By MICHAEL VIRTANEN Associated Press Writer
ALBANY — Ice is forming this week on picturesque Mirror Lake, weeks later than it once did as scientists continue to document a century-long warming trend.
"The weather is so variable, and the data sets are so few or incomplete, the ice cover is the one thing that stands out above everything else," said Curt Stager, professor of natural sciences at Paul Smith's College. "It's the most obvious, irrefutable sign of climate change in the North Country."
Stager and three other scientists co-authored a recent paper in the Adirondack Journal of Environmental Studies plotting regional climate changes since data collection began in the early 1900s. The data showed ice on Mirror Lake forming 14 or 15 days later and melting three or four days earlier than it did then, consistent with records from several other high-elevation Adirondack lakes.
Colin Beier, a researcher at the Adirondack Ecological Center of the State University College of Environmental Science and Forestry, said climate is affected by geography in the 6 million-acre Adirondack Park, a place with mountains, lake effects, weather from Canada and other local factors.
A separate preliminary trend analysis from 1950 to 2008 found high mean temperatures in the High Peaks area increasing a few degrees while those in the southwestern Adirondacks around West Canada Lakes were decreasing by a similar amount.
"There's a lot of hysteria about climate change right now," Beier said. "It's important for us as scientists to present as sober and clean a picture as possible."
The U.N. Intergovernmental Panel on Climate Change in 2007 found it "very likely" that most observed warming globally is due to the buildup of heat-trapping gases from burning fossil fuels. A 193-nation conference ended last weekend in Copenhagen with a limited agreement to address global warming amid acrimony over failure to reach a legally binding deal. Scientific debate continues over causes and forecasts.
With data from seven sites around the Adirondack region, the four scientists reported mean annual temperatures from 1926 to 2005 rose overall only "slightly," or about 1.5 degrees. However, measured over the most recent 30 years, the trend was more pronounced and statistically significant for the months of September, up an average of 4.7 degrees, and December, up 3.4 degrees. May was 1.7 degrees cooler.
Some of the best ice records came from Mirror Lake, which can be seen from Main Street in Lake Placid.
One of the longer-term goals of the research is to develop useful projections, with knowledge of underlying mechanisms and avoid the "oversimplification" of projecting historical trends forward, they wrote.
Stager noted that there was a warm spell in the 1950s in this part of the world and said that depending on the time frame used, it was possible to draw different conclusions. "If you start in the 1950s, it makes it seem like there's not much change. If you start in the '60s, it's a ramp upwards everywhere," Stager said.
The corrected United States Historical Climatology Network data they used came from Dannemora, Indian Lake, Lake Placid, Stillwater, Tupper Lake and Wanakena in the Adirondacks, as well as Lowville just west toward the Tug Hill Plateau.
They also found an increase in stream discharge over a century, indicating "an overall wetting trend," and more rain, particularly in August. Some migratory birds also are now arriving earlier.
[Photo: A dog sled navigates Mirror Lake during an earlier winter. 2004 Plattsburgh Press Republican File Photo]