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Arctic Climate Change

7. How will people and their environment be affected by Arctic warming?

  • 7.1 How will indigenous people be affected?
  • 7.2 What will be the effect of higher UV-radiation?
    • 7.2.1 Arctic ozone depletion
    • 7.2.2 Impacts of UV on people
    • 7.2.3 Impacts of UV on ecosystems
  • 7.3 How can various factors interact to cause impacts on people and the environment?
    • 7.3.1 Climate change and contaminants
    • 7.3.2 Human Health

7.1 How will indigenous people be affected?

The source document for this Digest states:

Indigenous communities are facing major changes
Indigenous communities are facing major changes

KEY FINDING #8

Indigenous communities are facing major economic and cultural impacts.

The Arctic is home to numerous Indigenous Peoples whose cultures and activities are shaped by the arctic environment. They have interacted with their environment over generations through careful observations and skillful adjustments in traditional food-harvesting activities and lifestyles. Through ways of life closely linked to their surroundings, these peoples have developed uniquely insightful ways of observing, interpreting, and responding to the impacts of environmental change.

Indigenous observations and perspectives are therefore of special value in understanding the processes and impacts of arctic climate change. There is a rich body of knowledge based on their careful observations of and interactions with their environment. Holders of this knowledge use it to make decisions and set priorities. The ACIA has attempted to combine knowledge and insights from indigenous people with data from scientific research, bringing together these complementary perspectives on arctic climate change.

Flexibility and adaptability have been key to the way arctic Indigenous Peoples have accommodated environmental changes over many generations. Current social, economic, political, and institutional changes play a part in enabling or constraining the capacity of peoples to adapt. The rapid climate change of recent decades, combined with other ongoing alterations in the world around them, presents new challenges.

Across the Arctic, indigenous people are already reporting the effects of climate change. In Canada’s Nunavut Territory, Inuit hunters have noticed the thinning of sea ice, a reduction in the numbers of ringed seals in some areas, and the appearance of insects and birds not usually found in their region. Inuvialuit in the western Canadian Arctic are observing an increase in thunderstorms and lightning, previously a very rare occurrence in the region. Athabaskan people in Alaska and Canada have witnessed dramatic changes in weather, vegetation, and animal distribution patterns over the last 50 years. Saami reindeer herders in Norway observe that prevailing winds relied upon for navigation have shifted and become more variable, forcing changes in traditional travel routes. Indigenous Peoples who are accustomed to a wide range of natural climate variations are now noticing changes that are unique in the long experience of their peoples.

Compiling indigenous knowledge from across the Arctic, a number of common themes clearly emerge, though there are regional and local variations in these observations.

  • The weather seems unstable and less predictable by traditional methods.
  • Snow quality and characteristics are changing.
  • There is more rain in winter.
  • Seasonal weather patterns are changing.
  • Water levels in many lakes are dropping.
  • Species not seen before are now appearing in the Arctic.
  • Sea ice is declining, and its quality and timing are changing.
  • Storm surges are causing increased erosion in coastal areas.
  • The sun feels “stronger, stinging, sharp”. Sunburn and strange skin rashes, never experienced before, are becoming common.
  • Climate change is occurring faster than people can adapt.
  • Climate change is strongly affecting people in many communities, in some cases, threatening their cultural survival.

Many indigenous communities of the Arctic depend primarily on harvesting and using living resources from the land and sea. The species most commonly harvested are marine mammals such as seals, walrus, polar bears, and narwhals, and beluga, fin, bowhead, and minke whales; land mammals such as caribou, reindeer, moose, and musk ox; fish such as salmon, Arctic char, and northern pike, and a variety of birds, including ducks, geese, and ptarmigan.

Indigenous Peoples throughout the Arctic maintain a strong connection to the environment through hunting, herding, fishing, and gathering. The living resources of the Arctic not only sustain Indigenous Peoples in an economic and nutritional sense, but also provide a fundamental basis for social identity, spiritual life, and cultural survival. Rich mythologies, vivid oral histories, festivals, and animal ceremonies illustrate the social, economic, and spiritual relationships that Indigenous Peoples have with the arctic environment. These traditions distinguish the food harvesting practices of Indigenous Peoples from conventional hunting.

