[jwplayer mediaid=”383″]

Reported by Kristofor Husted/MEDILL
Geochemist Larry Edwards discusses the connection between monsoon patterns and carbon dioxide.

by Kristofor Husted
Jan 11, 2011

Cave deposit samples from China are helping scientists resolve the timeline of the whole Earth’s climate history.

Knowing this history means better predictions of what’s to come with human-driven global warming speeding up the clock of climate change, scientists maintain.

“It’s not that previous workers got the age wrong. They got the age for the most part right,” said University of Minnesota geochemist Larry Edwards. “But we’re able to now really fine-tune that age in a big way.”

Courtesy of Larry Edwards Geochemist Larry Edwards' map shows caves in China where he finds clues about ancient monsoon patterns and climate change.
Courtesy of Larry Edwards
Geochemist Larry Edwards’ map shows caves in China where he finds clues about ancient monsoon patterns and climate change.

Edwards presented his newest findings at the recent Comer Conference on Abrupt Climate Change in Wisconsin.

Edwards and his team collect stalagmite samples and use isotopes to accurately date them. 

With this information, they can figure out where the monsoons brought wet weather centuries ago. These monsoon patterns in turn correlate to methane levels and cycles of climate change.

Methane that formed thousands of years ago got trapped in air pockets in ice sheets in places such as Greenland and Antarctica. Researchers can pull out ice cores, also used for dating our planet’s climate history, and measure the amount of methane found in the air pockets. 

Also sitting in the air pockets with methane is ancient carbon dioxide, a greenhouse gas that rises and falls in near lockstep with Earth’s rising and falling temperatures. 

Monsoon intensity has been linked to increased levels of atmospheric methane concentrations. Natural decomposition and animal digestion produce methane as well. But landfills, natural gas leaks, coal mining and agriculture produce lots more and are contributing to current levels of global warming.

Methane traps 20 times more heat in the atmosphere than carbon dioxide over a 100-year period, according to the U.S. Environmental Protection Agency.

From these connections between monsoons and methane, and methane and carbon dioxide, researchers can more accurately determine how much carbon was in the Earth’s atmosphere in ages past and link it to climate.


U.S. Geological Survey Scientists are reconstructing Earth’s climate history to understand what past changes reveal about the present and future.
U.S. Geological Survey
Scientists are reconstructing Earth’s climate history to understand what past changes reveal about the present and future.

by Gretchen Roeckerand Megan Taylor Morrison
Oct 12, 2011

In remote, rural Wisconsin, PVC pipe and white tarps transformed a section of an airplane hangar into a forum for some of the world’s top climate scientists to show the high stakes of ignoring a warming world.

Outside the hills are green and forested, but inside the talks focus on the climate science underpinning the double threat of drought and rising seas, already resulting from global warming. 

Thirty-three scientists gathered at the recent annual Comer Conference on abrupt climate change to share a year’s worth of research from across the globe. They sit at tables, chatting congenially. 

Gretchen Roecker/MEDILL Geochemist Irene Schimmelpfennig, of Columbia'sLamont-Doherty Earth Observatory, is a glacial sleuth. She calculates times when ice advances and retreats in the shrinking Swiss alpine glaciers bymeasuring the concentration of isotopes in rocky deposits.
Gretchen Roecker/MEDILL
Geochemist Irene Schimmelpfennig, of Columbia’sLamont-Doherty Earth Observatory, is a glacial sleuth. She calculates times when ice advances and retreats in the shrinking Swiss alpine glaciers bymeasuring the concentration of isotopes in rocky deposits.

In the front of the room, a wiry man with glasses and a beard stands and raises a small device to a microphone.


In the spirit of camaraderie at the conference, the quirky cow call announces the beginning of the meeting and tells researchers when the time for their presentations is running low. 

The man with the microphone introduces himself as Richard Alley, a geoscientist from Pennsylvania State University and a force field of energy. His noisemaker is a gift from Columbia University’s Wallace Broecker, the 80-year-old titan of climate change research who coined the term“global warming” in the 1970s.

“We have to get the science nailed on abrupt climate change,” Alley says, driving the last three words home with full-body, staccato accents. Things that happen so fast “really matter to people in the real world.”

It’s imperative “to tell people honestly and realistically what is happening and why it matters,” he adds.

In geologic terms, “abrupt” can describe changes that take place over centuries or millennia. But some of those shifts happen quickly– and all of them matter because they can help predict how humans are driving climate changes at a rapidly accelerating pace.

“In the next two days, we’re going to see what we learned,” Alley says.

Megan Morrison/MEDILL The trusted triad: Richard Alley, Wallace Broecker and George Denton. The three scientists carry on the late Gary Comer's philanthropic mission to seed ground-breaking climate research and organize the Comer Conference to share the findings each year.
Megan Morrison/MEDILL
The trusted triad: Richard Alley, Wallace Broecker and George Denton. The three scientists carry on the late Gary Comer’s philanthropic mission to seed ground-breaking climate research and organize the Comer Conference to share the findings each year.

Alley warmly welcomes the scientists, acknowledging Broecker and George Denton, a renowned climate scientist at the University of Maine. The three became close friends and advisers to Chicago philanthropist Gary Comer as he funded abrupt climate change research.

Since Comer’s death in 2006, they have continued to identify promising research for funding and to coordinate the meeting hosted by his children, Stephanie and Guy, at their family retreat. Together, they carry on a legacy that has committed some $50 million to climate change research projects and facilities since 2002. 

Over the last year, with help from the Comer Science and Education Foundation, scientists at the conference have studied ice, rocks and lakes from Asia to Argentina. By filling in missing pieces in the puzzle of the planet’s past, they are painting a robust picture of climate change and its predicted impacts on global warming. 

A modern perspective

Research this past year focused on what drives rises and falls in temperature, glacier size, and precipitation rates during the Holocene, the current geologic period that began with the end of the last ice age 12,000 years ago. Scientists compare past patterns of this relatively stable period to better understand today’s unprecedented warming trends.

Understanding past data can help society prepare to “make a contiguous plan” for future changes, said Jorge Strelin, a staff geologist with the Antarctic Institute of Argentina. 

“This area of science… is a very important topic to be considered at present because of climate change,” Strelin said. “We should be prepared to participate in climate change and to understand what will happen in the future.”

Although changes in temperature have occurred naturally over earth’s history, Denton said research reveals that current conditions no longer follow past trends.

“Under normal circumstances, the earth would be slipping back into an ice age,” Denton said. “Of course, the conditions aren’t natural now because humans are pumping CO2 into the atmosphere.” 

Carbon dioxide, or CO2, collects the air as by-product of burning fossil fuels. As it accumulates in the atmosphere, CO2 and other “greenhouse gases” form an invisible heat blanket, trapping thermal energy that would normally escape into space.

Gretchen Roecker/MEDILL To provide a space for scientists from around the world to present and display their research at the Comer Conference, an airplane hangar is transformed with tarps and tables.
Gretchen Roecker/MEDILL
To provide a space for scientists from around the world to present and display their research at the Comer Conference, an airplane hangar is transformed with tarps and tables.

The scientists gathered at the conference have looked closely at other potential causes for aberrant temperature patterns, such as ocean currents, sunlight and volcanic ash. Carbon dioxide, they believe, is the key factor and is rising at unprecedented levels due to human use of fossil fuel. 

Clues to climate patterns

In order to understand Earth’s recent climate history, these scientists collect and analyze materials from almost every continent. They find clues to past climate in tree rings, insects, cosmic ray isotopes, mile-long ice cores, lakebeds and caves. Tapping into this evidence, they calculate the past temperatures and chemical compositions on earth. 

“One of the general questions is always if climate changes are just regional or hemispheric or global,” said Irene Schimmelpfennig, a geochemist at Columbia’s Lamont-Doherty Earth Observatory. “If you have the same signals in very different parts”of the globe, ”that shows that there’s a link.”

For Schimmelpfennig and others studying glaciers, determining the age of moraines, the rock formations deposited as glaciers advance and exposed when they retreat, helps fill in a chronology of how a glacier has grown or shrunk in response to “climate forcings”like carbon dioxide and solar radiation.

