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Arctic Climate Change

6. How will settlements and infrastructures be affected by Arctic warming?

  • 6.1 How will coastal communities be affected?
  • 6.2 How will changes in sea ice affect marine transport?
    • 6.2.1 Sovereignty, security, and safety
    • 6.2.2 Sea ice changes could make shipping more challenging
    • 6.2.3 Oil spills: an example of the risks that accompany increasing access
  • 6.3 How will infrastructures be affected by the thawing ground?
    • 6.3.1 Transport on Land
    • 6.3.2 Impacts on infrastructure

6.1 How will coastal communities be affected?

The source document for this Digest states:

Coastal communities face increasing exposure to storms
Coastal communities face increasing exposure to storms


Many coastal communities and facilities face increasing exposure to storms.

Rising temperatures are altering the arctic coastline and much larger changes are projected to occur during this century as a result of reduced sea ice, thawing permafrost, and sea-level rise. Thinner, less extensive sea ice creates more open water, allowing stronger wave generation by winds, thus increasing wave-induced erosion along arctic shores. Sea-level rise and thawing of coastal permafrost exacerbate this problem. In some areas, an eroding shoreline combines coarse sediments with frozen seawater, creating huge blocks of ice that carry sediments for distances of over 100 kilometers. These sediment-laden ice blocks pose dangers to ships and further erode the coastline as they are carried along by the winds. Higher waves will create even greater potential for this kind of erosion damage.

Rising sea level is very likely to inundate marshes and coastal plains, accelerate beach erosion, exacerbate coastal flooding, and force salt water into bays, rivers, and groundwater, not only in the Arctic, but also around the world. Local sea-level rise depends on how much the oceans are expanding as well as on whether the local coastline is rising or subsiding due to forces affecting the earth’s crust (such as rebound from the last ice age). Arctic coasts show a wide variation in these trends, although low-lying coastal plains of the Arctic are generally not rising, making them more vulnerable to adverse effects of sea-level rise. Higher sea level at the mouths of rivers and bays will allow salt water to penetrate further inland. Storms that bring more intense rainfall at the coast will increase erosion by runoff and the amount of mobile sediment in coastal waters.

Coastal regions with underlying permafrost are especially vulnerable to erosion as ice beneath the seabed and shoreline thaws from contact with warmer air and water. Though little specific monitoring has yet been done, generally, the projected increase in air and water temperature, reduction in sea ice, and increase in height and frequency of storm surges are expected to have a destabilizing effect on coastal permafrost, resulting in increased erosion. Low-lying ice-rich permafrost coasts are thus most vulnerable to wave-induced erosion. One result of this erosion is that more sediment will be brought to coastal waters, adversely affecting marine ecosystems. Increased coastal permafrost degradation could also result in greater releases of carbon dioxide and methane. Coastal erosion will pose increasing problems for some ports, tanker terminals, and other industrial facilities, as well as for coastal villages. Some towns and industrial facilities are already suffering severe damage and some are facing relocation as warming begins to take its toll on arctic coastlines.

In the Alaskan village of Nelson Lagoon, residents have built increasingly strong break walls along the shore, only to see them destroyed by increasingly violent coastal storms. Their break walls were designed to brace the shore ice, which would in turn provide the major buffer from winter storm wave action. As winters have warmed, the buffer provided by the shore ice has been lost, allowing the full force of the waves to surge against the wall and the village. The pipeline that provides drinking water for the village was also threatened when storm waves eroded soil cover and caused a breach in the line.

Shishmaref, Alaska Faces Evacuation

The village of Shishmaref, located on an island just off the coast of northern Alaska and inhabited for 4000 years, is now facing the prospect of evacuation. Rising temperatures are causing a reduction in sea ice and thawing of permafrost along the coast. Reduced sea ice allows higher storm surges to reach the shore and the thawing permafrost makes the shoreline more vulnerable to erosion, undermining the town's homes, water system, and other infrastructure.

