Dwindling Snowfall: A Revealing Study on the Hardest Hit Regions
Alarming study reveals sharp decline in seasonal snowfall in the Northern Hemisphere since the 1980s due to the climate crisis, posing severe implications for water supply and ecosystem stability
Large parts of the US have experienced severe storms, including blizzards that have covered the Midwest and Northeast in snow. However, there is a concerning trend: several states that typically have snowy winters are now receiving more rain than snow.
A recent study released on Wednesday reveals that the human-induced climate crisis has led to decreased snowpack in most regions of the Northern Hemisphere over the past four decades, posing a threat to vital water supplies for millions of individuals.
In a warmer world, it may appear that snow would be less common, however, the connection between snow and climate change is intricate. Scientists have faced challenges in establishing a clear link between the two because accurately measuring snowfall has proven difficult. Data from ground observations, satellites, and climate models have provided conflicting signals on the impact of climate change on decreasing snowpacks. Surprisingly, some regions have even seen an increase in snowfall despite the warming climate.
The change in snowpack percentage due to climate change in river basins from 1981 to 2020 is depicted in the map. Regions in red show a decrease, while those in blue show an increase. The impact of climate change has led to an increase in snowpack in certain northern watersheds due to higher precipitation.
Dartmouth College researchers Alexander R. Gottlieb and Justin Mankin have published a study in the journal Nature that reveals significant decreases in snowfall in the northern regions of the world due to climate change since the 1980s. The study shows that areas in the US Southwest, Northeast, Central and Eastern Europe have experienced the most significant declines of between 10% and 20% per decade.
Less snow means less water supply
"It is evident that the adverse effects of climate change are impacting snow and water," stated Alexander Gottlieb, the primary researcher of the study and a PhD candidate at Dartmouth College. "Furthermore, each degree of warming will result in a greater reduction of our snow water resources."
The researchers discovered that the loss of snowpack speeds up when the average winter temperatures rise above minus 8 degrees Celsius (around 17 degrees Fahrenheit), which they have labeled as a "snow-loss cliff." Beyond this point, even small increases in temperature cause a rapid acceleration in snow loss.
This poses a significant challenge for communities that rely on snow for water. Climate change is already threatening many of the world's water supplies through more frequent and intense droughts and heat waves. The study predicts that as the planet continues to warm, heavily populated areas that depend on snow will experience a significant decrease in water availability in the coming decades.
Situated along the Ohio River in Stratton, Ohio, U.S., the coal-fired power plant of FirstEnergy Corp. W.H. Sammis Plant is a prominent fixture in the region, as of Monday, Dec. 4, 2017. These Ohio River towns, located just 30 minutes north of Pittsburgh, are characterized by the overwhelming presence of large, centralized power plants. In fact, it was in Shippingport, Pennsylvania, during the 1950s, that the federal government collaborated with private industry to construct the nation's first nuclear power plant. Photo credit: Justin Merriman/Bloomberg via Getty Images
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Justin Mankin, the senior author of the study and an associate professor of geography at Dartmouth, explained to CNN that as regimes shift from snow-dominated to rain-dominated in the winter, reservoirs can be left at half capacity or less. This raises the question of whether a rainy spring will be enough to compensate for water withdrawals downstream.
The study also examined river basins to assess the decrease in snow water resources. The findings revealed a decrease in snowpack across 82 out of 169 major Northern Hemisphere river basins, including the Colorado River in the US and the Danube River in Europe, with 31 of those showing clear evidence of human-caused climate change.
"Many of the world's inhabitants live in river basins that are teetering on the brink of a rapidly accelerating snow loss. Every degree of warming leads to further decline in snowpack," Mankin explained.
The researchers arrived at their conclusions by examining snowpack decreases in March from 1981 to 2020, as it offers a comprehensive overview of winter weather conditions, Mankin stated. He emphasized that the level of snow in March reflects the winter weather patterns before the arrival of spring, when the melting snow replenishes water reservoirs downstream for domestic and agricultural use.
"March snowpack is emblematic of everything that happened over the winter, and we do test the sensitivity of that measure," Mankin said.
The change in snowpack percentage due to climate change in the river basins of North America from 1981 to 2020 is shown on a map. A decrease is represented by the color red, while an increase is represented by the color blue. This data was provided by Alexander R. Gottlieb and Justin Mankin of Dartmouth College.
The reduced snowpack in the western US in consecutive years has provided a glimpse into potential future winters and springs for many parts of the Northern Hemisphere. This includes unprecedented water shortages and worsening wildfires, according to Mankin.
Snow plays a crucial role in preventing wildfires and reducing their severity. Unlike rain, which can quickly run off, snow melts gradually and releases water into the soil at a steady pace, lowering the risk of ignition and limiting fuel for fires to spread.
Copernicus Climate Change Service
The world is on the brink of surpassing a global warming limit, with 2023 being recorded as the hottest year yet. The decline in snowpack is taking a toll on regions that depend on winter recreational activities like skiing and snowboarding, which are important for their economies. Many ski resorts in the Northern Hemisphere are already struggling with these challenges, resorting to snow cannons to ensure there is enough snow to sustain their businesses. Some areas are reaching temperature levels that could make machine-made snow impractical.
Mona Hemmati, a postdoctoral research scientist at the Columbia Climate School, who was not part of the study, stated that the research offers "compelling evidence" of the impact of human-caused climate change on snow patterns.
"This study is groundbreaking in its methodology of separating the effects of human-caused climate change from natural climate variability," she told CNN. "It serves as a vital reminder of the increasing impact of climate change and the urgent need for immediate and collaborative action to address this global challenge."
