By Bryce Gray, Sarah Kramer, Neil Murthy, Danielle Prieur, Kevin Stark and Jia You –

As the leaves turn gold in southwest Wisconsin each fall, climate scientists from around the world gather there to share their latest findings on the causes and impacts of abrupt climate change.

This Comer Family Foundation’s annual conference on abrupt climate change draws leaders in the field  to address some of the Earth’s most pressing climate change puzzles and needs.

The scientists agree that as temperatures and carbon dioxide levels rise, the Earth faces increased threats of fresh water shortages, coastal flooding and extreme weather events. Trying to determine the speed and potential impact of a changing climate, Comer scientists representing institutions across the world pursue field research from Africa to the Swiss Alps.

“This ultimately comes down to a simple thing as it is easier to break something than to build it,” said Richard Alley, professor of geosciences at Pennsylvania State University. “When we think about what we are doing to the climate, cranking up CO2, it’s very, very unlikely that it turns the planet into Eden.”

Climate scientist and author Richard Alley plays a pivotal role at the Comer Family Foundation’s annual Conference on Abrupt Climate Change. (Sarah Kramer/Medill)

The researchers found that much of their data from all over the globe seemed to coalesce around a few key ranges in time, suggesting that the researchers from across disciplines might be zeroing on a much more precise picture about the nature of climate change through the ages.

Much of the research on display looked to the past to better predict possible climate responses, from the collapse of ice sheets in Greenland and Antarctica to historical variations in volcanic activity. Presenters also discussed advances in green technology and how our ancestors adapted to previous changes in climate.

One of the major questions facing the scientific community is how researchers can effectively communicate the exponential nature of abrupt climate change. Current climate models are built on scientists’ best knowledge about climate indicators like sea level rise, glaciers and the chemical composition of the oceans, but there may be other drivers or effects scientists have yet to decipher. This means that while nearly 200 countries pledged in Paris to limit warming to well below 2 degrees Celsius (3.6 degrees Fahrenheit), the world may soon be reaching a tipping point where this will no longer be possible.

The uncertainties in climate change research should motivate the public and policymakers to do more, not less, to address the potentially devastating consequences of abrupt climate change, said Alley. People buy auto insurance to protect themselves from the uncertainties of having a car accident. The most important story we need to tell about climate change is that adaptation will help the economy, he added.

Author and consultant Philip Conkling told the audience of predominantly scientists that the secret is in telling “character-driven stories about how climate is affecting real people’s lives.” Conkling cofounded the Island Institute in 1983 to examine climate change through the lens of communities along Maine’s sensitive archipelago. Philip Conkling & Associates helps not-for-profits and implement communications goals and strategic plans.

Philip Conkling says the importance of the climate change story is best told through local eyes. (Sarah Kramer/Medill)
Philip Conkling says the importance of the climate change story is best told through local eyes. (Sarah Kramer/Medill)

Klaus Lackner, director of the Center for Negative Carbon Emissions and professor at Arizona State University, is already working on a promising technology to sequester carbon from the atmosphere. Mitigation, he said, has to be a solution in order to repair the considerable damage already done by burning carbon. “I am now convinced that we will have to do carbon storage, carbon sequestration or carbon disposal,” said Lackner.

Many of the other scientists at the conference are looking at to the past to see how ancient climate shifts played out, even without human interference. The scientific community is hoping to understand the conditions before, after and during previous warming periods in order to make better predictions about our planet’s future.

Christine Chen, a third-year Ph.D. student at the Massachusetts Institute of Technology, studies lakes in the Andes Mountains in order to predict future precipitation patterns. “Water availability is a huge issue there,” said Chen, referring to the Central Andes region where she conducted her fieldwork. “Reconstructing how precipitation patterns changed in the past is highly relevant to what is happening and what is going to happen in these regions in the future.”

Klaus Luckner explains the device he designed to remove carbon dioxide from the atmosphere. (Sarah Kramer/Medill)
Klaus Luckner explains the carbon capture prototype he is designing to remove carbon dioxide from the atmosphere. (Sarah Kramer/Medill)

University of Nevada Ph.D. candidate Ben Hatchett is pursuing research that could help us understand the future of drought and water shortages closer to home. His model identifying the influence of temperature and precipitation over time on water levels in western Nevada’s Walker Lake watershed found that drought severity doesn’t all come down to precipitation.

“We can see that the impact of temperature is very important,” Hatchett said. Ongoing drought conditions are “on par” with historic anomalies in terms of precipitation, he said, but warns that the same does not hold true for temperature where megadroughts don’t reflect an earlier precedent.

“The temperature [now] could be pushing us outside the realm of the natural variability,” Hatchett said. With the arid western U.S. projected to warm even more in the future, that means additional pressure applied to strained water resources.

Many presentations showed powerful evidence that something big happened to atmospheric circulation in the Southern Hemisphere approximately18,000 years ago, when glaciers last reached their maximum extent in the last major ice age.  Mike Kaplan, geologist at Columbia University, has been working in Patagonia, at the southern tip of the Andes Mountains. Scientists had previously assumed the area only contained records of older ice masses. But during his 2013 field season, Kaplan and his colleagues found glacial deposits dating to that last glacial maximum. Kaplan’s work could provide crucial clues to when exactly the ice age started and ended in the Southern Hemisphere, furthering scientists’ understanding of how the climate system works.

With the world’s glaciers withering away, caves are emerging as an increasingly important setting for scientists to collect climate data. This past summer, Gina Moseley of the University of Innsbruck in Australia led the Northeast Greenland Caves Project. The group studied the mineral build-up in caves that creates formations such as stalagmites and stalactites, called speleothems, in order to try to fill in gaps in Greenland’s ice core records, especially around the last interglacial period – a stretch approximately 130,000 years ago, when warm temperatures disrupted ice formation.

Moseley and her spelunking colleagues are part of an increasingly popular field. The journal Science noted in 2006 that: “For paleoclimate, the past two decades have been the age of the ice core. The next two may be the age of the speleothem,” spire-like mineral deposits in caves that include stalagmites and stalactites.

