In 1976, Alejandra Melfo and her family joined the tens of thousands of Uruguayans fleeing their country’s military dictatorship. Melfo, who was 11 when her family arrived in Venezuela, remembers delighting in the lighthearted Venezuelan national anthem, and realizing that her blond hair and pale skin were unremarkable in a country where generations of Portuguese, Spanish, and Italian immigrants had also found refuge and opportunity.

When Melfo was a teenager, she and her family moved to the prosperous university city of Mérida, in the mountains of western Venezuela, and she became one of the many foreign-born students at the University of the Andes. The Venezuelan government had invested a sizable portion of the country’s oil wealth in education and research, and the university—the first in Latin America to be connected to the internet—was known throughout the continent and beyond for its scientific accomplishments. For Melfo, it became a professional home: A theoretical physicist, she joined the faculty even before she completed her doctorate, and served as a professor at the university for 25 years.

Though Melfo officially retired in 2016, she is one of the few faculty members still on the job. As Venezuela has descended into political and economic crisis, the university has endured rising street crime and armed raids of campus buildings. Professors and students have left in droves, and classrooms are dark and empty; because of the country’s crushing inflation, the remaining professors earn as little as $3 a month.

Melfo, who once focused her considerable energies on supersymmetric theory, now has a more tangible and pressing concern. High in the mountains above Mérida lie the fast-melting remnants of Venezuela’s once-extensive glaciers, and when they’re gone, the unique organisms they contain will also be lost to time. Melfo can no more save her adopted country’s glaciers than she can reverse its political and economic unraveling—but she knows Venezuela’s glaciers have a scientific legacy, and that she is determined to protect.

Mérida lies on a high plateau at the foot of the Sierra Nevada de Mérida, a range that includes five of Venezuela’s highest peaks: Humboldt, Bonpland, El Toro, El León, and Bolívar, all more than 15,000 feet above sea level. Thousands of years ago, the ridgelines of the Sierra Nevada were crusted with as much as 50,000 acres of permanent ice, which was protected from the tropical sun by aspect and elevation, and which advanced and retreated in response to global temperature cycles. By the 1830s, when the Italian soldier and geographer Agostino Codazzi surveyed the area on behalf of the newly independent Venezuelan government, a prolonged global cooling period now known as the Little Ice Age was coming to an end, and the glaciers were shrinking.

Locals noticed the difference: “For some time now, people have been saying that the snow in the Sierra is decreasing,” the Mérida storyteller Tulio Febres Cordero wrote in 1890. “The older neighbors point out, with sadness, all the places where the snow has completely disappeared.”

In 1910, detailed maps made by the Venezuelan explorer Alfredo Jahn showed that the Sierra Nevada glaciers had shrunk to a total extent of about 2,500 acres. In the small mountain towns above Mérida, some men still made a living as hieleros, or ice men: With machetes, they would chop blocks of ice from the glaciers, wrapping hundred-plus-pound blocks in thick leaves and storing them in leather suitcases. The hieleros would make the six-hour journey to Mérida, transporting the ice-filled suitcases by mule or on their own backs. The ice blocks, much diminished, would then be used to make the glacier-sourced ice cream sold in the central market.

Over the past century, as human activities increased global average temperatures far beyond those experienced during previous warming cycles, glacial melting in the Sierra Nevada accelerated. An aerial survey in 1952 showed that the total glacier area had shrunk by almost three-quarters in the previous four decades, to about 700 acres. By 1985, it was down to 200 acres, and in 2008, fewer than 80 acres of glacier remained.

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Average temperatures in Mérida are about 10 degrees warmer than they were 20 years ago, but the area is still much cooler than the rest of the country, and until the recent upheaval in Venezuela, the city was a popular destination for domestic and foreign tourists. Merideños pride themselves on their politeness and hospitality, and would often point the way to local attractions: glacier-fed mountain lagoons, the country’s national astronomical observatory, or the highest cable car in the world, which carries visitors from the edge of the city toward the top of the 15,633-foot-high Pico Espejo. Near the summit, in 1961, Venezuela held a national skiing competition. Under the right conditions, it is still possible to see snow.

