Qori Kalis glacier in 1983 and 2007
Glacial ice in the Peruvian Andes that took at least 1,600 years to form has melted in just 25 years, scientists reported Thursday, the latest indication that the recent spike in global temperatures has thrown the natural world out of balance.
The evidence comes from a remarkable find at the margins of the Quelccaya ice cap in Peru, the world’s largest tropical ice sheet. Rapid melting there in the modern era is uncovering plants that were locked in a deep freeze when the glacier advanced many thousands of years ago.
Dating of those plants, using a radioactive form of carbon in the plant tissues that decays at a known rate, has given scientists an unusually precise method of determining the history of the ice sheet’s margins.
Lonnie G. Thompson, the Ohio State University glaciologist whose team has worked intermittently on the Quelccaya ice cap for decades, reported the findings in a paper released…by the journal Science.
The paper includes a long-awaited analysis of chemical tracers in ice cylinders the team recovered by drilling deep into Quelccaya, a record that will aid scientists worldwide in reconstructing past climatic variations…
Of greater immediate interest, Dr. Thompson and his team have expanded on previous research involving long-dead plants emerging from the melting ice at the edge of Quelccaya, a huge, flat ice cap sitting on a volcanic plain 18,000 feet above sea level…
In the new research, a thousand feet of additional melting has exposed plants that laboratory analysis shows to be about 6,300 years old. The simplest interpretation, Dr. Thompson said, is that ice that accumulated over approximately 1,600 years melted back in no more than 25 years.
“If any time in the last 6,000 years these plants had been exposed for any five-year period, they would have decayed,” Dr. Thompson said. “That tells us the ice cap had to be there 6,000 years ago…”
Throughout the Andes, glaciers are now melting so rapidly that scientists have grown deeply concerned about water supplies for the people living there. Glacial meltwater is essential for helping Andean communities get through the dry season.
In the short run, the melting is producing an increase of water supplies and feeding population growth in major cities of the Andes, the experts said. But as the glaciers continue shrinking, trouble almost certainly looms.
Not that we have an overabundance of politicians who pay attention to science. Imagine how World War 2 might have turned out if the head of the Democrats back in the day – President Roosevelt – hadn’t listened to Einstein and Szilard?
We may not have needed to use the atomic bomb; but, we certainly needed to prevent Hitler from building one.