The world is threatened with total chaos? Billions of people at risk

Snowfall amounts are declining around the world as temperatures rise due to climate change.

Foto: Shutterstock/ Denis Radermecker
Foto: Shutterstock/ Denis Radermecker

This is according to new analyzes and maps by climatologists of the National Oceanic and Atmospheric Administration.

The lack of snow is not so harmless and it doesn't just mean that we will have less shoveling to do during the winter. It can lead to increased warming and disrupt the availability of food and drinking water for billions of people.

Climate scientists say the future of snowfall is pretty clear: A warmer world means that accumulated water in the atmosphere will fall to Earth as rain rather than snow.

It is possible that in the near future, climate change will cause more extreme winter storms and some years with increased snowfall, but as global temperatures increase, there will be fewer such years.

"Eventually the laws of thermodynamics mean that more and more of that snow will turn into rain," said Brian Bretschneider, a climatologist with the National Weather Service in Alaska and author of the analysis.

"You can get away with things like that for a while and some trends can be hidden, but in the end thermodynamics will win out," he said.

"Snow will also no longer fall in a linear fashion," said Justin Mankin, a climatologist and associate professor of geography at Dartmouth College.

Instead, there is a tipping point, which would mean that once a certain temperature threshold is reached, we can expect snow loss to increase.

"That means we can expect that a lot of places that haven't seen a massive decrease in snowfall could start to see less as soon as temperatures rise a bit more," Mankin told CNN.

"There has already been a 2.7 percent decline in annual global snowfall since 1973. The declining trend is particularly noticeable in the mid-latitudes of the Northern Hemisphere," the area north of the tropics and south of the Arctic, where much of the world's population lives.

"Less snowfall also means less snow that accumulates in the snowpack—the deep, persistent snowpack that builds up over the winter. It's critical to water supplies because it acts like a natural reservoir, storing water as snow during rainy periods and then releasing it into in the form of melted snow when water is harder to come by," University of Washington engineering professor Jessica Lundquist told CNN.

"The threat to water supplies from declining snowfall is most pronounced in areas subject to more extreme cycles of ups and downs in precipitation, such as California's Mediterranean climate," Lundquist said.

The arid U.S. West gets more than 50 percent of its water from snowpack, a 2017 study found. That study predicts snowpack levels in the West will continue to decline by more than one-third by 2100 under severe global warming.

In 2015, Mankin conducted a study showing that the two billion people who get their water from melting snow are at great risk of a reduction in snow by as much as 67 percent. These include parts of South Asia, which rely on Himalayan snowmelt; the Mediterranean, including Spain, Italy and Greece; and parts of North Africa such as Morocco, which rely on snowmelt from the Atlas Mountains.

"Snow loss becomes a big challenge," Mankin said.

"This is not necessarily an insurmountable challenge everywhere, but it is a significant management challenge, especially in places like the American West that are heavily dependent on snowmelt," he added.


page 1 of 5 go to page