In 2008, the Venezuelan ecologist Ángel Viloria predicted that the country’s glaciers would be entirely gone by 2020, making Venezuela the first country on Earth to lose all of its glaciers. Viloria, the director of the Venezuelan Institute for Scientific Research in Caracas, not only backed up his prediction with decades of research and observations, but also bluntly assigned blame: Human-caused climate change, he said, was largely responsible for the melting.

Government officials quickly disputed Viloria’s prediction. They claimed that the data he’d cited weren’t reliable; that the melting was caused not by human activities but by a long-term warming cycle; that a new era of “global cooling” would soon restore the glaciers.

Global cooling, however, did not come to the rescue. In 2009 and 2011, when the Venezuelan geologist Maximiliano Bezada and his American colleague Carsten Braun conducted the most recent aerial and ground surveys of the glaciers, they estimated that there were only 25 acres of ice left, all of it in a single glacier on Pico Humboldt.

“Glaciers have been a part of the identity of the Venezuelan mountains and their people for a long time, and their disappearance will leave a gap—both physically on the landscape, but also—and perhaps more importantly—spiritually. It was ‘normal’ to go to the mountains and see the glaciers. The ‘new normal’ for future generations will be a different Sierra Nevada,” Braun says.

Andrés Yarzábal, a microbiologist at the University of the Andes who had studied the effects of climate change in Antarctica, recognized that unique organisms were likely disappearing along with the ice. Though spending cuts by the Chávez government had made government research grants almost impossible to come by, Yarzábal managed to secure some support from the National Fund for Science and Technology for what he called the “Vida Glacial” project, including an expedition to Pico Humboldt and its glacier in 2012. The trek took five days, and the frigid, blustery conditions were grueling; to sterilize their collecting instruments, Yarzábal and his colleagues had to hunch over camp stoves in the freezing wind.

Alejandra Melfo, meanwhile, was expanding her research interests beyond physics to molecular biology and genetics, and a friend introduced her to Yarzábal. Like many others, she had noticed the retreat of the Sierra Nevada’s snow and ice, and she was both intrigued by Yarzábal’s research and impressed by the urgency of his mission. Melfo helped organize and search for private funding for a second expedition, this time to the glacier on Pico Bolivar, which has since disappeared. Melfo trained for several months with a professional climber before the expedition, and even helped Yarzábal through a life-threatening bout of altitude sickness during the trip.

Together, the two expeditions yielded 600 microbial strains, now stored in deep freezers at the university. About 30 percent of the strains have been identified so far; most are previously unknown to science, and among them are bacteria capable of dissolving phosphorus, an essential plant nutrient. “We were able to show that they behave as growth promoters of certain plants at low temperatures, so it’s possible that they could be useful as biofertilizers,” Yarzábal says. Such fertilizers, he says, could improve the sustainability of agriculture in mountain regions.

After Chávez’s death and the 2013 election of his successor, Nicolás Maduro, scientific research in Venezuela became even more challenging. Inflation made it difficult to buy basic lab supplies, much less the thousands of dollars of food, medicine, and equipment required for another glacier expedition. Outbreaks of street crime and paramilitary violence in Mérida made it dangerous for university researchers to work in the labs during weekends or at night. “We sometimes had to abandon experiments for weeks at a time,” Yarzábal says.

Yarzábal had even greater fears. His two children, 7 and 8 years old, were leaving school one afternoon when they heard gunshots. It turned out that another father from the school had witnessed an attempted kidnapping nearby, and used his own gun to kill two of the kidnappers.

Yarzábal, who, like Melfo, had emigrated from Uruguay to Venezuela as a child, realized that he had to leave the country that had once given him refuge. Yarzábal signed up with Prometeo, an Ecuadorian government program aimed at attracting scientific talent, and he and his family moved to Ecuador during his sabbatical year in 2014; he now works at the University of Cuenca.