While scientists have so far observed global warming of just less than a degree, the oceans could be distorting the true extent of the impact on the atmosphere of carbon dioxide emissions from fossil fuels, said Jeff Severinghaus, professor of geosciences at the Scripps Institution of Oceanography, part of the University of California at San Diego.

Jeff Severinghaus participates in one of the lively discussions that follow every Comer presentation. (Sarah Kramer/Medill)
Jeff Severinghaus participates in one of the lively discussions that follow each scientist’s presentations at the Comer Conference. (Sarah Kramer/Medill)

“The deep ocean is so enormous and it is a huge reservoir of cold water and it is becoming a little less cold right now. It means that it will take about 100 years to realize the full warming of 2 degrees. If we continue to burn fossil fuel we will be committing to more than 2 degrees.”

The implications of forces other than temperature make the climate puzzle even more challenging. Other presenters explored drivers of climate change that we could be missing. For example, Guleed Ali’s research on Mono Lake Basin in California suggested that scientists might have reframe current thinking about temperature and evaporation and consider other factors such as the jet stream.

Low temperatures during Earth’s ancient cold snaps should have meant decreased evaporation, and thus higher lake levels. But Ali’s research suggests that Mono Lake was likely as low as it is today. This data indicates that temperature and evaporation, both of which scientists consider drivers of the lake’s water level, seemed to have had a negligible role.

Ali has hypothesized that the North Atlantic Ocean’s circulation and its jet stream instead controlled climate then and now, “What I think might be controlling these lake levels is the state of the tropical circulation and the state of the North Atlantic Ocean’s circulation,” Ali said. “What I think is a possibility, just working hypothesis… is that the strength of the circulation in the North Atlantic Ocean is the controlling factor of the hydro-climate certainly in Mono Lake and much of western U.S.”

Some of the first scientists to lead the charge in researching climate change help organize the conference each year, including glaciologist George Denton of the University of Maine at Orono. Denton spoke on the collapse of the Antarctic ice sheets but, like other climate veterans at the conference, came to hear from the new generation of climate researchers. Many of them are Denton’s current or former students, presenting findings in a field where he has contributed several decades of research.

Richard Alley, Wallace Broecker and George Denton worked with the late Gray Comer to establish an international abrupt climate change research program.
Richard Alley, Wallace Broecker and George Denton worked with the late Gray Comer to establish an international abrupt climate change research program. (Medill Photo)

Climate change science pioneer Wally Broecker, the first scientist to use the term “global warming” in a 1975 paper for Science, is among the founders of the Comer Foundation’s climate change research program. In 2001, the late entrepreneur and philanthropist Gary Comer sought out Broecker, an oceanographer, geochemist and professor of geology at Columbia University. Partnering with Denton and Alley, the four men created a fellows program working with mentor scientists at 31 institutions to support the next generation of researchers and research on abrupt climate change. Seed money and grants also support seminal research in the field, with more than 125 global research projects on abrupt climate change supported since 2005.

In the opening remarks for the second day of talks, Alley spoke movingly on the origins of the conference and the Comer Family Foundation. Comer, founder of Lands’ End outfitting company and a native Chicagoan, started the foundation in 1986 to promote education, healthcare and the environment.

Dec. 22, 2015

Photo at top: Climate scientists Peter Strand (left) and Aaron Putnam (right) hike through the Altai Mountains of western Mongolia during their summer 2015 field season. Putnam and Strand’s research on the glaciers of central Asia is one of the many projects funded by the Comer Family Foundation. (Sarah Kramer/Medill)




By Kevin Stark –

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)


By Jia You –

Richard Alley works at the forefront of climate research, interpreting the time machine of climate past locked in ice cores he collected in some of the coldest places on Earth. The University of Pennsylvania geoscientist has spent more than 10 field seasons in Antarctica, Greenland and Alaska collecting clues from the ice sheets to tell us where climate may be heading now.

Alley frequently testifies before Congress, chaired the National Research Council’s Panel on Abrupt Climate Change and participated in the United Nation’s Intergovernmental Panel on Climate Change. He has also advised numerous administrations on climate change.

Alley has appeared in numerous television documentaries, and hosted “Earth: The Operators’ Manual,” a PBS special on climate change that he published as a book of the same title.

Alley shares his thoughts on why we must do more to address climate change and how that will bolster the economy.

“It is easier to break something than to build it,” he said at the Comer Abrupt Climate Change Conference held in southwestern Wisconsin this fall. “When we think about what we are doing to the climate, cranking up CO2, it’s very very unlikely that it turns the planet into Eden.”

View the videos for more comments.
Dec. 2, 2015

Photo at top: Veteran climate scientist Ricard Alley argues fixing climate is good for the economy. (Kelly Calagna/Medill)



By Lizz Giordano –

Low snowfall and a dry spring prompted an early start to making 2015 the second most widespread fire season on record in Alaska. In 2004, the worst season on record, fires consumed 6.6 million acres of forest.

This year, more than 5.1 million acres burned in 770 fires across the tundras and forests of the northernmost state, stretching firefighters and other resources thin. Warming Arctic regions and changing patterns of rainfall may be the cause as glaciers melt and temperatures in Alaska rise faster than in the lower 48 states.

In the last five decades, Alaskans and the country as a whole watched forest fires spike in the frequency and severity of forest fires, which have also resulted in the release of massive amounts of carbon into the atmosphere.

“There is more of a sense of urgency at the start of the [fire] season now,” said Tom Mowry, public information officer for Alaska’s Division of Forestry.

Created by Lizz Giordano with data from National Interagency Fire Center and Alaska Interagency Coordination Center.

The blazes so overwhelmed the division this summer that firefighters were forced to prioritize which fires to fight, according to Mowry. In a triage approach, fires that were not threatening homes or other important resources were often left to burn. The office also needed to bring in additional firefighters from the lower 48 states to aid in suppressing and controlling the fires. So far this year, the Division of Forestry has spent over $85 million to battle the most expensive fire season yet.

Fire frequency has doubled in Alaska over the past 25 years, said Eric S. Kasischke, professor of geographical sciences at the University of Maryland. He spent the summers of those years in Alaska studying fires.

