If global warming continues at its current rate, Frosty the Snowman won't be the only cultural-icon casualty. Consider the igloo — this Inuit ice hut can only be built where thick layers of hardpack snow form, and that snow will be difficult to come by as temperatures rise.
The weather outside may be frightful, but your cozy igloo will be a delightful 20–60 degrees Fahrenheit inside. It will also reinforce itself naturally, through constant melting and freezing, until it's strong enough to withstand natural disasters ranging from hurricane-force winds to (legend has it) over-curious polar bears.
Here's how to build your own igloo.
1. You'll need a sturdy stick. Find a clearing in hardpack snow. Make a circle where the base of the igloo will be. Tramp down the area inside for 15–30 minutes, then let rest for half an hour.
2. Grab a snow saw up to 20 inches long. In a nearby work area, cut blocks of hardpack snow 2.5 feet wide by 1.5 feet high by 0.5 feet deep.
3. Create base layer of igloo with blocks. One person works outside, one inside, to smooth blocks together and fill cracks.
4. Cut second row of blocks beveled at bottom so that the wall begins to climb and slant inward.
5. Fill final top hole with single block.
6. After igloo is complete, dig out floor with a snow spade to increase area of inner chamber. Then, dig entrance and cut one or two vents for air circulation.
Still have questions? This classic short film from 1949 shows how to make an igloo using only snow and a knife.
Story by Tobin Hack. This article originally appeared in Plenty in January 2008. The story was added to MNN.com in December 2009. Copyright Environ Press 2008.