The problem of coastal erosion has become increasingly serious in Shishmaref in recent years. Over a dozen houses have already had to be moved further from the sea. The 600 residents have watched as one end of their village has been eaten away, losing as much as 15 meters of land overnight in a single storm. The absence of sea ice also deprives the residents of their means of traveling to the mainland to hunt moose and caribou, as they would normally do by early November. Nowadays, the inlet is open water in the autumn.

Village elder, Clifford Weyiouanna says, “The currents have changed, ice conditions have changed, and the freeze-up of the Chukchi Sea has really changed, too. Where we used to freeze up in the last part of October, now we don't freeze ‘til around Christmas time. Under normal conditions, the sea ice out there should be four feet [1.2 meters] thick. I went out, and the ice was only one foot [0.3 meter] thick.”

Over the last 40 years, villagers estimate that they have lost hundreds of square meters of land. Robert Iyatunguk, erosion coordinator for the village, explains that the retreat of the sea ice is leaving the village more vulnerable to increasingly violent weather. “The storms are getting more frequent, the winds are getting stronger, the water is getting higher, and it's noticeable to everyone in town. If we get 12-14 foot [~4-meter] waves, this place is going to get wiped out in a matter of hours. We're in panic mode because of how much ground we're losing. If our airport gets flooded out, there goes our evacuation by plane.

Severe Erosion in Tuktoyaktuk, Canada

Tuktoyaktuk is the major port in the western Canadian Arctic and the only permanent settlement on the low-lying Beaufort Sea coast. Tuktoyaktuk’s location makes it highly vulnerable to increased coastal erosion due to decreased extent and duration of sea ice, accelerated thawing of permafrost, and sea-level rise. The Tuktoyaktuk Peninsula is characterized by sandy spits, barrier islands, and a series of lakes created as thawing permafrost caused the ground the collapse (“thermokarst” lakes). Erosion is already a serious problem in and around Tuktoyaktuk, threatening cultural and archeological sites and causing the abandonment of an elementary school, housing, and other buildings. Successive shoreline protection structures have been rapidly destroyed by storm surges and accompanying waves.

As warming proceeds and sea-level rise accelerates, impacts are expected to include further landward retreat of the coast, erosion of islands, more frequent flooding of low-lying areas, and breaching of freshwater thermokarst lakes and their consequent conversion into brackish or saline lagoons. The current high rates of cliff erosion are projected to increase due to higher sea levels, increased thawing of permafrost, and the increased potential for severe coastal storms during the extended open-water season. Attempts to control erosion at Tuktoyaktuk will become increasingly expensive as the surrounding coastline continues to retreat. The site could ultimately become uninhabitable.

Erosion Threatens Russian Oil Storage Facility

The oil storage facility at Varandei on the Pechora Sea was built on a barrier island. Damage to the dunes and beach due to the facility’s construction and use have accelerated natural rates of coastal erosion. The Pechora Sea coasts are thought to be relatively stable, except where disturbed by human activity. Because this site has been perturbed, it is more vulnerable to damage due to storm surges and the accompanying waves that will become a growing problem as climate continues to warm. As with the other sites discussed here, the reduction in sea ice, thawing coastal permafrost, and rising sea level are projected to exacerbate the existing erosion problem. This provides an example of the potential for combined impacts of climate change and other human-caused disturbances. Sites already threatened due to human activity are often more vulnerable to the impacts of climate change.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #5, p.78-81

6.2 How will changes in sea ice affect marine transport?

    • 6.2.1 Sovereignty, security, and safety
    • 6.2.2 Sea ice changes could make shipping more challenging
    • 6.2.3 Oil spills: an example of the risks that accompany increasing access

The source document for this Digest states:


Reduced sea ice is very likely to increase marine transport and access to resources.

