologic formations. Thousands of years ago it was completely covered in ice—there are several moraines of rock that formed thousands of years apart as the glacier retreated and discarded huge ridges of boulders in its wake.
Glacial meltwater carved this cave into the Potanin Glacier. The caves can be dangerous in the summer months when ice can break off without warning. (Kevin Stark / Medill)
It’s likely that one moraine formed during the Holocene (the last 10,000 years), another during the Little Ice Age (from 1300-1850), and both are positioned right next to current glaciers—at least, that’s what Mariah and Aaron suspect. The contrast is remarkable.
“It’s glacial geologist eye-candy,” Mariah says. “We are dating the moraine in a setting where the information is wonderfully preserved.” Mariah will take granite samples back to the University of Maine and apply the beryllium-10 surface-exposure dating technique to determine how long ago the rocks broke free from the retreating ice and were deposited here. Beryllium-10 collects in rock exposed to air due to cosmic rays bombarding Earth’s atmosphere.
The oldest moraine is grassed over and has been rounded into a rolling hill by thousands of years of rain and wind. The younger moraines are jagged, comprised of granite boulders, rocks, and cement-hard glacial silt, with little vegetation.
University of Maine graduate student Mariah Radue is sampling boulders near the Potanin Glacier in the Altai Mountains. (Kevin Stark / Medill)
Our campsite is a short hike from the glacier. We are camping at an altitude higher than 3,000 meters (9,843 feet).
Thankfully, the drone is fully functional—in large part as a result of patient troubleshooting by the Comer Foundation’s Scott Travis. Each morning is spent capturing images of the valley, which Mariah will transform into high-resolution maps.
“The pictures tell the story of the glacial history of this valley,” Mariah said. “There is so much value in understanding a complex landscape from the air. You can pick out patterns that you cannot see from the ground.”
Thin blue rivers flow along the face of the glacier and there are only a few peaks that are still covered in snow from winter. One day, I scramble down to a tongue of the glacier, at the base of the young moraine. Granite is piled all around me. Much of it has been cemented into place by glacial silt. In the tongue, I can see there is an ice cave forming, but it’s getting late, so I decide to come back the next day to shoot photos.
When I go back, dark storm clouds are forming in the distance. A few times I step in the wet silt, sinking up to my shin in the gray sludge. The puddles are the glacial equivalent of quicksand, so I try to walk only on the hard granite rocks.
I shoot a few gray photos. Then I’m back in camp in time to have a cup of coffee and hole up in my tent, the thunder clapping above. I plan a pre-dawn adventure to take photos with the morning sun shining into the cave.
Meanwhile, Aaron, Mariah and Scott are flying the drone each morning. Aaron is releasing and catching it, his coffee thermos resting uncertainly on a granite rock at his feet. After breakfast and droning, the group spends the rest of the day sampling rocks.
Mariah is getting great images and samples. By the end of our week, she’ll have more than 40 pieces of granite to analyze. “There is a specific order that things need to be done,” Mariah says. The group is getting into a rhythm. “When one person is done drilling, the next person is on the rock with a GPS.” Mapping the retreat of the glaciers from this composite of data means filling in the clues to where our climate is heading today and how fast it can change.
On one of our last mornings, I get up at half-past five in the morning to get photos of the cave. I eat a quick breakfast of dry cereal out of a pink plastic mug and drink coffee on the way to filter water from a runoff stream. My tent is covered with a sheet of frost, and my wet hiking socks are frozen enough to clap together.
I reach the tongue in time to see the sun slowly descending down an auditorium of ice. It’s cold. My cell phone camera won’t take photos until I warm it up inside my wool gloves tucked under my arm.
Despite the cold, as soon as the sun hits the glacier, small rivers of water start dripping off the ice. During the thunderstorm, rain cracked off a slice of the glacier and the entrance of the cave is partially blocked by a hunk of ice. I’m happy that I wasn’t under the wedge. I take a breath and move on to shoot photos of the melt river before joining the group for morning droning.
As we prepare to hike back down to the Tsagaan Gol Valley, the group is in high spirits. We’ll re-supply before hiking into an adjacent valley for more sampling. Mariah’s week at the Potanin Glacier was incredibly productive, and she’ll spend the next two years analyzing rocks collected from these moraines.