“What we can conclude from our reconstructions is that based on small climate changes glaciers fluctuated heavily,” Schimmelpfennig said, adding that the speed of the current glacial retreat seems to be unprecedented. “If the warming goes on like this, glaciers may disappear in a few years” in some parts of the world.

Joerg Schaefer, who heads the cosmogenic dating group at Lamont, refers to glaciers as “climate recorders” because of their sensitivity to shifts in temperature and ability to freeze data about climate conditions.

“Whenever a glacier is changing, it’s dramatic for the environment,” Schaefer said. “Whatever will happen in the near future will have dramatic impacts on the landscapes and the people living there.”

Dating glacial sediments

Along with Schimmelpfennig and other scientists and students, Schaefer has helped refine a popular new method used to calculate the timing of glacier growth and retreat: beryllium-10 surface exposure dating.

Beryillium-10 is an isotope formed when cosmic rays hit Earth’s surface. As a glacier retreats, cosmic rays react with oxygen, silicon and other elements in the uncovered rock to produce Be-10. The longer the rock is exposed, the more Be-10 accumulates. Scientists such as Schaefer and Schimmelpfennig use the concentration of Be-10 atoms to calculate the age at which the rock was exposed.

In the last year, Schaefer said, Be-10 dating has become much more precise as researchers have refined data on how quickly the isotope builds up naturally.

“That’s a real game-changer,” Schaefer said, because the recent progress gives scientists the key to glacier moraines, an almost untapped but near-global climate archive. “It really connects the paleo-record to present day, and it gives a continuous baseline against which you can calibrate the ongoing climate change.”

Backed by a more precise method, Schimmelpfennig, Schaefer and others have been able to show links between abrupt climate changes identified in Greenland and the Swiss Alps, such as the retreat of the last ice age glaciers at the beginning of the Holocene period.

Hydrology across history

While some scientists are exploring climate markers in glaciers at the poles and in New Zealand, Patagonia and Europe, others are investigating how water systems, temperature and climate intertwine by studying past and present shifts in Earth’s hydrology.

“A major result of the temperature change is a shift of rain belts and water supplies,” Denton said. “That’s the major message coming out of the paleoclimate changes, both for the ice age and for the Holocene.”

As the hemispheres heat or cool, the location of the highest mean temperatures moves north or south and pulls the rain belt with it, Denton said. This is the Earth’s thermal equator, and the shifts in it can cause lakes to turn into deserts and vice versa.

Aaron Putnam, a geochemist at the Lamont-Doherty Earth Observatory, and several of his colleagues who have received Comer funding, saw that shift first hand in Asia. The scientists sifted through clues revealing that a desert in western China was once a vast lake that dried out at the same time as the once-wet western United States.

Similar mid-latitude drying events could occur again as CO2-driven temperature rise transforms rain systems. 

“The northern hemisphere, because of its huge landmass, will warm more quickly than the southern hemisphere and more dramatically,” Denton said. The resulting changes in distribution and intensity of rainfall could worsen monsoons and cause severe drought.

“Potentially, we are messing with some big forces,” Denton said. 

At the end of the last ice age, a dramatic northward shift of the thermal equator happened “in something like 50 years,” Broecker said. 

As global warming continues the thermal equator, which marks the highest average yearly temperatures around the world, could quickly slide north again, altering water patterns around the planet.

Warming is currently causing measurable changes in water distribution south of Putnam’s parched desert. 

Adam Hudson, a University of Arizona geosciences graduate student, said he was eager to show the researchers his preliminary findings that the Tibetan Plateau region in Central Asia is rapidly getting wetter: in the last 30 years, the total lake area on the plateau has grown by up to 35 percent, likely because of melting permafrost.

“I’ve been thinking about this for about three weeks or so,” Hudson said of the fresh observations. “I was so excited about it I decided to present what I had so far.” 

Excitement about sharing research and getting feedback from peers spilled from official sessions into the outdoor dining tent over plates piled high with fresh tomato salads and sweet cornbread. Adi Torfstein, a geochemist from Lamont, said coming to the Comer Conference gives him a chance to talk to peers in an atmosphere he doesn’t find at larger science gatherings.

“There’s a lot of opportunity to interact and to talk to really essential people,” Torfstein said. “The big meetings are more industrial. That’s the magic of this conference — the proximity.”

Torfstein is studying the “dust archive” in ancient Dead Sea sediments to better understand the history of environmental conditions related to hydrology and dust storm frequency in the Middle East, where changes in water availability could severely impact agriculture and heighten political tensions.

“This area has its share of geopolitical problems,” Torfstein said, “and water scarcity, which is expected to be more severe in the near future, can only add to these problems.”

Melting ice, rising trends

As emcee Alley zipped through a colorful presentation on “Some Ice Stuff,”showing that paleoclimate research isn’t just about tracing the past, but about extending that sketch and its implications through the present and into the future. Studies of how vast swaths of ice and water have responded to temperature shifts in the past indicate that a warmer climate could mean meters of sea level rise above current coastlines.

“The trend in sea level is clearly up,” Alley said, noting that warmer temperatures are causing sea water to expand and increasing glacial melt.

In the last century, average temperatures have risen by 1.5 degrees F and estimates for future temperature rise from CO2 and other fossil fuel emissions range from about 3 to 15 degrees. The temperature rise could potentially have huge impacts for earth, Alley said. 

Greenland’s massive ice sheet, which is rapidly melting and dumping icebergs into the North Atlantic, could contribute to projected sea level rise of about one meter, Alley said. While Greenland’s ice is unlikely to slip suddenly into its salty surroundings, Alley said, the fate of glaciers at the opposite pole is far less certain. 

Thwaites Glacier, on the West Antarctic Ice Sheet, may be poised to slide off its current perch. If it doesn’t stabilize on another “bump” in the sea floor, Alley said, Thwaites could lead to the collapse of the ice sheet and a relatively rapid three-meter increase ocean levels.

“We don’t really know how fast it could go,” Alley said, cautioning that the physics of two-mile high ice cliffs isn’t yet well understood. “If the world’s going to do something that makes that meter of sea level rise this century too small, this is probably the place” where “there really could be an abrupt climate change.”

Studying the past, working for the future

Despite the uncertainties and challenges in understanding abrupt climate changes ancient and new, the scientists agreed that the support from the Comer Foundation and their globetrotting leaders and peers has helped accelerate vital work. Both the funding and the collaborative atmosphere of the conference assist their efforts. 

“It was Gary’s idea not only to help fund research, but to make sure the people who were doing it got together in a congenial way,” Broecker said. “We’ve worked hard to try to use the money that he put aside for us in a wise way, and also to make sure these meetings were fun for everybody and intellectually stimulating.” 

Comer began offering fellowships for climate researchers through the Comer Science and Education Foundation in 2004, three years after A relatively ice-free voyage through the historically ice-choked Northwest Passage spurred his interest in Earth’s changing climate. The foundation continues to provide young scientists with the funding needed to launch seminal research. 

The scientists agree that Comer’s funding has allowed them to gather data at an unprecedented rate. 

“Gary Comer probably generated 20 years of research in the course of five,” Putnam said.

The ability to push research frontiers and share results sheds a hopeful light on an uncertain future, Alley said.

“We’re doing good science the right way,” Alley said. “Getting it into the public eye is not just fun, it really is how our civilization works. We’re a little piece of that.”


by Rosa Lin
Oct 06, 2011

Both Northern and Southern hemispheres are heating up with global warming.

Yet scientists see differences in climate patterns between the hemispheres in past ages. 

Courtesy of Aaron Putnam Glaciers in the Southern Hemisphere have not shown the same climate history as glaciers in the Northern Hemispere.
Courtesy of Aaron Putnam
Glaciers in the Southern Hemisphere have not shown the same climate history as glaciers in the Northern Hemispere.

Their research, presented at the recent Comer Conference on abrupt climate change, underscores the unprecedented nature of our current climate change. 

Rapid warming is causing the unusual match of conditions. 

The climate of the hemispheres have not matched “on long time scales,” said Aaron Putnam, a post-doc at Lamont-Doherty Earth Observatory of Columbia University who studies glaciers in New Zealand. 

