A six-year regional study of the effect of climate change in the Mackenzie Basin was recently completed and results of "what-if" scenarios presented to stakeholders in the area.
"It's not just a matter of whether climate warming will change the physical capability of the land itself, but what happens to those people who live and work in the areas in question," says Stewart Cohen, project leader for the Mackenzie Basin Impact Study.
The United Nations Intergovernmental Panel on Climate Change has concluded that increased concentrations of carbon dioxide and other trace gases will lead to a warming of the world's climate. Retreating permafrost could potentially release huge sources of methane trapped by ice in the Canadian northwest.
Cohen, a member of UBC's Sustainable Development Research Institute (SDRI) and an Environment Canada scientist, led a team of researchers drawn from universities, institutes and government research centres across the country. Stakeholders involved in the study included representatives from aboriginal groups and industry as well as municipal, territorial, provincial and federal governments.
With a total area of 1.8 million square kilometres, the Mackenzie drainage basin is the largest of any river system in Canada. Stretching 4,241 kilometres, the Mackenzie River is the second longest river in North America next to the Mississippi.
Cohen says the purpose of the study was to produce an integrated regional assessment of climate change scenarios for the entire watershed. He adds that the study is one of the first of its kind to assess climate change impacts on terrestrial and freshwater ecosystems as well as the communities which depend on them.
A warming trend of 1.5 C this century, plus other signs of climate warming in the basin, such as thawed permafrost, prompted a study of the area which encompasses parts of the Yukon and Northwest Territories as well as northern B.C., Alberta and Saskatchewan.
Cohen says the basin may be particularly sensitive to variations in its climate because it has many transition zones such as the tree line and the northern limits of agriculture.
"In the North, agriculture could quite conceivably expand so the question becomes what would it expand onto," says Cohen. "It could be wildlife habitat, forestry or land on aboriginal territory. How would stakeholders respond?"
Scenarios of climate change suggest that the region could warm up by 4 to 5 C during the middle of the 21st century. These scenarios would affect the land, water and wildlife in many ways: water levels in Great Bear and Great Slave lakes would decline to below current minimum levels; forest yields would decline due to an increase in forest fires; increased thawing of the permafrost and accompanying landslides would occur in the Beaufort Sea coastal zone and Mackenzie Valley; peatlands would disappear from areas south of 60 degrees north and expand in northern areas; and caribou would be harmed by a rise in summer temperatures, which would probably be accompanied by an increase in harassment from insects.
A full report of the Mackenzie Basin Impact Study is expected in December.