The Morteratsch glacier in Switzerland has been shrinking ever since the Industrial Revolution. The glacier measured 5.3 miles (8.5 kilometers) long in 1860, but now is just 3.7 miles (6 kilometers). Every year, rising temperatures cause the glacier to lose dozens of meters in length. But scientists hope to reverse this trend using man-made snow as a type of sunblock.
The snow's job is to reflect sunlight away from the glacier, preventing it from heating up and melting. Snow has a relatively high albedo. In scientific terms, albedo refers to how well a surface reflects solar energy. There are no units, and values range between 0 and 1, with a 0 being a black surface that absorbs all solar energy and 1 being a perfectly reflective surface.
Ice has a pretty high albedo already, reflecting upwards of 70 percent of sunlight. But snow can reflect as much as 90 percent of the solar energy that hits a surface — and that near-30-percent increase in albedo makes a big difference. By producing man-made snow and distributing it throughout the summer, scientists hope to curtail the glacial ice's melt, and even allow the glacier to reverse the melting trend and grow a few meters each year.
The undertaking will be massive and expensive. You can't just blow a pile of snow on top of the glacier once and walk away. As snow melts, it forms ponds of liquid water atop the ice. These ponds have a lower albedo, meaning they absorb more energy and actually speed up the melting process, so multiple applications of snow will be necessary to keep the glacier protected.
According to Johannes Oerlemans, director of Utrecht University's Institute for Marine and Atmsopheric Research, covering a half-kilometer-square sector on the top of the glacier with a light layering of artificial snow throughout the summer should be sufficient to reverse the melting process. To produce that much snow, Oerlemans estimates the project will need 4,000 snow machines.
The plan calls for reusing meltwater, turning it into snow and eliminating the need to get water from somewhere else. That will help cut down on costs, but it would still be an enormously expensive endeavor. That being said, the Morteratsch glacier is a big tourist attraction for Switzerland. It could end up being a project that pays for itself through tourist cash.
Before the Swiss go all-in on the plan, Oerlemans and his team will conduct a pilot study, using their snow strategy to treat an artificial glacier. If the test is a success, then we may see more serious discussions about using snow machines to protect the ice.
Meanwhile, other scientists have similar ideas about how we could reverse Arctic ice melts. For example, have you heard about the plan to install wind-powered water pumps to generate more ice?