2013 The International Institute for Sustainable Development
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www.iisd.org ©2013 The International Institute for Sustainable Development **Subject to final design and copy edit better understand coastal processes. Carmack and MacDonald (2008) provide an excellent example of how the observations and wisdom of aboriginal elders was the stimulus that led to a successful research project on the Mackenzie Delta. Henri, Gilchrist, and Peacock (2010) provide an overview of the ways that TEK and Western science have interacted and complemented one another with respect to managing wildlife in the Hudson Bay region and discusses ways in which these two perspectives could converge in addressing the potential impacts of climate change on marine mammals and birds.
Evidence from a variety of sources paints a compelling picture of a rapidly changing marine ecosystem. Satellite observations provide a unique capacity to document the earlier break-up and later freeze-up of the seasonal ice cover and changes in sea-surface temperatures, while aboriginal hunters and trappers have a first-hand understanding of changes in the near-shore ice environment. Both categories of information can generate testable hypotheses for explaining the situations and changes that are observed.
Unfortunately, in most instances, there is very limited detailed understanding of how this system actually works. The vastness of the system and its harsh environment make it extremely difficult to carry out monitoring and research initiatives at spatial and temporal scales that can be readily extrapolated to the entire Hudson Bay Complex. Modelling initiatives continue to fill this need, but without corroborating monitoring and research the outputs of models, however sophisticated they may be, will have limited credibility.
The waters of Pacific and Atlantic origin meet in the Arctic Ocean, as they do in the Hudson Bay. This interaction has long been recognized as an important component of the global ocean circulation and climate system. The speed of climate warming in the Arctic and the decline of sea ice in the Arctic Ocean have added a new level of urgency and alarm. The title of one recent publication (McLaughlin et al., 2011) is: “The rapid response of the Canada Basin to climate forcing: From bellwether to alarm bells.” This title is fully consistent with the findings reported in many of the publications now appearing in the scientific literature. While the state of the Arctic Ocean clearly has implications for the global climate, it is entirely plausible that the rapid and accelerating loss of ice cover on the Arctic Ocean could be the harbinger of things to come in the Hudson Bay Complex.
www.iisd.org ©2013 The International Institute for Sustainable Development **Subject to final design and copy edit Since 1979, enabled scientists have been able to track the precipitous decline in the extent and volume of ice cover on the Arctic Ocean through satellite monitoring. This decline in the ice cover is both an indicator and a driver of climate change in the Arctic, the subarctic and indeed the rest of the planet. The documented declines in sea ice in the Arctic along with increasingly sophisticated climate modelling are fueling an unprecedented interest in the potential for the Arctic Ocean to become a major international route for commercial shipping and Arctic tourism. The potential reserves of oil and gas in the region are also driving activity in the Arctic and underlay much of the current interest in Arctic sovereignty.
The extent of the ice cover (15 per cent or more of the sea surface) of the Arctic Ocean reached its minimum on September 9, 2011. That minimum and the average ice cover for the month (4.6 million km²) are the second lowest in the 1979–2011 period (United States National Snow and Ice Data Center, 2011a). Figure 1 illustrates the decline in the extent of the average September ice cover. Atmospheric conditions were exceptionally conducive to rapid ice melt in 2007, the record year for the lowest September average ice cover (4.3 million km²). The last 5 years (2007–2011) are the five lowest September averages in the satellite record. The current trend in September average ice extents relative to the 1979–2000 average (7.04 million km²) is 12 per cent per decade. This trend is ominous, apparently relentless and, in the opinion of many experts, unstoppable in the foreseeable future.
While the decline in sea ice has been apparent for decades, the 2007 melt season was exceptional with atmospheric conditions leading to an unprecedented and unexpected loss of sea ice. Sonar readings from under-ice submarine voyages as well as from satellite observations indicate that the ice pack is now only about half as thick as it was in the 1980s. Many scientists (McCullough et al., 2011) now expect that the Arctic Ocean will be seasonally ice free in as little as one or two decades and that the Intergovernmental Panel on Climate Change was much too cautious when it predicted that the ice-free Arctic Ocean would not likely occur until 2030–2050 in its 2007 report.
www.iisd.org ©2013 The International Institute for Sustainable Development **Subject to final design and copy edit
Figure 1. Declining extent of September sea ice in the Arctic Ocean. The United States National Snow and Ice Data Center publishes an online monthly news letter, Arctic Sea Ice News & Analysis, on changing ice conditions in the Arctic. Figures 1 and 2 are from the October and December issues respectively. Figure 2 illustrates how the Arctic ice cover changed during 2011 compared to the average ice cover for the period from 1979–2000, as well for the years 2007, 2008, 2009 and 2010. This figure is for December 1, 2011 and, as noted, 2011 has tracked 2007 (the ice minimum year) very closely.
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