MAPPING THE TRACKS OF A GLACIER ACROSS 18,000 YEARS
By Destiny Washington
Traveling from the United States to China to Mongolia was exhausting. Between emotional exhaustion from saying goodbye to my parents—Valerie Washington and Byron West—and the physical exhaustion from flying for two days, I was extremely tired. It felt like I was in a permanent state of not knowing what time it was and wanting to sleep. Like, a lot.
But arriving in Mongolia has been a great experience. Especially since my team is full of interesting and funny people. They encourage questions and are willing to listen to any problem — and there are a lot — bothering people. They also take care of one another and worry about each other.
For example, on the drive to the Altai Mountains, Peter Strand (he’s a leader on this trip and a Ph.D. student from University of Maine) asked us to consider how the landscape formed in Mongolia. This was a hard question. I didn’t know but I made a guess. We saw sand dunes and I thought they might have formed from overgrazing cows and horses and other livestock. We never established a full answer, but this question framed our thinking for the trip.
I haven’t had the chance to study environmental science. I am unaware of a lot of the rock formations and what they mean for the environment, but Aaron Putnam, the lead scientist for the expedition, has studied Earth Science. I spent a lot of time with him in the car and he taught me quite about the rocks and their formations.
We were passing rocks near a volcano. He pointed them out and gave them the names Pahoehoe and A’A. They were Hawaiian names for volcanic rock. A’A rocks form a jagged point and jut up into the sky because of how they were formed. Pahoehoe is a flatter rock, which suggests that the magma cooled over the land and didn’t crack and break.
I’m expecting to learn how long it took the glacier to retreat in the Altai Mountains in Western Mongolia. I want to test the relationship that increased levels of CO2 in the atmosphere have to the melting glaciers. Scientists link CO2 levels, global temperature rise and the glaciers – one theory is that the more CO2 in the atmosphere, the faster the glacier will recede. To test this myself, I will track the glacier starting at the glacial maximum of the last Ice Age (roughly 18,000 years ago) using GPS mapping. The mapping will track the rate of recession over time. I’ll be sampling granite boulders found in the glacial moraines. The boulders were left by a retreating glacier and they are the best way to track the age of the glacier.
I am nervous because I’ll have to present the findings of this expedition in San Francisco at the American Geophysical Union conference later this year. The reason I’m nervous is that I don’t know a lot about what I’m presenting. Yet. So, I’m picking up important details of what I need to cover in the presentation. How do I talk about this without making it seem like it’s final? And, how do I explain why we study the boulders that we selected? I want to present the findings in the best light that I can. Even though I’m new at this, I know it’s extremely important to document climate change.
I’m glad that I’m here. This expedition is fun, and I’m excited to be part of it. I was worried that the scientists would be stuck-up, but they are actually pretty hilarious. Everyone is funny in their own way. With this team, this expedition will be a breeze or at least a fun Sudoku puzzle—challenging but rewarding. Either way, it will be a great trip with plenty of samples that will hopefully tell us the rate of recession of the glacier.
COSMIC RAYS CREATE CLUES TO A GLACIER’S RETREAT
By Kevin Stark
Purevdorj Purev-Ochir, a student at the Mongolian University of Science and Technology, drills into a granite boulder for samples to trace the retreat of a glacier. The Potananin Glacier is visible in the distance. (Kevin Stark / Medill)
Wednesday, July 6 – After several days of driving, we arrive at Tsagaan Gol, spend the night and prepare for our first field day. University of Maine’s Aaron Putnam and his team of graduate researchers will be reconstructing the history of Potanin glacier, just up the valley. They’ll be uncovering clues as to what caused the abrupt climate event that led to massive glacial melting at the end of the last ice age.
It’s our first day in Mongolia’s Altai mountains. We eat lamb stew and drink coffee as the sun warms our campsite. We are expecting seven camels and two horses to arrive. They will assist the 12 of us across rugged mountain trails. We all rode camels at a rest stop on our cross-Mongolia road trip, but we will be using the animals now to carry gear, not people.
