On a dreary June morning, a group of geologists hiked through the snow near the peak of the Dagu Glacier in southern China. The only sound up there, 3 miles above sea level, was rushing water, a constant reminder of the ice melting just beneath their feet. Porters went alongside them carrying big rolls of white fabric as they trekked upwards, oxygen canisters tucked into their fleece jackets. The sheets were to be strewn across more than 4,300 square feet of the mountain by the researchers. The film was created to reflect the sun’s rays into space, essentially sheltering the glacier from the heat and, ideally, retaining part of its ice.
Dagu has supported the lives of tens of thousands of people who live in its vicinity for decades. The glacier’s meltwater provides drinking water and contributes to hydropower generation. At the same time, the beautiful views of the Tibetan Plateau draw over 200,000 tourists every year, fueling an industry that employs over 2,000 people. All of this is now under threat as the world warms.
The Grim reality: Battling glacier melting in the face of climate change
The Chinese researchers had no illusions that their study would save Dagu. Over the last half-century, the glacier has lost over 70% of its ice. According to one researcher, such efforts are similar to a doctor simply attempting to prolong the life of a terminally ill patient by a few years. The only effective treatment would be to drastically cut emissions of planet-warming carbon dioxide, of which China is the world’s biggest source.
“All the human intervention methods that we’re working on, even if they prove effective, are only going to slow down” the melting, said Zhu Bin, the 32-year-old Nanjing University associate professor leading the expedition. “If the Earth keeps getting warmer, in the end, there is no way to protect the glaciers forever.” This was not the kind of fieldwork that Zhu had set out to do.
He was trained as a material scientist and spent the majority of his time in laboratories in Nanjing and New York, including more than a year investigating battery storage at Columbia University. Some of his academic colleagues were perplexed by his decision to abandon the convenience of conducting research in an air-conditioned environment. His family was concerned about his safety, but they eventually came around because they saw glacier preservation as “something difficult but right.”
Potential benefits and concerns of glacier covering with reflective material
It is not a novel notion to cover glaciers with sheets of reflective material. For nearly two decades, European ski resorts have used white blankets to protect their snow. However, China has only recently begun experimenting with the strategy. Small trials conducted on a glacier in Xinjiang and Dagu beginning in 2020 appear to have slowed their retreat.
This time, Zhu’s team was experimenting with a new material that, according to their research, has the potential to reflect more than 93% of sunlight and assist Dagu in actively losing heat. To reduce its environmental impact, the film is comprised of cellulose acetate, a natural fiber derived from plants. The chemical can also be employed as little particles deposited on less accessible glaciers by drones. The expedition’s first day did not go well. The plan was to use steam drills, timber frames, and nail guns to fix the white sheets to the glacier, but the crew experienced headaches and dizziness due to the high altitude. The waist-high snow became too risky to continue as they advanced deeper into the glacier. They decided to turn back when the weather forecast showed a rainstorm arriving in the next hour.
Previous research has shown that covering areas of glaciers with specific materials can minimize snow and ice melting by 50% to 70% when compared to unprotected surfaces. However, chemicals or plastic particles from the sheets could have a harmful influence on local ecosystems and downstream water quality, according to Matthias Huss, an ETH Zurich professor of glaciology. Covering massive glacier areas could have far-reaching and unanticipated repercussions.
“It’s a very good solution to locally combat the effect of climate change,” said Huss, especially when there are specific economic benefits. However, the real answer is “very clear,” he said: “It’s to save the climate.”
Importance of reducing carbon emissions
According to Johannes Oerlemans, a scientist at Utrecht University, the sheets that Zhu and his team carried up Dagu wouldn’t be effective on larger glaciers anyhow because they are continuously moving. “For small glaciers that are kind of dying and don’t move, you can cover them easily,” he said. “But as soon as the glacier moves, the cover is destroyed.”
According to Oerlemans, not only is the infrastructure required to lay the sheets on a huge glacier problematic, but dirt would certainly accumulate over time, darkening the surface and diminishing their capacity to reflect sunlight. Instead, he proposes the placement of artificial snow. Oerlemans worked on a project that aimed to spread snow created from meltwater on a Swiss glacier without the need for energy.
After the weather improved on the fourth day of the Dagu expedition, Zhu’s team was finally able to lay down the sun-reflecting sheets. They’ll return in September to take down the shields and measure how well they worked. Water samples were also collected by the researchers to assess the environmental impact. The experiment will last three to five years, after which the scientists will determine whether to test their materials on other glaciers in China or take them abroad.
The project is backed by the local tourism agency and digital behemoth Tencent Holdings Ltd., which contributed funding through a sustainability initiative. While there is a financial motivation to save Dagu, everyone engaged reiterates the same message: the most essential thing is to trim. the most important thing is to cut carbon emissions that are causing it to melt in the first place.
The great majority of glaciers on the planet are fast receding, resulting in rising sea levels
The Tibetan Plateau rose to its current height over tens of millions of years. When the Indian and Asia tectonic plates collided, the top became frigid enough to support the glaciers and snow that feed nearly all of the region’s major rivers, including the Ganges, Mekong, and Yangtze. They are vital lifelines for billions of people across Asia. In comparison, the opposite is occurring at breakneck speed: the plateau has lost more than 15% of its glaciers in just 50 years.
The great majority of glaciers on the planet are fast receding, resulting in rising sea levels and devastating floods. Partially covering them with sunlight-reflecting blankets is like putting a band-aid on a leaking wound. Even if the world manages to keep global warming below 2 degrees Celsius above pre-industrial levels – the aim most countries committed to when they signed the Paris Agreement in 2015 – less than half of the Alps’ about 4,000 glaciers will exist by the end of the century.
Huang Shihai, deputy director of the Dagu Glacier Management Bureau, has witnessed personally the effects of climate change on Heishui County, which is located at the glacier’s base. Since arriving there in 2006, he’s seen summers arrive earlier, winters get warmer, rivers become filthy, and extreme weather events become more often. Huang never wore short-sleeved shirts because he lived near the chilly mountain. He now starts wearing them as early as May of each year. He is continually concerned that Dagu will vanish and that the people who rely on it will suffer as a result. “There’s a sense of crisis,” he said.