Posted on September 14, 2012 by Bob Berwyn
Research finds that ice sheets can be very sensitive to short-term temperature variations. Photo by Bob Berwyn.
Study shows some glaciers and ice fields can respond quickly and dramatically even to short-lived climate changes
By Summit Voice
SUMMIT COUNTY — It’s pretty clear that glaciers and ice fields have been melting the past few decades under relentless global warming. But scientists aren’t sure exactly how fast the melting will proceed, whether it will speed up, or perhaps stabilize at some point.
A new study looking back at historic changes in response to climate variations may help answer some of those questions. The research shows that glaciers on Canada’s Baffin Island expanded rapidly during a brief cold snap about 8,200 years ago, suggesting that changes can be sudden and drastic.
“One of the questions scientists have been asking is how long it takes for these huge chunks of ice to respond to a global climate phenomenon,” said study co-author Jason Briner, PhD, a University at Buffalo associate professor of geology. “People don’t know whether glaciers can respond quickly enough to matter to our grandchildren, and we’re trying to answer this from a geological perspective, by looking at Earth’s history.” (more…)
Filed under: Environment, global warming, climate and weather | Tagged: Environment, global warming, climate, glaciers, Columbia University, Lamont–Doherty Earth Observatory, Baffin Island, Younger Dryas | 2 Comments »
Posted on January 31, 2012 by Bob Berwyn
New evidence from carbon-dated plant matter and lake sediments offer clues to sudden climate changes
Eruption column at Redoubt Volcano, Alaska. PHOTO COURTESY USGS.
By Summit Voice
SUMMIT COUNTY —Carbon-dating a trove of dead plant material emerging from under the Baffin Island icecap suggests that the vegetation was frozen and engulfed during a relatively sudden event that may have triggered the start of the Little Ice Age.
Both low-lying and higher altitude plants all died at roughly the same time, indicating the onset of the Little Ice Age on Baffin Island — the fifth largest island in the world — was abrupt. The team saw a second spike in plant kill dates at about A.D. 1450, indicating the quick onset of a second major cooling event.
Evidence from the new study suggests the centuries-long span of cooling temperatures began abruptly sometime between 1275 and 1300, following a 50-year-long episode of four massive tropical volcanic eruptions. (more…)
Filed under: climate and weather, Environment, global warming, Summit County news | Tagged: Baffin Island, climate, global cooling, global warming, Little Ice Age | 4 Comments »
Posted on January 6, 2011 by Bob Berwyn
Arctic sea ice continues to dwindle.
Air temps in large parts of Arctic more than 10 degrees above average, Antarctic sea ice is at above-average extent
By Summit Voice
SUMMIT COUNTY — With unusually warm air temperatures prevailing over the Arctic for the second year in a row, Arctic sea ice was at its lowest for December since satellite measurements began in 1979. At the same time, sea ice in Antarctica has remained at above average levels for the past four months during the spring melt season, according to a Jan. 5 bulletin from the National Snow and Ice Data Center.
Scientists with the center said sea ice extent average about 4.63 million square miles during December, about 104,000 square miles less than the previous minimum, set in 2006, and 1.35 million less than the 1979 to 2000 average. Since satellite measurements began, the linear rate of decline in Arctic sea ice extent is 3.5 percent per decade. (more…)
Filed under: climate and weather, Environment, global warming, Summit County Colorado | Tagged: antarctic sea ice, Arctic, Arctic sea ice, Baffin Island, Canadian Arctic Archipelago, Environment, global warming, National Snow and Ice Data Center, Polar ice packs, Summit County News | 1 Comment »