Our first leg should take two weeks—our plan is to hike to the Potanin glacier from the river valley in the Altai Tavand Bogd National Park. The water in this valley is milky white from run-off. Glaciers pulverize rock into a powder so fine that it’s suspended in the river water, and it doesn’t settle to the riverbed like sand. That’s why the water looks so milky. It’s beautiful. I drink coffee listening to the quiet roar of the river below.
By 9:30, the camels have not arrived and Aaron and Peter Strand are looking down the valley pensively. A delay now could eat away precious time for sampling, and the weather forecast for tomorrow is predicting hail and rain. While we’re waiting, Peter and Aaron give a workshop on collecting high resolution GPS data. Satellites drift, which can lead to imprecise field data. So the team establishes a base station that will constantly take readings for correcting the data later.
By 11 a.m., still no camels. Pete makes the call to salvage the afternoon and sample the moraine ridges down valley from our campsite. We’ve lost half a day and we’ll likely lose more time to the storm tomorrow. Aaron tells me this is the standard, not an exception. “I just try and relax,” Aaron said. So much is out of our control. We finish lunch, and prepare to leave when then our camels appear on the horizon. It’s too late for us to pack and hike for the glacier, so the team settles for half a day of sampling in the valley.
To determine how the glacier has fluctuated in the past, Aaron and Pete will map glacial moraines, ridges of rock debris discarded by a glacier. The rocks were left behind after the glacier retreated — just when that happened is a question they seek to answer. The moraine ridges we will be hiking over are the edges of where massive chunks of ice vaulted skyward when the climate was colder thousands of years ago.
Researchers like Pete and Aaron collect surface layer samples from polished granite boulders to discern the age of the moraines. They apply an isotopic method called beryllium-10 surface-exposure dating. The granite rocks we will be sampling—some as large as the largest American SUV—were once suspended in ice. The glacial ice melted and deposited the rock on the ridge. At that moment, the granite became exposed to a flux of particles created when cosmic rays from outer space collide with Earth’s atmosphere. The particles bombard the rock and affect oxygen and silicon in quartz, creating a cosmogenic byproduct called beryllium-10. These atoms accumulate in the rock surface and can be measured to determine how long ago the boulder was freed from the ice and dropped on the land.
Pete drills into the top of a boulder with a rock drill. He places wedges into the holes and methodically hammers them into the granite. Each hammer swing chimes with a pitch higher than the last. “It’s like playing a musical instrument,” Pete said. The rock begins to crack and soon he pulls away a plate-sized section of rock. Each sample is roughly 500 grams and 2 centimeters thick.
As Pete drills away, Aaron tells me that the wedging is “iron age technology.”
“It dates back to the Romans if not earlier,” he said.
The rock samples will be sent back to the University of Maine. “That is where they will be tortured,” Aaron jokes. They will undergo chemical processing by Aaron and others. Once dated, these samples can reconstruct glacier movement and the researchers can draw inferences about how Mongolia’s glaciers changed at the end of the Ice Age, generally. Reconstructing past climate change gives us clues to the pace of climate change occurring now.
Pete is leading the workshops today. It’s what Aaron calls the “cascade model” of education. He taught Pete. Now Pete is teaching University of Maine students Mariah Radue and Nathan Norris. Soon, they will be teachers to other students.
We hike to the top of another moraine. It’s hard hiking, straight up with no trails. Large granite boulders jut out of the ground amid bedrock. We sample that moraine, before a smaller group splits off to hike higher, up to roughly 2,760 meters in elevation. The air is thin.
Up high, it’s quiet except for a few birds chirping and the slow rumble of the white river in the valley below. I have a direct line of site into the to Potananin glacier. A band of sunlight is gleaming off the ice. That is our destination and our home for the next two weeks, if the weather and everything else allows us access.
DRIVING ACROSS THE VAST GRASSLANDS OF MONGOLIA IN SEARCH OF CLIMATE CLUES
By Kevin Stark
Gary Comer College Prep’s Destiny Washington celebrating at the top of a volcano peak in the Khangai region. “We’ve passed a lot of landscapes, you can see how the country is divided,” Destiny said. (Kevin Stark/Medill)
July 1—July 4. After days of organizing, we are ready to leave the city of Ulaanbaatar.
