Cold Regions Engineering: Climatic Warming Concerns for Alaska

Recent climatological data indicate that a climatic warming is in progress in Alaska, and global circulation climate models predict accelerated climatic warming as a result of global atmospheric changes. Permafrost temperature logs in deep boreholes on the North Slope of Alaska indicate warming by as much as 4° C during the last century. In areas south of the Arctic Circle, permafrost temperatures are generally within 3° C of thawing and deep borehole temperature logs show evidences of warming at some sites while temperatures appear stable at others. Observations near several experimental highway sites, which have continued for as long as 20 yr, have shown a permafrost warming of 0.1–0.6° C at the 9.15‐m (30‐ft) depth. Global “greenhouse” warming forecasts indicate that the high latitudes of the earth may warm by about 3–12° C by the middle of the next century as the result of an effective doubling of the greenhouse gas content of the atmosphere. Engineers designing for these latitudes, which include most of Alaska, would appear to be justified in using an estimated air temperature warming of about 1° C per decade until more refined forecasts become available.