Over 1600 years of glacial ice in the Peruvian Andes has melted in just the last 25 years, new research from Ohio State University has found. The fact that ice caps that took such a long time to form, melted so rapidly, really says something about how out of the “norm” recent temperatures have been.
The new research is based on a “remarkable” new find at the edges of the Quelccaya ice cap located in Peru. The Quelccaya ice cap is the planet’s largest tropical ice sheet. Amazingly, as the ice there has begun to rapidly melt in the modern era, “plants that were locked in a deep freeze when the glacier advanced many thousands of years ago” have become uncovered.
These plants have been dated through the use of “a radioactive form of carbon in the plant tissues that decays at a known rate.” This has provided researchers with an uncommonly precise way to determine the historical margins of the ice sheet.
The new research 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.”
Such analyses will take time, but the researchers say that the preliminary evidence shows, “for example, that the earth probably went through a period of anomalous weather at around the time of the French Revolution, which began in 1789. The weather presumably contributed to the food shortages that exacerbated that upheaval.”
“When there’s a disruption of food, this is bad news for any government,” Dr. Lonnie Thompson, an Ohio State Glaciologist, stated in an interview with The New York Times.
Many modern analysts have made a similar connection between food shortages and the “Arab Spring”, and the Syrian civil war. It is extremely likely that food shortages in the near future caused by climate change will lead to further political instability and probably war in some regions.
“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. Several years ago, the team reported on plants that had been exposed near a meltwater lake. Chemical analysis showed them to be about 4,700 years old, proving that the ice cap had reached its smallest extent in nearly five millenniums.”
“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.”
As of right now, climate change is having the most pronounced effects on high latitudes and high altitudes. “Sitting at high elevation in the tropics, the Quelccaya ice cap appears to be extremely sensitive to the temperature changes.”
“It may not go very quickly because there’s so much ice, but we might have already locked into a situation where we are committed to losing that ice,” said Mathias Vuille, a climate scientist at the State University at Albany in New York.
“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.”
Douglas R. Hardy, a University of Massachusetts researcher who works in the region, said, “How much time do we have before 50 percent of Lima’s or La Paz’s water resources are gone?”
The new research was just published in the journal Science.
Image Credit: Lonnie G. Thompson/Ohio State University