ENVIRONMENT

In the Swiss Alps, efforts to stop glacial melting have become commonplace. Each year, for example, a group of residents makes its way to the Rhône Glacier to cover up the ice in huge white blankets. (Smithsonian)

Adapt our activity to learn more about how light-colored surfaces have a cooling effect on Earth.

Teachers, scroll down for a quick list of key resources in our Teachers Toolkit.

Discussion Ideas

• How do white blankets help mitigate melting on the Rhône Glacier?
  • Light colors have a high albedo. This means they reflect much more radiation (heat and light) than dark colors. A black object is black because it absorbs all light; it’s not reflecting any color. White objects reflect all color.

• Have the low-tech white blankets been an effective tool against glacial melt?
  • Yes. Melting in the impacted area may be reduced by as much as 70%. (!)

• Is this a solution to the problem of glacial melt in the Alps, the Arctic, and elsewhere?
  • No. The stopgap measure cannot reasonably address the entirety of the Rhône Glacier itself, much less the massive ice sheets that cover Antarctica and Greenland.
  • Ultimately, reducing greenhouse gas emissions and slowing the current global warming trend is the only real solution. “Even if you have a way of restoring ice in the Arctic, it does not solve the CO2 problem, it doesn’t solve acidification of the oceans, it doesn’t fully decrease temperatures. It helps, but it doesn’t solve anything,” says one researcher.

• What are some other ways scientists are working to combat glacial melt? Read through this E&E News article for some help.
  • One organization, Ice911, hopes to mimic the blanketing idea on a larger scale with different material. Ice911 aims to “preserve Arctic ice by spreading our eco-friendly reflective sand on top of ice in strategic locations.”
  • Similarly, another research group “hopes to save Switzerland’s Morteratsch Glacier by blowing reflective artificial snow across its surface.”
  • Another suggestion is the use of wind-powered pumps “to draw seawater out of the ocean and onto the surface of the ice. Doing so during the winter would allow the pumped water to refreeze and thicken the existing sea ice.”
  • Another idea is to build a series of sills at the mouth of tidewater glaciers. Sills are freestanding structures made of stone, sand, or other material placed close offshore. These barriers would slow the process of warm ocean water melting the glaciers.

• The high-tech solutions listed above are examples of geoengineering, the large-scale manipulation of the earth to change one or more of its systems (here, the water cycle). Are the Rhône Glacier blankets an example of geoengineering?
  • Not really. The reflective fleece blankets are too small-scale to really be considered a geoengineering effort.
  • Unlike the ambitious geoengineering plans and proposals, the Rhône Glacier blankets are a great example of boots-on-the-ground engineering, already at work.

TEACHERS TOOLKIT

Smithsonian: This Swiss Town Is Protecting Its Glacier With a Blanket

AFP: Blankets cover Swiss glacier in vain effort to halt icemelt

Nat Geo: Feedbacks of Ice and Clouds

E&E News: Geoengineering: Can we refreeze the Arctic? Scientists are beginning to ask

Ice911