Our caravan will drive for the next four days, covering more than 1,500 kilometers (900 miles) on paved roads when we’re lucky, but mainly on gravel, dirt and even sand. We are planning our average speed at 10.3 miles per hour, with a maximum speed 75miles per hour.
At one point, we’ll climb to an elevation of 8,300 feet.
Driving out of UB, the traffic flows in interweaving strands of Hyundai vans, large tourist buses, and small cars. We pass neighborhoods with colorful gray, red and blue homes, piles of coal, and a shipping container that had been turned into a restaurant. Soon we’ve left the city, driving through the open steppe, a high-elevation grassland stretching from UB to the Altai mountains in Western Mongolia.
Ninjin Tsolmon and Purevdorj Purev-Ochir, two students from the Mongolian University of Science and Technology, have joined us and we are guided by Boldoo, Khurola, Tsooboo, Tumur, and Manlai from Hovsgol Travel, a Mongolian fly fishing and travel company.
Ph.D. student Peter Strand poses an observational question for the students to consider during the days of travel. Why do the landscapes look the way that they do? The countryside is defined by rolling hills and peaks that have been rounded by years of rain and wind. In some places, there are sand dunes, and we visit a dormant volcano. “There is evidence that the environment has changed in the past, and water is the main theme,” Aaron Putnam says.
The group is constructing a story of past climate, a history of the landscape. Without this story, we are lost in a world as vast as the wide open steppe. “What’s your story?” Rebecca Solnit asks in her book “The Faraway Nearby.” She writes, “It’s all in the telling.”
There is plenty of time for storytelling on this long drive. Putnam and Strand’s interest in the demise of the last Ice Age is in part to inform our understanding of the story of human-driven climate change now. The Comer Foundation’s Scott Travis tells me that he has been telling and retelling this story for two decades. “I feel responsible for the world I’m leaving for the next generation,” he says.
Black kites, a predatory bird with a five-foot wingspan, glide above our car. Not far out of UB, we pass a marathon in progress, and a runner descends a hill and runs past a dozen horses. We drive for most of the day, taking a break to ride camels.
Gary Comer College Prep student Destiny Washington rides in the back seat of a black truck. “The drive was bumpy and exhausting, at some points,” she says. But Aaron was in the front seat narrating the journey with geological descriptions of the landscape. It was like “having the Discovery channel in the car,” Destiny says.
After driving for many hours across the flat and grassy steppe, we pull off the road at the site of a wide canyon. It reminds me of the Snake River in Idaho, a giant gash in the ground that seems to appear out of nothing. It reminds me of a summer I spent in central Idaho leading backpacking trips and hitchhiking during my time off. Now, as then, we sleep where we’d like, pulling off the road and setting up our tents along a creek or lakeshore.
For breakfast one morning we eat hard-boiled eggs and biscuits, ready to get underway. But our van stalls in the parking lot, making a bleating sound similar to the cows that had been grazing around our tents at night. We have a loose distributor, which bent a connecting rod. Tsooboo, from Hovsgol Travel, has a new one and a lift rod in the truck and makes the necessary repairs in a matter of hours. “That’s amazing,” Scott Travis says.
The group’s caravan is made up of three sport utility vehicles and a van loaded with food and supplies. (Kevin Stark/Medill)
The group waits in the parking lot eating chocolate pastries and drinking water out of plastic bottles during the repair. Later in the day we stop for a lunch of noodles and pickled vegetables. Scott and Aaron work on flying the drone—an important piece of the program for mapping glacial moraines and providing high-quality images of our field sites. Google Earth has really poor pictures of these places.
The drone has been frustrating and, so far, not functional. Scott struggles with it under the poplar tree. He practiced flying a different one at his home in Wisconsin. That drone entered an automatic flight pattern triggered by a low battery and flew itself into a different poplar tree—prompting an expensive run to the store to purchase the drone we are using now. (Days later, we solve the drone problem to everyone’s relief.)
We leave, and the paved road ends, and the new dirt road soon splits into several different paths, all crossing back and forth. Sheep are sleeping and, Erdenee Erdenekhuu, the driver of my truck, honks a few times and they get up slowly and saunter away.