Access to food resources is often related to travel access and safety. For example, changes in the rate of spring melt and increased variability associated with spring weather conditions have affected access to hunting and fishing camps. For example, when Inuit families in the western Canadian Arctic go out to camps at lakes for ice fishing and goose hunting in May, they travel by snowmobile, pulling a sled, staying on snow-covered areas or using coastal sea-ice and frozen rivers. However, warmer springs have resulted in earlier, faster snowmelt and river break-up, making access difficult. The availability of some species has changed due to the inability of people to hunt them under changing environmental conditions. For example, the reduction in summer sea ice makes ringed seals harder to find. Climate-related changes in animal distributions are occurring, and larger changes are projected. For example, northward movement of the pack-ice edge is expected to reduce the availability of seabirds as food resources to many arctic communities.

As Indigenous Peoples perceive it, the Arctic is becoming an environment at risk in the sense that sea ice is less stable, unusual weather patterns are occurring, vegetation cover is changing, and particular animals are no longer found in traditional hunting areas during specific seasons. Local landscapes, seascapes, and icescapes are becoming unfamiliar, making people feel like strangers in their own land.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #8, Indigenous communities are facing major economic and cultural impacts, p.92

Seals Become Elusive for Inuit in Nunavut, Canada

Observed Climate Change Impacts in Sachs Harbour, Canada

Indigenous knowledge and observations of current trends

7.2 What will be the effect of higher UV-radiation?

    • 7.2.1 Arctic ozone depletion
    • 7.2.2 Impacts of UV on people
    • 7.2.3 Impacts of UV on ecosystems

The source document for this Digest states:

KEY FINDING #9

Elevated ultraviolet radiation levels will affect people, plants, and animals.

Ultraviolet radiation (UV) reaching the earth’s surface is a growing concern in the Arctic, largely due to depletion of stratospheric ozone caused by emissions of chlorofluorocarbons (CFCs) and other manmade chemicals over the last 50 years. Ozone depletion over the Arctic has been severe and is greatest in the spring when living things are most vulnerable.

While the international treaty known as the Montreal Protocol (and subsequent amendments that strengthened it) has phased out the production of most of these ozone-destroying chemicals, many have long atmospheric lifetimes and so those previously released will continue to destroy ozone for decades to come. Ozone depletion in the Arctic is highly sensitive to changes in temperature, meaning that ozone levels are likely to be strongly influenced by climate change, even though the fundamental depletion processes involve ozone-destroying chemicals produced by human activities.

Although the uncertainty in future ozone projections is high, the long timeframe for ozone recovery suggests that the Arctic is very likely to be subject to elevated levels of UV for several decades. Increased UV levels are likely to affect many living things in the Arctic. In humans, excess levels are known to cause skin cancer, sunburn, cataracts, cornea damage, and immune system suppression. Ultraviolet radiation is also known to cause or accelerate damage to a number of materials used in the region’s infrastructure. There are also likely to be wide-ranging impacts on natural ecosystems.

Many people confuse the issues of ozone depletion and climate change. While the two are related in a number of ways, they are driven by two distinct mechanisms. Human-induced climate change results from the build up of carbon dioxide, methane, and other greenhouse gases that trap heat in the lower atmosphere (called the troposphere), causing global warming. Ozone depletion results from the human-induced build-up of chlorinated chemicals such as byproducts of CFCs and halons that break apart ozone molecules through chemical reactions that take place in the stratosphere.

The United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) have undertaken periodic assessments of changes in stratospheric ozone and ultraviolet radiation. The most recent UNEP/WMO Scientific Assessment of Ozone Depletion was completed in 2002. The ACIA has built upon and extended the findings of that assessment.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #9, Elevated ultraviolet radiation levels will affect people, plants, and animals, p.98

7.2.1 Arctic ozone depletion

The source document for this Digest states:

The ozone layer absorbs UV from the sun, protecting life on earth from exposure to excessive levels of UV. Ozone depletion may thus lead to increases in UV levels at the earth's surface. The most severe depletion has taken place in the polar regions, causing the so-called Antarctic “ozone hole,” and a similar, though less severe, seasonal depletion over the Arctic. Varying degrees of depletion extend around the globe, generally becoming less severe with increasing distance from the poles.

