Emerging Patterns: Unveiling the Disappearing Snowfall Zones
Declining global snowfall due to human-caused climate change is revealed in new maps and analysis by a NOAA climate scientist, highlighting the urgent need to adapt water management strategies
Global snowfall is decreasing due to human-caused climate change and rising temperatures, according to a recent analysis and maps by a NOAA climate scientist. This decline in snowfall has significant implications, as it not only means less shoveling but also poses a threat by further contributing to warming and disrupting access to food and water for billions of people.
Climate scientists predict that in a warmer world caused by human pollution, precipitation is more likely to be in the form of rain rather than snow. Although there may be some years of increased snowfall due to extreme winter storms, the overall trend is towards less snowfall, especially as global temperatures continue to rise.
"According to climate scientist Brian Brettschneider, the laws of thermodynamics indicate that continued warming will lead to a shift from snow to rain. While trends may be temporarily hidden, the overall impact of rising temperatures will prevail. Additionally, climate scientist Justin Mankin notes that the decline in snow is not a direct result of rising temperatures. Instead, there is a tipping point, and once a certain temperature threshold is reached, the losses will accelerate."
"According to Mankin, the places that have not yet experienced significant declines in snowfall may begin to see them with further warming. Data from the European Union's Copernicus Climate Change Service analyzed by Brettschneider shows a 2.7% decrease in global annual snowfall since 1973. This trend is most evident in the mid-latitudes of the Northern Hemisphere, where a large portion of the world's population, including the US, is located."
The sun is more direct at lower latitudes compared to the higher latitudes, especially during spring and fall when it still snows. The white of snow acts like a car's sun shade, deflecting sunlight and its heat back to space. Without it, more sunlight is absorbed by the ground, warming the atmosphere.
This aerial photo taken on January 8, 2023 shows an early morning view of Beiji Village in Mohe, northeast China's Heilongjiang Province.
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Even with global warming, extreme cold snaps continue to occur, leading to dangerous temperature drops. A decrease in snowfall also results in less snow gathering into snowpack, impacting water supplies. Snowpack acts as a natural reservoir, storing water during wet periods and releasing it as snowmelt during drier times, as explained by University of Washington environmental engineering professor Jessica Lundquist in an interview with CNN.
In regions with more extreme precipitation cycles, like the Mediterranean climate in California and the American West, declining snow poses a significant threat to water supplies, according to Lundquist.
"California serves as the prime example - as it does not rain in the summer there, snowmelt runoff becomes vital for ecosystems, agriculture, and urban areas during the dry season," Lundquist explained to CNN.
Snowpack is a crucial source of water for over 50% of the arid West's water supply, according to a study from 2017. This study also projected that snowpack levels in the West could decrease by over one-third by 2100, particularly under a high emissions scenario.
The map illustrates a significant decrease in snowfall over the past 50 years, particularly in parts of the western US. This aligns with other research indicating a decline in snowpack at over 90% of measured western sites.
The maps show an increase in snowfall in the Northeast, highlighting the complex changes in precipitation patterns due to climate change, according to scientists interviewed by CNN.
"Although the overall trend for total snowfall is positive, the trend for days per year with snowfall is negative," Brettschneider explained. This indicates that more snow is falling over fewer days, potentially indicating the predicted increase in extreme snowfall events associated with climate change.
A person is attempting to clear their driveway of over a foot of snow using a snowblower during a powerful Nor'easter in Rutland, Massachusetts on March 14, 2023. - Forecasters are predicting that a significant Nor'easter will bring heavy snow and high winds to the East Coast on Wednesday. (Photo by Joseph Prezioso / AFP) (Photo by JOSEPH PREZIOSO/AFP via Getty Images)
Joseph Prezioso/AFP/Getty Images
As the Arctic warms, noreasters may get worse
According to Mankin, global warming leads to an increased likelihood of snowfall extremes due to the enhanced moisture reservoir in the atmosphere. Brettschneider also noted that the increase in Northeast snow is partly attributed to the time period being analyzed. The data before the 1970s is less reliable, and starting the analysis in the 1970s included some extremely snowy years for that region. Had the analysis started earlier, it might have shown a decline.
Managing water with less snow
The impact of reduced snowfall on the worldwide water supply is much more intricate than the straightforward notion that less snow results in decreased water availability, according to Mankin. Numerous dynamic snow-related factors and geographical location greatly affect the implications.
Mankin emphasized that the crucial factor in monitoring water availability is not the quantity of snow, but rather the water content within the snow, which can vary significantly. A light, powdery snow will contain less water, while a compact, heavy snow will have a higher water content.
Furthermore, Mankin pointed out that the same intense precipitation events responsible for increased snowfall may also result in more rain, potentially offsetting any water loss from the snow.
But the scope of the problem of missing snow is still massive.
Sunset at Mount Tai in Tai'an, China on May 23, 2018. Mount Tai holds significant historical and cultural importance and is situated north of Tai'an city in Shandong Province. (Credit Image: © SIPA Asia via ZUMA Wire) Jia Guangrui/SIPA/Zuma
New research suggests that microplastics may be able to induce cloud formation and impact the weather. According to a study conducted by Mankin in 2015, as many as 2 billion people who depend on melting snow for water could face declines of up to 67%. This alarming trend is particularly concerning for regions such as South Asia, the Mediterranean, and North Africa, where snowmelt is a crucial source of water. These areas include the Himalayas, Spain, Italy, Greece, and Morocco, all of which are at risk of experiencing significant reductions in snowmelt.
Mankin pointed out that the study failed to address hyperlocal water management and potential strategies to counteract the loss of water from melting snow. She emphasized that the decline in snowpack poses a significant management challenge, especially in regions like the American West that heavily rely on snowmelt runoff.
Mankin and Lundquist emphasized the importance of ongoing research to fully comprehend the complex connection between snow and water supplies, especially on a very specific local level. This understanding will enable water managers to effectively plan for the unpredictable impact of snow on water resources.
"There is no simple solution - it will require a combination of approaches and resources at different levels, which can only be devised once the full scope of the issue is understood and delineated," Mankin stated.
Mankin pointed out that if these places are only managing water based on the current status quo, global warming will disrupt that. She added that our infrastructure and management practices are based on historical climate, which is not relevant to the changing climate we now face.
