Impacts on infrastructure
face hydrology as they relate to permafrost all affect plant Impacts of predicted global climatic changes on Arctic
communities and productivity of ecosystems. The ob- infrastructure are of increasing concern
39,55
. Warming
served changes in permafrost temperatures and active- and thawing of permafrost may pose a threat to hu-
layer thickness can affect diversity and biomass of plant man lives as well as to infrastructure. Construction
communities
50
. Thawing of ice-rich permafrost can re- activity and existing infrastructure usually increase
sult in the replacement of boreal forest with wetlands
51,52
. the heat flow into the ground, due to heating of build-
This reduces the habitat area for caribou and other ter- ings and build-up of snow, and can result in warming
restrial mammals and birds, while it increases the area of permafrost. This ongoing permafrost degradation,
favourable for aquatic birds and mammals. The thawing which can cause instability of building foundations,
of permafrost with little ground-ice may result in replace- may be accelerated by increasing air temperatures. In
ment of the boreal forest ecosystems with steppe-like addition, projected increases in air and soil tempera-
habitats. Long-term permafrost degradation will continu- tures, precipitation, and storm magnitude and fre-
ously increase subsurface water drainage, especially in quency are very likely to increase the frequency of ava-
sandy soils, which will increase dryness of soils and place lanches and landslides. In some areas, the probability
significant stress on vegetation. Increased drainage will of severe impacts on settlements, roads and railways
also shrink ponds in the degrading permafrost area, dra- from these events may increase due to warming and
matically affecting aquatic ecosystems
47,53,54
. thawing of permafrost. Structures located on sites
(a) (b)
Figure 7.6: Effects of thawing permafrost on infrastructure.
(a) Permafrost thawing caused differential settlement in the foundation of this apartment building in the Russian republic of Yakutia.
The building partially collapsed only days after the first cracks appeared in the walls.
(b) A thermokarst depression in Fairbanks, Alaska. Ground ice melted, creating a void within the ground.
Photos: V. Romanovsky
190 GLOBAL OUTLOOK FOR ICE AND SNOW