Observations over the past 50 years show a decline in arctic sea-ice extent in all seasons, with the most prominent retreat in summer. Recent studies estimate arctic-wide reductions in annual average sea-ice extent of about 5-10% and a reduction in average thickness of about 10-15% over the past few decades. Measurements taken by submarine sonar in the central Arctic Ocean revealed a 40% reduction in ice thickness in that area. Taken together, these trends indicate an Arctic Ocean with longer seasons of less sea-ice cover of reduced thickness, implying improved ship accessibility around the margins of the Arctic Basin (although this will not be uniformly distributed).

Climate models project an acceleration of this trend, with periods of extensive melting spreading progressively further into spring and autumn. Model projections suggest that sea ice in summer will retreat further and further away from most arctic landmasses, opening new shipping routes and extending the period during which shipping is feasible.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #6, Reduced sea ice is very likely to increase marine transport and access to ressources p.82

6.2.1 Sovereignty, security, and safety

The source document for this Digest states:

As the decline in arctic sea ice opens historically closed passages, questions are likely to arise regarding sovereignty over shipping routes and seabed resources. Issues of security and safety could also arise. One impact of the projected increase in marine access for transport and offshore development will be requirements for new and revised national and international regulations focusing on marine safety and environmental protection. Another probable outcome of this growing access will be an increase in potential conflicts among competing users of arctic waterways and coastal seas, for example, in the Northern Sea Route and Northwest Passage. Commercial fishing, sealing, hunting of marine wildlife by indigenous people, tourism, and shipping all compete for use of the narrow straits of these waterways, which are also the preferred routes for marine mammal migration.

With increased marine access in arctic coastal seas – for shipping, offshore development, fishing, and other uses – national and regional governments will be called upon for increased services such as icebreaking assistance, improved ice charting and forecasting, enhanced emergency response in dangerous situations, and greatly improved oil-ice cleanup capabilities. The sea ice, while thinning and decreasing in extent, is likely to become more mobile and dynamic in many coastal regions where fast ice and relatively stable conditions previously existed. Competing marine uses in newly open or partially ice-covered areas will call for increased enforcement presence and regulatory oversight.

Increasing access in the Arctic Ocean will require ships transiting the region to be built to higher construction standards compared with ships operating in the open ocean. International and domestic regulations, designed to enhance maritime safety and marine environmental protection in arctic waters, will need to take into account that each ship will have a high probability of operating in ice somewhere during a voyage. Such ships will have higher construction, operational, and maintenance costs.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #6, Sovereignty, Security, and Safety, p.84

6.2.2 Sea ice changes could make shipping more challenging

The source document for this Digest states:

Not all agree that reduced sea ice, at least in the early part of the 21st century, will necessarily be the boon to shipping that is widely assumed. Recent sea ice changes could, in fact, make the Northwest Passage less predictable for shipping. Studies by the Canadian Ice Service indicate that sea ice conditions in the Canadian Arctic during the past three decades have been characterized by high year-to-year variability; this variability has existed despite the fact that since 1968-1969 the entire region has experienced an overall decrease in sea-ice extent during September. For example, in the eastern Canadian Arctic, some years – 1972, 1978, 1993, and 1996 – have had twice the area of sea ice compared with the first or second year that follows. This significant year-to-year variability in sea ice conditions makes planning for regular marine transportation along the Northwest Passage very difficult.

In addition, results of research at Canada’s Institute of Ocean Sciences suggest that the amount of multi-year sea ice moving into the Northwest Passage is controlled by blockages or “ice bridges” in the northern channels and straits of the Canadian Arctic Archipelago. With a warmer arctic climate leading to higher temperatures and a longer melt season, these bridges are likely to be more easily weakened (and likely to be maintained for a shorter period of time each winter) and the flushing or movement of ice through the channels and straits could become more frequent. More multi-year ice and potentially many more icebergs could thus move into the marine routes of the Northwest Passage, presenting additional hazards to navigation. Thus, despite widespread retreat of sea ice around the Arctic Basin, it is clear that the unusual geography of the Canadian Arctic Archipelago creates exceptionally complex sea ice conditions and a high degree of variability for the decades ahead.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #6, Sea Ice Changes Could Make Shipping More Challenging, p.84

