The ice sheet covering Greenland is four times bigger than California — and holds enough water to raise the global sea level more than twenty feet if it were to melt. Today, sea levels are rising, and the melting of Greenland is a major contributor. UVM geologist Paul Bierman from the College of Arts and Sciences and his students have traveled to this remote island many times, seeking to better understand: how fast could Greenland melt in a warming world? 

Now, Bierman’s latest study, in the journal Nature, provides powerful new insight into this question—and has generated media stories around the world, including in TIME magazine, Scientific American, the BBC, Popular Science, Agence France-Presse, and many other outlets.

“The melting we are seeing today,” Bierman says, “may be out of the bounds of how the Greenland ice sheet has behaved for many millions of years.”

To make better predictions about the future of the ice sheet, Bierman and other scientists have tried to understand its past, hoping to glean what the ice was doing millions of years ago when the Earth was three or more degrees Fahrenheit warmer than it is now. But their understanding of the ice sheet's complex behavior before about 125,000 years ago has been fragmentary at best.

Bierman’s new study—with one of his students and a team of other scientists—was paired with another study in Nature. Both applied an innovative new technique: using radioactive isotopes found in quartz to estimate how long the island's bedrock was exposed to the sky versus buried under the ice. This approach allowed the scientists to peer into the deep history of the Greenland ice sheet, looking back millions of years farther than previous techniques allowed. But the new, deeper view raised an important scientific debate about the ice sheet’s behavior, which plays out in recent media coverage.

“We must recognize the importance of advancing polar science to understand how our world works. And, right now, because we're pumping huge plumes of greenhouse gases into the atmosphere, we really need to know how our world works,” Bierman says.

That’s why he and students will continue their trips to the remote frozen corners of the planet (like this helicopter expedition over Greenland’s glacial landscape) and back to UVM’s globally pioneering Cosmogenic Nuclide Laboratory—looking for the future in the history of ancient ice.