Tucson Standard

Ice melting from glaciers worldwide is significantly impacting freshwater resources and contributing to rising global sea levels, according to a recent study by an international research consortium that includes scientists from the University of Arizona.

Christopher Harig, an assistant professor in the Department of Geosciences at the University of Arizona, co-authored the study published in Nature. He stated, "Today, glaciers are melting 36% faster than they did 20 years ago." The research found that glaciers have been losing an average of 273 billion tons of ice annually over this period.

In 2000, glaciers—excluding Greenland and Antarctica's continental ice sheets—covered 272,287 square miles and contained approximately 134,182 billion tons of ice. Over two decades, global glacier volume decreased by about 5%, with regional losses varying from 2% on Antarctic and Subantarctic Islands to 39% in central Europe.

The amount of ice lost increased by 36% in the latter half of the study period (2012-2023) compared to the first half (2000-2011). Overall glacier mass loss during this time was 18% higher than Greenland's ice sheet loss and more than double that of Antarctica's.

"Glacier ice loss is a key part of sea-level rise today, and we expect it to get even larger in the future," Harig noted. He emphasized that coastal communities rely on sea-level rise estimates for planning purposes.

Between 2000 and 2023, glaciers collectively lost 7,211 billion tons of ice, contributing nearly three-quarters of an inch to global sea-level rise. On average, glaciers lost 301 billion tons per year—equivalent to an annual sea-level rise equaling .03 inches or about the thickness of a credit card. The rate increased significantly from 254 billion tons per year initially to 346 billion tons later.

Michael Zemp from the University of Zurich explained: "To put this in perspective, the 273 billion tons of ice lost annually amounts to what the entire global population consumes in 30 years."

Inés Dussaillant from the University of Zurich highlighted glaciers' importance as freshwater resources for local communities in Central Asia and Central Andes during warm and dry seasons.

The study was part of GlaMBIE (Glacier Mass Balance Intercomparison Exercise), aiming to estimate global glacier mass loss accurately. Coordinated by World Glacier Monitoring Service at University of Zurich with collaborators like University of Edinburgh and Earthwave—a UK-based data science company—the initiative compiled data from around 450 contributors organized into teams using various observation methods.

Eric Cicero from Harig's group contributed as a co-author on this paper. Funding came primarily through European Space Agency’s FutureEO program with additional support from International Association for Cryospheric Sciences among others under leadership by World Glacier Monitoring Service alongside partners such as Earthwave plus over thirty other research teams globally.