“So the only time where we actually see synchrony between the hemispheres over at least the last 10,000 years – if not much farther back than that – is during the last century.” 

And that synchrony consists of rapid warming. 

Researchers showed how the Northern Hemisphere experienced climate fluctuations from the last ice age, about 12,000 years ago, to the generally warm period of the Holocene era, roughly the past 10,000 years. Scientists are now ramping up research on climate change in the Southern Hemisphere during the same period. 

“One of the big questions was, have these changes that we’ve noticed in the Northern hemisphere” been global changes? Putnam said. “And that’s really important to understand.” 

Climate scientists focus on glaciers in their research as glaciers are key indicators of climate. 

“We’re looking to see how the glaciers have changed in the past, and we use that to learn how the climate’s changed in the past because the climate controls the glaciers,” said Mike Kaplan, a glacial geologist at the Lamont-Doherty Earth Observatory at Columbia University. He studies the glaciers of Patagonia, a region in southern South America including parts of Argentina and Chile, and maps glacial retreats with cosmogenic dating. 

“Glaciers leave a record on the landscape of where they’ve been,” Kaplan explained, helping scientists to measure their more dramatic retreat in past decades. 

When glaciers retreat, they leave a ring of sediment and rocks called a moraine. An analogy can be made to the rings on a bathtub as the water slowly drains. Scientists measure the ages of those rings using cosmogenic and radiocarbon dating to determine when the glacier advanced and retreated. Mapping out when a glacier advances or retreats gives scientists a good idea of the climate change during a time period. 

“It’s like a proxy for what past climate has done,” Kaplan noted. 

With the knowledge of past climate behavior, scientists can better predict future climate behavior. 

Climate in the Northern Hemisphere of the past thousand years can be described as a “hockey stick,” with temperatures gradually going down, with some fluctuations, into the cool period of the Little Ice Age, roughly 1400 – 1850 AD, and then suddenly shooting up in the last 100 years. 

In the Northern Hemisphere, glaciers have remained relatively small throughout the Holocene, though they spread during the Little Ice Age. 

“In the Southern Hemisphere, in South America – Argentina and Chile – and New Zealand, we don’t see that pattern,” Kaplan said. 

“We see a different pattern.” 

Kaplan found that in Patagonia and Lago Argentino, the period that glaciers stretched to their largest during the Holocene was between 6,000 and 4,000 years ago, not during the Little Ice Age. 

Glaciers advance and retreat on a regular basis, but in the Southern Hemisphere glaciers have retreated farther in each cycle, while in the Northern Hemisphere glaciers have in general steadily advanced. 

John Mercer, a pioneer glacial geologist at Ohio State University, proposed this hypothesis back in 1968. But it wasn’t until the last 10 years that an improved form of dating using an isotope called beryllium-10 allowed scientists to accurately date the glacial changes and confirm the hypothesis. 

Aaron Putnam is one of those scientists and confirmed the hemispheric differences when he studied the Southern Alps of New Zealand. 

In Europe, the Medieval Warm Period allowed Vikings to sail across the Atlantic Ocean and settle in Greenland, while during the Little Ice Age people could safely skate across the River Thames in England. However, the Southern Hemisphere showed a very different picture. 

“[The New Zealand glaciers] were more extensive during Medieval times implying colder conditions, and they were retreating during the Little Ice Age, implying warming conditions,” Putnam said. “This asynchrony seems to go back through the last 10,000 years.” 

Putnam stresses the importance of the evidence that the hemisphere climates haven’t synchronized. “One of the main arguments against the present warming being due to human cause is people think it’s related, it’s just part of the cycle,” Putnam said. 

But with these new findings, scientists see that the natural cycle consists of contrasting climate between the hemispheres – not synchrony. The present trend of simultaneous warming between the hemispheres is a break from observed pattern, and that is what is alarming. 

“We think it’s most likely due to atmospheric CO2 rise,” Putnam concludes. 

But what accounts for this past difference in climate patterns between the hemispheres? 

“That, we’re still trying to figure out,” Kaplan said. 

Scientists are still in the process of collecting data to see what exactly the differences are between the hemispheres. 

Ideas about possible causes include differences in ocean currents and differences in insolation, which is the amount of energy received from the sun. The hemispheres are anti-phase in terms of insolation: because of the tilt of Earth’s axis, when one hemisphere receives more energy from the sun, the other hemisphere receives less. 

The insolation-based theory works well in part. However, it runs into some problems in southern South America. By its predictions, glaciers in the region should have been at their maximum around 10,000 years ago. However, they were at their maximum 6,000-4,000 years ago. 

An influential factor could be that southern South America is much closer to Antarctica, a significant mass of ice, which could exert a significant force on its climate. 

“There are reasons to suspect Antarctic climate to be different than European climate,” Kaplan said. “It’s affected by different natural climate variability, [such as] different ocean processes.” 

With man-induced global warming, it may be that the days of natural climate variability are numbered.


Gretchen Roecker/MEDILL Joerg Schaefer travels far and wide to study climate change and works to reduce his carbon footprint in life every day.
Gretchen Roecker/MEDILL
Joerg Schaefer travels far and wide to study climate change and works to reduce his carbon footprint in life every day.


















by Megan Taylor Morrison
Oct 06, 2011

Top climate scientists such as Richard Alley and Joerg Schaefer share what they do to reduce their carbon footprints. Individual efforts count in the planet-sized challenge of human-influenced global warming.


by Rosa Linand Gretchen Roecker
Oct 06, 2011

China, with one of the world fastest growing economies and skyrocketing energy use, still left a gaping hole in the global climate change map – until recently.

Aaron Putnam, a geoscientist from Columbia University’s Lamont-Doherty Earth Observatory, asked the obvious question: “Why don’t we complete the global compilation and go to Asia?”

Courtesy of Aaron Putnam/University of Maine A tree in the Tarim Basi
Courtesy of Aaron Putnam/University of Maine
A tree in the Tarim Basi

A year ago, Putnam flew to China to scope out the research situation. On a whim, he steered to the Tarim Basin, the vast oval desert nestled between the Tien Shan mountains to the north and the Kunlun range to the south. 

There, in the middle of a sea of sand, he found something unexpected: trees.

And not just any trees – poplars, which thrive in damp regions, near wetlands and rivers, and whose desiccated trunks were rising out of layered silt, a hallmark of lake-beds. 

Curious about when and how the parched land could have been home to water-loving trees, Putnam launched a scientific investigation. With the help of Hai Cheng and his colleagues at Xi’an Jiaotong University in central China’s Shaanxi province, what began as “a boondoggle to central Asia” in summer 2010 grew into a team treasure hunt a year later. 

In their journey through the Taklamakan Desert, Putnam and his sand-combing crew survived sweltering heat, navigated dunes and bureaucratic red tape, and unearthed signs of an ancient wet world.

Putnam added the data from China to research collected pole to pole with the teamwork of climate science greats Wallace Broecker and George Denton. Together, they are filling in a picture of how Earth works. The secrets unearthed in the Chinese desert help scientists understand how the planet responds to climate shifts and what could happen as emissions drive global temperatures up and push precipitation patterns to extremes.

Courtesy of Aaron Putnam/Univ.Maine Map of Tarim Basin.
Courtesy of Aaron Putnam/Univ.Maine
Map of Tarim Basin.


Photo by Gary Comer Icebergs break off and flow through Greenland’s coastal waters. The stunning ice armada comes at a potentially high cost to the island’s disappearing ice sheet.
Photo by Gary Comer
Icebergs break off and flow through Greenland’s coastal waters. The stunning ice armada comes at a potentially high cost to the island’s disappearing ice sheet.

by Gretchen Roecker
Oct 06, 2011

When the late philanthropist and entrepreneur Gary Comer cruised through the Northwest Passage off Greenland’s coast and into the Arctic in 2001, he knew something was wrong. Two weeks earlier, his yacht, Turmoil, had run into an ice barrier about halfway up the coast, a typical obstacle in the normally frozen Northwest Passage. That ice was gone.

“He recognized that even though this was a great adventure, it really meant the Arctic was changing very rapidly, and he wanted to do something about that,” said Philip Conkling, president of the Island Institute in Maine and Comer’s fellow seafarer.

That “something” was pouring energy and money into abrupt climate change research, starting in Greenland. Comer had sold his company, Lands’ End, to Sears in the early 1990s, and dedicated his fortune to supporting science, education and other causes.

“It is one of the premiere places to get histories of climate change,” said geologist Richard Alley of Pennsylvania State University. “There are just these huge wonderful climate records that we can pull out.” 

Pulling out those records lets scientists fill in clues about current climate change. Alley’s work on ice cores extracted from the middle of the island has uncovered natural archives of temperature, measured from air pockets trapped far below the surface in these “time machines,”  as Alley calls them.

Similar ice cores in Antarctica link temperature rise with climbing carbon dioxide levels, which are today almost 25 percent higher than at any point in the past 650,000 years. 

Greenland, the largest island on Earth, is almost entirely quilted in a sheet of ice more than 1,000 miles long, 600 miles wide and two miles thick, built up from millennia of snowfall. The bedrock beneath the frozen layers is secure in the North Atlantic, but according to NASA satellite data the ice sheet blanket is disappearing at a rate of at least 100 billion tons per year – equivalent to a billion blue whales’ worth of mass. That’s twice the rate measured in the mid-1990s.  

Photo by Philip Walsh Greenland’s vast ice sheet covers 90 percent of the island, but is drawing back its margins to as warmer temperatures melt the frozen layer.  Geologist George Denton and author Philip Conkling, who recently published "The Fate of Greenland," stand as specks on the barren bedrock.
Photo by Philip Walsh
Greenland’s vast ice sheet covers 90 percent of the island, but is drawing back its margins to as warmer temperatures melt the frozen layer. Geologist George Denton and author Philip Conkling, who recently published “The Fate of Greenland,” stand as specks on the barren bedrock.

“A lot of people are worried about changes in the Greenland ice sheet,” said Meredith Kelly, a Dartmouth College geoscientist and Comer fellow, because it holds enough fresh water to raise sea level worldwide by at least six meters, or about 20 feet, if it melts. “That would inundate a lot of people living along coastlines and cause a lot of massive changes for civilizations and for people to deal with.”

Following Comer’s alarmingly easy passage to the Arctic Ocean, Comer and Conkling connected with renowned geoscientist Wallace Broecker, of Columbia University’s Lamont-Doherty Earth Observatory. By 2002, the three men joined Alley, University of Maine geologist George Denton and a crew of climate scientists on Turmoil, bound for east Greenland. 

Today, with support from the Comer Science and Education Foundation, some of those same scientists are scrambling to study clues revealed at the sheet margins as the ice melts in search of historical context for how and why Greenland’s ice sheet is slipping into the sea.

Why Greenland?

Long before Comer offered his ship as a research vessel, Broecker, Alley and other paleoclimatologists studied fingerprints of Earth’s climate history in Greenland’s frozen landscape. They looked for traces of  how and why the planet has periodically fluctuated from warm to cool, wet to dry, inhabitable to habitable.

Photo courtesy of Thomas Lowell Scientists Thomas Lowell, Brenda Hall and Meredith Kelly study west Greenland’s ice caps, the frozen domes perched on plateaus. Ice caps tower over the humans who hunt for climate clues at their edges, but are dwarfed by the vast ice sheet. Because of their relatively small size, ice caps offer more manageable research sites for scientists trying to learn about past and present climate changes.
Photo courtesy of Thomas Lowell
Scientists Thomas Lowell, Brenda Hall and Meredith Kelly study west Greenland’s ice caps, the frozen domes perched on plateaus. Ice caps tower over the humans who hunt for climate clues at their edges, but are dwarfed by the vast ice sheet. Because of their relatively small size, ice caps offer more manageable research sites for scientists trying to learn about past and present climate changes.

Evidence of sudden past temperature shifts in ice cores drilled in Greenland in the 1960s sparked Broecker’s seminal “conveyor belt” theory of thermohaline circulation in the ocean. The “conveyor belt” refers to the cycle where cold water heavy with salt sinks in the North Atlantic near Greenland and flows southward toward Antarctica, while warm Gulf Stream water moves northward along the surface, eventually cooling and sinking as it loses heat to the air. The flow brings climate signals between the poles.

“That blew my mind,” Broecker said. “Thinking about how those events happened got me onto the whole conveyor belt thing.”

Greenland’s unique features have been a gold mine for other researchers in the decades since Broecker’s brainstorm. 

“It’s the big cold ice sheets” that make Greenland an excellent location for climate research, Alley said, because they provide a range of useful records not captured from smaller glaciers. “We can do a really good job of learning the history of atmospheric composition, we can learn the history of snowfall, we can learn the history of temperature.” 

Ice cap canaries

While Alley’s ice cores show conditions at the center of the island, the edges of those “big cold ice sheets” intrigue climate scientists because they advance and retreat with even slight temperature shifts.

Geologists Brenda Hall of the University of Maine and Thomas Lowell of the University of Cincinnati have returned to Greenland five times since their first trip funded by Comer in 2002. Since that initial journey, they have fast-forwarded their focus to the Holocene, the current interglacial during which human civilizations have risen, fallen and spread across the continents.

Gretchen Roecker/MEDILL Meredith Kelly, of Dartmouth College, presents her research on lakebeds near the west Greenland ice caps. Kelly uses radiocarbon dating techniques to find out how the ice caps – and the ice sheet – have grown and shrunk in response to changing conditions.
Gretchen Roecker/MEDILL
Meredith Kelly, of Dartmouth College, presents her research on lakebeds near the west Greenland ice caps. Kelly uses radiocarbon dating techniques to find out how the ice caps – and the ice sheet – have grown and shrunk in response to changing conditions.

Along with Kelly, Hall and Lowell are documenting how eastern Greenland’s ice has grown and shrunk over the 10,000-year period since the last major glacial period, when ice covered much of North America, Europe and Asia. Rather than studying the massive ice sheet that drapes most of the island, they focus on the smaller domed ice caps that dot Greenland’s plateaus. 

“We’re working on the ice caps in part because they’re easier to work on, but our premise is that the ice caps are recording the same climate that the ice sheet is recording,” Hall said.

Using the small ice caps as proxies for the larger ice sheet provides information not available from other records about how the ice reacts to temperature shifts, Kelly said.

“The ice core records tell us a ton of information about what’s going on in the atmosphere,” Kelly said, “but they don’t tell us how the margin of the ice sheet is responding to warmings or coolings.”

In order to track those responses across thousands of years, Lowell, Hall and Kelly are chasing the retreating ice caps, which melt away to reveal evidence of life from earlier periods.

“Because these glaciers are in a retracted position,” Lowell said, “we see all kinds of weird things along the glacial margins.” Since 2005, Lowell has identified at least 16 species preserved by the ice, from sedges and trees to lemming droppings.

Photo courtesy of Thomas Lowell Thomas Lowell scours ice cap margins for organic materials, such as leaves and wood, uncovered by the retreating glaciers.
Photo courtesy of Thomas Lowell
Thomas Lowell scours ice cap margins for organic materials, such as leaves and wood, uncovered by the retreating glaciers.

While Lowell collects organic samples preserved in the margins of the shrinking caps, Hall and Kelly drill into nearby lakebeds to suck out tubes of sediment. They analyze the layers and fish for seeds, leaves and insects trapped in the mud. They use radiocarbon dating methods to figure out approximately how long ago each sample was buried by the ice.

The retreating ice gives them unique access to information on glacial behavior, Hall said. Over the past five years their records have grown as the melting caps uncover more materials. But the unhealthy ice caps also signal rapid changes in the ice sheet whose impacts that could spill out across the globe.

“They’re the canaries,” Lowell said. Like the songbirds whose deaths once warned miners of toxic gases leaking below ground, the ice caps’ watery demises signal conditions that could be fatal for the larger ice sheet.

Lowell and Hall said they can’t predict how human actions ultimately will influence natural climate shifts, but that their records help others model what is likely to lie a few years or centuries ahead.

“Our work better documents how things looked in the past,” Lowell said, so that “the projections for the future are more refined.”

Projections aren’t necessary to see that Greenland’s ice is disappearing. Lowell, Hall and Kelly simply watch the ice caps shrinking away from year to year. Conkling, who recently helped Broecker, Alley and Denton write “The Fate of Greenland,” an account of their trips on Turmoil and their work on the island, said he and Comer witnessed the powerful melt.

“Every 10 minutes an enormous wall of ice would just go into the water,” Conkling said. “There were dying glaciers everywhere we went. You couldn’t say that climate change isn’t happening.”

Though Greenland’s ice sheet isn’t likely to collapse into the ocean abruptly, Alley said, warming temperatures will spur more melting – common estimates from recent studies indicate that Greenland could contribute to at least a three-foot increase in sea level this century. The thawing margins add fresh water to the ocean that directly raises sea levels and could alter ocean circulation, eventually impacting the southern hemisphere and factors from carbon dioxide levels to fish populations.

“It’s a tremendous player in climate future,” Alley said.

Keys to the future revealed in the past

Preliminary results show that Greenland’s ice has been a big climate player throughout time, with evidence for advances and retreats that might correspond to bumps in the relatively stable Holocene climate. Lowell’s samples suggest a rapid thawing at the end of the last glacial period about 11,000 years ago that left the area almost ice-free.

Hall’s lake records show that at least one ice cap was smaller than its present size in from about 10,000 to 1,000 years ago AD, through middle of the Medieval Warm Period, a few centuries marked by slightly higher average temperatures in the North Atlantic when Norse sailed from Europe to settle in Greenland. She also found evidence for an ice advance between 1000 and 1150 AD, marking the onset of the “Little Ice Age,” the common name for a cold period spurred by a small temperature drop in the north that might have contributed to the decline of those settlements.  

“It’s important to understand natural variability because these natural climate changes in the Holocene are relatively small,” Hall said. Those relatively small ups and downs in precipitation and temperature can generate big changes in what the planet looks like. 

The approximately 6 degrees Celsius (10.8 F) warming that ended the last major ice age and the much smaller changes that marked the Medieval Warming and Little Ice Age might seem like tiny temperature shifts. But Hall said the obvious impact of slight changes not only on ice caps but also on living populations underlies her research.

“History shows us the effect that 1 degree Celsius can actually have on civilizations,” Hall said. “We really need to have a better understanding of what causes these natural climate changes, in order to have an understanding of whether or not we might trigger one of these inadvertently in the future.”

Global temperatures are already rising rapidly compared to past, natural shifts. According to NASA, the planet has warmed about 1.5 F since the burst of fossil fuel-burning industrialization in the late 1880s. While human-induced warming in the Arctic isn’t yet extreme, that could change if heat-trapping carbon emissions aren’t significantly reduced: estimates for additional temperature rise through 2100 under a “business-as-usual” scenario range from about 3 to 15 F, according to Alley’s book, “Earth: The Operator’s Manual.”

Studying patterns in how ice in the northern hemisphere has responded to the Holocene’s temperature swings, Kelly said, provides information about how climate changes naturally – and how projected extra warming could amplify that process. 

“It gives us a natural baseline for how climate has changed in the past,” Kelly said, “and it also enables us, when we put together these global records from Greenland to the Swiss Alps to New Zealand, to try to understand the mechanisms that cause climate change.”

For example, Kelly said, she and fellow scientists have observed that a cooling period caused glacial growth about 3,000 years ago in Greenland, Europe, Peru and New Zealand. That similarity could point to something influencing climate in both hemispheres, like a change in Broecker’s conveyor belt or in atmospheric circulation, she said.  

Carrying on a legacy

The retreating small ice caps offer a “window of opportunity” to study climate history, Lowell said. And while those canaries of climate change could disappear without greatly affecting sea level or climate mechanisms, they act as heralds for much larger consequences of warming.

“The ice caps could melt and nobody would notice,” Hall said. “But they are very sensitive climate indicators, and the records we get from that can help us really understand the ice sheet, which is the big player.”

A decade after Comer’s sail through a strikingly ice-free Northwest Passage, members of his research crew still hold their positions as human players in Earth’s climate future. Comer’s daughter, Stephanie, who was on that legendary Turmoil voyage, and his son, Guy, are carrying on their father’s legacy by continuing to support climate researchers through his foundation. 

Hall, Lowell and Kelly don’t know what lies in Earth’s future, but by tracing the hidden histories revealed by melting ice caps, they are revealing a sensitive, interconnected planet whose climate and conditions can hinge on a few degrees of warming or cooling.


NASA Droughts and floods linked to global warming threaten  every continent,  according to U.N.'s climate envoy.
Droughts and floods linked to global warming threaten every continent, according to U.N.’s climate envoy.

by Gretchen Roecker
Oct 04, 2011

U.N. special envoy on climate change Dr. Gro Harlem Brundtland and her 22-person international commission started warning countries to avert global warming in 1987. Twenty-five years later, the former Norwegian prime minister said the ongoing lack of international cooperation to curb carbon emissions and invest in clean energy threatens us all.

Already, drought, hunger and disease connected to rising temperatures jeopardize “our common future,” she told a large audience at the University of Illinois at Chicago.

International investment in clean energy is crucial for putting people and the planet on track for a viable future, according to Brundtland, a world leader on global warming and human health. But sluggish national and global talks on climate change strategies means scenarios for severe consequences of fossil fuel-driven temperature rise etch a hazardous path for the world’s growing population.

“In the U.S. the debate has been much more divisive,” than in Europe, Brundtland said. “Based on the scientific evidence, questioning the human link to climate change ought to be history by now, but it’s not.”

Changing the politically divisive climate isn’t up to the politicians alone, Brundtland added, and people need to use their voting power to convince leaders to take action on an international scale.

“Many challenges of sustainable development can be solved within sectors, within countries – but not climate change,” Brundtland said. “We are all victimized, nobody can hide from it. ”

Linked problems, linked solutions

Climate change is directly tied to another of the most pressing global problems the world faces today – poverty, said Brundtland, former head of the World Health Organization.

About 70 percent of people in the developing world depend on agriculture, but the droughts and floods projected to increase with warming could threaten their livelihoods. At the same time, as countries industrialize, their energy demands climb. If fossil fuel-burning plants remain the cheapest, easiest option, the carbon emissions from these countries will soar.

Increasing both energy efficiency and use of renewable resources such as wind and solar power lie at the heart of a strategy to reduce emissions that could spur economic development where it is most needed, Brundtland said.

Energy innovation can benefit rich and poor countries alike.

“Clean energy projects will transfer technology to the developing world and will lead to substantial financial flows to developing countries,” she said, by allowing them to harness available sunlight and wind and supply energy needed for economic growth.

Reducing the world’s carbon footprint can’t rely on a handful of forward-thinking countries, Brundtland said. Heat trapped by carbon pumped out of coal-fired power plants in Illinois doesn’t warm only the Midwest. Expanding deserts inland and sea level rise on the coasts won’t respect geopolitical boundaries.

A common future

“What kind of world could we live in if we don’t take action?”

That question posed by Alexander Esche, a 23-year-old UIC chemical engineering graduate student, galvanized the urgency of Brundtland’s call to action to halt human-induced climate change.

“We have a number of very dangerous trends that are increasing,” Brundtland said, such as those visible in the poles’ rapidly melting ice caps, where fresh water is streaming into the oceans and sunlight normally reflected off snowy surfaces is being absorbed as heat, amplifying worldwide warming. “We are seeing the sea level increasing, so island states could be flooded over.”

UIC’s Institute for Environmental Science and Policy sponsored Brundtland’s talk on “Our Common Future: Sustainable Development in a Deteriorating World.”

More than 250 people packed the UIC conference rooms to hear her assessment of how to address the dual climate challenges of economic and environmental threats. The public lecture drew students, local environmental leaders and a number of Norwegian Americans, including Chicago attorney Paul Anderson, the honorary consul general of Norway for Illinois.

“It’s not every day we get one of the most famous Norwegians visiting Chicago,” Anderson said. “She’s such a dynamic force.” 

Brundtland served as Norway’s first female and youngest prime minister for 10 years. She directed the World Health Organization from 1998 to 2005. She was the driving force behind the U.N.’s Brundtland Commission, the 22-person group that defined challenges and strategies for sustainable development in its 1987 “Our Common Future” report.

Twenty-five years after “Our Common Future,” many of those challenges remain, Brundtland said.

“We warned about global warming, about desertification, forest degradation, scarcity of water and clean energy,” Brundtland said. “Trends today are still unsustainable. The climate threat is real and urgent.”

Changing the climate conversation

For Thomas Theis, the director of IESP, bringing Brundtland’s perspective to Chicago was a way to encourage discussion on a critical issue.

“We sponsor events like this to get the conversation going,” Theis said.

Brundtland stoked that conversation at UIC just two days before the final talks preparing for this winter’s U.N. Convention on Climate Change in South Africa, where member states will determine the fate of the expiring 1997 Kyoto Protocol. The protocol established an international emissions-reduction pact that the U.S. never ratified.

Denial of human-caused climate change and reluctance to put a price on carbon in the U.S. choke progress toward emission reductions and a clean energy economy, Brundtland said.

“We need to get involved in the political discussion, instead of just responding to it,” Theis said. “The issue of climate change is an important one, and it’s not going to go away 20 years down the road.”

Think locally, act globally

In order to spur international action, Brundtland said, it might be time to flip-flop the popular slogan “think globally, act locally” that has long girded sustainable development efforts.

Acting globally doesn’t mean ignoring opportunities to make individual cities more environmentally and economically sustainable, she said. Changes made on a local level, such as those envisioned by the Chicago Climate Action Plan, can help cool the global greenhouse.

“What you decide to do in this city determines the future: the city life, its parks, roads and transportation systems, its opportunities, its livelihoods,” she said.

The Chicago plan’s strategies include encouraging biking and walking, reducing air pollution and investing in solar and wind technology, all of which could benefit human, environmental and economic health.

“It’s a very ambitious plan, and it will be huge if it’s achieved,” Theis said. “It absolutely fits in the idea of sustainable development – it demands major reductions, but it’s holistic, because it looks at the health of citizens and of the city at the same time.”

Yet no single city can substitute for imperative global action, Brundtland said.

“There is no alternative to continue building the moral and the scientific basis for taking more shared responsibility across nations and continents,” Brundtland said. “It is up to each and every one of us to do our part in making that happen.”


by Kristofor Hustedand Michelle M. Schaefer
Mar 17, 2011

Whoop! There it is.  

Whooping cranes, silvery-blue butterflies and Blanding’s turtles are just a few of the species who could preserve their habitat in the proposed national wildlife refuge straddling five counties in Wisconsin and Illinois. The refuge area harbors native habitats necessary for the survival of nearly 110 threatened or endangered plant and animal species.

Kristofor Husted and Michelle Schaefer/MEDILL Of the 350,000 acres spread across five counties in Illinois and Wisconsin, about 23,000 are already protected at regional, state and private levels. Up to 30,000 acres may potentially be federally protected should the U.S. Fish and Wildlife Service’s preferred course of action deem so.
Kristofor Husted and Michelle Schaefer/MEDILL
Of the 350,000 acres spread across five counties in Illinois and Wisconsin, about 23,000 are already protected at regional, state and private levels. Up to 30,000 acres may potentially be federally protected should the U.S. Fish and Wildlife Service’s preferred course of action deem so.

The area—dubbed Hackmatack—is the landing ground for the whooping crane, an endangered species and a major reason some people are calling for federal protection. Only about 400 exist in the wild today.

The U.S. Fish and Wildlife Service is currently surveying about 350,000 acres spread across McHenry and Lake counties in Illinois and Walworth, Kenosha and Racine counties in Wisconsin. 

About 23,000 of those acres encompass land already protected at regional, state and private levels. The refuge is ultimately expected to encompass an additional 10,000 to 30,000 acres.

The entire survey area covers several towns, farmland and private property, an area known as Hackmatack based on the Algonquin name for the indigenous taramack tree. 

“The refuge system celebrated its 100th anniversary in 2003,” said Friends of Hackmatack member Cindy Skrukrud, of McHenry County. “And at that time they said, ‘Oh, there’s a wildlife refuge within an hour’s drive of every major metropolitan area.’ Well, that’s probably true for Madison and Milwaukee but it’s not true for Chicago. 

Courtesy of U.S. Fish and Wildlife Service. Map of the 350,000 acre Hackmatack study area.
Courtesy of U.S. Fish and Wildlife Service.
Map of the 350,000 acre Hackmatack study area.

“I mean the closest refuges now are Horicon up in [northern] Wisconsin and then the Savannah District of the Mississippi River Fish and Wildlife Area. And both of those are 150 miles from Chicago. So we’d certainly be the refuge in Chicago’s own backyard,” she said. 

For the land to gain federal protection, the wildlife service must put together a formal recommendation specifying the acreage to be protected in different locations.

“The basic premise is to look at the lands within the study area and see how they will best fit within the objectives set forth in the preliminary project proposal,” stated wildlife service biologist Gabriel DeAlessio. “We are using land cover data, potential natural vegetation data (derived from soils data), hydrology, housing growth predictions, other conservation lands and a few other data sets.”

The primary project proposal identifies several species that require large blocks of grasslands and wetlands, according to DeAlessio. By using those species requirements as guidelines, he can try to identify the existing blocks of these natural ecosystems and the potentially restorable blocks of them. 

“Under this scenario, we may seek to restore and protect larger acreages with limited woody vegetation,” he stated.

Perhaps the most recognizable endangered animal under the study scope is the whooping crane. These birds migrate from the Necedah National Wildlife Refuge in Wisconsin all the way to Florida, according to wildlife biologist and conservation planner Gary Muehlenhardt of the Fish and Wildlife Service.

Kristofor Husted/MEDILL The lands in the proposed Hackmatack refuge area include streams, wetlands, grasslands and prairies and 110 threatened or endangered plants and animals.
Kristofor Husted/MEDILL
The lands in the proposed Hackmatack refuge area include streams, wetlands, grasslands and prairies and 110 threatened or endangered plants and animals.

Operation Migration leads the whooping cranes on their migration with an ultralight aircraft. The tallest birds in North America use the wetlands as a pit stop on their thousand-mile migration.

“The proposed area encompasses a lot of wetlands and the whooping cranes need the wetlands for summering and for staging areas along migration route,” said Heather Ray, representative for Operation Migration.

Restoring the wetlands provides the cranes a place to refuel on frogs and dragon fly larvae as well as a spot to rest. In the summer, these birds use the wetlands to nest.

Another possible scenario would be to designate the newly protected land in between several of the already regionally protected land sites. This would connect the sites into larger, continuous areas instead of the isolated pockets of protected land currently located throughout study zone.

Once the U.S. Fish and Wildlife Service submits its recommendations – Muehlenhardt said he hopes to have those finished by summer – the public will have a chance to comment. People can voice their comments in writing or at one of the public meetings the wildlife service will hold to present its findings.

In October 2010, the wildlife service held two open houses in Illinois and two in Wisconsin on the proposed refuge that would be called the Hackmatack National Wildlife Refuge. More than 500 people attended these meetings and about 80 percent of the attendees expressed overwhelming support for the conservation plans, according to Lenore Beyer-Clow, policy director for Openlands, a nonprofit land-conservation group in the Chicago area.

Friends of Hackmatack, which includes the support Openlands, the Sierra Club and other conservation groups, originally proposed the refuge.

Other supporters saw it as a draw for recreational use and tourism, Muehlenhardt said.

Some landowners in the area had concerns about regulatory oversight, though. 

“We told them just because we’re drawing lines on a map, it doesn’t mean there’s any more restrictions on that land,” he said.

After the public comment period, Muehlenhardt’s team will make any changes deemed necessary and submit it to the regional director. If approved, the next step is a review in Washington, D.C. 

The refuge could involve purchasing land, acquiring easements and working with partners and individual landowners.

“I’m hoping that if it gets that far, all that support down there will translate into funds [for the refuge],” Muehlenhardt said. Local sponsors will be expected to raise funds  to purchase lands and easements. 

“It would be great to have an additional partner in this area working on land conservation too,” Skrukrud said. “We’ve got that at the state level. We’ve got it at the county level. We have the park district level. 

“Some of these parcels here are owned by people who just put conservation easements on their own private land. But by having a national wildlife refuge in this area, then we would also be protecting the land at the federal level.”

Related Links

U.S. Fish and Wildlife ServiceFriends of HackmatackOperation Migration

Did you know?

“Hackmatack” is the Algonquin Indian word for the tamarack tree.


by Tyler Moss, Lindsey Valichand Jennifer Wholey
Mar 17, 201

“Food is power.”

Michigan farmer and livestock producer Nate Robinson has known this for years.

Tyler Moss/MEDILL  Illinois corn production in 2009, including locations of ethanol plants across the state.
Tyler Moss/MEDILL
Illinois corn production in 2009, including locations of ethanol plants across the state.

Rising food costs impact every person in every country across the globe, diminishing the ability of millions of families to meet other essential needs. Increasing floods and drought due to global warming is expected to push food prices higher yet—it’s happening already.

Robinson is feeling these effects both at his farm in Cassopolis, Mich., and at the grocery store. He finds himself taking a lower margin, despite the fact that he is forced to raise prices as food production becomes more expensive.

“Unfortunately, the consumer ultimately will pay for this rising cost. Everyone has to eat,” Robinson said. “We go to the grocery store as a family and when we do, we’re a little bit in sticker-shock.”

America is particularly vulnerable to the toll climate change can take on food. 

The U.S. is the largest producer of corn in the world, generating more than 10 million of the world’s nearly 23 million bushels of corn in 2000, the most recent statistic from the National Corn Growers Association. Experts say our country must be poised to take on a larger burden of worldwide food supply as crop yields of rice and corn in the tropics drop by an estimated 20 to 40 percent due to climate change. 

The issue

Although the causes for rising food prices are numerous, “global climate destabilization” (as the experts prefer to call it) is playing a significant role.

Lindsey Valich/MEDILL
Lindsey Valich/MEDILL

Many of the world’s agricultural hubs have been hit with massive flooding, in places as far flung as the Midwest and Bangladesh. While some skeptics are convinced this is just part of the Earth’s natural weather cycles, changes marked over time have convinced many that climate change is responsible for the erratic weather.

If that is the case, it will only get worse over time as farmers face unpredictable growing seasons and unexpected weather patterns.

The global ability to feed the growing population is a product of the Green Revolution, said Lewis Ziska, plant psychologist with the USDA’s Agricultural Research Service in Beltsville, Md. The Green Revolution is a term used to describe the development of semi-dwarf cereal varieties in the 1950s and 1960s that could grow with less fertilizer and water.

“The result was a doubling or tripling of cereal production,” Ziska said. “Cereals, particularly corn, wheat and rice, are the foods that feed the world.”

There is no question that weather plays a significant role in food production, said Jeff Andresen, geologist and researcher of agricultural meteorology and applied climatology at Michigan State University in East Lansing. 

“Weather, and its longer term climate, are the most important, uncontrollable variables in food production,” said Andresen, who is also the state climatologist for Michigan.

Lindsey Valich/MEDILL
Lindsey Valich/MEDILL

While climate change at present is often thought of in terms of rising global temperatures, it also encompasses erratic weather patterns.

“There is some suggestion that the frequency and magnitude of extremes might increase,” Andresen said. “It is a major fear because these extremes have a disproportionately high impact on food production.”

Iowa, for instance, has experienced two so-called 500-year floods in a period of 15 years—one in 1993 and one in 2008. A 500-year flood is one with a probability of occurring once every 500 years in any given year.

Developed countries have farms thousands of acres large, typically of only one or two varieties of cereal, Ziska said.

“Essentially these farms are monoculture,” he said, “and do not have the biological diversity to adapt well to extreme events.”

Farmers have the ability to adjust to increasing temperatures because it is something they can anticipate from year to year, Andresen said. Changes in extreme weather variability, such as flooding, are much more difficult to handle because major storms are unpredictable.

Lindsey Valich/MEDILL Climate change affects production of the top three crops in the U.S.--corn, soybeans and wheat.
Lindsey Valich/MEDILL
Climate change affects production of the top three crops in the U.S.–corn, soybeans and wheat.

Effects of climate change cover direct impacts and indirect impacts, he said.

Direct impacts consist of mass flooding, droughts and other extreme weather events that are directly linked to the changing climate. Indirect impacts are associated changes that will cause problems further down the line, such as the prevalence of mold because of moist crop stocks, or insects living year round because of higher temperatures.

Direct impacts 

Carbon dioxide is the thermostat for climate change. As levels rise in the atmosphere, so do temperatures, a phenomena documented in hundreds of thousands of years of data from ancient air pockets trapped in ice cores from places such as Antartica and Greenland. At 390 parts per million, carbon dioxide levels are higher now than they have been in more than 600,000 years. 

As carbon dioxide and other greenhouse gases continue to be pumped into the Earth’s atmosphere, erratic weather patterns that disrupt global agriculture are becoming more and more frequent, said Steve Kolmes, director of environmental studies at the University of Portland in Oregon. And as the atmosphere continues to warm, major storms will become even more forceful.

In 2010, Russia banned all exports of grain after millions of acres of their wheat supply was destroyed in a severe drought. Floods in countries such as Bangladesh and Australia are current examples sever weather, Kolmes said. 

“In the last year, the Bangladeshi floods submerged something like a quarter of the country,” he said. “And the cyclone that just went through Australia took out much of the banana crop.”

Kolmes prefers the term “global climactic destabilization” to global warming.

That is because the term global warming can be misleading, as impacts will differ in different parts of the world. For instance, in some places sea level shifts are causing inundation, he said, and even temporary inundation can damage a crop. In other places, increased temperatures can destroy yields as soil loses moisture due to evaporation.

“An example is rice,” Kolmes said. “The yields of rice plants drop badly when the nights stay warmer. The projections are that the tropical crops of rice and corn are going to drop in their yields maybe 20 to 40 percent.”

The logical conclusion is that, as weather makes food production more difficult, prices will rise and global hunger will become an even more serious issue.

“We developed an agriculture based on a very long, stable climate,” he said. “And it appears, at least for the foreseeable future, that we’ve disrupted that appreciably.”

Indirect impacts

One example of an indirect impact of climate destabilization can be seen in Michigan’s fruit trees.

“Public enemy number one for apple growers is the apple cobbler moth,” Andresen said. “It lays eggs on apples. When the egg hatches, the larvae eat through a wormhole in the apple and the apple becomes unsellable.”

Apple cobbler moths are cold blooded, Andresen said, meaning their survival is dependent on temperature. Moths are already surviving through warmer winters. If temperatures warm as projected, there will be extra generations of the moths surviving through the growing season, making the insect much more difficult for farmers to control.

The example illustrates how as the planet continues to heat up, insects will be able to live through the colder seasons, thus having the potential to damage agriculture.

Another indirect impact of climate change is on food security, said Ewen Todd, a retailing expert and professor at Michigan State.

A study by the European Environment Agency in Copenhagen in October 2008 found a link between increased global temperature and outbreaks of salmonella in Europe. As temperature went up, so did the number of cases. Although the specific reason for why this is occurring is currently unknown, Todd said, the correlation is clear.

The issues pose danger here in the U.S. as well.

One of the major food security concerns is the heating of oceans and other bodies of water, he said. Vibrio, a type of bacteria responsible for foodborne illness, grow in warm water.

“Vibrio include cholera, but that’s not a major pathogen for North America,” Todd said. “There is another one called parahaemolyticus that is probably in the water all over the place, but needs high temperatures to grow into large numbers.”

Another food security issue stemming from climate change is the increased prevalence of toxic fungi or mycotoxins as a result of mass flooding, he said. These molds can grow in crops like wheat, cotton and corn.

“The big one is called asatoxin,” Todd said. “People can spray for this, but in some countries that’s not feasible.”

Small amounts of asatoxin will only make people sick when consumed repeatedly over many years, he said. Yet countries such as the U.K. restrict crop imports with even small traces of the toxin from going into circulation. If flooding and droughts produce more mold in Africa’s poorer nations where farmers cannot afford to eradicate it, then those farmers will no longer be able to sell their crops.