“Prior to 1990, there were seven large fire years in 40 years, or one large fire season every six years.  Since 1990, there have been nine large fire years in 26 years, or one large fire season every 3 years,” said Kasischke.

Three of the top five wildfire seasons in Alaska have occurred since 2004. The U.S. has experienced five of the top 10 worst fire seasons in terms of acreage burned just the last ten years. Federal fire suppression costs have surged more than 500 percent in the last 30 years, tipping the scale at $1.52 billion for 2014 alone.

One theory that could explain the increase in large fire years, is warming in the arctic region causes oscillation or fluctuations of water temps in the oceans which in turn influences atmospheric circulation, according to Kasischke. This can bring high pressure systems with warm, dry air to Alaska, creating conditions conducive for forest fires.

“It’s not so much warming itself, but it’s warming combined with patterns of precipitation that have contributed to the frequency of fires,” said Kasischke.

Average monthly temperatures have risen in Alaska in the last few decades – 3 degrees Fahrenheit overall in the last 60 years, according to Climate Central. Kasischke said Alaska is experiencing greater climate warming than other areas of the U.S., with most of this warming occurring during the winter months.

“A warm early spring that results in a rapid melting of the snowpack can increase early season fire risk, while a cool spring that delays the melting of the snowpack can reduce early season fire risk,” said Kasischke.

Department of Agriculture The Aggie Creek Fire is located 30 miles northwest of Fairbanks, AK. The fire was started by a lightning strike on Jun. 22, 2015 and has consumed an estimated 31,705 acres. USFS photo.
Department of Agriculture
The Aggie Creek Fire is located 30 miles northwest of Fairbanks, AK. The fire was started by a lightning strike on Jun. 22, 2015 and has consumed an estimated 31,705 acres. USFS photo.

Forest fires are a vital component of a healthy ecological landscape and many trees actually need fires to germinate. Much of Alaska is covered in permafrost, and this permanently frozen soil prevents decomposition, storing carbon dioxide. Normal fires burn one-third to one-half through this layer but the permafrost usually rebuilds quickly, storing carbon once more and resulting in no net change to the levels of carbon in the atmosphere. However, during severe fires, two-thirds to the entire permafrost layer can be consumed. The entire layer will not be able to be rejuvenate, resulting in a net increase of carbon into the atmosphere.

“All other factors being equal, a more severe, deeper-burning fire will result in a net transfer of carbon to the atmosphere,” said Kasischke. “If there is a continuing increase in severe fires that burn deeper into the surface organic layer, there will be an increase in warming of frozen soils, which will increase decomposition of soil carbon, releasing more carbon to the atmosphere.”

Kasischke and his colleague Elizabeth Hoy estimated in a journal article that the amount of emissions released from Alaskan fires in 2004, the worst fire season on record in Alaska, was equal to all the emissions from domestic airlines and railroads for 2003 in North America.

Mowry said he sees dramatic weather variations from one year to the next.

“In 2014, we burned 230,000 acres, then it started raining and didn’t stop,” said Mowry. “This year we burned 5.1 million acres. And what’s going to happen next year is anybody’s guess but the trend is toward larger fire seasons earlier and that is what we are preparing for.”

Photo at top:The Aggie Creek Fire is located 30 miles northwest of Fairbanks, Alaska. The fire was started by a lightning strike on Jun. 22, 2015 and has consumed an estimated 31,705 acres. USFS photo.


Photo at top: Mono Lake in the Eastern Sierra of California (Guleed Ali/Columbia University)

By Kevin Stark –

Throngs of demonstrators frustrated with government inaction on climate change filled the streets of Manhattan in fall. They wore cardboard cutout life preservers that said “preserve our communities.” They carried a giant sunflower, nearly the width of a city street. Colorful signs, young and old, a cross-section of America.

And there was Yonig Goldsmith wearing a white robe like a prophet, but carrying a graph like a climate scientist. He is a climate scientist and the white robe was a lab robe.

“The scientists—there were not that many—but we all stood with signs that were posters of different plots [on graphs] showing what is happening,” Goldsmith said.

What role should science play in climate change advocacy?

This fall, Goldsmith and other scientists at the Comer Abrupt Climate Change Conference in southwestern Wisconsin grappled with this question. The conference is hosted by the Comer Family Foundation, which supports widespread climate research, and it brought together top climate scientists working from Antarctica to Greenland and everywhere in between.

Yonig Goldsmith and Allison Jacobel, graduate researchers at Columbia University, representing the science community at a September climate march in Manhattan. (Alice Bell/flickr)

The scientists agree that Earth is rapidly warming and that poses risks to human well being. But researchers do not agree on how to best take up the challenge of telling the climate change story. In emotion their responses range from optimistic to despondent, in strategy from advocacy to a focus on economic growth.

How do we talk about climate change so that people care even while they worry about making the rent? How do scientists communicate the threat of an abruptly warming planet to a public that often requires clarity, brevity, and certainty?

In December, world leaders will gather in Paris for the United Nations climate-change conference. Advocates are hopeful that the first global pact to limit greenhouse-gas emissions will be signed. Remember, in 1997 a framework was drawn up in Kyoto, Japan, to take a firm stand, but “the agreement failed on the international stage,” Jonathan Chait writes in New York magazine.

Goldsmith is a Columbia University doctoral candidate studying ancient lake levels in China. He believes that now that a global agreement is likely to be forged, scientists need to take an active roll in the advocacy debate. He is somewhat of an outlier among his colleagues.

To be clear, researchers should not be activists based on the premise of scientific objectivity, Goldsmith said. But researchers should not be on the sidelines either.  For Goldsmith, scientists need to be there, holding evidence. Pointing to data. Stating the case. “CO2 is rising. The oceans are warming. The glaciers are melting with an exclamation mark,” Goldsmith said.

Is there collaboration in climate messaging within this community? Does anybody agree?

Action Agenda

Goldsmith and I spoke about the role of scientists in the policy debate at the conference, several months after the march in Manhattan. He was preparing to participate in another march the following week at Columbia University, where he is a doctoral candidate studying with climate pioneer Wally Broecker.

Broecker, a geochemist at Columbia University, coined the phrase global warming in the 1970s and became the “Grandfather of Climate Science.”  He famously told the New York Times, “The climate system is an angry beast and we are poking at it with sticks.”

During the 1970s, believing that immediate action was needed to mitigate global warming, Broecker sent letters to senators, wrote papers, and generally “tried to advocate in this way—that is his avenue” Goldsmith said.

But for Goldsmith, letters and papers are no longer enough. Goldsmith says this to his veteran colleagues at the conference: you are the most “influential climate scientists in the world” and you have to “get up and talk about this.”

Broecker’s response (and the conversation) mirrors the greater debate within the science community. For Broecker, his role is as a scientist—not at all an activist—and to be credible he must remain objective and neutral, he says..

Goldsmith agrees that scientists need to be careful about discrediting their research, but he does see a need for a more active roll for researchers in the public debate.  “Scientists are the ones that have to say, this is what what we work on, this is the logic, this is what we have. This is the evidence,” he says.

Researchers should focus on  understanding  the science. Activists should focus on divestment from fossil fuels, Goldsmith said. He points to the success of writer and environmentalist Bill McKibben, winner of the Right Livelihood prize in 2014 and founder of McKibben organized the Manhattan march.

McKibben is leading an international movement to ‘divest,’ from the fossil fuel industry. He encourages organizations, universities, and others to withdraw financial investment from the oil and coal industry. Today, economists consider investing in the oil industry as a risk, in part, because of this advocacy (oil prices are dropping drastically because of over-supply which strengthens the argument for divestment).

Scientists marched with charts instead of protest signs in Manhattan (Alice Bell/flickr)
Scientists marched with charts instead of protest signs in Manhattan (Alice Bell/flickr)

“I very much believe in the economics approach because it makes sense to people,” Goldsmith said. “It is not this vague suffering of some whatever in some place in the world, which we cannot relate to.”

But only a handful of science researchers are actively engaged in the economics debate—Richard Alley of Penn State ranking among the most prominent. So, what does he think?

Alley said that communicating his fascination for science to a public audience was a “transition” and a “jolt,” and that policy is lagging behind the science. But he believes he found a message that will resonate with people: business.

Today, Alley is widely regarded as one of the best communicators of climate science. Alley, a glaciologist and geosciences professor  at Penn State, wrote the book  “Earth: The Operator’s Manuel,” the companion book to a widely popular PBS documentary (both were significantly more popular than the “Fate of Greenland”).

He also may be a perfect messenger as someone who is “right of center” and has “enjoyed working for an oil company and benefited from its largesse.” Alley believes the answer to the problem of how to engage with the public about climate change has the power of the free market behind the message.

He said that people will take action to reduce carbon emissions “because there is money to be made as much as ethically important things to do.”

It is not the case that doing the right things for future generations means “hurting ourselves now,” he said. He sees business opportunities and innovation where other see downsizing if we hope to reduce emissions.

The former vice president and author of “An Inconvenient Truth,” Al Gore is also advancing what has been called “sustainable capitalism” through Generation Investment Management, a company that “shifts the incentives of financial and business operations” to reduce damage to the environment caused by “unsustainable commercial excesses,” according to a recent article in The Atlantic.

Gore and Alley agree that including environmental and social impact on corporate activity can actually result in bullish gains in capital and that there is “money to be made,” (as Alley put it) and that returns can be better than just as good (according to Gore).

Gore has been able to prove that money can be made in sustainable energy investments, but there is no a guarantee that climate change will be solved on a policy level, or even that the renewable market will replace traditional oil and coal.  As Bill Gates put it in a separate Atlantic article, renewables will be “uncertain compared with what’s tried-and-true and already operating at unbelievable scale.”

Even the message of the melting ice can be a tough sell.

Philip Conkling co-wrote  “The Fate of Greenland: Lessons form Abrupt Climate Change” with Alley, Broecker, and University of  Maine climate researcher George Denton. The book chronicled the melting  ice sheet covering much of Greenland, the culmination of years of science and many voyages in the glacial North.

The book was supposed to “change the world, or at least make a little ripple,” Conkling said.  But it sold 4,633 copies. “It was like, what a disappointment,” Conkling said.

Conkling is the founder of the Island Institute, a non-profit that advocates for the remote coastal communities off the coast of Maine and in other areas. He is a rare non-science presenter at the Comer conference.

He lectured on how to tell the climate story and began by saying, “I was going to subtitle this presentation 35 years of failure but I thought that would be a little grim.”

Still, the success of collaboration between communities and the Island Institute encourages him. His newest enterprise, Philip Conkling and Associates, is a consulting firm that guides the vision and planning of non-profits.

Islands aren’t the only places that need protection as the climate risks grow.

Hurting Ourselves Now

A few months ago, I was talking about sea-level rise and development in the San Francisco Bay Area on a local radio program. I had just published an investigative package with a local news organization that detailed $21 billion worth of current bayside development projects in an area that scientists say could be flooded by the end of the century as glaciers melt, pouring more water into the oceans.

The station took a call from a skeptical listener who said the research was full of  “could be” statements and projections and wondered what about the research was news.

The caller and often apathetic policymakers are a problem for journalists and scientists who worry about what will happen if carbon emissions continue to climb and the planet continues to warm dramatically and quickly.

The biggest sticking point often for public engagement is the uncertainties that are inherent in climate modeling. Projections of sea-level rise – one of the key threats -fall in ranges. The projections are a product of highly complicated scientific models, and researchers can run different scenarios of action (and inaction) to mitigate carbon dioxide emissions.

Sea-level rise projections fall in a range at the end of the century. (Intergovernmental Panel on Climate Change)

With the United Nations fifth assessment in 2013, the  Intergovernmental Panel on Climate Change predicted that sea levels could rise between 11 and 36 inches by the year 2100, depending on how aggressively carbon emissions are reduced.

