Voices of the Warming North Being Heard

Submitted by Carla Browning
Phone: (907) 474-7778
12/11/02

San Francisco - Alaska scientists are talking about unprecedented warming up north, and people are listening.

On December 7, 2002, two University of Alaska scientists stood up before a room filled with reporters to present their evidence of global warming at high latitudes. Writers for the New York Times, the San Francisco Chronicle, Science News and more than 20 other national news outlets asked questions of Larry Hinzman, Terry Chapin and three other scientists during a press conference at a meeting of the American Geophysical Union. Hinzman is a hydrologist with UAF’s Water and Environmental Research Center; Chapin is a researcher with the Institute of Arctic Biology.

More than 9,000 scientists who study Earth and space gather each year in San Francisco at the AGU conference. Most of the thousands of studies unveiled at the conference are noticed by a few of the scientists’ peers, but Hinzman and Chapin stepped onto a larger stage at the AGU press conference room to present their research to media members hunting for story ideas.

Their opportunity to deliver their message of warming in Alaska was not random chance. A committee that organizes the fall meeting decided Hinzman’s research was significant and accessible enough to merit a press conference, and Hinzman asked four other scientists to join him. They carried to the table varying evidence that the far north is experiencing warmth never before seen in recorded history.

Terry Chapin spoke of changes on Alaska’s north slope and on the Seward Peninsula; shrubs are invading tussock tundra and white spruce trees are advancing up arctic valleys where they have never been seen before. The transition from tundra plants to shrubs and trees also creates more warmth, because shrubs and trees capture and radiate more heat than tundra plants.

Atmospheric scientist Mark Serreze of the University of Colorado told the reporters of thinning sea ice on top of the world.

"The Arctic Ocean sea-ice extent is the minimum area it’s ever been in the era of satellites," he said.

This past summer was a strange one on top of the world, featuring conditions researchers had not seen before.

"In 2002, there were extremely stormy and warm conditions in the Arctic Ocean," Serreze said. The blustery conditions opened more cracks between rafts of sea ice, allowing the ocean to absorb heat. Sea ice reflects about 80 percent of the sunlight that hits it; open water absorbs more than 80 percent of the sunlight that reaches it.

Satellite imagery also allowed Konrad Steffen, an ice-sheet specialist at the University of Colorado, to determine that the Greenland ice sheet melted in areas where it never had before. Steffen and his colleagues detected meltwater on large sections of the ice sheet that had formerly remained frozen year-round. That meltwater could also be responsible for the decreasing size of the icecap by percolating through the glacier and creating a lubricating film on top of bedrock that might be speeding the ice’s journey to the sea.

Mankind’s role in the many changes in the north is almost certain, but human responsibility is hard to prove. Despite the uncertain origin of the warming, Hinzman said one thing is clear: the far north is sending an urgent message, and scientists are hearing the call.

"Taking all these studies together, I think we have a very compelling case for rapid change in the Arctic," he said.

The Alaska Science Forum column is provided as a public service by the Geophysical Institute, University of Alaska Fairbanks, in cooperation with the UAF research community. Ned Rozell is a science writer at the institute. He can be reached by email.