Global climate change, also known as global warming, is one of the most challenging elements of global environmental change. If atmospheric concentrations of carbon dioxide and other "greenhouse gases" continue to increase, global mean air temperatures are expected to rise 1.5 degrees to 4.5 degrees C within the next several decades. High-latitude regions are projected to experience above-average increases. What effects would such a warming have in the Canadian Arctic? In a recently completed study of the Mackenzie Basin in north-western Canada, regional stakeholders provided their responses to the "what if?" scenario of climate change in their region. This scenario includes more frequent landslides due to permafrost thaw, lower minimum annual river and lake levels, more forest fires, and lower yield from softwoods. These impacts could offset potential benefits from a longer growing and ice-free season. Regional stakeholders, including provincial and territorial governments, aboriginal organizations, and the private sector, felt confident about their abilities to adapt, so long as climate change would be predictable and gradual. Some potential impacts, however, could be very significant for renewable resources and aboriginal communities, and some stakeholders spoke of intervention into national and international policy arenas to raise awareness outside of the Mackenzie Basin.