Greenland is on track to lose ice faster than in any century over the last 12,000 years, study finds

An infographic displays a graph showing simulated ice loss rates in southwestern Greenland for the past 12,000 years and forward to 2100. The infographic shows that ice loss this century could starkly outpace that of all past centuries over the study period unless human societies severely curb greenhouse gas emissions.

Credit: Bob Wilder / University at Buffalo

The research places the ice sheet’s modern decline in historical context, providing a robust look at how this century’s losses could starkly outpace prior changes

Release Date: September 30, 2020

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Video: Greenland's ice losses

Scientists working in Greenland. The video describes the study's findings, showing that Greenland's ice loss rates in the 21st century could starkly outpace that of all prior centuries over the past 12,000 years.
“Basically, we’ve altered our planet so much that the rates of ice sheet melt this century are on pace to be greater than anything we’ve seen under natural variability of the ice sheet over the past 12,000 years. We’ll blow that out of the water if we don’t make severe reductions to greenhouse gas emissions. ”
Jason Briner, professor of geology
University at Buffalo

BUFFALO, N.Y. — If human societies don’t sharply curb emissions of greenhouse gases, Greenland’s rate of ice loss this century is likely to greatly outpace that of any century over the past 12,000 years, a new study concludes.

The research will be published on Sept. 30 in the journal Nature. The study employs ice sheet modeling to understand the past, present and future of the Greenland Ice Sheet. Scientists used new, detailed reconstructions of ancient climate to drive the model, and validated the model against real-world measurements of the ice sheet’s contemporary and ancient size.

The findings place the ice sheet’s modern decline in historical context, highlighting just how extreme and unusual projected losses for the 21st century could be, researchers say.

“Basically, we’ve altered our planet so much that the rates of ice sheet melt this century are on pace to be greater than anything we’ve seen under natural variability of the ice sheet over the past 12,000 years. We’ll blow that out of the water if we don’t make severe reductions to greenhouse gas emissions,” says Jason Briner, PhD, professor of geology in the University at Buffalo College of Arts and Sciences. Briner led the collaborative study, coordinating the work of scientists from multiple disciplines and institutions.

Scientists standing in front of a helicopter.

Left to right: Scientists Alia Lesnek, Jessica Badgeley, Allison Cluett, Brandon Graham, Nicolás Young, and Jason Briner in Greenland. Lesnek, Badgeley, Cluett, Young and Briner, who led the study, are among co-authors of the new paper in Nature. Credit: Jason Briner

“If the world goes on a massive energy diet, in line with a scenario that the Intergovernmental Panel on Climate Change calls RCP2.6, our model predicts that the Greenland Ice Sheet’s rate of mass loss this century will be only slightly higher than anything experienced in the past 12,000 years,” Briner adds. “But, more worrisome, is that under a high-emissions RCP8.5 scenario — the one the Greenland Ice Sheet is now following — the rate of mass loss could be about four times the highest values experienced under natural climate variability over the past 12,000 years.”

He and colleagues say the results reiterate the need for countries around the world to take action now to reduce emissions, slow the decline of ice sheets, and mitigate sea level rise. The research was largely funded by the U.S. National Science Foundation.

Combining ice sheet modeling with field work, real-life observations

The Greenland Ice Sheet, viewed from above.

The edge of the Greenland Ice Sheet. Credit: Jason Briner

The study brought together climate modelers, ice core scientists, remote sensing experts and paleoclimate researchers at UB, NASA’s Jet Propulsion Laboratory (JPL), the University of Washington (UW), Columbia University’s Lamont-Doherty Earth Observatory (LDEO), the University of California, Irvine (UCI) and other institutions.

This multidisciplinary team used a state-of-the-art ice sheet model to simulate changes to the southwestern sector of the Greenland Ice Sheet, starting from the beginning of the Holocene epoch some 12,000 years ago and extending forward 80 years to 2100.

