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Far in the state of Sierra Nevada, massive glaciers are vanishing and expected to melt away completely by the start of the coming hundred years, leaving ice-free peaks for the first time in human history, new research has found.

Ancient Origins of Sierra Nevada Ice Masses

The mountain range’s ice sheets are more ancient than previously known, tracing back many thousands of years, with some as old as the most recent glacial period, according to a report published recently.

“Our pieced-together ice age record indicates that a future glacier-free Sierra Nevada is without precedent in the history of humankind since known peopling of the Americas ~20,000 years ago,” the article states.

Global Risk to Glaciers

Ice masses around the world are at risk amid the climate crisis. A study published in the month of May of the current year found that almost forty percent of glaciers are doomed to melt because of climate warming. If this warming rises by 2.7C, which the planet is currently on track for, as many as seventy-five percent will disappear, causing sea level rise and mass displacement.

Throughout the American west, glaciers have diminished substantially since they were initially recorded in the 1800s, according to the report.

Focus on Major Glaciers

The new research centers on four Sierra Nevada glacial masses – the Palisade, Lyell, Maclure and Conness ice sheets – that are among the largest and probably oldest in the range. Their durability during global heating makes them “bellwethers” for examining glacier disappearance in the western region, the article notes.

Study Techniques and Results

Researchers examined newly uncovered base rock around the glaciers and took samples to determine how extensively the region was covered by ice. They found that the glaciers have covered large areas of the range for far longer than earlier believed – since prior to people occupied North America.

The state's glacial sheets attained their peak extents as early as thirty thousand years ago, the study's researchers wrote, and one of the glaciers experts looked at is believed to have grown 7,000 years ago, earlier than previously believed. The loss of glaciers, for the first time in recorded history, demonstrates the dramatic impacts of the climate change, a researcher of the study said.

Environmental and Representational Consequences

“We’ll be the first to witness 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 representational decline. Global warming is very abstract, but these ice masses are tangible. They’re iconic features of the American West.”