Evaluating Changes in River Systems and the Cryosphere in Canada: Insights from the Global Water Futures Modeling Synthesis

In an era of rapid climate change, the need for reliable information to support adaptation has never been greater. Changes resulting from warming temperatures and shifting precipitation patterns are influencing snowmelt dynamics, freeze-thaw cycles and basin response. These shifts may transform Canada’s environmental systems in profound and unprecedented ways. The Global Water Futures modelling research was developed to address these evolving challenges, providing insights into how Canada’s major river basins may respond to these changes. This work focuses on the pan-Canadian application of the MESH land-surface hydrology model across the Yukon, Fraser, Columbia, Mackenzie, Nelson, Churchill, Great Lakes-Saint Lawrence, and Saint John Basins, covering more than 5 million square kilometres. The model simulations integrate bias-corrected, downscaled climate projections to explore future scenarios. We detail the innovative workflows and tools developed for this research and present key findings on glacier retreat, permafrost thaw, and shifting river flow regimes. These results underscore the critical need for adaptive, forward-thinking water resource management to build resilience and strengthen the adaptive capacity of Canada’s watersheds.