The difference between the low and high projections could mean billions of dollars in adaptation planning for coastal communities. And that’s without even looking beyond this consensus figure to other, less conservative projections. The gap, reflecting the rate of melting of the vast polar ice sheets, often leaves policymakers scratching their heads.

Which is another way of saying, it leaves policymakers inactive.

The report I published with a team at the San Francisco Public Press found 27 bayfront megaprojects – including new headquarters of Facebook, LinkedIn, Google – all in low-lying areas that climate scientist say could flood by the end of the century.

While interviewing policymakers, the uncertainty came up a lot, mostly as an excuse for why no specific sea-level rise regulation on the books for business in the Bay Area.

“It may be unwise—and expensive—to require immediate measures to adapt to wide-ranging, highly uncertain sea-level rise projections further out in time,” wrote San Francisco Mayor Ed Lee in a memo to a civil grand jury convened before the investigative package ran.  His administration has said that sea-level rise regulation needs to be written with nuance to adapt to changing science.

A map from the San Francisco Public Press. Production by Maia Wachtel, Marcea Ennamorato and Brittany Burson, UC Berkeley CAGE Lab. Illustration by Clark Miller. Find the interactive version by Amanda Hickman at (Reporting Kevin Stark/Medill)

Alley said that inaction because of uncertainty is short-sighted, and compared it to not buying car insurance just because there’s no certainty we will have an accident.

“The uncertainties actually motivate doing more,” Alley said. “You do not know whether or not you will be run over by a semi on the way to work, but you should buy a safe car, buckle your seatbelt and not drink while you are driving.”

Alley said scientists need to “care deeply and passionately about how things work,” but communicating this message to the public is a difficult challenge—and one that a new generation of researchers is leaning into by taking journalism classes and putting off research to collaborate with science reporters.

While the scientific community is in consensus that badly needed mitigation of the rate of carbon dioxide being released into the atmosphere is needed to slow the current rapid period of global warming, not all scientist agree that financial markets will solve the problem.

Guleed Ali, a graduate student at the Department of Earth and Environmental Sciences at Columbia University, is skeptical of the marketsplace solving the problem.

“We are here today because of business” pushing fossil fuel use, he said. He sees winning support from other perspectives.

Ali researches the geomorphic record of Mono Lake, which is a large, shallow saline soda lake in the Eastern Sierra of California, and he often speaks to the local community about his work.

Through trial and error—or “talk and blab” as he put it—Ali found that people engage more with images, or in his case, with art. Ali produces graphic images that explain the dense science. “That is the most straightforward way to penetrate that initial wall,” Ali said. “Art is something that is engaging. It is disarming.”

Science is a world of charts, graphs, data points, but Ali sees the world differently. “For someone like me, pictures are so much simpler,” he said. “They give life to these inanimate things that we write about.”

Ali said the route to solving the issue of global warming is through the hearts and minds of the public. People need to “see with their own eyes,” he said.

“If you see steam coming out of the bowl you know that the bowl is hot,” Guleed said. “It’s steam.”

The problem is that the majority of the public in the United States is disconnected from the changes that are taking place in the Earth’s climate. He said it is “abundantly clear” for those communities—“farmers and pastorals”—that are connected to the earth in a direct way.

Guleed Ali of Columbia University includes beautiful images that he draws along with complicated data in scientific talks.

The question for some of Ali’s colleagues is this: can engaging with people on an emotional level—providing steam-from-the-bowl evidence that the world is rapidly warming—move the public fast enough to mitigate warming?

The “ultimate objective” of the International Panel on Climate Change to stabilize greenhouse gas concentrations at a level that would prevent “dangerous anthropogenic interference” with the climate system—read: keep the world climate from being so screwy that society cannot grow food or live in coastal communities.

This temperature level is 2 degrees Celsius higher than pre-industrial levels. Today, we have already reached half that level of temperature rise and the other half is already spooled into the atmosphere.

If 2 degrees does not seem like a big deal—temperatures can vary 20 or 30 degrees in any given day. But it is important to to understand that the figure represents global average. If the global average temperature rises above the 2-degree mark, atmospheric climate will be disrupted. The world could see severe drought, less rain but more severe storms, and it will be a challenge to grow food to feed the world’s population.

It is clear from conversations at the Comer conference that every one agrees on one thing – the story of climate change needs to be told. All of the researchers I spoke with are doing this in some way. But, it was also clear that the science community doesn’t agree on how to tell the story. They are still debating, proposing and challenging – which they do in their science as well.

But they all keep trying to tell the story. And they all seemed to have hope.

“People will get there,” Ali said. “We are doing this for that reason.”



These Pinus jeffreyi stumps on the West Walker River (dubbed the “Stine stumps” after the researcher who identified them and dated them) took root in a dry medieval period before being killed by increased precipitation and subsequent flooding. Scientists say the area’s medieval drought was comparable to current conditions in terms of precipitation, but warn that higher temperatures associated with the ongoing drought present new challenges.
These Pinus jeffreyi stumps on the West Walker River (dubbed the “Stine stumps” after the researcher who identified them and dated them) took root in a dry medieval period before being killed by increased precipitation and subsequent flooding. Scientists say the area’s medieval drought was comparable to current conditions in terms of precipitation, but warn that higher temperatures associated with the ongoing drought present new challenges.

By Bryce Gray –

The nearly five-year drought afflicting California and Nevada has restricted water usage, emptied reservoirs to historic low levels, and even caused the land to sink in areas of extreme groundwater depletion.

As Ben Hatchett will tell you, the ordeal has left climate scientists with many of the same questions as everybody else.

“How bad is this drought, actually?,” asked Hatchett, a Ph.D. candidate at the University of Nevada-Reno, speaking at the Comer Abrupt Climate Conference in Wisconsin this fall. “Does it happen frequently? Is it the worst possible?”

Hatchett is working to answer those questions and others as he attempts to put the drought in proper historical context. He says the region has seen dry spells like this before – particularly in medieval times when the area underwent at least two prolonged “megadroughts,” and may have experienced another one 2,500 years ago.

“From a precipitation-only perspective, this drought is very comparable to the average severity of these medieval droughts,” Hatchett said.

But, contrary to popular belief, the length and severity of drought doesn’t solely depend on precipitation. Hatchett’s analysis of centuries of climate data shows that temperature is one key factor in exacerbating drought – a problematic realization with global warming expected to drive temperatures beyond medieval levels.

“We can see that the impact of temperature is very important,” Hatchett said.

Hatchett developed a model to gauge the historic influence of temperature and precipitation based on past water levels in Nevada’s Walker Lake watershed, just east of the Sierra Nevada mountain range. Although his model reflects that current drought conditions are comparable to past declines in precipitation, the same doesn’t apply for temperature, he said.

“The precipitation deficits or anomalies with this current drought are on par and within the range of natural variability, but the temperature could be pushing us outside the realm of the natural variability,” Hatchett said. He added that he and his colleagues are confident that the temperature anomalies are driven “in large part due to anthropogenic forcing on the climate system.”

A chart outlining the medieval simulations of Hatchett's model shows the corresponding level of Walker Lake based on various temperature and precipitation conditions.
The medieval simulations of Hatchett’s model show the corresponding level of Walker Lake based on various temperature and precipitation conditions. (Courtesy of Ben Hatchett)

Hatchett says that future climate projections for California and Nevada demonstrate uncertainty regarding precipitation, but quite uniformly predict that the region will get warmer. He warns that an unprecedented spike in temperatures represents a unique threat to the plants and crops that comprise the region’s ecosystems and economy.

“Most of these plants are pretty adaptable to precipitation variability but when you start altering temperature regimes, you start to push these boundaries, especially for these plants that are living on the edge of their happy medium,” Hatchett said.

“That can push these ecosystems past these threshold points,” he added.

Hatchett said that a logical next step for researchers is to examine the meteorological causes of drought, including the high-pressure systems that periodically hunker down over California for an extended period of time, diverting storms and rain away from the region.

“[That’s] kind of our next step, as far as trying to understand what causes it to be dry for so long,” he said.

Hatchett’s words were reinforced by Scott Stine, another Sierra Nevada-based climate scientist who spoke at the conference. Stine’s past paleoclimate research in the Walker Lake Basin is memorialized by the so-called “Stine stumps” – a stand of once-stately pine trees that grew in the medieval dry period before being drowned out by the return of wetter conditions. Stine, a professor at California State University, East Bay, supports the theory that a “block” of high-pressure meteorological conditions has played a major role in the area’s past and present dry spells.

“We have a storm track moving way northward, leaving California high and dry,” Stine said, explaining that the widely meandering weather patterns can divert precipitation as far north as Alaska. “This appeared to be going on in medieval times,” he added, noting that when California was stricken by severe drought, precipitation-dependent glaciers in Alaska were growing.

Whatever the weather may bring, Hatchett hopes that a greater understanding of drought will lead to improved water management practices throughout the West. But even the most resilient systems may be hard-pressed to overcome another megadrought.

“This really frames how susceptible we are, ‘cause four years is causing all kinds of grief,” Hatchett said. “These things go on for 50, 100, 200 years. It’s almost like a reality check.”

December 1, 2015

Capturing carbon dioxide: How scientists are grabbing greenhouse gas emissions

Capturing carbon dioxide: How scientists are grabbing greenhouse gas emissions

By Neil Murthy –

That may look like a solar panel on the rooftop near Tucson, Arizona. But think again. It a carbon dioxide collector and we may be seeing a lot more just like it in the future.

A prototype collector invented by Klaus Lackner, director of the Center for Negative Carbon Emissions at Arizona State University, is perched on the roof of the center our ability to sponge CO2 out of the air. With temperatures rising and carbon emissions from fossil fuels kicking those temperatures upward, Lackner is tackling greenhouse gases in an  ambitious way. His team of scientists have capitalized on the properties of a unique material—known as anionic exchange resins—that captures carbon dioxide from the atmosphere when the material is dry and releases it when the material is wet. The warm temperatures and low humidity of Arizona make it an ideal place to test this technology, since the material can most effectively capture carbon dioxide in the dry desert air. There’s no humidity to dampen the long leaves of the resin.



By Neil Murthy –

Christine Chen is a scientist on a mission.

Thousands of miles away from the Massachusetts Institute of Technology where she is a third-year doctoral student, Chen reached one of the most remote regions on Earth equipped with a knapsack, a rudimentary rock hammer and a burning question—can ancient lakes in the Andes Mountains shed light on past climate, clues that can then be used to predict future climate change?

Satellite image of the northwest corner of Agua Caliente I. The white arrows indicate the location of the ancient abandoned shorelines, which form a bathtub-like ring pattern. Photograph courtesy of Christine Chen. (Neil Murthy/Medill)
Satellite image of the northwest corner of Agua Caliente I. The white arrows indicate the location of the ancient abandoned shorelines, which form a bathtub-like ring pattern. Photograph courtesy of Christine Chen. (Neil Murthy/Medill)

The question is long established in the field of earth science and has prompted exploration into the world of “paleoclimates” (or “ancient” climates). As the planet currently undergoes unprecedented change in terms of rising global temperatures, scientists have long speculated that by critically analyzing past changes in Earth’s climate, they can develop climate models that can be used to predict temperature and precipitation changes of the future. Of greatest uncertainty is how rainfall patterns will change in the future.

“For the modern climate, we’ve got rain gauges and we can calculate rates of evaporation,” explained Chen at the annual fall Comer Conference on abrupt climate change. “But no one was around thousands of years ago to set up a rain gauge. Lake level changes are a proxy for water availability.”

Most of the work on lake levels and paleoclimate has been done on European and North American lakes, Chen said. South American lakes are markedly underrepresented in the scientific literature, and Chen hopes that her work in the Andes will bring South America to the global forefront of much needed data. She sees in the barren landscape as a treasure trove of ancient knowledge, revealing answers to ages-old mysteries of climates and precipitation patterns.

