A new study suggests human-caused climate change is behind a sharp drop in spring snowpack across large parts of the Northern Hemisphere, including a swath of Ontario and Quebec. People walk on the snowless streets of Place Jacques Cartier in Old Montreal, Wednesday, Jan. 3, 2024. THE CANADIAN PRESS/Ryan Remiorz
TORONTO – A new study suggests human-caused climate change is behind a sharp decline in spring snowpack across large parts of the Northern Hemisphere, including a swath of Ontario and Quebec.
The study published in the journal Nature cuts through the noise of standalone measurements and models to find climate change has altered spring snowpack across 31 major river basins in the Northern Hemisphere, including the St. Lawrence-Great Lakes.
The researchers out of New Hampshire’s Dartmouth College say although observations in the St. Lawrence had previously suggested snowpack trends were small and insignificant, their study indicates anthropocentric climate change was responsible for a seven per cent drop in March snowpack per decade over 40 years.
PhD student Alex Gottlieb says he and his co-author arrived at the results after comparing several major datasets to confidently pinpoint snowpack trends, then compared those trends to climate models simulating snowpack levels in the absence of human-caused greenhouse gas emissions.
Gottlieb says despite some inconsistencies between individual datasets, when you put them together, it’s clear the long-term snowpack trend for some major basins is “really only consistent with a world in which we’ve emitted as we have.”
John Pomeroy, a leading Canadian expert in water resources and climate change who was not part of the study, says Canada is already seeing the effects of lower spring snowpack in the form of droughts and wildfires.
This report by The Canadian Press was first published Jan. 10, 2024.
