Concerns over melting glaciers in mountains like El Plomo

On a clear day, the imposing hill The lead in Chile, peaking at 5,400 meters above sea level, is visible from Santiago. The snow-capped, glacier-covered Andean mountain has been climbed and venerated for centuries, and the Incas performed human sacrifices at its summit.

The path to its summit remains the same path left by the Incas, with archaeological remains scattered around. In 1954, an Inca mummy was discovered near the summit, perfectly preserved thanks to the dry and cold conditions of the mountain.

But today, El Plomo Hill is collapsing. Rising temperatures due to climate change have caused glaciers to retreat and permafrost to melt. New lagoons have formed and disappeared, landslides have injured climbers, and huge sinkholes have opened up, blocking the old path to the summit.

“Every year it changes more. Every year we see more sadness,” Francisco Gallardo, a 60-year-old muleteer who has worked in the mountains since he was 14, told Reuters at the federation’s base camp, about 1,300 metres (4,300 feet) below the summit.

Gallardo said his family has worked in El Plomo for generations, but he thinks they have about a decade left before they’re forced to move.

“We’ll have to look elsewhere. Let’s see what we can do (…) Start in the south,” he said.

Just a few years ago, the final push to the summit required crossing a glacier. Now, the final climb is a rocky slope. Gallardo said mules were able to reach another camp about 500 meters higher and remembers them feeding on grass around base camp.

The Federation camp was deserted during a visit in April, with earth and stones piled near the mountain slopes that Gallardo said were usually covered in snow and ice.

“The changes we are seeing are unprecedented in recent human history,” said Pablo Wainstein, a civil engineer who has studied Andean and Arctic glaciers and permafrost for more than two decades.

The Andes have different types of frozen formations, such as covered and uncovered glaciers, in addition to rock glaciers. The latter, composed of a mixture of debris and terrestrial ice, respond more slowly to climate changes than bare glaciers where the ice is exposed.

At high elevations, mountains can also have a layer of permafrost, defined as ground that has temperatures below freezing for more than two years. When there is ice in permafrost, it can bind soil, gravel, and sand together.

“If permafrost degrades, it no longer ‘cements’ the ground and causes more rockfall in mountainous terrain,” Wainstein explained, adding that permafrost change is more difficult to study because it involves the thermal state of the ground and is not visible at the surface.

Glaciers in the Andes are understudied compared to other regions because of their size and the distance from many mountains, Wainstein says.

Among the best witnesses of these changes are the people who work in the mountains, who climb the same routes year after year, decade after decade.

Osvaldo Segundo Villegas began working in mountain rescue in 1964 and participated in the rescue of the Uruguayan rugby team, an accident that inspired the Oscar-nominated film, The Snow Society.

Villegas, now 80, says his first ascent of El Plomo was in the 1960s, when a long glacier traverse was required and the slopes were covered in magnificent 10-foot-high “penitentes”: thin layers of compacted snow and ice facing the sun, which form when compacted snow melts in the cold, dry Andean air.

Some hanging glaciers that I used to climb are now just rock walls. “When you’re not here, and I’m not here, everything will be lost. And that’s how it will be,” he said. “The same thing is happening in Patagonia (…) there are several places where there was ice, big glaciers, now where there were glaciers, there is forest.”

Wainstein says the changes are consistent with scientific predictions. The Andes are the longest in the world and have some of the fastest-disappearing ice caps. Venezuela was the first country to lose its last glacier last May.

The Andes are home to about 99% of the world’s tropical glaciers, which are more susceptible to climate change because they are constantly near or at freezing. Data from the US National Oceanic and Atmospheric Administration (NOAA) show that global temperatures have risen by 0.06 degrees Celsius per decade since 1850, accelerating to 0.20 degrees Celsius per decade since 1982.

The Andes are a vital part of the South American water cycle. Their snow caps store water as snow and ice during the winter and slowly melt during the warmer months. They provide water to millions of people in the region, not only for direct consumption but also for agriculture, hydropower and mining.

The retreat of the glaciers has exposed acidic rocks for the first time in centuries, making the meltwater acidic and contaminated with heavy metals that then leach into other reserves, an increasingly scarce resource for many South American countries crossed by the Andes.

Heavy and erratic rainfall has degraded ecosystems, making them more vulnerable to erosion, landslides and flooding.

Temperatures are rising faster at higher altitudes. A study published in the International Journal of Applied Earth Observation and Geoinformation shows that winter daytime temperatures on the surface of the Andes have increased by 0.50 degrees Celsius per decade since 2000 at an altitude of 1,000 to 1,500 meters, but have increased by 1.7 °C above 5,000 meters.

Octavio Salazar made his first ascent of the season on Peru’s Mount Yanapaccha in early May. “It shouldn’t rain,” he said at base camp. At this time of year, the rains would normally have passed at an altitude of 5,000 meters; any precipitation should be snow.

Salazar and his brother Eloy are an indigenous Quechua people who have spent decades climbing the mountains of Peru’s Cordillera Blanca in the department of Ancash, the largest glacier-covered area in the tropics and home to several 6,000-meter peaks, including the highest in the country.

The brothers opened an expedition agency in 2010. One of their first activities that season was ice climbing to the summit of Yanapaccha, at more than 5,400 meters above sea level.

As they rounded a rocky hill to begin the ice climb, they found that the glacier had retreated several metres since last season. They now had to descend again through an unstable rock moraine to reach the glacier, which was blackened by dirt, pollution and the lack of new snowfall.

The nighttime crossing of the glacier required jumping over crevasses, traversing thin ice traverses and quickly crossing rockfall hazard zones. The summit, known for offering some of the best views of the Cordillera Blanca, was shrouded in gray, freezing rain that formed a layer of ice around everything it touched.

“We believe that, in fact, the climate is undergoing such drastic changes that many times they call into question all knowledge,” said Edson Ramírez, a park ranger and risk assessor for Huascarán National Park, which includes 90% of the Cordillera Blanca.

“That raindrops fall at 5,000 meters above sea level is neither common nor natural. That is, it is an indicator that the pressure and temperature are totally modified,” Ramirez said.

Rain also prevents new snowpack from forming to replace the mass of the glacier as it slowly moves down the mountain.

“By not having more glacier in the upper part to cover the cracks and everything else, it becomes a difficult labyrinth to cross,” Ramirez explained.

It’s not just the changing weather that has led to more accidents, but there’s also been an increase in visitors, many of whom have limited experience, Ramirez says.

But even experienced guides are at risk. Last year, Edgar Huamán was crossing an area of ​​Huascarán, Peru’s highest mountain. He was guiding two French clients when an ice bridge collapsed, killing him.

“He was one of the best guides, quite strong,” said Rusbel Vidal, who earned his certification from Huamán.

Climate change is also affecting where and how winter sports are played. Pastoruri Mountain in Peru used to host ski competitions and is now a disappearing glacier, with the remaining ice field sealed off due to the risk of icefall.

“Any human activity carries risks, but that doesn’t mean we won’t want to enjoy our mountains,” said Cristian Ramírez, head of the mountain rescue unit in Santiago, Chile.

“The Andes are the backbone of this territory,” he said. “In a way, they modulate our lives because they collect ice, they collect water (…) Ultimately, mountains are life and we are privileged to be able to have a mountain range next to us.”