By Michael MacCracken, Chief Scientist for Climate Change Programs, Climate Institute
Changes in climate that have already taken place are manifested in the decrease in extent and thickness of Arctic sea ice, permafrost thawing, coastal erosion, changes in ice sheets and ice shelves, and altered distribution and abundance of species.
Intergovernmental Panel on Climate Change (IPCC),
Third Assessment Report (2003)
Nowadays snows melt earlier in the springtime. Lakes, rivers and bogs freeze much later in the autumn. Reindeer herding become more difficult as the ice is weak and may give way… Nowadays the winters are much warmer than they used to be. Occasionally during winter time it rains. We never expected this; we could not be ready for this. It is very strange… The cycle of the yearly calendar has been disturbed greatly and this affects the reindeer herding negatively for sure…
Larisa Avdeyeva, Lovozero, Russia
Over the past three years, a team of scientists from the eight Arctic nations has worked with representatives of the six indigenous peoples to summarize what has been happening in the Arctic and project ahead what the impacts of warming are likely to be. Both scientific findings and indigenous experiences agree—the Arctic is warming rapidly and the environmental consequences are widely apparent.
These results and many more are a result of the Arctic Climate Impacts Assessment (ACIA), the results of which were first presented publicly at an international scientific symposium held from 9-12 November in Reykjavik, Iceland. ACIA was conducted under the auspices of the Arctic Council and its Arctic Science Committee. The Council was created by international treaty and has as its members Canada, Finland, Iceland, Denmark/ Greenland/Faroe Islands, Norway, Russia, Sweden, and the United States, as well as six Indigenous People’ Organizations representing the Aleut, Athabaskan, Gwich’in, Saami, and other indigenous peoples of the Arctic.
While the major focus of the assessment is on the potential impacts of future changes in climate, the ACIA began with an analysis of how the present climate is changing. Warming over northern land areas, particularly Siberia and northwestern North America has been much greater than elsewhere in the world, and this is to be expected given the melting back of snow and ice cover that is amplifying the warming in these regions. The changes are compatible with model simulations of changes due to human modification of the concentration of greenhouse gases during the 20th century, leading quite directly to the projections that the Arctic will warm by several times as much during the 21st century as it did during the 20th century. The amplified warming in the Arctic, in turn, directly contributes to overall global warming, as well as causing changes in the Arctic that create impacts over the rest of the globe; accelerated sea level rise due to melting of mountain glaciers and ice sheets being the most important example. Thus, not only the people of the Arctic have an interest in what is happening there.
The results of five climate models were drawn upon to derive projections of future climatic change. Each model was run using two emissions scenarios, one near the mid-range of IPCC estimates, and one indicating somewhat lower than average emissions. That these relatively modest emissions scenarios caused the Arctic to warm by roughly 3 to 6ºC over the 21st century indicates why there is so much concern about human-induced warming in this region.
Relying on these scenarios of plausible change, ACIA’s team evaluated what the projected warming would mean for the region. The analyses indicate that the natural environment will be very strongly impacted, with substantial shifts in vegetation zones that cause significant reduction of tundra regions where many birds go for summer breeding. As permafrost melts and these vegetation shifts occur, forest ecosystems will be particularly vulnerable to fire and pests. Wildlife will also be significantly affected, especially those animals like the polar bear and walrus that depend on sea ice reaching near land at various times during the year and caribou that depend on frozen rivers and open tundra regions in the course of their annual migrations. Marine fisheries will also be altered, for many depend on events going on at the edge of the sea ice.
People in the Arctic are also likely to experience serious impacts. Many indigenous communities were located along the coast so they could hunt for food on land and sea ice as well as from the open waters. Not only will their harvesting of food be hindered as wildlife populations are affected, but the retreating sea ice is already starting to expose their coastal communities to greater erosion from winter storms and higher sea levels; already a few long-established villages are having to plan very expensive relocations. As the environment of the Indigenous Peoples of the Arctic changes, their cultural heritage is threatened, with the extensive natural knowledge that has been developed over many generations no longer being useful or valid. Shifting to a social structure based on products brought in from afar and sold rather than gathered has the potential to seriously disrupt the community’s internal and external relationships and rich and wonderful traditions of all helping each other to gather the means to survive through the long polar nights. Practices and identities developed over many centuries may well be lost as irrelevant and impractical to a warmer world.
While it would seem that the longer duration of open water could bring many benefits, great care will need to be taken as a result of the floating ice that could catch ships in its grasp, or even cause damage to ships and thereby lead to pollution of this pristine, and slow-healing, environment. In addition, although ocean transportation will become easier, land transportation will become more difficult as permafrost melts and the soils stay frozen for shorter and shorter periods each year. Thus, while there is likely to be increased access to coastal areas, moving resources over land to ships may well become more problematic.
The thawing of the permafrost is also going to destabilize buildings and other infrastructure such as roads, airports, sewage systems, pipelines, and industrial facilities. Future development is going to require new design elements to account for the changes, thereby increasing construction costs. Thawing permafrost also has the potential for diverting water courses and changing the water table, affecting both ecosystems and water resource infrastructure.
While warming is of utmost concern, there are actually multiple influences affecting the region. Reduced concentrations of stratospheric ozone are likely to persist for several decades, increasing levels of UV radiation for vulnerable species in the spring and also increasing exposure to humans, who will be outside more with warmer conditions. The Arctic is also experiencing increased levels of mercury and other toxic contaminants that can work through the food chain, affecting various species and eventually humans.
That warming is already so far along that it is causing noticeable impacts makes it clear that continuing onward with no serious international program to limit emissions will lead to warming that will transform the Arctic into a completely unfamiliar place for many plants and animals, leading to at least local extinctions and an on-going situation of relatively rapid changes that do not allow time for many Arctic species to adapt. For those of us in the rest of the world, the significance and difficulty of dealing with rapid changes in climate should be a lesson that we must alter the carbon-based energy path that we are on—and soon.
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