The trucks jockey for the lead, raising a cloud of dust and sand behind us. Khuraa, a driver of one of the other trucks, hits a rut and blows a tire. Fortunately, we have ample spares and it’s a quick fix.
Later that afternoon, we stop at a park in the Khangai region, the site of a mid-continental volcano. It’s a fresh looking landscape, with new geologic formations in the midst of older mountains. There are yellow, purple and white clusters of flowers.
“Lava flows contain some of the most fertile land in the world,” says University of Maine student Nathan Norris, hiking by large vesicular basalt boulders.
The morning of our last day’s drive, we wake up at Hyargas Nuur. The water is salty and I can taste it as I wash my face. For breakfast, we have sardines, sesame biscuits and coffee with real milk. We drive for most of the day. Suddenly, the Altai Mountains come into view. “It’s like coming across the plains and then there are the Rockies,” Scott says.
The final stretch of our drive is along a river valley – mountain peaks on our right and elm, spruce, and poplar trees lining the Houd River on our left. In the distance, glaciers are on top of black mountains, our destination and home for the next month.
OUR CLIMATE ODYSSEY BEGINS
By Kevin Stark
Kevin Stark and Scott Travis at breakfast on the first morning outside of Ulaanbaatar. Instant coffee and biscuits are a staple of mornings on the road. (Destiny Washington/Gary Comer College Prep)
June 30, 2016 – Our journey for a summer of climate change research in the Altai Mountains – where Russia, China and Mongolia all meet – began as our plane descended into the Chinggis Kahn Airport in Ulaanbaatar, Mongolia. Looking out the airplane window, I saw a cluster of ger—traditional homes made of wood and felt—located on the outer ring of the city. The majority of UB’s residents live in this expanding district where many of hundreds of thousands of people have left Mongolia’s degraded grassland.
In the past century, Mongolia’s temperature has increased more than 2 degrees Celsius (3.5 degrees Fahrenheit), twice the global average. Once vast grazing lands are drying up and threatening the country with drought. Many people are fleeing the rural areas, where they have lived for generations to find work in the city.
The expanding ger district is a symptom, in part, of today’s warming climate – a telescope into the complicated intersection of cultural and environmental challenges other large cities may face in the coming decades as human-related climate change continues warming at an unprecedented rate.
It’s a fitting image for our trip. Our group is beginning a collaborative, intergenerational scientific and educational effort to examine links among climate, glaciers and modern society in the Bayan-Ölgii Province of Western Mongolia. University of Maine’s Aaron Putnam leads this expedition, and he has assembled a team of young scientists, students, climate research assistants and guides. Everyone is gathered to study the demise of glaciers at the end of the last Ice Age.
Destiny Washington at an open air market in Ulaanbaatar where the group purchased cookware and other supplies for the trip. (Kevin Stark/Medill)
Aaron was awarded an early career development grant from the National Science Foundation to use surface-exposure and radiocarbon dating techniques to develop a chronology of glacial retreat during the “most important natural warming event in human history,” approximately 18,000 years ago. The warming abruptly ended the last ice age and Putnam is looking for the switches that cause such climate events. Aaron and his team can detect how and why climate has changed in the past by reconstructing the geologic record found in the ancient rocks of the mountains. In doing so, he hopes to have a better understanding of how our climate is changing today.
I’m embedded as a reporter chronicling the trip to complete my graduate journalism degree at Northwestern University’s Medill School of Journalism. I’m here along with Destiny Washington, a 17-year old high school student, selected from among her peers at Chicago’s Gary Comer College Prep to be included in this experience. This is her first time out of the country. “It has been an exciting blur of sleeping and being awake,” she said. “I’m just trying to take it all in. The air, the buildings and structures.”
Destiny’s environmental science teacher Jessica Stevens is with us too, and we assembled in the airport in Chicago and spent nearly two days traveling to Mongolia by way of Beijing. “Going through customs was really different,” Destiny said.
“That was the first time I’ve actually seen you hate something – like I could see it on your face,” Stevens said.
“My brain was like, this is too much,” Destiny said with a laugh.
Destiny and I will be documenting this trip from the field on the pages of this blog, primarily. But there will be contributions to our coverage as well from Stevens and University of Maine students Peter Strand, Mariah Radue, and Nathan Norris.
