Cryosphere Connections: Dynamics of Change in Our Frozen World
Speakers:
Luke Copland (University of Ottawa) and
Pascale Roy-Léveillée (Université Laval)
Glacier changes across the Canadian Arctic and beyond in a warming climate
Luke Copland, University of Ottawa
The Arctic is currently warming 3-4x faster than the global average, which is having significant impacts across the cryosphere. On glaciers in the Canadian Arctic we are seeing marked increases in surface melt, surface thinning, negative surface mass balance and a retreat from the ocean. This has included the loss of ~300 km2 of marine-terminating glacier termini over the past decade. However, there has been a variable velocity response: most glaciers are slowing down that terminate on land, but a few that terminate in the ocean are speeding up as they are nearing flotation due to recent thinning. In this presentation these changes are reviewed and placed in the context of pan-Arctic changes, where glaciers and the Greenland Ice Sheet are losing mass at a combined rate of up to 500 Gt yr-1 (1.4 mm yr-1 sea level rise equivalent).
Local expressions of global change: community-level impacts of permafrost thaw in the Canadian North
Pascale Roy-Léveillée, Université Laval
Permafrost degradation raises international concern for its global impacts on the carbon and mercury cycles, yet it is at the local and regional scales that effects of thaw are observed and experienced first and most directly. There are more than 150 communities located in the continuous and discontinuous permafrost zones of Canada, of which many face permafrost hazards such as ground subsidence, slope failure, contaminant mobilisation, or icing expansion that can threaten infrastructure stability, reduce water quality, or impede access to traditional foods. The surface expression of permafrost thaw varies widely in nature and magnitude across space, reflecting important differences in permafrost conditions, ecosystem resilience, and physiographic context. This presentation reviews impacts of permafrost thaw using contrasting examples from Canadian communities and discusses how collaborative field-based efforts centered on community priorities can produce datasets and models that support northern resilience to permafrost thaw in a warming climate.