The accumulated annually averaged loss of ozone over the Arctic has been about 7% since 1979. But this obscures much larger losses at particular times of the year and on particular days, and it is these losses that have the potential for significant biological impacts. The largest ozone reductions have occurred in spring, with average springtime losses of 10-15% since 1979. The largest monthly deviations, 30-35% below normal, were in March 1996 and 1997. Daily ozone values were 40-45% below normal in March-April 1997. Major ozone losses (defined as greater than 25% depletion) lasting several weeks have been observed during seven of the past nine springs in the Arctic.

Factors Determining UV at the Surface. Ozone levels directly influence the amount of UV reaching the earth's surface. Surface UV levels are also strongly affected by clouds, the angle of the sun’s rays, altitude, the presence of tiny particles in the atmosphere (which scientists refer to as aerosols), and the reflectivity of the surface (determined largely by the extent of snow cover, which is highly reflective). These factors change from day to day, season to season, and year to year, and can increase or decrease the amount of UV that reaches living things at the surface. The highest doses of UV in the Arctic are observed in the spring and summer, due primarily to the relatively high angle of the sun. The low sun angle during autumn and winter creates a great deal of diffuse UV scattered from the atmosphere and reflected off snow and ice. Reflectance off snow can increase the dose received by living things at the surface by over 50%.

The various factors affecting UV doses can have multi-faceted effects, some of which are likely to be influenced by climate change. For example, snow and ice reflect solar radiation upward, so plants and animals on top of the ice are likely to receive lower doses as snow and ice recede due to warming. On the other hand, plants and animals below the snow and ice, which were previously protected by that cover, will receive more UV as snow and ice recede. The projected reduction in snow and ice cover on the surface of rivers, lakes, and oceans is thus likely to increase the exposure of many living things in these water bodies to damaging levels of UV. In addition, the projected earlier spring melting of snow and ice cover comes at the time of year when UV radiation is most likely to be elevated due to ozone loss.

Variations Over Time and Space

The ozone depletion and resulting increase in UV levels at the surface in the Arctic have not been symmetrical around the pole. Depletion is also not consistent over time; some years show strong depletion while others do not, due to variations in the dynamics and temperature of the stratosphere. There is a great deal of natural variability in ozone levels, and along with the long-term changes due to human activities, natural variations continue to occur. Transport of ozone can result in days of very high or very low UV levels. Because of the nature of ozone depletion, elevated UV is generally observed in spring, when biological systems are most sensitive. Increased UV doses, especially when combined with other environmental stresses, pose a threat to some arctic species and ecosystems.

Arctic Ozone Recovery Delayed by Climate Change

No significant improvement in stratospheric ozone levels over the Arctic is projected for the next few decades. One reason is that increasing levels of greenhouse gases, while warming the troposphere, actually cool the stratosphere. This can worsen ozone depletion over the poles because lower temperatures strengthen the swirl of winds known as the polar vortex and encourage the formation of polar stratospheric clouds. The icy particles of these clouds are sites on which ozone-destroying chemical reactions occur. And the vortex isolates the stratosphere over the Arctic and prevents ozone from outside the region from replenishing the depleted ozone over the Arctic. Thus, for the next few decades, ozone depletion and elevated UV levels are projected to persist over the Arctic. At the same time, a reduction in springtime snow and ice cover due to warming is likely to expose vulnerable young plant and animal life to elevated UV levels.

Because ozone depletion is expected to persist over the Arctic for several more decades, episodes of very low spring ozone levels are likely to continue. Model results anticipate up to a 90% increase in springtime UV doses for 2010-2020 relative to those in 1972-1992. Because the models used to make these projections assume full compliance with the Montreal Protocol and its amendments, ozone recovery is likely to be slower and UV levels higher than projected if the phase-out of ozone-depleting chemicals is not achieved as outlined by the Protocol and its amendments.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #9, Arctic Ozone Depletion, p.98

7.2.2 Impacts of UV on people

The source document for this Digest states:

Human beings receive about half their lifetime UV dose by the time they are 18 years old. Current elevated UV levels in the Arctic indicate that the present generation of young people is likely to receive about a 30% greater lifetime UV dose than any prior generation. Such increases in UV doses are important to people of the Arctic because UV can induce or accelerate incidence of skin cancer, cornea damage, cataracts, immune system suppression, viral infections, aging of the skin, sunburn, and other skin disorders. Skin pigmentation, while protecting to some extent against skin cancer, is not an efficient protector against UV-induced immune system suppression. The immunosuppressive effects of UV play an important role in UV-induced skin cancer by preventing the destruction of skin cancers by the immune system. Some evidence suggests a connection between exposure to sunlight and non-Hodgkin's lymphoma and autoimmune diseases such as multiple sclerosis, with the relationship suggested to be via the immunosuppressive effects of UV. Because UV is known to activate viruses such as the herpes simplex virus through immune suppression, increased UV could increase the incidence of viral diseases among arctic populations, particularly as climate warming may introduce virus-carrying insect species to the Arctic.

Eye damage is of particular concern in the Arctic. UV has traditionally been measured on a flat, horizontal surface, but this does not represent the way a person receives a UV dose. People, who are generally vertical when outside, receive a higher dose than a horizontal surface, largely due to reflection from snow. Measurements incorporating this fact indicate that springtime ozone depletion could contribute greatly to UV effects on the eyes due to the significance of snow reflection. Observations show that UV doses to vertical surfaces such as the eyes are higher at the end of April than at any other time of the year. These high doses suggest that the amount of UV received when looking toward the horizon can be equivalent or greater than the amount received when looking directly upward. People can reduce the risks of UV-induced health effects by limiting their exposure through the use of sunscreens, sunglasses, protective clothing, and other preventative measures.

In addition to the impacts on human health, UV radiation is known to adversely affect many materials used in construction and other outdoor applications. Exposure to UV can alter plastics, synthetic polymers used in paint, and natural polymers present in wood. Increased UV exposure due to ozone depletion is therefore likely to decrease the useful life of these materials and add costs for more frequent painting and other maintenance. High surface reflectivity due to snow cover and long hours of sunlight in spring and summer along with springtime ozone losses can combine to deliver a high cumulative UV dose to vertical surfaces such as the walls of buildings, leading to degradation of susceptible materials. The high winds and repeated freezing and thawing that occur in the Arctic may exacerbate materials problems that can develop as a result of UV damage. The costs of early replacement imply rising infrastructure costs that are likely to be paid for by individuals.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #9, Impacts of UV on People, p.102

7.2.3 Impacts of UV on ecosystems

The source document for this Digest states:

Ecosystems on Land

Plants and animals show a variety of effects from increased UV radiation, though these effects vary widely by species. In the short term, a few species are projected to benefit, while many more would be adversely affected. Long-term effects are largely unknown. In addition to direct effects, animals will be indirectly affected by changes in plants. For example, pigments that are needed to protect plants against UV also make them less digestible for the animals that depend upon them. So while some plants can adapt to higher UV levels by increasing their pigmentation, there are often wider implications of this adaptation for dependent animals and ecosystem processes. Increased UV also has long-term impacts on ecosystem processes that reduce nutrient cycling and can decrease productivity.

Springtime in the Arctic is a critical time for the birth and growth of animals and plants. Historically, ozone had been at its highest levels in the spring, offering living things the heightened UV protection they needed during this sensitive time. Since ozone depletion due to manmade chemicals became a problem several decades ago, spring is now the time of year with the largest losses of stratospheric ozone. Longer daylight hours in springtime also add to UV exposure. Increases in UV also interact with climate change, such as the warming-related decrease in springtime snow cover, creating the potential for increased impacts on plants, animals, and ecosystems.

Birch Forests at Risk from Impacts of UV and Warming on the Autumn Moth. One example of a documented impact of increased UV that also has interactions with climate warming involves the autumn moth, an insect that eats the leaves of birch trees, causing tremendous damage to forests. Increased UV modifies the chemical structure of the birch leaves, greatly reducing their nutritional value. The moth caterpillars thus eat up to three times more than normal to compensate. Increased UV also appears to improve the immune system of the autumn moth. In addition, UV destroys the polyhydrosis virus that is an important controller of the survival of moth caterpillars. Increased UV is thus expected to lead to increased caterpillar populations that would in turn lead to more birch forest defoliation. At the same time, winter temperatures below -36˚C have previously limited the survival of autumn moth eggs, controlling moth populations. When winter temperatures rise above that threshold, caterpillar survival increases. Thus, observed and projected winter warming is expected to further increase moth populations, thus increasing damage to birch forests. The damaging impacts of climate change are likely to exceed the impacts of UV on birch forests.

