Some of the most iconic and well-known glaciers around the world—including those in Yosemite and Yellowstone national parks in the United States—may be doomed to melt away by 2050 because of human-caused climate change, according to a new report from Unesco and the International Union for Conservation of Nature (IUCN).
One-third of the glaciers located within World Heritage sites will disappear, no matter how much humans try to halt global warming, within the next 30 years, the report says.
As for the other two-thirds of glaciers, many are on track to dry up by 2100. But there's still time to save them by limiting global temperature rise to the Paris Agreement goal of 2.7 degrees Fahrenheit (1.5 degrees Celsius) above pre-industrial levels, the researchers say. But as it stands now, things aren’t looking good on that front: One estimate predicts there’s a 50-50 chance global average temperatures will cross that threshold within the next four years.
There are some 18,600 glaciers situated within 50 World Heritage sites, and these roughly ten percent of the planet’s total glacierized area. (The other 90 percent is in Antarctica, where there are no World Heritage sites.)
The World Heritage glaciers include those in the Dolomites of Italy and on Tanzania’s Mount Kilimanjaro, as well as the world’s highest glaciers (near Mt. Everest) and the longest glacier (located in Alaska). World Heritage sites also encompass some of the last remaining glaciers in Africa.
Since 2000, these iconic glaciers—which span more than 25,000 square miles—have been retreating at a faster pace because of greenhouse gas emissions, which are causing global temperatures to rise. They’re losing about 58 billion tons of ice every year, and that water is flowing into the world’s oceans. Per the report, melting World Heritage glaciers are responsible for nearly five percent of sea-level rise across the globe.
“What is quite unprecedented in the historical record is how quickly this is happening,” Beata Csatho, a glaciologist with the University of Buffalo who was not involved with the report, tells the BBC’s Patrick Hughes. “In the middle of the 1900s, glaciers were quite stable. Then there is this incredibly fast retreat.”
Some of the most at-risk glaciers include those in the Three Parallel Rivers of Yunnan Protected Areas in China, which have lost 57.2 percent of their mass since 2000, the fastest melting of any Unesco glacier. Behind those, the glaciers located inside Argentina’s Los Alerces National Park have lost 45.6 percent of their mass since 2000.
Losing these glaciers means saying goodbye to some of the world’s most impressive and long-standing natural wonders. But beyond that, many communities around the world rely on water from glaciers for energy, agriculture and household use.
“When glaciers melt rapidly, millions of people face water scarcity and the increased risk of natural disasters such as flooding, and millions more may be displaced by the resulting rise in sea levels,” says Bruno Oberle, IUCN’s director general, in a statement.
Glaciers also support a variety of ecosystems and generate economic activity via tourism. On top of that, they have cultural significance to many Indigenous groups, such as to the Māori in New Zealand and communities in the Peruvian Andes, per the report.
Based on the report’s findings, Unesco is advocating for a dramatic reduction of greenhouse gas emissions on a global scale. The agency, which is part of the United Nations (U.N.), also wants to create an international fund for preserving and studying glaciers.
Unesco and IUCN issued the report just a few days before the start of the U.N.’s annual climate change conference, COP27, which is now underway in Sharm El-Sheikh, Egypt. They hope the findings will serve as “a call to action” for the world’s leaders, says Audrey Azoulay, Unesco’s director-general, in the statement.