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Deep in California’s Sierra mountain range, massive glaciers are disappearing and expected to dissolve entirely by the beginning of the next century, leaving summits without glaciers for the initial occasion in human history, new research has found.

Age-Old Beginnings of Sierra Range Glaciers

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

“Our reconstructed ice age record shows that a coming glacier-free Sierra Nevada is without precedent in human history since known peopling of the Americas around twenty thousand years ago,” the article declares.

Worldwide Risk to Glaciers

Glaciers globally are under threat amid the climate emergency. A study published in May of this year determined that almost forty percent of glaciers are destined to thaw because of climate warming. If such heating rises by 2.7C, which the world is presently on track for, as many as seventy-five percent will vanish, causing sea level rise and large-scale relocation.

Throughout the Western United States, ice formations have shrunk substantially since they were initially recorded in the 1800s, according to the report.

Focus on Major Glaciers

The recent study centers on four Sierra Nevada glaciers – the Palisade, Lyell, Maclure and Conness glaciers – that are some of the largest and likely oldest in the range. Their durability during climate warming makes them “indicators” for studying ice loss in the west, the study notes.

Research Methods and Results

Scientists looked at recently exposed base rock around the ice formations and took samples to determine how long the area was covered by ice. They found that the ice masses have enveloped swaths of the mountain system for much longer than previously known – since before people inhabited North America.

The state's glacial sheets attained their maximum positions as long ago as 30,000 years ago, the article’s authors wrote, and one of the ice bodies researchers looked at is believed to have expanded seven thousand years ago, earlier than once thought. The disappearance of glaciers, for the initial time in human history, demonstrates the dramatic impacts of the climate change, one author of the investigation said.

Ecological and Symbolic Impact

“We’ll be the first to see the ice-free peaks,” said the study's lead researcher, the study’s lead author. “This has ecological implications for plants and animals. And it’s a symbolic loss. Climate change is highly intangible, but these glaciers are concrete. They’re iconic features of the Western U.S..”