Freshwater Ecosystems

Some freshwater species, such as amphibians, are known to be highly sensitive to UV radiation, though the vulnerability of northern species has been little examined. Climate-related changes are projected in three important factors that control the levels of UV that reach living things in freshwater systems: stratospheric ozone, snow and ice cover, and materials dissolved in water that act as natural sunscreens against UV. Reduced stratospheric ozone is expected to persist for several decades, allowing increased UV levels to reach the surface, particularly in spring.

More significantly for aquatic life, the warming-induced reduction in springtime snow and ice cover will decrease protection for plants and animals normally shielded by that cover, leading to major increases in underwater UV exposure. White ice and snow form significant barriers to UV penetration; just two centimeters of snow can reduce the below-ice exposure to UV by about a factor of three. This is especially important in freshwater systems that contain low levels of dissolved matter that would shield against UV.

Lakes and ponds in northern areas of the Arctic generally contain much less dissolved material than those in the southern part of the region, due mainly to the greater vegetation that surrounds water bodies in the south. Arctic waters also contain little aquatic vegetation. In addition to the low levels of dissolved matter and resulting deep penetration of UV in arctic lakes and ponds, many of these freshwater systems are quite shallow. For example, the average depth of more than 900 lakes in northern Finland and about 80 lakes in arctic Canada is less than 5 meters. As a consequence, all living things, even those at the bottom of the lakes, are exposed to UV radiation.

Some of the first impacts of warming will be associated with the loss of permanent ice cover in far northern lakes; these impacts are already taking place in the Canadian High Arctic. As the length of the ice-free season increases, these effects will be amplified. However, climate warming is expected to increase levels of dissolved matter in many arctic freshwater systems as warming increases vegetation growth. In addition, thawing permafrost could increase the amount of sediment stirred up in the water, adding protection against UV. These changes could partially offset the increases in UV due to reduced snow and ice cover and to decreased ozone levels.

Marine Ecosystems

Phytoplankton, the tiny plants that are the primary producers of marine food chains, can be negatively impacted by exposure to UV radiation. Severe UV exposure can decrease productivity at the base of the food chain, perhaps by 20-30%. Current levels of UV negatively affect some secondary producers of marine food chains; UV-induced deaths in early life stages and reduced survival and ability to reproduce have been observed. Damage to the DNA of some species in samples collected from depths of up to 20 meters has been detected. Some species suffer strong negative impacts while others are resistant, depending on season and location of spawning, presence of UV screening substances, ability to repair UV-induced damage, and other factors.

There is clear evidence of detrimental effects of UV on early life stages of some marine fish species. For example, in one experiment, exposure to surface levels of UV killed many northern anchovy and Pacific mackerel embryos and larvae; significant sub-lethal effects were also reported. Under extreme conditions, this experiment suggested that 13% of the annual production of northern anchovy larvae could be lost. Atlantic cod eggs in shallow water (50 centimeters deep) also show negative effects due to UV exposure.

UV-induced changes in food chain interactions are likely to be more significant than direct effects on any one species. For example, UV exposure, even at low doses, reduces the content of important fatty acids in algae, decreasing the levels of these essential nutrients available to be taken up by fish larvae. Since fish larvae and the chain of predators through the food web require these essential fatty acids for proper development and growth, such a reduction in the nutritional quality of the food base has potentially widespread and significant implications for the overall health and productivity of the marine ecosystem. Exposure to UV radiation has many harmful effects on the health of fish and other marine animals, notably the suppression of the immune system. Even a single UV exposure decreases a fish’s immune response, and the reduction is still visible 14 days after the exposure. This could cause increased susceptibility to disease by whole populations. The immune systems of young fish are likely to be even more vulnerable to UV as they are in critical stages of development, resulting in compromised immune defenses later in life.

Recent studies estimate that a 50% seasonal reduction in stratospheric ozone could reduce primary production in marine systems by up to 8.5%. However, as with freshwater systems, cloud cover, ice cover, and the clarity or opaqueness of the water will also be important factors in determining UV exposure.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #9, Impacts of UV on Ecosystems, p.103

7.3 How can various factors interact to cause impacts on people and the environment?

    • 7.3.1 Climate change and contaminants
    • 7.3.2 Human Health

The source document for this Digest states:

KEY FINDING #10

Climate change in the Arctic is taking place within the context of many other changes, such as chemical pollution, increased ultraviolet radiation, and habitat destruction. Societal changes include a growing population, increasing access to arctic lands, technological innovations, trade liberalization, urbanization, self-determination movements, increasing tourism, and more. All of these changes are interrelated and the consequences of these phenomena will depend largely on interactions among them. Some of these changes will exacerbate impacts due to climate change while others alleviate impacts. Some changes will improve peoples’ ability to adapt to climate change while others hinder their adaptive capacity.

The degree to which people are resilient or vulnerable to climate change depends on the cumulative stresses to which they are subject as well as their capacity to adapt to these changes. Adaptive capacity is greatly affected by political, legal, economic, social, and other factors. Responses to environmental changes are multi-dimensional. They include adjustments in hunting, herding, and fishing practices as well as alterations in the political, cultural, and spiritual aspects of life. Adaptation can involve changes in knowledge and how it is used, for example, using newfound knowledge of weather and climate patterns. People can alter their hunting and herding grounds and the species they pursue, and build new partnerships between federal governments and Indigenous Peoples’ governments and organizations.

The particular environmental changes that create the greatest stresses vary among arctic communities. For example, threats to human health from persistent organic pollutants (POPs) and the reduction in sea ice are extremely serious for Inuit in northern Canada and western Greenland, but not as important to Saami in northern Norway, Sweden, and Finland. For the Saami, freezing rain that coats reindeer forage with ice is of great concern, as is the encroachment of roads on grazing lands.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #10, Multiple influences interact to cause impacts to people and ecosystems, p.106

7.3.1 Climate change and contaminants

The source document for this Digest states:

Contaminants including POPs and heavy metals transported to the Arctic from other regions are among the major environmental stresses that interact with climate change. Certain arctic animal species, particularly those high on the marine food chain, carry high levels of POPs such as DDT and PCBs. Global use of these chemicals peaked in the 1960s and 1970s and their manufacture has since been banned in most countries. However, pollutants emitted prior to these controls persist in the environment and are transported, primarily by air currents, from industrial and agricultural sources in the mid-latitudes to the Arctic where they condense out of the air onto particles or snowflakes or directly onto earth's surface.

POPs become increasingly concentrated as they move up the food chain, resulting in high levels in polar bear, arctic fox, and various seals, whales, fish, seabirds, and birds of prey. Arctic people who eat these species are thus exposed to potentially harmful levels of these pollutants. Levels of concern have been measured in blood samples from people in various arctic communities, for example, in eastern Canada, Greenland, and eastern Siberia, with strong variations observed around the region.

Mercury is the heavy metal of greatest concern in parts of the Arctic. Mercury from distant sources is deposited onto snow in the Arctic where it is released to the environment when the snow melts in springtime, at the onset of animal and plant reproduction and rapid growth, when living things are most vulnerable. Coal burning, waste incineration, and industrial processes are the major sources of global mercury emissions. Current mercury levels pose a health risk to some arctic people and animals, and because mercury is so persistent, mercury levels are still increasing in the region, despite emissions reductions in Europe and North America.

Winds carry contaminants, and precipitation deposits them onto the land and sea. Temperature plays a role in determining the distribution of contaminants between air, land, and water. Projected climate change-related alterations in wind patterns, precipitation, and temperature can thus change the routes of contaminant entry and the locations and amounts of deposition in the Arctic. More extensive melting of multi-year sea ice and glaciers results in the rapid release of large pulses of pollutants that were captured in the ice over years or decades.