“It’s a trade issue,” Todd said. “It means that some of these African countries can’t export, so [the mold] is a barrier.”

In some cases, crops in Africa have been stored under moist conditions ideal for the growth of mold, he said. People who eat these plants get acutely sick, resulting in future problems such as kidney damage.

“You have this extreme situation where people don’t like to eat them,” Todd said. “But they’re under starvation conditions and they have to.”

As the planet heats up and bodies of water continue to evaporate, more moisture hangs in the air, he said. With more moisture in the air, mold growth is more extensive. Erratic weather conditions will stress the plant, making it more susceptible to mold penetration. Mold spores could start to grow under these moist conditions, and during metabolism growing would produce the toxin.

“We think mycotoxins are well established in global climate change,” Todd said. “We think they will be a major factor.”


Making agriculture more efficient and productive is one of the best ways to combat the food crisis resulting from climate change, Andresen said. Though they are highly controversial, one of the possible solutions is the continued proliferation of GMOs, or genetically modified organisms.

“Production efficiency and GMOs – those are two issues linked to one another,” he said. “A lot of the food that is produced never makes it to a table or plate. It gets lost because of substandard harvest practices or pests. That could be improved globally if we were able to prevent some of the losses that regularly occur.”

The genes of crops such as corn and wheat could be modified to be less susceptible to environmental factors like insects, mold or harsh weather conditions. Robinson uses GM cold tolerant seed at his farm in Michigan to extend the growing season.

“I’ve already asked for the cold tolerance seed to come in so I can plant it when it’s a little colder,” he said. “It’ll sit there and wait ’till the temperature gets right and not rot.”

Despite the misgivings of those on the organic and all-natural bandwagon, many farmers do not see GMOs as any sort of mad science, Robinson said. To them, it is just a tool to combat changes in weather. 


Perhaps one of the most controversial potential solutions to combate climate change is biofuel.

While some praise it as the miracle cure to reduce petroleum use—one of the biggest contributors to global climactic destabilization—others argue that biofuels are responsible for just as much greenhouse gas, if not more. 

Research has shown that biofuels burn cleaner than petroleum. But experts worry about the carbon footprint of using agricultural land to produce crops for biofuels. Furthermore, increased production of biofuels means more corn is grown for ethanol instead of for food.

“As countries are trying to do something about their carbon emissions, they’re going to biofuels a lot, and the biofuels are largely being diverted from food crops,” said Steve Kolmes, professor of biology and environmental studies at the University of Portland in Oregon.

So while many farmers continue to grow corn, it just never enters the food chain, Kolmes said. As biofuel use continues and soybeans get turned in biodiesel, corn gets turned into ethanol, food prices will go up and food availability will go down.

“One of the basic principals of economics is that when you increase the demand of something you increase the price,” said Tim Searchinger, research scholar at Princeton University. “It’s the growth in demand rather than a shortage in supply that is the key cause of the food crisis right now.”

The U.S. is the world’s largest producer of corn, and 80 percent of corn produced in the U.S. is used to feed livestock, poultry, and for fish production all over the world, according to a 2009 report by the Environmental Protection Agency.

The demand for corn and grain has roughly doubled since 2004, according to Searchinger, who said this is mostly because of an increased demand for biofuels.

“The biofuels have not quite doubled the rate of growth and that’s the single biggest factor keeping things out of balance,” he said.

Because biofuel, unlike weather, is something we can control, Searchinger said we must work to make biofuel production more efficient.

“It’s not that we don’t have enough land to produce biofuels—we do,” said Bruce Dale, chemical engineer at Michigan State University. “It’s more a matter of choosing good systems and getting started on those so that over time those can be more dominant.”

There are right ways and wrong ways to produce biofuels, according to Dale. Double cropping—growing a second crop on the same land after the first crop is harvested—is one option. This may include planting grasses or legumes in the winter following the summer harvest of corn and soybeans. These crops could be used solely for biofuels rather than human food consumption.

“It’s more the efficiency with which we use land,” Dale said. “If we would just start growing double crops on our corn land we would impact the quality of soil, we would reduce green house gases and it would provide a lot of plant material for production in biofuels.”

Another option Dale suggested is making biofuel out of the non-edible parts of the plant, such as the leaves or the cellulose in corn stalks.

“If we can make biofuel by digesting the cellulose in corn stalks, we could have both the food and the fuel crop,” Kolmes said. “So there are technical fixes that might make biofuels have a much more neutral impact on the food supply.”

The issue clearly requires more research – and soon.

“We need to invest in agriculture research and infrastructure,” Ziska said. “And we needed to do it yesterday.”

The future

Projections by climate modelers in the past generally showed that by 2100, things are going to be bad, Kolmes said.

The problem is that everything is happening much faster than the models predicted. Even the most pessimistic of the climate models is being outstripped by the rate of change.

“It’s really hard to get out your crystal ball on this one,” he said.

While certain aspects of the issue might be foggy, the ultimate prescription is not: food shortages will result in higher food prices.

If, in fact, climate change will interfere with global agriculture as predicted, then action needs to be taken quickly. Research and development must become a priority, Andresen said.

Governments need to put aside their developmental differences and realize this is a global issue, Todd said. Climate change will affect people everywhere. Hunger and starvation are tangible concerns. An international strategy is imperative.

When asked what the future holds for climactic destabilization and rising food prices, Kolmes laughed sadly.

“I mean, it snowed in San Francisco,” Kolmes said, an unusual result of increasing evaporation of ocean water. “The rules of predictability were predicated on an atmosphere that we have changed. So instability, I’m afraid, is the new norm.”


Photo by Gary Comer Water from melting glacier in Greenland.
Photo by Gary Comer
Water from melting glacier in Greenland.

by Mike DiFerdinando
Oct 11, 2011

With increasing temperatures on Earth, glaciers melt and ocean levels rise ever more rapidly, claiming coasts and causing floods. But global warming will have other serious impacts on the planet’s water resources.

“A lot of these mountainous areas, including the western United States, the water resources used by the general population are largely glacial fed. Or they’re in mountain reservoirs,” said Brent Goehring, a climate scientist at Purdue University and participant in the 2011 Comer Conference on abrupt climate change. “You can kind of think of the glaciers as a natural meter reservoir. It accumulates water during the winter, and then during the summer when it melts, it lets it out at a nice consistent rate.”

While the same amount of fresh water overall may be available in a given year in the absence of glaciers, the way it comes out of the systems will different. 

“If it’s just snow and there aren’t any glaciers, per say, it’s going to come out really fast in the spring or the early summer and there wont be any water for the late summer. And the later summer is really when you need water, especially for growing produce.”

Goehring said that a more serious threat might come in the peak of summer when there may no longer be enough fresh water to drink for some populations. This has already begun in places like the Andes where melting glaciers threaten the water supply of a developing region. 

The disappearance of glaciers may also put a dent in the amount of clean energy resources we have. Not only are glaciers providing water for consumption, but they also provide a steady stream of hydroelectric power. This is especially true of countries like Switzerland and Norway that rely heavily on hydroelectric power.

“The glaciers are accumulating snow and ice, and then during the summer when some areas of southern Europe need all this energy for air conditioning, the glaciers melt and all this sub-glacial water is diverted into a tunnel and it goes through a hydroelectric power plant,” Goehring said. 

Another less publicized result of melting glaciers is the economic impact on tourism, especially the Alps in Switzerland and surrounding countries whose economies rely on the income they provide.  According to the World Trade Organization, tourists spent $17.1 billion in Switzerland in 2008 and the industry accounts for 4.4 percent of the Swiss workforce.

“You’re still going to have tourists going there for the beautiful mountains but you’re not going to have this classic Matterhorn scene with glaciers in the background and Heidi yodeling,” Goehring said.

“The sad truth is that as long as people argue about (whether there’s a climate problem) it’s kind of a fiddling while Rome burns,” said Toby Koffman, a climate scientist at the University of Maine. “We’ll see in years and maybe decades to come that it was a mistake to delay action on reducing greenhouse gas emissions.”

Medill School Of Journalism, Media, Integrated Marketing Communications
1845 Sheridan Road, Evanston, IL 60208-2101 © 2020 Northwestern University