6.2.3 Oil spills: an example of the risks that accompany increasing access

The source document for this Digest states:

Along with increasing access to shipping routes and resources comes an increasing risk of environmental degradation caused by these activities. One obvious concern involves oil spills and other industrial accidents. A recent study suggests that the effects of oil spills in a high-latitude, cold ocean environment last much longer and are far worse than first suspected.

In 1989, the Exxon Valdez oil tanker slammed into a reef while maneuvering to avoid ice in the shipping lanes and poured 42 million liters (11 million gallons) of crude oil into Alaska's Prince William Sound. The spill was the worst tanker disaster ever in U.S. waters, killing at least 250 000 seabirds and thousands of marine mammals. It forced the closure of commercial fishing grounds and areas traditionally used to gather wild foods. Scientists knew the immediate effects would be devastating but some predicted the environment would recover as soon as the oil weathered and dissipated. Instead, they found that marine life suffered for many years, and continues to suffer, because even tiny patches of remnant oil reduced survival, slowed reproduction, and stunted growth. Lingering oil has created cascading problems for fish, seabirds, and marine mammals.

The recent study found that Valdez oil was still embedded in Prince William Sound beaches in the summer of 2003. “The oil is oozing into holes,” said Stanley Rice of the National Marine Fisheries Service laboratory in Juneau, Alaska, who led a team that dug about 1000 pits in beaches in 2003. “There, the oil is like it was two or three weeks after the spill.” Sea otters and other animals digging for food are exposed to the oil and its ill effects, Rice said. Studies of sea otters, harlequin ducks, salmon, and shellfish suggest that patches of oil that persist on some beaches release enough hydrocarbons to cause chronic problems that will continue for some species for many years.

Experts say that the overall strategy for arctic spills must be preventative. New regulations for ships, offshore structures, port facilities, and other coastal activities must be designed to reduce the risk of spills through enhanced construction standards and operating procedures. Nevertheless, spills are expected, and spill response operations in the Arctic will be more complex and demanding in ice-covered waters than in Prince William Sound or open seas, especially since effective response strategies have yet to be developed.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #6, Oil Spills: An Example of the Risks That Accompany Increasing Access, p.85

6.3 How will infrastructures be affected by the thawing ground?

    • 6.3.1 Transport on Land
    • 6.3.2 Impacts on infrastructure

The source document for this Digest states:


Thawing ground will disrupt transportation, buildings and other infrastructure.

6.3.1 Transport on Land

The source document for this Digest states:

Unlike most parts of the world, arctic land is generally more accessible in winter, when the tundra is frozen and ice roads and bridges are available. In summer, when the top layer of permafrost thaws and the terrain is boggy, travel over land can be difficult. Many industrial activities depend on frozen ground surfaces and many northern communities rely on ice roads for the transport of groceries and other materials. Rising temperatures are already leading to a shortening of the season during which ice roads can be used and are creating increasing challenges on many routes. These problems are projected to increase as temperatures continue to rise. Frost heave and thaw-induced weakening are major factors affecting roadway performance; transportation routes are likely to be particularly susceptible to these effects under changing climatic conditions. In addition, the incidence of mud and rockslides and avalanches are sensitive to the kinds of changes in weather (such as an increase in heavy precipitation events) that are projected to accompany warming.

Impacts of Thawing on the Oil, Gas, and Forestry Industries. Because of warming, the number of days per year in which travel on the tundra is allowed under Alaska Department of Natural Resources standards has dropped from over 200 to about 100 in the past 30 years, resulting in a 50% reduction in days that oil and gas exploration and extraction equipment can be used. These standards, designed to protect the fragile tundra from damage, are currently under review and may be relaxed, raising concerns about potential damage to the tundra. Forestry is another industry that requires frozen ground and rivers. Higher temperatures mean thinner ice on rivers and a longer period during which the ground is thawed. This leads to a shortened period during which timber can be moved from forests to sawmills, and increasing problems associated with transporting wood.

