A new discovery in Peru has given scientists a greater reason to be concerned about global warming. Part of the Quelccaya ice cap in the Peruvian Andes, which took 1,600 years to form, has almost completely melted over the past 25 years. The find was made by a team of Ohio State glaciologists, led by Lonnie G. Thompson, a professor in their School of Earth Sciences.
The team of scientists has been intermittently studying the Quelccaya ice cap for a decade. While observing the margins between the ice cap, they found rapid melting, which revealed plants that had been frozen there thousands of years ago as the ice cap slowly expanded. They used carbon dating, a technique that uses the amount of an isotope of carbon left in an organic material in order to determine its age.
Several years ago, Thompson’s team found some plants that resurfaced after slight melting of Quelccaya. A chemical analysis of these plants revealed them to be about 4,700 years old.
Now, thousands of feet more of the ice cap have melted, uncovering plants that the s
cientists dated as 6,300 years old. Thompson concluded that the amount of ice he has seen melt over the past 25 years formed over the course of 1,600 years —from 6,300 years ago to 4,700 years ago.
Research done by other scientists on the Quelccaya ice cap suggests that this isn’t the first time the edges of the ice cap have melted. However, what makes the current state of melting so alarming is its speed: the ice cap is melting faster than any other ice cap on the geological record since the end of the last ice age.
The melting of Quelccaya could have a gradual effect of global warming by increasing the average temperature of the Earth’s atmosphere. Global warming is thought to be primarily caused by an increase in greenhouse gases in the atmosphere. The accumulation of greenhouse gases can be the direct result of human activities like deforestation and burning fossil fuels.
Right now, global warming has a greater influence on higher latitudes and altitudes. Because the Quelccaya ice cap is on a volcanic plain 18,000 feet above sea level, it is very sensitive to changes in temperature. Some climate scientists believe that the glacier is so sensitive to temperature changes that there may already be no way of saving it, although the ice cap will take a while to melt simply because of the sheer volume of ice there.
The Quelccaya ice cap isn’t the only ice cap being threatened by global warming. Glaciers throughout the Andes are melting rapidly, spreading concern within populations near the Andes. They rely heavily on water from glaciers in order to survive in the dry season.
Right now, the rapid melting of the glaciers is providing these communities with extra water, which is leading to an increase in population. However, in the long run, this society faces losing much of their water supply.
Also included in their research was an analysis of chemical tracers in ice cylinders that the scientists found by drilling deep into Quelccaya. The scientists hope that an analysis of these chemicals will help them to understand and discover more about past climatic variations.
This will take time, but there are already some preliminary findings, including a suggestion that there was a period of anomalous weather at around the time of the French Revolution. This could have led to the food shortages that fueled the uprising. The full findings were published online recently in the journal Science.
