Canadian Institute for Climate Studies Climate Change Impacts for British Columbia  

Implications of Climate Change for British Columbia and the Yukon inferred from the Second Assessment Report of the Intergovernmental Panel on Climate Change Working Group II

An analysis prepared by

Eric Taylor, Science Division

Environment Canada

February 15, 1996

1. Updates from the IPCC.

Updated information on climate change was released in January 1996 by the Intergovernmental Panel on Climate Change (IPCC). The IPCC was established in 1988 by the World Meteorological Organization (WMO) and UNEP to assess the most up-to-date scientific and technical research in the field of climate change. The IPCC is organized into three working groups: Working Group I concentrates on science, Working Group II on impacts and response options, and Working Group III on economics and other cross-cutting issues. This note summarizes the findings of the recently received Second Assessment Report of Working Group II and identifies implications for British Columbia and the Yukon.

2. Climate change impacts globally and for British Columbia and the Yukon.

As a consequence of possible temperature increases and changes in water availability, a substantial fraction of the existing forested area of the world would undergo major changes in broad vegetation types, particularly in temperate and northern latitudes. Climate change over the next century is expected to push isotherms (lines of equal temperature) northward 150-550 km or result in an altitude increase of 150-550 metres. In B.C. and the Yukon, this could result in changes in tree species, increased frequency of forest fires, and more frequent outbreaks and extended ranges of pests and pathogens.

It is estimated that between one third and one-half of mountain glaciers mass could disappear in the next century as a result of climate change. Along with snow cover disturbance, this would affect the seasonal distribution of river flow in British Columbia and the Yukon and could reduce the flow considerably in summer in southern British Columbia. Reductions in areas extent and depth of permafrost in the Yukon could lead to damage to infrastructure in some areas and significant changes to ecosystems.

In mountainous areas of British Columbia and the Yukon, a vegetation shift over the next century to higher elevations could cause some species to become extinct due to disappearance of habitat or reduced migration potential. The skiing industry, of economic importance to many British Columbia communities, could be shortened throughout the province and even eliminated in marginal areas.

Globally, deserts are expected to generally become more extreme; that is, hotter but not significantly wetter. Conceivably, deserts in the southern interior of British Columbia could also expand their range northward as well as increasing their altitude boundaries. Borderline semi-arid areas in the lee of the coast range in other parts of British Columbia could become desertified.

Sea level rise could result in erosion of shores and associated habitat, increased salinity of estuaries and freshwater aquifers, and some coastal flooding. Coastal ecosystems most at risk in British Columbia and the Yukon are saltwater marshes, coastal wetlands, and river deltas. Changes in these systems could have negative effects on freshwater supplies, fisheries and biodiversity. Previous work in British Columbia has suggested that migrating fish stocks will also be at risk due to increased temperatures and reduced flows in rivers and streams. Indirect impacts on British Columbia from sea level rise could be increased immigration pressure due to the 92 million people living in low lying areas around the globe who would be put at risk due to a combination of storm surges and a sea level rise of 50 cm.

Human health is likely to be impacted adversely by climate change. Predominant impacts are expected to include increases in the potential transmission of vector-borne infectious diseases such as malaria, dengue, yellow fever and some viral encephalitis resulting from extension of the geographical range and season for vector organisms. Little or no information is available to assess the impact of this on British Columbia or the Yukon.

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© 1996-1999 Canadian Institute for Climate Studies CICS, Victoria.
Last update on 24 September 1999 by Trevor Murdock