Managing worldwide emissions that contribute to global climate problems can have implications for U.S. forests, including nonfederal forests. One approach to emission management is "emission trading," whereby one country agrees to limit emissions below their specified portion of worldwide levels and allow other countries to increase their emission outputs. However, instead of limiting emission levels, countries may choose to provide additional absorption capacity by enlarging their forest areas, which could be nonfederal forests in the United States (Moltke 1990). That approach is acknowledged to be potentially difficult to implement, especially with regard to distribution of emissions among countries. The European community suggests that it is possible to implement and that forests should be used as an element in the emission-absorption equation (Marland 1988, Moltke 1990). If the approach were considered worldwide, including the U.S., nonfederal-forest owners could be expected to play a part in absorption-emission plans, even to the point of being active in programs designed to expand their area for such purposes.
Migratory wildlife do not recognize international boundaries and domestic political boundaries (Flather et al. 1994). Nonfederal forests are important in providing the necessary habitat for the survival of wildlife. Large intact forests serve as migration corridors for the north-south movement, particularly across the United States, Canada, and Mexico borders, of neotropical migrants and large carnivorous mammals and their prey. For example, 250 of the 750 bird species found in the United States and Canada spend their summers in North American forests and winters in Central American forests. Large intact temperate coniferous forests of the United States and Canadian Rockies provide important connections for woodland caribou and large carnivores from source areas in Canada to population sink areas in the United States. Intact forests in the northeastern and southeastern United States provide important nesting habitat for neotropical migrants that winter in Mexico and Central America. Coastal Pacific forests located within the Pacific flyway are important for bird migrations and for maintaining connections between grizzly-bear populations in British Columbia and those in the Northern Cascades of Washington. Similar examples exist in the mid-Atlantic states flyway used by neotropical migratory songbirds and waterfowl. The role of nonfederal forests in providing key habitat linkages is important. Whether existing policies and programs are appropriate, well focused, and adequately financed is open to conjecture. The type of incentives that might be used to encourage owners of nonfederal forests to undertake actions to further the habitat of the internationally migrating species of wildlife are of special concern (Schmidheiny 1992).