There are several other ways that climate change can alter contaminant pathways into the Arctic. Recent evidence suggests that salmon migrations undergo large, climate-related variations and that Pacific salmon may respond to change by moving northward into arctic rivers. These salmon accumulate and magnify contaminants in the Pacific Ocean, and transport them into arctic waters. For some lakes, fish may bring in more POPs than does atmospheric deposition. Similarly, changing bird migrations have the potential to transport and concentrate contaminants in particular watersheds. For example, Norwegian researchers studying Lake Ellasjoen found that seabirds serve as an important pathway for contaminants (in this case POPs) from marine to freshwater environments.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #10, Climate Change and Contaminants, p.106

Case study of interacting changes: Saami reindeer herders

7.3.2 Human Health

The source document for this Digest states:

Climate change will continue to affect human health in the Arctic. The impacts will differ from place to place due to regional differences in climate change as well as variations in health status and adaptive capacity of different populations. Rural arctic residents in small, isolated communities with a fragile system of support, little infrastructure, and marginal or non-existent public health systems appear to be most vulnerable. People who depend upon subsistence hunting and fishing, especially those who rely on just a few species, will be vulnerable to changes that heavily affect those species (for example, reduced sea ice and its impact on ringed seals and polar bears). Age, lifestyle, gender, access to resources, and other factors affect individual and collective adaptive capacity. And the historic ability to relocate to adapt to changing climatic conditions has been reduced as settlements have become permanent.

There are likely to be both adverse and beneficial outcomes of climate change on human health in the Arctic. Direct positive impacts could include a reduction in coldinduced injuries such as frostbite and hypothermia and a reduction in cold stress. Death rates are higher in winter than in summer and milder winters in some regions could reduce the number of deaths during winter months. However, the relationship between increased numbers of deaths and winter weather is difficult to interpret and more complex than the association between illness and death related to high temperatures. For example, many winter deaths are due to respiratory infections such as influenza, and it is unclear how higher winter temperatures would affect influenza transmission.

Direct negative impacts are likely to include increased heat stress and accidents associated with unusual ice and weather conditions. Indirect impacts include effects on diet due to changes in the access to and availability of subsistence foods, increased mental and social stresses related to changes in the environment and lifestyle, potential changes in bacterial and viral proliferation, mosquito-borne disease outbreaks, changes in access to good quality drinking water, and illnesses resulting from sanitation system problems. Health effects may also arise from interactions between contaminants, ultraviolet radiation, and climate change.

Indigenous people in some parts of the circumpolar North are reporting incidences of stress related to high temperature extremes not previously experienced. Impacts include respiratory difficulties, which, in turn, can limit an individual’s participation in physical activities. However, fewer cold days associated with the warming trend in many regions during the winter are reported to have the positive effect of allowing people to get out more in the winter and alleviating stress related to extreme cold.

Climate-related changes in fish and wildlife distribution are very likely to result in significant changes in access to and the availability of traditional foods, with major health implications. A shift to a more Western diet is known to increase the risks of cancer, obesity, diabetes, and cardiovascular diseases among northern populations. Decreases in commercially important species, such as salmon, are likely to create economic hardship and health problems associated with reduced income in small communities.

Climate stress and shifting animal populations also create conditions for the spread of infectious diseases in animals that can be transmitted to humans, such as West Nile virus.

Safe drinking water and proper sanitation are critical to maintaining human health. Sanitation infrastructure includes water treatment and distribution systems, wastewater collection, treatment and disposal facilities, and solid waste collection and disposal. Permafrost thawing, coastal erosion and other climate-related changes that adversely affect drinking water quality, limit efficient delivery, or cause direct damage to facilities are likely to lead to adverse impacts on human health.

Increases in extreme events such as floods, storms, rockslides, and avalanches can be expected to cause an increase in injury and death. In addition to such direct impacts of these events, indirect effects could include impacts on the availability of safe drinking water. Intense rainfall events can also trigger mosquito-borne disease outbreaks, floodrelated disasters, and, depending on existing water infrastructure, contamination of the water supply.

Mental health is also likely to be affected by climate related changes in the Arctic. Reduced opportunities for subsistence hunting, fishing, herding, and gathering are likely to cause psychological stresses due to the loss of important cultural activities. Flooding, erosion, and permafrost thawing related to climate change can negatively affect village habitability and infrastructure, and result in population dislocations and community disruption with resultant psychological impacts.

Source & ©: ACIA Impacts of a Warming Arctic: Arctic Climate Impact Assessment  (2004),
 Key Finding #10, Human Health, p.110


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