Climate change, carbon, and forestry in northwestern North America: proceedings of a workshop November 14-15, 2001 Orcas Island, Washington.

Interactions between forests, climatic change and the Earth's carbon cycle are complex and represent a challenge for forest managers -they are integral to the sustainable management of forests.In this volume, a number of papers are presented that describe some of the complex relationships between climate, the global carbon cycle and forests.Research has demonstrated that these are closely connected, such that changes in one have an influence not only on the other two, but also on their linkages.Climatic change represents a considerable threat to forest management in the current static paradigm.However, carbon sequestration issues offer opportunities for new techniques and strategies, and those able to adapt their management to this changing situation are likely to benefit.Such changes are already underway in countries such as Australia and Costa Rica, but it will probably take much longer for the forestry sector in the Pacific Northwest region of North America (encompassing Oregon, Washington, Montana, Idaho, British Columbia and Alaska) to change their current practices. Climatic ChangeClimate is dynamic and is always changing.Around 15,000 years ago, much of the northern half of North America was covered by ice sheets; today only tiny remnants remain.Several sources of information, including both direct measurements and proxy evidence, have revealed that temperatures in the northwest of North America are increasing.Mote (this volume) reviews what we know about recent changes in the climate of the Northwest.During the 20th century, average annual temperature warmed by 0.6°C on the coast of British Columbia, 1.1°C in the interior and 1.7°C in the northern part of the province (Mote 2003).The temperature changes recorded in, for example, Fort St. James in British Columbia during the 20th century match very closely in pattern the changes in sea-surface temperatures recorded globally (Coulson 1997).These changes are reflected in the number of growing degree days, which increased by 16 percent in northeast British Columbia, by 13 percent on the Coast and in the southern interior, and by 5 percent in the central interior.Lakes and rivers are becoming ice-free earlier in the year, and the water temperatures of the Fraser River have increased.A number of glaciers in British Columbia (Brugman et al. 1997) and northern Washington (Granshaw 2002) have shrunk in size.Precipitation in southern British Columbia has been increasing by 2 to 4 percent per decade, primarily in the winter, and a 50 percent increase has been recorded in northeastern Washington and southwestern Montana during the 20th century.By 2100, temperature increases of between 1.4°C and 5.8°C relative to 1990 are expected.Globally, the Intergovernmental Panel on Climate Change (IPCC 2001) predicted higher maximum temperatures (very likely), higher minimum temperatures (very likely), reduced diurnal temperature ranges (very likely), more intense precipitation (very likely, over many areas), and increased risk of drought (likely, in mid-latitude continental interiors).The actual nature of climatic change at a particular site will depend on a variety of local factors, and considerable efforts have gone into downscaling the results of global models to individual regions.Such downscaling is considerably more difficult in mountainous areas, with clear implications for northwestern North America.

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