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Deep in California’s Sierra mountain range, massive glaciers are disappearing and projected to melt away entirely by the start of the next century, leaving ice-free peaks for the initial occasion in recorded human existence, new research has discovered.

Age-Old Origins of Sierra Range Ice Masses

The mountain range’s ice sheets are older than earlier understood, tracing back tens of thousands of years, with some as ancient as the most recent glacial period, according to a report published last week.

“Our pieced-together ice age record indicates that a future glacier-free Sierra Nevada is unprecedented in the history of humankind since known peopling of the Americas ~20,000 years ago,” the study declares.

Global Risk to Ice Formations

Ice masses around the world are under threat amid the climate emergency. A study released in May of this year found that nearly 40% of glaciers are destined to melt because of global heating. If this warming increases by 2.7 degrees Celsius, which the planet is currently on track for, as many as seventy-five percent will disappear, causing ocean level increase and large-scale relocation.

Throughout the American west, ice formations have shrunk significantly since they were first documented in the late 19th century, according to the report.

Focus on Key Ice Bodies

The recent study focuses on four Sierra Nevada glacial masses – the Palisade, Lyell, Maclure and Conness glaciers – that are some of the largest and likely most ancient in the range. Their longevity during global heating makes them “indicators” for examining glacier disappearance in the west, the study states.

Research Methods and Findings

Scientists looked at recently exposed bedrock around the glaciers and collected specimens to ascertain how long the area was covered by ice. They found that the glaciers have covered swaths of the mountain system for far longer than earlier believed – since before people occupied North America.

California’s glacial sheets attained their maximum positions as long ago as 30,000 years ago, the article’s authors wrote, and one of the glaciers researchers looked at is believed to have expanded seven thousand years ago, sooner than previously believed. The loss of ice formations, for the first time in recorded history, shows the profound impacts of the climate change, one author of the study said.

Environmental and Representational Consequences

“We’ll be the first to see the glacier-less summits,” said the study's lead researcher, the study’s lead author. “This has environmental ramifications for plants and animals. And it’s a symbolic loss. Global warming is highly intangible, but these glaciers are concrete. They’re iconic features of the Western U.S..”