Degrading Permafrost

Air temperature, snow cover, and vegetation, all of which are affected by climate change, affect the temperature of the frozen ground and the depth of seasonal thawing. Permafrost temperatures over most of the sub-arctic land areas have increased by several tenths of a ˚C up to 2˚C during the past few decades, and the depth of the active layer is increasing in many areas. Over the next 100 years, these changes are projected to continue and their rate to increase, with permafrost degradation projected to occur over 10-20% of the present permafrost area, and the southern limit of permafrost projected to shift northward by several hundred kilometers.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #7, Transport on Land, p.86

A permafrost primer

6.3.2 Impacts on infrastructure

The source document for this Digest states:

Building damaged due to permafrost thawing in Russia
Building damaged due to permafrost thawing in Russia

Projected increases in permafrost temperatures and in the depth of the active layer are very likely to cause settling, and to present significant engineering challenges to infrastructure such as roads, buildings, and industrial facilities. Remedial measures are likely to be required in many cases to avoid structural failure and its consequences. The projected rate of warming and its effects will need to be taken into account in the design of all new construction, requiring deeper pilings, thicker insulation, and other measures that will increase costs.

In some areas, interactions between climate warming and inadequate engineering are causing problems. The weight of buildings on permafrost is an important factor; while many heavy, multi-story buildings of northern Russia have suffered structural failures, the lighter-weight buildings of North America have had fewer such problems as permafrost has warmed. Continuous repair and maintenance is also required for buildings on permafrost, a lesson learned because many of the buildings that failed were not properly maintained. The problems now being experienced in Russia can be expected to occur elsewhere in the Arctic if buildings are not designed and maintained to accommodate future warming.

Structural failures of transportation and industrial infrastructure are also becoming more common as a result of permafrost thawing in northern Russia. Many sub-grade railway lines are deformed, airport runways in several cities are in an emergency state, and oil and gas pipelines are breaking, causing accidents and spills that have removed large amounts of land from use because of soil contamination. Future concerns include a weakening of the walls of open pit mines, and pollutant effects from large mine tailing disposal facilities as frozen layers thaw, releasing excess water and contaminants into groundwater.

The effects of permafrost thawing on infrastructure in this century will be more serious and immediate in the discontinuous permafrost zone than in the continuous zone. Because complete thawing is expected to take centuries, and benefits (such as easier construction in totally thawed ground) would occur only after that time, the consequences for the next 100 years or so will be primarily negative (that is, destructive and costly).

Yakutsk, Russia Experiences Infrastructure Failure as Permafrost Thaws In Yakutsk, a Russian city built over permafrost in central Siberia, more than 300 buildings have been damaged by thaw-induced settlement. The infrastructure affected by collapsing ground due to permafrost thaw includes several large residential buildings, a power station, and a runway at Yakutsk airport. Some ascribe a large proportion of the city’s recent problems to climatic warming, though others believe that better construction practices and maintenance could have prevented much of the trouble.

Research on the impacts of warming on infrastructure indicates that even small increases in air temperature substantially affect building stability, and that the safety of building foundations decreases sharply with increasing temperature. This effect can result in a significant decrease in the lifetime of structures as well as the potential failure of structures.

As global warming continues, detrimental impacts on infrastructure throughout the permafrost regions can be expected. Many of these impacts might be anticipated, allowing structures to be re-designed and re-engineered to withstand additional pressures under changing climatic conditions. This will certainly incur costs, but can avoid the dramatic infrastructure failures being experienced in Yakutsk and elsewhere in the Arctic.

