CGRG Bibliography of Canadian Geomorphology
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Author : Burn, C.R.; Barrow, E.; and Bonsal, B.
Date : 2004.
Title : Climate change scenarios for Mackenzie River valley.
Publication : Geo-Engineering for the Society and its Environment. 57th Canadian Geotechnical Conference and the 5th joint CGS-IAH Conference. Hilton Quebec Hotel, Old Quebec. October 24-27, 2004.
Issue :
Page(s) :
Abstract
The Mackenzie Gas Project is the largest development recently proposed in northern Canada. The objective is to produce natural gas from three fields in the Mackenzie delta area, and to transport the gas and associated natural gas liquids 1200 km south in a pipeline system. The impact of climate change on project operations and infrastructure must be considered during the environmental assessment and regulatory process. In this case, climate change scenarios are required to represent the range of conditions of upper Mackenzie valley through to the delta and Tuktoyaktuk Coastlands. There are numerous scenarios available for prediction of climate change. The purpose of this paper is to select representative scenarios that may be used by this project and others in Mackenzie valley. A principal application of the scenarios is to predict temperature changes in permafrost and active-layer development along the pipeline right-of-way. In the project region, existing climatic data are sufficient to calculate normals for Hay River, Fort Simpson, Norman Wells, Inuvik and Tuktoyaktuk. Annual mean temperatures at these stations are well correlated for 1958-2000, and at each station the annual mean temperature has increased since 1970. The rate of warming at Inuvik is 0.74ºC/decade. In contrast, precipitation records from the region are poorly correlated. General circulation models (GCMs) are the tools used to simulate global climate, in order to investigate the response of the atmosphere to increasing concentrations of greenhouse gases. The Canadian Climate Impacts Scenarios Project of Environment Canada uses 29 simulations to evaluate potential changes in the climate of Canada. These simulations are the result of implementing four IPCC-approved “storylines” of future emissions’ patterns in seven GCMs. Future climate is projected by considering the change from baseline conditions with present levels of greenhouse gases. Output for temperature and precipitation from various GCMs has been examined to determine the model’s ability to reproduce the magnitude and spatial variability of observed baseline climate, i.e. from records collected in 1961-1990. GCMs simulate these aspects well for temperature, but tend to overestimate the baseline precipitation for the region. Mackenzie River valley occupies three or four grid cells in GCM output. In most simulations, climatic change in the north is distinct from changes projected for southern parts of the valley. For any point, the representation of potential change is best obtained by using a weighted average of data from the cell including the point and the surrounding eight cells. On this basis, the project region is divided into a northern and southern sector, with the boundary approximately at the latitude of Fort Good Hope. In the paper we will present, for upper and lower sectors of the valley, the 86th, 50th and 14th percentile scenarios for climate change, based upon changes in annual and winter temperature. The impact of these scenarios on climate normal statistics (seasonal and annual temperatures and precipitation, and annual freezing and thawing degree-days) will be presented for stations in the valley, along with a comparison of the rate of change in simulated climate with recorded trends. Simulations will be provided for 2010-39 and 2040-69.
Bibliography of Canadian Geomorphology