Glaciers in Yosemite National Park have been included on a list of threatened glaciers that are ‘highly likely’ to disappear by 2050, according to a new UNESCO study in partnership with the International Union for Conservation of Nature .
A third of the glaciers at 50 UNESCO World Heritage sites, including Yosemite, are expected to disappear over the next 30 years regardless of efforts to curb global warming, says the UNESCO report released this week. Its findings indicate that the remaining glaciers in the World Heritage Site could still be saved if temperature increases do not exceed 1.5 degrees Celsius compared to the pre-industrial period.
The 18,600 glaciers listed on the 50 World Heritage sites represent about 10% of the Earth’s glaciers. They include the tallest glacier, next to Mount Everest, and the longest, in Alaska.
“Glaciers are of crucial importance for sustaining life on Earth,” UNESCO said. “They provide vital water resources to half of humanity. They have significant cultural and religious significance to many local communities and attract millions of tourists worldwide.
Yosemite National Park Glaciers
Yosemite’s two glaciers, the Lyell and Maclure glaciers at the source of the Tuolumne River, could disappear much sooner. Yosemite National Park geologist Greg Stock expects them to melt within the next five to 20 years.
“The loss of glaciers will reduce flows in the upper Tuolumne River, especially in drought years,” Stock said, “with impacts on downstream ecosystems.”
Technically, Yosemite’s Lyell Glacier is no longer a glacier, because glaciers move, by definition. Stock said the most accurate description now is that Lyell is a stagnant patch of ice. He thinks it might have stagnated in the early 2000s. Investigations this year have confirmed it’s no longer moving, Stock said, because it’s no longer thick enough to sink.
Maclure Glacier is still moving, Stock said, but has slowed since it was last measured 10 years ago.
“Since they were first mapped and photographed in 1883, the Lyell and Maclure glaciers have lost about 90% of their ice volumes,” Stock said, “meaning only 10% remain. of what was first photographed in 1883″.
Yosemite park rangers described conditions at Lyell in an April update for the National Park Service.
“As we traversed beneath what was once Lyell Glacier, it was not hard to imagine the disappearance of snow and ice across the globe,” the rangers wrote. “The glacier is now considered a stagnant patch of ice because it is no longer descending and is rapidly shrinking in size. Not only is the annual global snow and ice cover less, but it is melting earlier. …
“This spring in Yosemite, river flows peak in early April instead of late May or June. Remember, if you live in the American West, your water probably came from the sky in the form of a beautiful, delicate snowflake. Each dendrite is as beautiful and as important as all life on this fragile little planet, including you! So please take care of each other and our only home, Mother Earth.
Urgent action is needed to save what remains
Urgent action is needed to safeguard these unique places for future generations, according to the study.
“Half of humanity depends directly or indirectly on glaciers as a source of water for domestic use, agriculture and energy,” UNESCO said. “Glaciers are also pillars of biodiversity, feeding many ecosystems.”
Other threatened glaciers in North America include those in Yellowstone National Park, which are also “highly likely” to disappear by 2050. In the Waterton-Glacier International Peace Park, straddling Canada and Montana , glaciers have lost 26.5% of their volume over the past 20 years. years.
“This report is a call to action,” said UNESCO Director-General Audrey Azoulay. “Only a rapid reduction in our CO2 emissions can save the glaciers and the exceptional biodiversity that depends on them.”
In addition to the drastic reduction of carbon emissions, UNESCO is advocating for the creation of an international fund for the monitoring and preservation of glaciers. Such a fund would support research, improve communication between stakeholders, help reduce risk and help warn people of danger.
Glaciers studied by UNESCO have been retreating at an accelerating rate since 2000 due to carbon dioxide omissions, the report says, and are currently losing 58 billion tonnes of ice each year, equivalent to the combined annual consumption of water. from France and Spain. These melting glaciers are also responsible for nearly 5% of observed global sea level rises.
“When glaciers melt rapidly, millions of people face water scarcity and increased risk of natural disasters such as floods,” said IUCN Director General Bruno Oberle, “and millions of ‘others could be displaced by the resulting rise in sea level’.
This story was originally published November 5, 2022 12:14 p.m.