Photograph of tufas at Agua Caliente I. These lighter-colored tufas are found coating large darker-colored volcanic boulders throughout the landscape and provide valuable clues about past lake level changes. Photograph by Christine Chen. (Neil Murthy/Medill)
Photograph of tufas at Agua Caliente I. These lighter-colored tufas are found coating large darker-colored volcanic boulders throughout the landscape and provide valuable clues about past lake level changes. (Photograph by Christine Chen)

The lakes that Chen studies, Agua Caliente I, Laguna de Tara and Salar de Loyoques, are vestiges of much larger lakes from thousands of years ago. With no outlets such as streams or rivers from these lakes, they depend on the competing forces of rainfall and evaporation to maintain water levels. As a result, Chen hypothesizes that higher water levels indicate periods when rainfall was plentiful. By matching water levels with the time record, Chen can then evaluate how global temperature patterns affected past rainfall. This will provide important lessons that will shape current climate models on what changes we might expect in rainfall patterns in the future.

“Reconstructing past rainfall amounts is not easy; using lake levels is the best way to do this,” said Yoni Goldsmith, a doctoral student at the Lamont-Doherty Earth Observatory of Columbia University. “Using a variety of geochemical, geophysical and biological methods, it is possible to decode these climatic signals and reveal how climate changed in the past.”

A cursory glance at Google Earth images of Agua Caliente I, Laguna de Tara and Salar de Loyoques clearly shows that these lakes were once mighty bodies of water. Now, they are more like large salt flats.

“We can see awesome bathtub-like ring features,” Chen said, referring to a series of concentric circular patterns extending from the lakes. “These bathtub-like rings are essentially ancient abandoned shorelines,” she said.

On the ground, the bathtub ring pattern is not nearly as striking, and the ancient shorelines are marked by white rocky formations that to a lay person seem beautiful but not of great scientific import. But to Chen, the answers to her questions lie within these rocky formations coating the ancient shorelines. Chen calls these formations “tufas”, and thanks to their biological origin, their presence provides valuable insights into past conditions for these ancient lakes.

Tufas, fossilized remains of algae reefs, are made of calcium carbonate. When the algae making up these reefs were alive, they lived on the shore close to the water surface in order to get sunlight for photosynthesis. By analyzing the tufas back in a lab at MIT, Chen has figured out when these algal reefs were last alive, before they became fossilized into stone. And that gives her a timeline for the shrinking bathtub rings.

Many of the tufas—some located more than 60 meters away from the modern shoreline—fall between 15,000 to 25,000 years old. Based on those results, Chen can infer that thousands of years ago, these lakes were nearly four times larger than they are today, indicating that the barren landscape was once a lush terrain that was hospitable for more kinds of life.

Chen also looks at other formations known as ikaites, which are calcium carbonate crystals that form at the bottom of lakes within the mud only when the water is at very cold, near-freezing temperatures.

Photograph of ikaite deposits at Laguna de Tara. These calcium carbonate formations are found in protected spaces beneath large boulders that shield it from the harsh landscape. Photograph by Jay Quade. (Neil Murthy/Medill)
Photograph of ikaite deposits at Laguna de Tara. These calcium carbonate formations are found in protected spaces beneath large boulders that shield it from the harsh landscape. Photograph by Jay Quade. (Neil Murthy/Medill)

“Not only do the ikaite deposits give us a constraint on how high the lake was, but it also tells us the paleotemperature—how cold it was back then,” explained Chen. “This is pretty cool because usually proxies only give you one parameter, but we’ve got two. So that’s pretty exciting to find.”

Chen hopes to apply the same technique of finding the age of tufas and tracing abandoned shorelines to other ancient lakes in the Chilean Andes. She will then compare these data with temperature records from nearby ice cores from Andean glaciers to get a better idea of why these lakes were larger in the past.

“If we know what caused these lakes to get bigger, what caused these lakes to get smaller, then maybe we will have an insight on what these lakes will do in the future and what is causing them to shrink or expand,” said Chen.

Chen’s work comes at a time when the Central Andean region has been experiencing decreased rainfall and increased evaporation rates over the past 50 years, which has significantly strained local Andean communities. She hopes that her scientific contributions might help policymakers identify regions that are more sensitive to water availability issues, and divert resources to communities that are most likely to be adversely affected by future climate change.

Photo at top: A closed-basin lake in the beautiful barren landscape of the high Andes. Photograph by Christine Chen.


By Danielle Prieur –

Photo Courtesy D. Funkhouser and G. Ali Tufas in Mono Lake.
Photo Courtesy D. Funkhouser and G. Ali Tufas in Mono Lake.

Climatologist Sidney Hemming of Columbia University first came to the Mono Lake Basin in California to assist her husband, Gary Hemming, with his research but found important links between prehistoric lake levels and current drought conditions.

“I first went out there to collect water samples with my husband who was interested in boron isotopes,” Hemming said. These isotopes offer scientists clues about the ocean’s prehistoric chemistry.

What started as an experiment in learning how to date sediments in the Mono Lake Basin, became an on-going project to generate the most complete record of water levels beginning with the Last Glacial Maximum, approximately 20,0000 years ago. “It’s one of those places you keep coming back to,” Hemming said, speaking to colleagues at the Comer Abrupt Climate Change Conference in Wisconsin this fall.

These lake levels reveal patterns in climate which allow scientists like Hemming to build models which predict modern climate patterns.

Guleed Ali, one of Hemming’s graduate students at Columbia University, is now researching with her in the  Mono Lake Basin. “He’s getting into real lake level history studies,” Hemming said. Like Hemming, Ali has added to the water level record for the area.

“There was a potential to really pull out a highly resolved lake fluctuation record just from the sedimentary observations,” Ali said.

For the past year Ali, like Hemming before him, used a combination of carbonate towers called tufa (left behind by microbes), sediment dating and the water level record that has been generated by other scientists in the Mono Lake Basin to bolster this record.

“So it’s really two parts: the sedimentary observations…and then dating those sedimentary packages,” Ali said. After returning from the field this year, however, Ali had much more than a water level record. He had what he calls “an enigma.”

“He’s onto a fairly special, specific thing…but it has that caveat that it depends on not only how well he’s done, but on how well everybody else has done before him,” Hemming said.

