The climate of the Arctic has shown an unprecedented rate of change during the past 50 years. Over the last half century, the Canadian Arctic has experienced significant increases in both temperature and precipitation, consistent with trends in other circumpolar regions. Increases in air temperature have resulted in many of the most extreme warm years throughout the entire Canadian North being recorded in the last decade, with the greatest temperature increases observed over the western Arctic. All global climate models project continued increases in temperature and precipitation over the Canadian Arctic, with greatest temperature changes at higher latitudes. As a result, there will continue to be significant changes in the physical environment, particularly in the cryosphere (snow, glaciers, permafrost and river/lake/sea ice).
There is increasing evidence that changes in climate are already having impacts on ecological, economic and human systems in northern regions, and that some individuals, communities and institutions are already taking action to reduce harmful impacts. Current levels of exposure to climate-related changes and sensitivities, as well as limitations in adaptive capacity, make some northern systems and populations particularly vulnerable to the effects of climate change. Key findings include the following:
- Climate-induced changes in the cryosphere (permafrost, sea ice, lake ice and snow) have important implications for infrastructure maintenance and design. Much of the infrastructure in the North is dependent upon the cryosphere to, for example, provide stable surfaces for buildings and pipelines, contain wastes, stabilize shorelines and provide access to remote communities in the winter. Permafrost warming and thaw may require remedial action or further engineering modifications to existing infrastructure. Waste retention ponds and lakes that rely on the impervious nature of permafrost to retain environmentally hazardous materials are a particular concern. Climate change is already being considered in the design of most major projects in the North, including tailings containment structures, pipelines and roads, and large buildings. In the longer term, marine and freshwater transportation will need to shift its reliance from ice routes to open-water or land-based transport systems. Coastal areas and communities will also become more vulnerable to erosion due to loss of sea ice compounded by increased storminess and rising sea levels. Changes in the timing of river flows will require modifications to the infrastructure and flow strategies used in generating hydroelectricity.
- As the climate continues to change, there will be consequences for biodiversity shifts and the ranges and distribution of many species, with resulting impacts on availability, accessibility and quality of resources upon which human populations rely. This has implications for the protection and management of wildlife, fisheries and forests. The northward migration of species, and disruption and competition from invading species, are already occurring and will continue to alter terrestrial and aquatic communities. Shifting environmental conditions will likely introduce new animal-transmitted diseases and redistribute some existing diseases, affecting key economic resources and some human populations. Stress on populations of iconic wildlife species, such as the polar bear, at the southern limit of their distribution will continue as a result of changes to critical sea-ice habitat. Where these stresses affect economically or culturally important species, they will have significant impacts on people and regional economies. Widespread proactive adaptation to these changes will be required in natural resource management sectors.
- Increased navigability of Arctic marine waters and expansion of land- and fresh water –based transportation networks will lead to a less ‘remote' northern Canada, bringing both opportunities for growth in a range of economic sectors and challenges associated with culture, security and the environment. Diminishing sea ice, particularly in Hudson Bay and the Beaufort Sea, and a lengthened summertime shipping season associated with warming, will increase opportunities for shipping and passage within Canadian Arctic waters. It is likely that adaptations in the form of increased surveillance and policing will be required. Loss of sea ice and fresh ice will also lead to the development of marine ports and all-season road networks to interior portions of the northern mainland and Arctic islands, particularly to access natural resources whose development has previously been uneconomic. Socioeconomic and cultural impacts on Arctic communities from increased economic activity, including increased marine traffic and access associated with the opening of the Northwest Passage, may be far reaching.
- While maintaining and protecting aspects of traditional and subsistence ways of life in many Arctic Aboriginal communities may become more difficult in a changing climate, new opportunities will also be presented. Young and elderly Aboriginal residents, in particular those pursuing aspects of traditional and subsistence-based ways of life in more remote communities, are the most vulnerable to the impacts of climate change in the North. An erosion of their adaptive capacity via the social, cultural, political and economic changes taking place in many communities today will further challenge their abilities to adapt to changing environmental conditions. However, enhanced economic opportunities may provide significant benefits to communities, making the net impacts on human and institutional vulnerability difficult to predict.