Ice-free peaks in California for first time in human history

 New study finds, unprecedented glacier melting will lead to ice-free peaks in California for first time ever  

The glacier melt in California’s Sierra Nevada mountains is unprecedented, a new study shows. Mountain glaciers are a key feature of various US national parks, such as Yosemite National Park in California. But as the Earth warms, many of these century-old ice masses are rapidly melting. New research shows massive glaciers in Sierra Nevada projected to melt away by the beginning of the next century. This new study demonstrates just how novel the melt is for California’s Sierra Nevada glaciers. They are among the ice masses in the western US which the authors describe as “public-facing emblems of climate change”. Deep in California’s Sierra Nevada, massive glaciers are disappearing and projected to melt away completely by the beginning of the next century, leaving ice-free peaks for the first time in human history. The mountain range’s glaciers are older than previously known, dating back tens of thousands of years, with some as old as the last ice age.

The study looked at four glaciers in the Sierra Nevada: the Conness, Maclure, Lyell, and Palisade glaciers.  These formations are good “bellweathers” for looking at glacier disappearance, as they have withstood the test of time and industrial-era warming. Glaciers are losing more water each year than the world will consume in three decades, study warns. By analysing samples from exposed bedrocks, researchers were able to determine that the ice has been around far longer than previously thought. The glaciers have been around for at least the entire Holocene, or the 11,700 years since the last ice age. “Our reconstructed glacial history indicates that a future glacier-free Sierra Nevada is unprecedented in human history since known peopling of the Americas ~20,000 years ago,” the article states. Glaciers around the world are under threat amid the climate crisis. Study found that nearly 40% of glaciers are doomed to melt because of global heating. If such heating increases by 2.7C, which the world is currently on track for, as many as 75% will disappear, causing sea level rise and mass displacement.

Flowing ice was first documented in the region in the late 19th century. The eventual disappearance would mark the first time these mountain tops have been glacier-free. In the western US, mountain glaciers are projected to disappear by 2100 CE, according to previous research. Across the American west, glaciers have shrunk significantly, according to the article. The new research focuses on four Sierra Nevada glaciers – the Conness, Maclure, Lyell and Palisade glaciers – that are among the largest and likely oldest in the range. Their longevity amid climate warming makes them “bellwethers” for examining glacier disappearance in the west.

The melting of glaciers is a global phenomenon.  A recent study revealed that each year, as glaciers melt. Researchers looked at recently exposed bedrock around the glaciers and took samples to determine how long the area was covered by ice. They found that the glaciers have covered swaths of the range for much longer than previously known, since before humans occupied North America. There is potential for glaciers to bounce back if global warming is somehow reversed.  However, even if this were to occur, it would not happen in our lifetime. A recent study simulated glacier change under ‘overshoot scenarios” up to 2500. These are situations where the planet surpasses the 1.5°C limit up to 3°C, and then cools back down. “Our models show it would take many centuries, if not millennia, for the large polar glaciers to recover from a 3°C overshoot,” says Dr Lilian Schuster, lead author of the study. California’s glaciers reached their maximum positions as early as 30,000 years ago and one of the glaciers researchers looked at is thought to have expanded 7,000 years ago, earlier than previously believed. The disappearance of glaciers, for the first time in human history, shows the dramatic effects of the climate crisis.

“We’ll be the first to see the ice-free peaks,” said Andrew Jones, the study’s lead author and a doctoral student at the University of Wisconsin-Madison. “This has ecological implications for plants and animals. And it’s a symbolic loss. Climate change is very abstract, but these glaciers are tangible. They’re iconic features of the American West.” Europe has also seen enormous melting due to global warming. In Switzerland, the home to the most glaciers in Europe, more than 1,000 small glaciers have already disappeared. The Venita Glacier in Italy has also been greatly affected by the warming climate. Rapid melting and unstable terrain make it unsafe to visit, so geologists must now rely on remote monitoring tools to assess damage. Glaciers in Sweden and Norway are also melting faster than ever before. In 2024, the warmest year in Europe’s history, these glaciers experienced an average melt of approximately 1.8 metres. This exceeds historical averages. Glacial collapse is also becoming more frequent, threatening local communities. For example, a massive glacier landslide buried the majority of a Swiss alpine village earlier.