Floods and Slides

Another set of climate-related problems for arctic infrastructure involves floods, mudslides, rockslides, and avalanches. These events are closely associated with heavy precipitation events, high river runoff, and elevated temperatures, all of which are projected to occur more frequently as climate change progresses. Soil slopes are also made less stable by thawing permafrost, and this is expected to result in more slides. Some transportation routes to markets are sensitive to the types of weather events that are expected to increase as climate continues to warm. Protecting or improving these routes will be required.

Impacts of Thawing Permafrost on Natural Ecosystems

Important two-way interactions exist between climate-induced changes in permafrost and vegetation. As permafrost thaws, it affects the vegetation that grows on the surface. At the same time, the vegetation, which is also experiencing impacts due to climate change, plays an important role in insulating and maintaining the permafrost. For example, forests help sustain permafrost because the tree canopy intercepts the sun’s heat and the thick layer of moss on the surface insulates the ground. Thus, the projected increase in forest disturbances such as fire and insect infestations can be expected to lead to further degradation of permafrost, in addition to what is projected to result directly from rising temperatures.

In some northern forests, certain tree species (notably black spruce) utilize the ice-rich permafrost to maintain the structure of the soil in which they are rooted. Thawing of this frozen ground can lead to severe leaning of trees (sometimes referred to as “drunken forest”) or complete toppling of trees. Thus, even if a longer, warmer growing season might otherwise promote growth of these trees, thawing permafrost can undermine or destroy the root zone due to uneven settling of the ground surface, leading instead to tree collapse and death. In addition, where the ground surface subsides due to permafrost thaw, even if the trees do not fall over, these sites often become the new lowest points on the landscape. At least seasonally, these places fill with water, drowning the trees.

The potential for many shallow streams, ponds, and wetlands in the Arctic to dry out under a warming climate is increased by the loss of permafrost. As permafrost thaws, ponds connect with the groundwater system. They are thus likely to drain if losses due to downward percolation and evaporation are greater than re-supply by spring snowmelt and summer precipitation. Patchy arctic wetlands are particularly sensitive to permafrost degradation that links surface waters to groundwater. Those along the southern limit of permafrost, where increases in temperature are most likely to eliminate the relatively warm permafrost, are at the highest risk of drainage. Indigenous people in Nunavut (eastern arctic Canada) have observed recently that there has been increased drying of rivers, swamps, and bogs, to the extent that access to traditional hunting grounds and, in some instances, migration of fish, have been impaired. There is also a high risk of catastrophic drainage of permafrost-based lakes, such as those found along the western arctic coast of Canada.

In other places, warming of surface permafrost above frozen ground and associated collapsing of ground surfaces could increase the formation of wetlands, ponds, and drainage networks, particularly in areas characterized by heavy concentrations of ground ice. Such thawing, however, would also lead to dramatic increases in sediment being deposited into rivers, lakes, deltas, and coastal marine environments, resulting in significant impacts to aquatic life in these bodies of water.

Changes to the water-balance of northern wetlands are especially important because most wetlands in permafrost regions are peatlands, which may absorb or emit carbon (as carbon dioxide or methane) depending on the depth of the water table. There are many uncertainties in projections of these changes. One analysis suggests that an increase in temperature of 4˚C would reduce water storage in northern peatlands, even with a small and persistent increase in precipitation, causing peatlands to switch from emitting carbon dioxide to the atmosphere to absorbing it. It is also possible that the opposite could occur, whereby warming and drying could cause the rate of decomposition of organic matter to increase faster than the rate of photosynthesis, resulting in an increase in carbon dioxide emissions. A combination of temperature increase and elevated groundwater levels could result in increased methane emissions. Projections based on doubling of pre-industrial carbon dioxide levels, anticipated to occur around the middle of this century, suggest a major northward shift (by 200-300 kilometers) of the southern boundary of these peatlands in western Canada and a significant change in their structure and vegetation all the way to the coast.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #7, Impacts on infrastructure, p.88

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