Ali’s discovery of low water levels during the Last Glacial Maximum – as low as where present day water levels in the Mono Lake Basin should be if it were not for the drought – might change how scientists think about temperature, evaporation, and the jet stream.That’s because the Last Glacial Maximum-about 20,000 years ago-marks the peak range of the glaciers during the last great ice age.

Ali’s “enigma” of low water levels during the Last Glacial Maximum is an enigma for two reasons. First, during cold periods during an ice age, lower temperatures should have meant decreased evaporation. Second, this decreased evaporation should have led to higher water levels as more water remained in the basin sometimes in frozen form. Instead, Ali’s data suggests that temperature and evaporation, both variables which scientists know play a role in water levels, may not be enough to explain water levels during the Last Glacial Maximum.

Instead, Ali has hypothesized that the North Atlantic Ocean’s circulation, its jet stream, controlled climate then and still has an impact today across large areas. “What I think might be controlling these lake levels is the state of the tropical circulation and the state of the North Atlantic Ocean’s circulation,” Ali said. “What I think is a possibility, just a working hypothesis…is that the strength of the circulation in the North Atlantic Ocean is the controlling factor of the hydro-climate certainly in Mono Lake and much of the western U.S.”

Jet streams, fast moving wind currents in Earth’s atmosphere, are known to control weather. If the jet stream led to the hydro-climate in the Last Glacial Maximum, it also might be causing the present extreme droughts in California.

“During times when circulation is weakened or perhaps is close to being off…that subtropical jet strengthens,” Ali said.

Ali plans on returning to Mono Lake this year, but with a different experiment based on this jet stream hypothesis. “The mechanism I would like to test is something that can be used to explain today’s hydro-climate, but [also] something 20,000 years ago,” Ali said. “Something that is controlling the wetness or dryness.”

Until he returns to the field, Hemming says one thing is certain. “There seems to be a unifying observation that there’s dramatic change across that interval consistent with Guleed’s findings in the Mono Basin.”

This consistency across global, water records contributes to a model which can better predict the effects modern climate change might have on water levels and weather. “The way we try to understand global climatic patterns…is by looking at the global picture, many different sites from the North to the South,” Ali said. “We’re going through global paleo-climate to piece together all the pieces of evidence in the global picture all at the same time.” That will reveal “climate patterns in the past,” Ali said.

Nov. 24, 2015

Photo at top: Spires of tufa at Mono Lake. (Courtesy of D. Funkhouser and G. Ali)

Greenland caves reveal climate drivers beyond temperature

Greenland caves reveal climate drivers beyond temperature

By Danielle Prieur –

Paleoclimatologist Gina Moseley found an old Kodak film box when she entered a cave in northeast Greenland last year? It gave her the clue that few people had stopped there since the 1960s. An American scientist left behind a note in the 1960s film box and it was untouched when Moseley and her team found it. Probably few people had stopped there since.

She and her team discovered some new caves in the hostile and hard to reach environment of the 26 caves they explored.

Mineral formations called speleothems formed by rainwater and carbon dioxide slowly dissolve carbonates such as limestone above the caves and then redeposit them inside the caves where they seep. These dramatic spindles and towers of stalagmites and stalactites offer scientists clues as to prehistoric climate patterns.

“From what we understand no one had entered these upper, higher level caves,” said Moseley, a post-doctorate researcher at the University of Innsbruck, Austria. That’s because of the arduous climb to reach the caves across an almost Alpine ski slope, she said, speaking to colleagues at the Comer Abrupt Climate Change Conference in Wisconsin this fall.  .

As part of the Northeast Greenland Caves Project, Moseley and her team, know that half of the field research is getting to the site. For this study alone, the science team “flew up the east coast of Greenland,” she said. “Then we crossed the lake about 20 km wide in an inflatable boat and finally set up base camp on the east shore and hiked to where the caves are.”

Although Moseley and her team now hold the record for the “most northerly explored cave on the face of the planet,” they also hold a much more important scientific one: the first speleothem paleoclimate record of Greenland.

A speleothem or flowstone formation on a wall, floor or ceiling of a cave that can be studied to determine temperature and evaporation at a particular time.

“That’s interesting because today the region is too arid and it’s a permafrost zone, so you wouldn’t have any modern calcite deposition in the caves,” Moseley said. “Their presence means, at some point in the past, it must have been warmer and wetter for water to flow and for the flowstone to form.”

What Moseley and her team found in these caves is a treasure trove for scientists. “We found flowstone everywhere,” she said. “Even though there was so much material…we found a thinner flowstone and this was the youngest material and we took some of this.”

By the end of their field research, Moseley and her team had, “documented 26 caves, collected 16 calcite samples, three water samples, two sediment samples and one bone and feather sample,” enough to generate a record and to question her own hypothesis  “about what controls oxygen isotope composition in the speleothems.”

“Instead, we need to look at seasonality or something else…temperature’s not the main control,” Moseley hypothesized. Until she can perform further research to determine what controls this the oxygen isotope composition so crucial to speleothem deposition in caves, her uranium-thorium dating completed so far of her speleothem samples has generated a record for the first time in these caves.

“There was quite a nice spread of age in the Holocene,” she said. The holocene is our own epoch in time, going back 10,000 years. But flowstones come from much earlier marine isotope stages, placing their deposition between 220,000 and 550,000 years ago, Moseley said.

Moseley’s hypothesis could mean that seasonal changes, as a result of climate change, affect the control of speleothem formation.

The team is planning to uranium-thorium date these samples and to radiocarbon-date a dead bird. The bird “appeared to be much larger than anything else we had seen there,” indicating that it’s possibly very old and from a different climate.

Moseley came to Greenland to “find out when it was warmer and wetter than it is now and get more information about climate during those warm intervals,” she said. She accomplished both while setting records in cave exploration. Her future field research holds “huge potential for extending the record.” By extending it, Moseley said she and scientists like her help improve climate predications for the future and understand better what might lead to extreme changes in temperature and climate.
Nov. 20, 2017

Photo at top: Gina Moseley and the research team in Greenland. (Courtesy of the Northeast Greenland Caves Project)

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