Strand is a Ph.D. student—he and Aaron will be leading the scientific study. Putnam likes to say that glaciers are great thermometers. As climate cools and warms, glaciers recede and advance leaving evidence on the landscape in the form of moraines—a glacial “wake” formed with granite boulders that glaciers move around like pebbles.
A thunderstorm delayed the group’s red-eye flight from Beijing to Ulaanbaatar (Kevin Stark/Medill).
David Putnam, a geoarchaeologist at the University of Maine at Presque Isle and Aaron Putnam’s dad, is with us for the first leg of the journey but will be separating to join a different research team. David is incredibly knowledgeable and has spent his career working in the field – with the stories you might expect from years traversing glaciers. Everyone is a little disappointed that he’s leaving. (I think he might be too). “You’ll have fun with your new group,” Destiny reassured him.
The group has come together over the last few days in UB. I’ve learned that the field work glaciologists love to pursue is a small percentage of the effort. If our trip were a pie chart, one large slice would read logistics, and another would read unexpected delays. “Science is 99 percent unrelenting work and 1 percent fun; but that 1 percent makes it worth it,” Aaron said.
Which is where Scott Travis comes in handy. He works for the Comer Foundation,which has helped make it possible for us to be here. Scott has played a key role as a climate research assistant on trips to Greenland, New Zealand, Patagonia and Bhutan (several with Aaron).
At this point in the trip, we’ve had several delayed flights, missing bags and a kidnapped drone that was confiscated by security at the Beijing airport. At one point—minutes before our flight was supposed to depart from China to Mongolia—a thunderstorm delayed our red-eye flight for another five hours. “It’s a good thing we rushed through security,” Aaron said.
But that has passed, and as I write this, we are preparing for a morning departure.
Over the next few weeks, our expedition team will travel to the isolated landscape of the Altai Mountains. This range is a petri dish from which to study the position of these former ice tongues.
Photo at top: University of Maine’s Aaron Putnam reviews a road map by headlamp on the group’s first night in camp in Mongolia. (Kevin Stark/Medill)
A mystery from some 18,000 years ago directly impacts how scientists understand the threat of climate change today.
The Earth, shivering though the end of an ice age, rapidly warmed in the Southern Hemisphere, just like it is warming globally today.
At the Comer Conference on abrupt climate change, climatologist Jeff Severinghaus, presented a possible answer to the mystery. “Just what in the heck caused the rapid period of warming?” said the professor of geosciences of the Scripps Institution of Oceanography in San Diego.
If scientists can answer this question, they can resolve a degree and a half of uncertainty in current climate modeling, the difference between projections that show a fairly habitable planet or an Earth with massive drought that could kill “millions,” Severinghuas said.
“This means a really radically different planet,” he said.
Severinghaus’ hypothesis is that a “stripping of clouds” that normally cover the ocean over the equator caused a dramatic warming in ancient global temperatures in the Southern Hemisphere, a period of time that offers a mirror for the current abrupt period of climate change.
Clouds above the equator that typically reflect heat from the sun dissipated and Earth was rapidly heated by the ocean absorbing the sun’s rays. “It is the color of the planet,” Severinghaus said. “Just as simple as that. White clouds reflect sunlight. Dark ocean absorbs sunlight.”
Jeff Severinghaus presenting his theory of what caused a mysterious 18,000-year rapid warming of the Earth’s atmosphere (Kevin Stark/Medill)
At the time, glaciers were melting in the Northern Hemisphere. The theory is that cold fresh water gushing into the ocean in the North pushed a large rain belt into the Southern Hemisphere, disrupting tropical atmospheric circulation and displacing low-level clouds with thunderstorms.
The low-level clouds typically reflect sunlight back into space. Without this band of clouds, the dark-colored ocean would absorb heat from the sun—just like a “parking lot on a hot summer day,” Severinghaus said.
Currently, the modelers and the climatologists are debating whether this rain belt that typically appears as thunderstorms over the Eastern Pacific Ocean in the Northern Hemisphere could form further south.
Scientists call the cloud band the Intertropical Convergence Zone, but sailors call it the “doldrums.” Severinghaus said that moisture records from ice cores and a now-dry lake bed in Bolivia are evidence that massive storms dumped rain and snow 18,000 years ago.