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This past fall, the only trained microbiologist left in the laboratory was Johnma Rondón, the second-youngest researcher on the entire Vida Glacial project team. Rondón, who helped identify the microbial strains from the glaciers as part of his doctoral dissertation, was responsible for maintaining the strains stored in the freezers in Yarzábal’s lab—no easy task in a country where power failures are frequent. “Many times I would come to the lab on Mondays to find puddles of water around the freezers caused by prolonged blackouts,” he says.

On October 28, Rondón left Venezuela, too, becoming one of the estimated 3 million Venezuelans—some 10 percent of the population—to have emigrated in recent years. The border between Venezuela and Colombia, once one of the busiest in the world, is now closed to traffic, so Rondón planned to cross the border by foot. He made a farewell visit to the lab, leaving some climbing gear with Melfo in hopes that she would once again be able to access the glacier. Melfo hugged him goodbye.

When Rondón reached the border city of Cúcuta, Colombia, he traveled to the Colombian capital of Bogotá, and from there to Buenos Aires, Argentina. He is now a postdoctoral student in Argentina, and unless conditions change in Venezuela, he doubts he will return.

Melfo kept a blog during this time, writing not only about fermions and glaciers but also about longing. She described the absence of her colleagues; the quiet labs; the empty homes inhabited by caretakers who water the plants in exchange for shelter.

“M. doesn’t work in the lab anymore,” she wrote in November. “Neither does A. or W., or J., who was the last to leave. Inside, the work tables are clean, the test tubes sit on their shelves, the Petri dishes are inside their sterile bags; the samples are inside the fridge, in the right order, frozen. J. didn’t erase the blackboard, and it still has an equation on it. The lab still has the quality of a home, even though A. has taken his kids’ pictures. It still echoes with the joy M. felt when the money for the incubator finally arrived, and the laughter of W. His lighter is still in the place he left it.”

Melfo and a few university colleagues continue to maintain the freezers, though blackouts are frequent and often lengthy. With no resources to continue her work in molecular biology, she is once again expanding her research interests, this time into ecology, and she and a handful of remaining biology students are monitoring the impacts of climate change on high-altitude biodiversity as part of the GLORIA-Andes project. They must write up their field data forms by hand because their printers have run out of ink. Their rubber boots are broken; their camping tents, and even their gloves and scarves, are borrowed. Supplies are stored in a recycled cardboard box once used for government-subsidized food staples. “Someone will donate a bit of cooking oil, others will give some rice, and when we have collected enough, we head out,” Melfo says. If the weather turns bad during a day of fieldwork, they put up umbrellas and and keep going, because rescheduling the trip would require too much gasoline.

“Five years ago, even three years ago, we had scholarships for postgraduates and funding for expeditions,” Melfo reflects. “Now we are a poor country, without money for fieldwork.”

Melfo continues to seek international funds and support for glacier research in Venezuela. She edited a book, Se Van Los Glaciares (The Glaciers Are Going), that includes chapters written by Yarzábal, Bezada, and others, and drew national media attention when it was published last summer. She says she still hopes to return to the highest peaks of the Sierra Nevada: She wants to see what kind of bacteria are left in the remaining ice, and what the retreating glacier has revealed. Even when the glaciers completely disappear, she argues, the decades of data and the surviving microbial samples can be used for comparative studies in the Andes and elsewhere. “The investigation of the glaciers of Venezuela has no expiration date,” she says.

On December 11, International Mountain Day, the president of Venezuela’s National Parks Institute, Josué Lorca, visited Mérida to announce measures intended to lengthen the life of the glacier on Pico Humboldt—the same glacier whose pending disappearance the government denied a decade ago. During Lorca’s press conference, officials presented plans to clean up waste from the national park near the glacier, demarcate safe camping areas, and ban tourist visits to what’s left of the ice. They refused to take reporters’ questions.

Melfo spent the Christmas holiday with her family in Uruguay, but she has returned, once more, to the empty lab, the broken boots, and the handwritten data sheets. She has returned, voluntarily, to the country that welcomed her as a child. She says she doesn’t want to leave a place that truly feels like hers, or abandon the few remaining students who insist on continuing their studies. The Sierra Nevada of Mérida, she says, is her home—even though it rarely snows here anymore.

Translated from Spanish by Ruxandra Guidi.