Ken Pedersen, expedition leader at the Norwegian Troll Research Station in Antarctica, briefs a group of visiting environment ministers and other representatives from more than a dozen nations Monday.
"Our preliminary finding is that there's a slight warming trend in East Antarctica," American glaciologist Ted Scambos told the group of visiting environment ministers.
It was an early estimate regarding just one region of a huge continent, drawn from first analyses of ice cores drilled along the team's route. But it caught the ear of the visiting politicians, who are this year weighing a new global deal for cutting greenhouse-gas emissions to avert the worst of climate change.
"It's important to hear the latest science," said Hilary Benn, Britain's environment minister. "I was impressed that they're finding temperatures rising. But there is still so much not known."
Representatives from more than a dozen nations, including the U.S., China and Russia, rendezvoused at the Norwegian research station with the scientists completing the last leg of a 1,400-mile, two-month trek over the ice from the South Pole.
The 12-member Norwegian-American Scientific Traverse of East Antarctica was a leading project in the 2007-2009 International Polar Year. It is a mobilization of 10,000 scientists and 40,000 others from more than 60 countries engaged in Arctic and Antarctic research in the past two southern summer seasons.
Learning more about historic temperature trends has been a prime concern in examining whether global warming -- already occurring elsewhere on the planet -- might cause Antarctica's store of ice to start melting, raising sea levels, potentially to a disastrous point for coastal cities and shorelines worldwide.
Speaking to the environment ministers over breakfast, Kim Holmen, research director for the Norwegian Polar Institute, the Troll station's operator, noted that scientists had generally thought Antarctica as a whole was not warming in recent decades. But a recent study in the journal Nature shook that view.
"This new analysis shows us actually the whole of Antarctica has been warming," Holmen said.
The preliminary finding from the on-the-ground Traverse expedition, if it is confirmed, would reinforce the Nature study, which extrapolated temperature trends by blending satellite information with scarce weather station data available in and around Antarctica.
By drilling deep cores into the annual layers of ice sheet, the trekkers from the South Pole were also gathering data on how much snow has fallen historically.
Such work will be combined with another IPY project, an effort to map by satellite information about Antarctic ice sheets over the past two summers, an attempt to assess how fast ice is being pushed into the sea.
Then scientists may understand better the "mass balance" -- how much the snow, originating with ocean evaporation, is offsetting the ice pouring seaward. That, in turn, would help them judge how fast and high ocean levels may rise from Antarctic melt.
Since Antarctica accounts for 90 percent of the world's ice, "a small change in accumulation rate in this area could lead to significant sea-level rise," Tom Neumann, American leader of the Traverse, told the ministers.
The visitors also included the environment ministers of Algeria, the Czech Republic, Finland, Norway and Sweden. Other countries were represented by climate policymakers and negotiators, including Xie Zhenhua of China and Dan Reifsnyder, a deputy assistant U.S. secretary of state.
During their long day here under the brilliant 17-hour sunlight of a dying southern summer, when the temperature still dropped to -20 degrees Celsius (near-zero Fahrenheit), the group traveled by snow tractor over the 500-meter-deep (1,500-foot-deep) ice sheet to stand in awe before Judulsessen, a jagged wall of towering peaks in the 2,400-meter-high (8,000-foot-high) Gjelsvik Mountains.
It was a spectacular finish to four days together for the ministers, whose original two-day weekend visit was shortened to a Monday day trip after rough Antarctic weather repeatedly canceled their flight in.
During their stranded weekend in Cape Town, South Africa, 3,000 miles to the north, they spent hours behind closed doors discussing and debating the global climate negotiations, with the help of chief U.N. climate scientist Rajendra Pachauri and Britain's Lord Nicholas Stern, an expert on the economics of climate change.
Erik Solheim, Norway's environment minister and sponsor of the unusual trip, clearly hoped the informal atmosphere might help smooth the difficult, ongoing formal talks.
"It was an extraordinary concentration of people," said Martin Bursik, the Czech environment minister. "And the quality of the debate was extraordinary."