The World in 2050_ Four Forces Shaping Civilization's Northern Future - Laurence C. Smith [163]
369 Canada and Russia maintain that these passages are domestic waters under their control; the United States and others maintain they are international straits and thus freely available to use without declaration or permission. These and other nontrivial impediments to transnational shipping in the Arctic are described in AMSA 2009.
370 I suppose someday there might be more of them—perhaps by 2100 or 2150, if globalization hasn’t collapsed into a pile of fiefdoms—together with booming new Arctic port cities. The geography of distance, along with further sea-ice reductions in store, is just too compelling. But this won’t happen by 2050, the time frame of this book’s thought experiment.
371 Some 1.2 million passengers took cruise ships to the region in 2004; three years later the number had more than doubled. By 2008 some 375 cruise-ship port calls were scheduled for Greenland’s ports and harbors alone (AMSA 2009, p. 79).
372 From personal interviews with Mike Spence, mayor of Churchill, June 28, 2007, and L. Fetterly, general manager, Hudson Bay Port Co. (owned by OmniTRAX), June 30, 2007. Apparently there is a powerful lobby for keeping Canada’s grain running east-west on its longer, nationalized rail link to Thunder Bay, rather than on the shorter, privately held north-south line to Churchill.
373 Permafrost is also commonly studded with massive lenses of ice, which occupy less volume and may drain away entirely if it melts. This sets the stage for some highly irregular ground settling if the permafrost starts to thaw. Trees lean drunkenly and fall over. Oddly shaped sinkholes called “thermokarst” appear and fill with water, and other odd phenomena.
374 Borehole temperatures in permafrost are generally warming everywhere around the northern latitudes, but to varying degrees as a function of depth and location. In Alaska it has warmed as much as +3°C since the 1980s, but a more typical range is 0.5°-2°C. For a summary of observed permafrost temperature changes, see Table 6.8 and associated discussion on pp. 210-213, ACIA (2005).
375 The presence of permafrost helps to hold water near the land surface. L. C. Smith, Y. Sheng, G. M. MacDonald, L. D. Hinzman, “Disappearing Arctic Lakes,” Science 308 (2005): 1429.
376 North of 45° N latitude, the single most important determinant of northern lake abundance is glaciation history, followed by the presence or absence of permafrost. On average, glaciated landscapes contain about four times as many lakes as nonglaciated landscapes; permafrost roughly doubles lake numbers. From GIS analysis of northern hemisphere lake distribution, I estimate that in a “permafrost-free” world, the number of known, mapped lakes north of 45° N latitude would be reduced from roughly 192,000 to 103,000 (-46%) and their total inundation area reduced from about 560,000 to 325,000 km2 (-42%). However, that is an extreme scenario. More realistic for 2050 is an overall reduction of known lakes to 155,000 (-15%) and 476,000 km2 (-15%), respectively. These numbers are underestimates because the true number of Arctic lakes (i.e., unmapped) is in the millions. L. C. Smith, Y. Sheng, G. M. MacDonald, “A First Pan-Arctic Assessment of the Influence of Glaciation, Permafrost, Topography and Peatlands on Northern Lake Distribution,” Permafrost and Periglacial Processes 18 (2007): 201-208, DOI:10.1002/ppp.581.
377 So-called “continuous” permafrost will decline even more, by 19%-53%. 2050 forecasts from the CGCM2, ECHAM4/OPYC3, GFDL-R30, HadCM3, and CSM climate models, ACIA (2005), Table 6.9. Seasonal thaw depth refers to the depth of the active layer at the ground surface, which thaws out in summer and refreezes in winter. Typical active layer depths are ten to one hundred centimeters.
378 The percentage of dangerous buildings in large villages and cities ranges from 22% in Tiksi to 80% in Vorkuta, including 55% in Magadan, 60% in Chita, 35% in