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Historically an important transportation corridor in the Northwest Territories, climate change has shortened the duration of the Mackenzie River's navigational season. Communities rely increasingly on airlift as the growing volatility affects barging operations, leading to higher overall freight costs. Using an options approach, we present a methodological framework that supports flexible infrastructure decision making, accounting for the impacts of climate change uncertainty. We apply this method to the decision of whether to continue barging on the Mackenzie River, or connect the entire corridor by extending the all-weather Mackenzie Valley Highway, explicitly considering uncertainties in river barging conditions. We first model river open season days as a stochastic process; barging is dependent on the number of open season days, which in turn is affected by climate change. Second, we evaluate the expected cost of barging and airlift each season using a modified Black-Scholes model. Finally, we use real options to determine how long construction of the all-weather highway may be deferred. The results indicate that it is advisable to defer construction nearly a decade, in balancing the costs of construction against climate change uncertainty. This paper demonstrates that when we explicitly incorporate the impact of climate change on project valuations, particularly those in northern and Arctic Canada where these impacts are considerable, project valuations can change significantly such that all-weather road construction is supported, even if it is deferred to future years. This method can assist federal and territorial governments in communicating the impacts of climate change on communities, and provide another tool to support multi-layered, complex transportation infrastructure investment decisions that address these rapidly changing environments. [ABSTRACT FROM AUTHOR]

The Canadian Arctic has been undergoing profound and damaging environmental changes in recent decades at an ever-accelerating rate. In addition to climate change, a wide variety of other factors are dramatically affecting water quality, biodiversity, land stability and ice reliability. These changes have a particularly negatively impact upon population health, local transportation, traditional knowledge, cultural identity, food supply and lifestyle of the Inuit. This paper examines the threats being imposed upon the Inuit in the Canadian Arctic and their capacity to respond directly through exercising opportunities available through recent land claim settlements and northern governments in which they play a dominant role. The paper then considers the limited capacity of the federal government to deal with northern environmental issues and the potential available through enforcing international environmental agreements and human rights. [ABSTRACT FROM AUTHOR]

The MacKenzie Global Energy and Water Cycle Experiment (GEWEX) Study, Phase 1, seeks to improve understanding of energy and water cycling in the Mackenzie River basin (MRB) and to initiate and test atmospheric, hydrologic, and coupled models that will project the sensitivity of these cycles to climate change and to human activities. Major findings from the study are outlined in this paper. Absorbed solar radiation is a primary driving force of energy and water, and shows dramatic temporal and spatial variability. Cloud amounts feature large diurnal, seasonal, and interannual fluctuations. Seasonality in moisture inputs and outputs is pronounced. Winter in the northern MRB features deep thermal inversions. Snow hydrological processes are very significant in this high-latitude environment and are being successfully modeled for various landscapes. Runoff processes are distinctive in the major terrain units, which is important to overall water cycling. Lakes and wetlands compose much of MRB and are prominent as hydrologic storage systems that must be incorporated into models. Additionally, they are very efficient and variable evaporating systems that are highly sensitive to climate variability. Mountainous high-latitude subbasins comprise a mosaic of land surfaces with distinct hydrological attributes that act as variable source areas for runoff generation. They also promote leeward cyclonic storm generation. The hard rock terrain of the Canadian Shield exhibits a distinctive energy flux regimen and hydrologic regime. The MRB has been warming dramatically recently, and ice breakup and spring outflow into the Polar Sea has been occurring progressively earlier. This paper presents initial results from coupled atmospheric–hydrologic modeling and delineates distinctive cold region inputs needed for developments in regional and global climate modeling. [ABSTRACT FROM AUTHOR]

This paper examines the social networks of country food sharing in Ulukhaktok, Northwest Territories, Canada, in light of our current understanding of the relationship between climate change and Arctic peoples. Most recent work on the impacts of climate change on Arctic peoples has tended to focus on conceptual frameworks appropriate for this field of inquiry or to document perceived threats of climate change. This research incorporates a social network approach to document the association between different economic strategies (full-time worker, part-time worker, hunter) and categories of kin. It demonstrates that the sharing patterns of hunters favor the cultivation of ties with distant and collateral kin, while those of wage earners favor ties with parents and siblings. These different affiliations point to different vulnerabilities to change. For example, hunters pursue a strategy that provides the flexibility and connections necessary for adapting to changing environmental circumstances but increases their vulnerability to economic and political changes that restrict their ability to generate cash. Wage workers, despite a steady income, are more vulnerable to environmental change as it affects traveling conditions, potential hazards, and hunting success. [ABSTRACT FROM AUTHOR]

Summary: Concern has been expressed regarding the impacts of climate change on freshwater aquatic ecosystems in arctic regions. Populated with lakes controlled by flooding from spring break-up ice jams, arctic deltas such as the Mackenzie Delta in northern Canada are particularly sensitive to changing ice break-up conditions and the hydroclimatic controls on break-up and ice-jam flooding. An understanding of these controls is necessary for assessing future climate change effects. This paper presents an assessment of hydroclimatic conditions controlling break-up over the period 1974–2006, with a focus on extreme flood events. Both the upstream driving force, capturing elements of the spring discharge hydrograph, and the downstream resistance force, describing the competence of the downstream ice cover, were quantified with reference to the Mackenzie River at Arctic Red River hydrometric station such that the contribution of each to the severity and timing of break-up could be explored. Results show that the severity of peak break-up stage is most influenced by upstream discharge and the balance between upstream and downstream melt, while timing is related to delta ice conditions and the rise of the spring hydrograph. The highest peak stage events require a rapid rise in discharge and high peak discharge. Minimal downstream melting degree-days and greater ice thickness are also important, although no relationship of these appears to control the level of backwater produced from broken ice and ice jamming effects. The pattern of rapid (protracted) upstream melt and lower (higher) intensity melt in the delta characterizes the highest (lowest) break-up events. For the most severe events, upstream forces are important in controlling discharge-driven events, while an altered hydrologic response occurring for ice-driven events was noted, meriting future examination. Finally, trends toward a longer prebreak-up melt interval, lower peak discharge, rate of rise in discharge, and ice thickness, and higher freeze-up stage were observed, with greater variability of these controls and break-up severity in the most recent decade. [Copyright &y& Elsevier]

The observations of community members and instrumental records indicate changes in sea ice around the Inuit community of Igloolik, in the Canadian territory of Nunavut. This paper characterizes local vulnerability to these changes, identifying who is vulnerable, to what stresses, and why, focusing on local and regional use of sea ice for the harvesting of renewable resources and travel. This analysis is coupled with instrumental and sea ice data to evaluate changing temperature/wind/sea ice trends over time, to complement local observations. We demonstrate the relationships between changing sea ice conditions/dynamics and harvesting activities (i.e. dangers and accessibility), with specific emphasis on ringed seal and walrus seasonal hunting, to illustrate current sea ice exposures that hunters are facing. Community members are adapting to such changes, as they have done for generations. However, current adaptive capacity is both enabled, and constrained, by social, cultural, and economic factors that manifest within the modern northern Hamlet. Enabling factors include the ability of hunters to manage or share the risks associated with sea ice travel, as well as through their flexibility in resource use, as facilitated by sophisticated local knowledge and land/navigational skills. Constraining factors include the erosion of land-based knowledge and skills, altered sharing networks, as well as financial and temporal limitations on travel/harvesting. The differential ability of community members to balance enabling and constraining factors, in relation to current exposures, comprises their level of vulnerability to sea ice change. [ABSTRACT FROM AUTHOR]