On the globe, the changes will be a difference of millimeters, but on a worldwide scale, they could mean the displacement of tens of millions of people. One of the main reasons: The Greenland ice sheet, a gargantuan expanse of ice roughly the size of the Gulf of Mexico, is melting—and it's doing so faster than anyone imagined.
Over the past few years, the ice sheet spewed 250 gigatons of ice into the ocean, or "two-and-a-half times all the ice in the Alps," Steffen said, turning the globe and planting his finger in the center of Europe.
In October, former Vice President Al Gore and the U.N. Intergovernmental Panel on Climate Change won the Nobel Peace Prize for drawing attention to global warming. Earlier this year, the U.N. panel published a report concluding that human influences likely were to blame for planet-wide climate change. It warned that as glaciers and ice sheets melted and caused the oceans to swell through thermal expansion, sea levels would rise between 18 and 59 centimeters by 2100.
But Steffen, known to everyone as Koni, believes the Greenland ice sheet is deteriorating faster than predicted by these models. By the end of the century, he said, the oceans could rise by roughly 3 feet.
And when he makes predictions like this, powerful people listen. Steffen is a worldwide authority on Greenland's ice sheet and the director of the Cooperative Institute for Research in Environmental Sciences. The joint institution of CU and Boulder's National Oceanic and Atmospheric Administration is the largest research unit at the university, with a $50 million budget and a staff of 550.
In early October, just before winning the Nobel Prize, Gore visited Boulder to meet with its many celebrated climate scientists. Steffen wasn't there—he was at a conference in Sydney—so Gore made sure they talked by phone. "He had follow-up questions at least as good or better than my graduate students," the professor said.
Steffen's recent research on Greenland's ice sheet wasn't included in the U.N. panel's study because it had yet to be fully understood and peer-reviewed. But it will appear in a report he is preparing for the Bush administration. It's an issue he hammered home several weeks ago during a presentation to Congress, at which he was asked to explain how much of Greenland's ice was melting each year. Enough to make a column of water encompassing the entirety of the District of Columbia and stretching nearly a mile into the sky, he replied. "That got some attention," he said in a thick Swiss accent.
It started in 1975, when Steffen, a grad student from Zurich, spent the summer studying the Arctic climate on an island 400 miles from the North Pole. Every summer and two entire winters since, he's traveled to the Arctic Circle, and from 1990 onward, he's focused much of his attention on Greenland.
"We knew more about the backside of the moon than we did about Greenland, data-wise," he said.
Summer on the ice sheet is a relative term. During the seven weeks Steffen and his team of grad students and scientists spend there each year, nighttime temps usually drop to 24 degrees below zero. "I seem to like the extremes," he said. "I am not afraid of cold."
In 1990, Steffen built a research station on the Greenland ice sheet, and by 1995, his team began having problems of a different sort: The station itself was coming apart. The living areas had been flooded with meltwater, monitoring towers sunk deep into the ice were toppling over.
This wasn't expected to happen, since the station was located on the ice sheet's "equilibrium line," the point where winter snowfall was supposed to cancel out summer melt. But the melt had been outpacing snowfall, and the equilibrium line was moving. Although he had gone to Greenland to study the climate, he ended up studying climate change.
Over the next decade, they watched the average winter temperature on the ice sheet increase by 6 degrees, an amount so improbable that their colleagues at first didn't believe them.
The ice, it seemed, was moving toward the sea faster than could be explained by rising temperatures alone. The researchers concluded that meltwater was making its way through the ice and lubricating the bedrock below. This allowed the ice to spread out faster and made it more susceptible to melting—which is why Steffen believes the U.N. panel's sea-level predictions are significantly understated.
"This is something some glaciologists thought would not happen, and it had major implications about how fast climate changes could affect the ice flow, cause changes in ice mass and sea-level rise," said Jay Zwally, a NASA glaciologist who tracked the speed of the ice.
Some scientists say the Earth could be entering a phase that in hundreds or thousands of years will lead to the dissolution of the Greenland ice sheet and raise the sea level by 21 feet. Worse yet, Steffen recently led a study showing that an area of ice the size of California had melted in west Antarctica, a region thought to be largely undisturbed by global warming.
But making people care is a challenge.
Climate "is never local," he said. "Greenland shows the environment can change quite fast. We could see similar change here in Colorado."
This summer, House Speaker Nancy Pelosi visited Steffen's research station. Both on the ice sheet and in Boulder, Steffen is participating in a research campaign called the International Polar Year, in which 5,000 scientist from 60 nations are focusing on what is causing—and what can be done about—the dramatic changes in Arctic and Antarctic regions.
"You always ask yourself, 'There is uncertainty. What happens if I send out the wrong message?'" he said. "But that was five years ago. Now there is no question the sea level is rising. I am starting to worry that my kids are going to have quite a different world from the one I grew up in."
This article originally appeared in Westword.