Environmental change in Garibaldi Provincial Park, Southern Coast Mountains, British Columbia

Geoscience Canada, Sept, 2004 by Johannes Koch, Brian Menounos, John J. Clague, Gerald D. Osborn

Long-term changes in solar insolation, however, cannot explain the shorter, decadal-scale changes in climate inferred from the geological and historical records, including those of the last century. Most of these shorter-term climate changes are driven by complex, poorly understood, ocean-atmosphere effects (Clark et al., 2002), by short-term changes in the total output of radiation from the Sun (Lean, 2002), by volcanism (Angell and Korshover, 1985), or by some combination of these factors (Paul and Schulz, 2002). Environmental changes since the end of the Little Ice Age, however, suggest that the climate of the twentieth century was unusual in the context of the Holocene. The changes include average global surface warming of about 1[degrees]C (Bradley and Jones, 1993), recession of some glaciers from their most advanced positions of the last 10,000 years to positions they likely have not occupied in the last 8000 years (Koch et al., 2004), and concurrent upward migration of treeline from its lowest Holocene level to a level most likely not reached in the last 7000 years (Kullman, 2001). If this trend continues into the future, we may pass through a threshold from the present climate regime into a new, different one, with unexpected consequences for all of us.

ACKNOWLEDGEMENTS

We thank the British Columbia Mountaineering Club and its President Michael Feller for giving us access to their archive of historical photos of Garibaldi Provincial Park. We are also grateful to British Columbia Archives for access to the original glass negatives of the first geodetic survey of the park by A.J. Campbell, and to BC Parks and the rangers of Garibaldi Park, especially Chris Platz, for their support. Funding for the research was provided by the Natural Sciences and Engineering Research Council of Canada, Simon Fraser University, the University of British Columbia, and the Geological Society of America. B.H. Luckman and an anonymous reviewer provided valuable comments that improved the quality of the paper.

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