A circular saw against a boulder, kicking up dust.

Scientists collect samples from boulders in Greenland. These samples contain chemical isotopes that can help scientists determine the ancient boundaries of the ice sheet. Credit: Jason Briner

Scientists tested the model’s accuracy by comparing results of the model’s simulations to historical evidence. The modeled results matched up well with data tied to actual measurements of the ice sheet made by satellites and aerial surveys in recent decades, and with field work identifying the ice sheet’s ancient boundaries.

Though the project focused on southwestern Greenland, research shows that changes in the rates of ice loss there tend to correspond tightly with changes across the entire ice sheet.

“We relied on the same ice sheet model to simulate the past, the present and the future,” says co-author Jessica Badgeley, a PhD student in the UW Department of Earth and Space Sciences. “Thus, our comparisons of the ice sheet mass change through these time periods are internally consistent, which makes for a robust comparison between past and projected ice sheet changes.”

The shadow of a helicopter viewed from above against white ice.

To study the ice sheet’s ancient boundaries, scientists visit remote areas of Greenland accessible only by helicopter. Credit: Jason Briner

“We have significantly improved our understanding of how anomalous future Greenland change will be,” says co-author Joshua Cuzzone, PhD, an assistant project scientist at UCI who completed much of his work on the study as a postdoctoral researcher at JPL and UCI. “This work represents a massive success for multidisciplinary science and collaboration, and represents a framework for future successful multidisciplinary work.”

Cuzzone and other researchers at UCI and JPL led ice sheet modeling, leveraging the work of colleagues at UW, who used data from ice cores to create maps of temperatures and precipitation in the study region that were used to drive the ice sheet model simulations up to the year 1850. Previously published climate data was used to drive the simulations after that date.

Scientists Elizabeth Thomas and Nicolás Young collecting a sample from a boulder.

Study co-author Elizabeth Thomas, University at Buffalo assistant professor of geology, collects a sample from a boulder in Greenland. Such samples contain chemical isotopes that can help scientists determine the ancient boundaries of the ice sheet. At left is study co-author Nicolás Young, associate research professor at Columbia University’s Lamont-Doherty Earth Observatory. Credit: Jason Briner

UB and LDEO scientists partnered on field work that helped validate the model by identifying the ice sheet’s boundaries in southwestern Greenland thousands of years ago.

“We built an extremely detailed geologic history of how the margin of the southwestern Greenland Ice Sheet moved through time by measuring beryllium-10 in boulders that sit on moraines,” says co-author Nicolás Young, PhD, associate research professor at LDEO. “Moraines are large piles of debris that you can find on the landscape that mark the former edge of an ice sheet or glacier. A beryllium-10 measurement tells you how long that boulder and moraine have been sitting there, and therefore tells you when the ice sheet was at that exact spot and deposited that boulder.

“Amazingly, the model reproduced the geologic reconstruction really well. This gave us confidence that the ice sheet model was performing well and giving us meaningful results. You can model anything you want and your model will always spit out an answer, but we need some way to determine if the model is doing a good job.”

A continuous timeline of changes to the Greenland Ice Sheet

Scientists Allison Cluett and Alia Lesnek, working outdoors, examining a sample of lakebed mud.

Study co-authors Allison Cluett and Alia Lesnek examine a sample of lakebed mud from Greenland. Such samples help scientists reconstruct the ice sheet’s ancient boundaries. Cluett is a University at Buffalo PhD student, and Lesnek is a University at Buffalo PhD graduate and postdoctoral scholar at the University of New Hampshire. Credit: Jason Briner

The study makes an important contribution by creating a timeline of the past, present and future of the Greenland Ice Sheet, Briner says. The results are sobering.

“We have long timelines of temperature change, past to present to future, that show the influence of greenhouse gases on Earth’s temperature,” Briner says. “And now, for the first time, we have a long timeline of the impacts of that temperature — in the form of Greenland Ice Sheet melt — from the past to present to future. And what it shows is eye-opening.”

Scientist Nicolás Young perches atop a large boulder to chisel a sample from it.

Nicolás Young, associate research professor at Columbia University’s Lamont-Doherty Earth Observatory, collects a sample from a boulder in Greenland. Such samples contain chemical isotopes that can help scientists determine the ancient boundaries of the ice sheet. Credit: Jason Briner

“It is no secret that the Greenland Ice Sheet is in rough shape and is losing ice at an increasing rate,” Young says. “But if someone wants to poke holes in this, they could simply ask, ‘how do you know this isn’t just part of the ice sheet’s natural variability?’ Well, what our study suggests is that the rate of ice loss for this century will exceed the rate of ice loss for any single century over the last 12,000 years. I think this is the first time that the current health of the Greenland Ice Sheet has been robustly placed into a long-term context."

Despite these sobering results, one vital takeaway from the model’s future projections is that it’s still possible for people and countries around the world to make an important difference by cutting emissions, Briner says. Models of the RCP2.6 and RCP8.5 scenarios yield very different results, with high-emission scenarios producing massive declines in the ice sheet’s health, and significant sea level rise.

Scientists Jason Briner and Heidi Roop in Greenland, aboard a boat or pontoon.

The study’s first author, University at Buffalo geology professor Jason Briner (right), in Greenland with Heidi Roop, assistant professor of climate science at the University of Minnesota and former postdoctoral scholar at the University at Buffalo. Credit: Elizabeth Thomas

“Our findings are yet another wake-up call, especially for countries like the U.S.,” Briner says. “Americans use more energy per person than any other nation in the world. Our nation has produced more of the CO2 that resides in the atmosphere today than any other country. Americans need to go on an energy diet. The most affluent Americans, who have the highest energy footprint, can afford to make lifestyle changes, fly less, install solar panels and drive an energy-efficient vehicle.”

“This study shows that future ice loss is likely to be larger than anything that the ice sheet experienced in the Holocene — unless we follow a low-carbon emission scenario in the future,” Badgeley says.

Scientists Jessica Badgeley and Alia Lesnek collecting rock samples in Greenland.

Co-authors Jessica Badgeley from the University of Washington (standing) and Alia Lesnek from the University at Buffalo collect rock samples in Greenland in August 2017. The study used beryllium isotopes in the rocks to get dates for the glacier’s edge in southwestern Greenland at different times in order to compare their age and location to the modeled changes in the size of the Greenland Ice Sheet. Credit: Nicolás Young / Columbia University

The study’s authors include Jason P. Briner, Alia J. Lesnek, Elizabeth K. Thomas, Allison A. Cluett and Beata Csatho from the University at Buffalo; Joshua K. Cuzzone from the University of California, Irvine (UCI) and NASA’s Jet Propulsion Laboratory (JPL); Jessica A. Badgeley, Eric J. Steig and Gregory J. Hakim from the University of Washington; Nicolás E. Young and Joerg Schaefer from Columbia University’s Lamont Doherty Earth Observatory; Mathieu Morlighem from UCI; Nicole-Jeanne Schlegel and Eric Larour from JPL; Jesse V. Johnson and Jacob Downs from the University of Montana; Estelle Allan and Anne de Vernal from the Université du Québec à Montréal; Ole Bennike from the Geological Survey of Denmark and Greenland; and Sophie Nowicki from NASA’s Goddard Space Flight Center, who joined UB’s faculty in fall 2020.

In addition to the NSF, the research received support from the Natural Sciences and Engineering Research Council of Canada, Fonds de recherche du Québec, NASA and the G. Unger Vetlesen Foundation.

A tent set up in a remote area at the edge of a body of water.

To study the ice sheet’s ancient boundaries, scientists travel to remote areas of Greenland to collect samples of rock and lakebed mud that provide clues to the ice sheet’s ancient margins. Credit: Jason Briner

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