Climate change impacts, adaptation, and the technology interface - Environmental and Human Security in the Arctic - page 118

dropped from over 200 to about 100 in the past 30 years, resulting in a 50 per
cent reduction in days that oil and gas exploration and extraction equipment
can be used.
Other model-based projections from the Canada Country Study (Maxwell
1997) for the Canadian Arctic indicated a possible warming from 5 to 7°C,
including most of the Arctic Islands, and a warming of up to 10°C over cen-
tral Hudson Bay. Such a warming would have a devastating effect on ice
conditions in Hudson Bay to support polar bear habitats. Precipitation in the
North is also likely to increase by up to 25 per cent.
Despite the age of the report, there is considerable information in the
Canada Country Study (Maxwell 1997) that is still very pertinent and rele-
vant to the design and construction of northern buildings and infrastructure,
especially in the sections given to describing the physical environment and
the socio-economic sectors. The discussion on the physical environment of
Canada's North includes:
• Hydrology;
• Permafrost;
• Sea ice and icebergs (including glaciology);
• Sea level and coastal processes;
• Freshwater ice (including freshwater lakes and riverine processes).
One challenge of the coming decades will be to increase university- and
community-based monitoring efforts of environmental change in northern
regions to provide the measurements for comparison with the projections of
computer-based climate models. Climate models are necessary because the
climate statistics available from recent decades is insufficient to assess the
probability of future climate averages or extremes (Lahey 2002).
Climate models contain mathematically simplified approximations of the
key processes and relationships in the environment, among atmospheric,
ocean, fresh water systems, ice and land surface variables, and include how
these processes impact the climate over time. The models are driven by
changes in CO 2 , and other gases in the atmosphere, which may cause heating
or cooling. The models are known by the GCM acronym, which stands for
either 'General Circulation Models' or 'Global Climate Models'. The opera-
tion of a computer-based GCM is calibrated by putting past conditions into
the model, and then observing whether the model will 'spin up' over time to
give the climate conditions observed today. The model components are con-
nected together so that atmosphere, ocean, land and ice interact on a daily
basis. As the model runs forward, the modelled climate evolves to provide
climate snapshots at future times.