Study: Global loss of glaciers more substantial than previously thought

A global loss of glaciers resulting in rising sea levels is far more substantial than previously thought, a study published Thursday in the journal Science reveals.

Scientists from around the world — including one from Carnegie

Mellon University — used what is called a glacier evolution model, inputting different temperatures and precipitation levels into a coding program to glean context about the worstand best-case scenarios for the world’s glaciers. The study was partly funded by NASA.

Given current warming trends, the planet’s glaciers are on track to lose at least a quarter of their mass by 2100, and that is a bestcase scenario that would involve “considerably more (climate) targets set by other countries, now,” said David Rounce, an assistant professor of civil and environmental engineering at CMU.

Not just a scientific exercise, the modeling could predict a massive impact on iconic places on the map like the Alps and the Andes mountain ranges and on resources such as freshwater supplies to communities near them.

“Glaciers are like slow-moving rivers, so modeling their flow is really important,” Rounce said.

Rounce and his colleagues’ model predicted the world would lose between 50% and 83% of all glaciers by 2100 and see the sea level rise by 3.5 to 6 inches.

One of the keys is temperature changes that scientists see triggered by greenhouse gasses, as they trap heat and intensify storms. If the global temperature increases 4 degrees Celsius above the average set before the arrival of heavy industry in the

20th century, the model predicts nearly half of all glacial mass will be lost.

The scientists also measured the number of glaciers that would be lost. They examined each condition with a 1.5-degree Celsius global temperature increase as well as a 4-degree Celsius temperature increase (a range of approximately 35 to 40 degrees Fahrenheit).

An increase of 1.5 degrees Celsius might not seem like much, but climate scientists are calling it catastrophic.

While numerous efforts are underway to curb production of greenhouse gasses, a November New Yorker article by science journalist Elizabeth Kolbert found that even when countries pledge carbon neutrality this does not always translate to direct action.

“Eighty-three percent is a shocker,” said Bryan Mark, a professor of geography at Ohio State University who has studied glacial science for decades in the Andes and other mountain environments.

“We would lose the Alps, the Andes, and Glacier National Park would become Glacier Grave National Park,” said Mark, who was not involved in the present research.