Nature Climate Change - Large sinuous rivers are slowing down in a warming Arctic
“It’s potentially a disruptive idea. It may potentially reshape the way we think about northern environments and the way they are adapting to the changing climate”
A new study, published in Nature Climate Change, shows that the climate change impact on Artic rivers may not be what we had previously expected, specifically that the speed at which these rivers migrate will actually decrease, rather than increase. This could change the way scientists look at northern environments and is important for community planning. Rising temperatures and melting permafrost were thought to speed up the river's position change. However, the “shrubification” of the Arctic is slowing that down. The permafrost thawing means that more vegetation can grow. This is making riverbanks more stable, preventing erosion. Additionally, the surface water runoff that would typically cause erosion is now being used by the new plant life.
“The dynamics of these rivers reflect the extent and impact of global climate change on sediment erosion and deposition in Arctic watersheds. Understanding the behavior of these rivers in response to environmental changes is paramount to understanding and working with the impact of climate warming on Arctic regions.”
Hikers cross a bridge going across the Yukon River near Whitehorse on Friday, July, 22, 2016. Scientists have long believed rapid warming in the Arctic would cause river channels to move faster, but a new study has found the opposite may be true for large, winding rivers in the region. THE CANADIAN PRESS/Jonathan Hayward
This study looked at 10 winding rivers wider than 100m in permafrost territory. The authors emphasized that this is likely not applicable to smaller streams, and more data and studies are needed. This type of impact assessment will not be available in the first iteration of the Canada1Water project, but it is something we hope it can perform in the future. Currently, the Canada1Water project aims to give water resource managers, policymakers, and communities the tools to make informed decisions about water management.
“We tested the hypothesis that large sinuous rivers in permafrost terrain are moving faster under a warming climate and we found exactly the opposite. Yes, permafrost is degrading, but the influence of other environmental changes, such as greening of the Arctic, counteracts its effects. Higher temperatures and more moisture in the Arctic mean the region is greening up. Shrubs are expanding, growing thicker and taller on areas that were previously only sparsely vegetated.”
Want to read more about this study? Read the review articles below: