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Deep in the state of Sierra Nevada, enormous glaciers are disappearing and projected to melt away entirely by the start of the next century, resulting in summits without glaciers for the first time in recorded human existence, new research has discovered.

Ancient Beginnings of Sierra Nevada Glaciers

The range's ice sheets are older than earlier understood, tracing back many thousands of years, with a few as ancient as the last ice age, according to a report released last week.

“Our pieced-together ice age record shows that a future ice-free Sierra Nevada is without precedent in human history since documented peopling of the Americas ~20,000 years ago,” the study states.

Worldwide Threat to Ice Formations

Ice masses globally are at risk amid the climate crisis. A study published in May of this year found that nearly 40% of glaciers are destined to thaw because of climate warming. If such heating increases by 2.7C, which the world is currently on course for, as up to 75% will vanish, leading to sea level rise and mass displacement.

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

Focus on Key Ice Bodies

The new research focuses on four Sierra Nevada glacial masses – the Palisade, Lyell, Maclure and Conness ice sheets – that are some of the largest and likely oldest in the mountain chain. Their longevity amid global heating makes them “bellwethers” for examining glacier disappearance in the western region, the study states.

Study Techniques and Findings

Scientists examined newly uncovered bedrock around the ice formations and took samples to determine how long the area was blanketed by ice. They found that the glaciers have covered swaths of the mountain system for far longer than previously known – since prior to humans inhabited North America.

California’s glaciers attained their peak extents as early as 30,000 years ago, the study's researchers wrote, and a particular of the glaciers experts studied is believed to have grown 7,000 years ago, sooner than previously believed. The loss of ice formations, for the first time in recorded history, shows the dramatic effects of the climate crisis, a researcher of the investigation said.

Environmental and Symbolic Impact

“We’ll be the first to see the ice-free peaks,” said Andrew Jones, the principal investigator. “This has ecological implications for flora and fauna. And it’s a representational decline. Climate change is highly intangible, but these glaciers are concrete. They’re symbolic elements of the Western U.S..”