Scientists are fighting to harvest ice cores as glaciers melt

September 13 (Reuters) – Scientists compete to collect ice cores, along with records of long-frozen climate cycles, as global warming melts glaciers and ice sheets. Some say it is running out of time. And in some cases, it’s too late.

Late last year, German-born chemist Margit Schwikowski and a team of international scientists attempted to collect ice cores from the Grand Combin Glacier on the Swiss-Italian border for a supported climate monitoring effort. by the United Nations.

In 2018, they had explored the site by helicopter and drilled a shallow test core. The core was in good shape, Schwikowski said: it had well-preserved atmospheric gases and chemical evidence from past climates, and the radar that penetrated the ground showed a deep glacier. Not all glaciers in the Alps retain snow in both summer and winter; if all went as planned, these cores would have been the oldest so far, he said.

But in the two years it took scientists to return with a complete drilling rig, some of the information that had been trapped in the ice had disappeared. Freeze-thaw cycles had created icy layers and ponds of melted water across the glacier, which another team member described as a water-laden sponge, making the core useless to science. basic climate.

The sudden deterioration “tells us exactly how sensitive these glaciers are,” said Schwikowski, head of the analytical chemistry group at the Paul Scherrer Institute in Villigen, Switzerland. “We only arrived two years ago.”

The mission at Grand Combin underscores the great challenge scientists face today in collecting ice cores: some glaciers are disappearing faster than expected. Understanding is causing a renewed urgency, causing those who specialize in harvesting ice cores to accelerate missions, rethink where to aim, and expand storage capacity.

(Click here for an interactive Reuters chart showing how scientists extract ice cores and retrieve historical climate records.)

According to the United Nations, almost all glaciers in the world are shrinking. In its most comprehensive climate report to date, published in August, the UN concluded that “human influence is likely to be the main driver of the almost universal retreat of glaciers globally since the 1990s.” . The report also said that without immediate large-scale action, the average global temperature will reach or exceed 1.5 degrees Celsius above the pre-industrial temperature in 20 years.

The rate at which glaciers lose too much also increases. A study published in April in the scientific journal Nature found that glaciers lost 227 gigatons of ice annually between 2000 and 2004, but increased to an average of 298 gigatons a year after 2015. A gigaton is the equivalent of a billion metric tons. A gigaton of ice would fill New York City Central Park and be 341 meters (1,119 feet) high.

Currently, approximately 10% of the Earth’s surface is covered by glacial ice, according to the National Snow and Ice Data Center in Boulder, Colorado.

If a glacier melts and no longer accumulates snow, it means that it also does not capture atmospheric gases today so that scientists can study them in the future.

Two years ago, Sweden’s southern peak of Mount Kebnekaise lost the country’s highest point designation after a third of the summit glacier melted.

For Schwikowski, the disappearance of glaciers is not just a professional blow; it is also an emotional success. “Mountains look different without them, barren,” he said. In the Alps, glacier-free mountains are “absolutely terrifying.”

“COMPLETE SHOCK”

Last September, Schwikowski was wrapped in snow as the wet ice cylinders came out of the Grand Combin holes. The dampness surprised her, she said. Cold water drained from pieces of ice core that should have been solid. And the core, which should have been translucent, had perfectly clear sections.

Ice cores like those at Grand Combin have helped scientists illustrate the impact of humanity on the earth’s climate, providing a record of greenhouse gases dating back long before industrialization. The ice retains small air bubbles: direct evidence of past atmospheres. Ice also captures air pollutants, pollen, and other temperature and precipitation measurements in a single file, all on the same time scale, sometimes at the resolution of individual stations.

Another member of the Grand Combin expedition, Italian climate scientist Carlo Barbante, said the rate at which ice from the alpine massif had melted in recent years was “much higher than before.” Finding the wet cores was a “complete shock,” he said.

As a result, Barbante and other scientists, including Schwikowski, accelerated plans to extract a core from the Colle Gnifetti Glacier at the top of Monte Rosa in the Alps, a few hundred meters higher than Grand Combin. In June, several months ahead of schedule, they were launched. The two cores they drilled were of good quality, Barbante said.

Barbante said he also hopes to arrange a trip to Mount Kilimanjaro, the highest mountain in Africa and the only possible ice core site left on the continent, next year or next year. A study cited in the recent UN report calculated that the current warming has already set in motion the meltdown that will remove all mountain glaciers by 2060.

A discovery made in 2009 by American scientist Douglas Hardy about the mummified remains of a 19th-century pig in one of the highest points on the mountain glaciers suggests that part of the climatic history that the scientists hope to recover. “The implication of this is that we have lost [the] the time recorded over the last 200 years, ”Hardy said.

Barbante and Schwikowski are part of a group led by scientists called Ice Memory that is trying to build an archive of glacier ice cores around the world. Ice Memory is endorsed by the main UN cultural agency, the United Nations Educational, Scientific and Cultural Organization (UNESCO).

So far they have drilled in Europe, Bolivia and Russia. The cores are temporarily stored in Europe, but the plan is to send them to Antarctica for long-term storage, as the site would not depend on electricity, which could be disrupted.

“A hundred years from now, when the alpine glaciers are completely gone, we will have the samples” for future generations of scientists, Barbante said.

EXPANSION OF ICE STORAGE

Beyond greenhouse gases, scientists say they could use ice cores to study the DNA of ancient bacteria and viruses that could reappear as the world warms. Frozen insects and plant pollen could also reveal stories of the world’s forests and their fire cycles.

Another team of scientists, whose findings were published in July in the scientific journal Microbiome, found nearly 15,000-year-old viruses in two ice core samples taken from the Tibetan plateau in China. The findings identified genetic codes for 33 viruses, at least 28 of which were new to scientists.

This team of scientists included U.S.-based ice core paleoclimatologists Lonnie Thompson and Ellen Mosley-Thompson, who are husband and wife.

Lonnie Thompson said the speed with which the ice is disappearing has spurred plans to expand storage facilities at the Ohio State University ice core, which began raising funds last year. He hopes to raise $ 7 million. So far it has raised about $ 475,000 through donations and commitments, according to the school’s Byrd polar and climate research center. The renovation will double the storage capacity of the facility to exceed 13,550 meters of ice cores.

Some of the cores that Thompson and his team have collected are the only ice left from some glaciers. Two of Kilimanjaro’s six ice cores in Africa, which his team drilled in 2000, have disappeared. So have the sites that drilled in 2010 in Papua, Indonesia. Others are likely to disappear in 50 years, Thompson said.

In some cases, lakes formed on the surface of glaciers as the ice melted, a red flag indicating melting could be faster than previously predicted models. He said it was a wake-up call that the cores needed to be harvested as soon as possible.

“Ice has a wonderful record not only of climate, but also of the forces of climate,” the main causes of climate change, Thompson said.

Report by Cassandra Garrison in Mexico City, Clare Baldwin in Hong Kong and Marco Hernandez in Singapore Edited by Simon Scarr, Katy Daigle and Cassell Bryan-Low

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