The air was thin as scientists trudged through the snow near the peak of the Dagu Glacier in southwestern China on a gloomy June morning. It was quiet up there, 3 miles above sea level, except for the sound of running water – a constant reminder of the ice melting beneath their feet. As they trekked upwards, oxygen canisters tucked into their fleece jackets, porters walked alongside carrying thick rolls of white fabric. The researchers planned to spread those sheets designed to reflect sunlight and help glaciers lose heat.
Glaciers are melting fast. They’re a source of fresh water for rivers, and if they melt faster than they can be replaced, that water will flow into the oceans, raising sea levels worldwide. It’s a problem that’s difficult to solve. Even if the world can keep global warming below the 2 degrees Celsius target most countries agreed to in the Paris Agreement; most glaciers are expected to melt entirely by the end of this century. The blankets, which are white to reflect light before it strikes the ice, may slow that decline, but they won’t stop it.
“If the glaciers disappear, it’s a catastrophe,” says Zhu Bin, a Nanjing University associate professor leading the expedition. “We need to take every measure possible.”
The team’s first day on the glacier didn’t go well. The crew struggled in the waist-high snow, battling headaches and dizziness from the altitude. They couldn’t get the materials in place and had to turn back. It was a frustrating setback, reflecting the difficulty of doing this work.
The researchers finally finished laying down their sun-reflecting blankets a few days later. They’ll return in September to remove the shields and assess their effectiveness. They’ll also collect water samples to see if there are any environmental consequences. The project will run for three to five years, after which the scientists will decide whether to try using their material on other glaciers in China or abroad.
The effort to preserve Dagu reflects a more comprehensive determination in China and worldwide to identify ways to respond to climate change. Many of these approaches can potentially have unexpected and unintended consequences, including the risk of contaminating water supplies with chemicals or plastic particles. That’s why scientists must evaluate them carefully, think about the bigger picture, and not jump into any quick fixes. But this doesn’t mean there’s no hope for avoiding the worst of climate change, which will still require enormous cuts in emissions. It also requires the development of technologies to remove carbon dioxide from the atmosphere, a process known as carbon dioxide removal (CDR) that can potentially offset the impacts of climate change and prevent its worst effects. China is the first to announce that it plans a large-scale deployment of CDR, and others are following suit.