Published on July 19th, 2010 | by Susan Kraemer
One Way Climate Change Will Change the Way We Build
A village in Alaska has had to find a way to counteract the effects of an ongoing permafrost melt that has destabilized the ground beneath homes in the village. New building techniques may be the result.
With a 3.3° C rise in the region’s average air temperatures over the last twenty years, some buildings have cracked and slipped in the Alaskan village of Salluit on the Hudson Strait, because the permafrost beneath the village is melting. Ground temperatures have risen a third as much.
These structural problems are due to the permafrost melt as the result of global climate change that has already begun. Alaska is one of those regions that has warmed by more than the global average.
Although climate change so far averages out to just 1° C or so worldwide, that world average is the sum total of all the regional increases in some places, and in other places; decreases, forming the new global average temperature.
Previously, the plan was to simply abandon the village, and build a new one, but, as you can imagine, it is an emotionally wrenching decision for a whole village to abandon its homes. So residents worked with an soils engineering firm on a new land use and development plan that enabled them to keep some of the original homes.
To avoid problems in the future, new construction techniques will be used, says the consulting company the village hired; FoTenn urban planning and design of Otttawa.
They will still grow the small village of 1,200, up to doubling its numbers, by building new homes only on a nearby outcropping of bedrock where they can sink more pylons into the bedrock. But existing structures on the sinking permafrost will be retrofit in a way to cool the earth under them, preventing further slippage.
New buildings will be engineered differently, and old buildings retrofit. Special pipes will be sunk in the ground around the buildings that will keep the ground cool using thermosiphon technology. Cooled water is run through the pipes, cooling the surrounding earth. New building codes will require this new way of building in Alaskan regions where the permafrost is melting.