Today’s scientific models need to be pinned on data that “you can hang your hat on,” Severinghaus said. He and his colleagues are paleo-climatologists, which means they reconstruct ancient Earth climates to better predict the scientific understanding of where the planet’s climate is heading now.
Some modelers don’t think that the cloud shift is plausible but the “paleo-evidence is screaming at us that it did,” Severinghaus said. The more we understand the past, the more we can understand about the future, he said. A full understanding of this dramatic period of global warming—informed by accurate data—can provide more clarity for policy-makers globally.
Today’s World
The low-level clouds currently cover a huge area of the Eastern Pacific Ocean, reflecting heat into to space.
If these clouds were to dissipate in the future because of ice melting in Antarctica and Greenland—in the same way that Severinghaus proposes happened centuries ago—the Earth could get hotter faster.
This is a threatening global future.
For decades, climate scientists like Severinghaus have been urging people to burn less fossil fuels, which emits the greenhouse gas carbon dioxide and holds heat in the atmosphere. Scientific models show that by doubling the rate of carbon dioxide in the atmosphere compared to the pre-industrial age, global temperatures will rise to the point that causes widespread drought, extreme weather, and poses an threat to human life as we know it.
As Earth weathered ice ages and hot spells across the past 1 million years, ice cores show that carbon dioxide levels ranged from just under 200 parts per million during the cold snaps to nearly 300 parts per million during warm cycles. Since the industrial age, CO2 levels have risen to the current levels of approximately 400 parts per million. A doubling from pre-industrial levels would bring us to about 600 parts per million and levels are rising at just over 2 ppm per year.
With that amount of carbon dioxide in the atmosphere, Severinghaus said temperatures will rise by about 2 degrees Celsius (3.6 degrees Fahrenheit). The Paris climate accord approved by 195 nations earlier this month seeks to cap temperature rise at below 2 degrees. Many climate experts agree that 2 degrees of temperature rise is the tipping point where changes in crops, water supply and disease can already cause widespread suffering.
But, for nearly 4 decades, global temperature predictions have always been packaged with 1.5 degrees of uncertainty, effectively spinning the heads of policymakers who say that they need precise figures to craft meaningful legislation. So some models show the atmosphere warming by as much as 4 degrees Celsius (about 7 degrees Fahrenheit) above pre-industrial levels.
Climate skeptics use the uncertainty—inherent and common in modeling—to discredit the science and as a justification for inaction. Researchers are working feverishly to reduce the uncertainty.
Climate Models
Severinghaus researches ancient climate, but the same grouping of equatorial clouds that interests him has puzzled present-day scientists who use models to make predictions about the Earth’s climate future.
Whether or not this cloud bank is able to “see-saw” between hemispheres is “the single biggest conflict in all the climate models,” Severinghaus said.
Some models show this cloud bank disappearing in the future (a result of that 4 degrees of warming) while other models do not, suggesting 2 degrees of warming. The difference of the two models is why predictions about future global climate always include uncertainty.
Climate skeptics and reluctant policymakers often point to uncertainties in warming projections as evidence that immediate action on global warming can wait.
If proven correct, Severinhaus’ hypothesis could go a long way to reducing the uncertainty about how fast the Earth is currently warming, which is linked to greenhouse gases building in the atmosphere due to fossil fuels use.
Comer Conference
At the fall climate conference hosted by the Comer Family Foundation, Severinghaus put the theory before his colleagues. The foundation supports widespread climate research and, each fall, the conference in southwestern Wisconsin brings together top climate scientists who pursue their research across the globe.
There was widespread “enthusiasm for the idea,” said Sidney Hemming, a professor of earth and environmental studies at the Lamont-Doherty Earth Observatory of Columbia University. “I liked it,” she said.
Severinghaus stressed that his idea is only a theory and the requires more research, but the methodology for that research is not yet clear.
Guleed Ali, a doctoral student working with Hemming, said he wonders how the cloud system functions and how science will test the hypothesis.
“How would you measure this, a ‘sunburn index?’” he said.
Photo at top: Sea surface temperatures at the start of 2010. (NASA)
