SNOW MAY VANISH IN THE WEST: “In about 35 to 60 years, mountainous states are projected to be nearly snowless for years at a time if greenhouse gas emissions continue unchecked and climate change does not slow,” wrote Diana Leonard in an article published by the Washington Post (December 2021)

Note to Reader:

Diana Leonard is a science journalist covering natural hazards, weather, climate change. She is a regular contributor to the Washington Post. In December 2021, the Washington Post published her story about a study that warns of impending water supply problems due to nearly snowless mountains in about 35 to 60 years.

Snow may vanish for years at a time in Mountain West with climate warming

“Decades ahead, the ‘potential for persistent low-to-no snow to disrupt the [Western U.S.] water system is substantial, potentially even catastrophic’, the study’s authors write. Published in Nature Reviews Earth and Environment in October, the paper provides an overview of how Western snowpack has changed and what it will look like over the course of this century,” wrote Diana Leonard.

What the Future Looks Like

A team led by scientists at Lawrence Berkeley Laboratory says the snowpack — a critical piece of California’s delicate water delivery system, not to mention a source of winter recreation for Northern Californians — could essentially vanish for years at a time as the warming climate erodes snowfall.

The scientists’ newly-published study doesn’t say snow would disappear forever. Instead, it predicts that much of the Sierra would experience five straight years of “low-to-no snow” starting in the late 2040s. The mountain region could endure 10 straight years with little or no snow beginning in the late 2050s.

“In all regions, an abrupt transition occurs in the mid- to- late twenty-first century,” the study says. By the second half of the century, more than three-quarters of all winters in the West’s mountain ranges will be classified as having little to no snow.

Study Abstract

“Anthropogenic climate change is decreasing seasonal snowpacks globally, with potentially catastrophic consequences on water resources, given the long-held reliance on snowpack in water management,” stated the lead authors Erica R. Siirila-Woodburn and Alan M. Rhoades of the Lawrence Berkeley National Laboratory, located in Berkeley, California.

“In this Review, we examine the changes and trickle-down impacts of snow loss in the western United States (WUS). Across the WUS, snow water equivalent declines of ~25% are expected by 2050, with losses comparable with contemporary historical trends.”

“There is less consensus on the time horizon of snow disappearance, but model projections combined with a new low-to-no snow definition suggest ~35–60 years before low-to-no snow becomes persistent if greenhouse gas emissions continue unabated.”

“Diminished and more ephemeral snowpacks that melt earlier will alter groundwater and streamflow dynamics. The direction of these changes are difficult to constrain given competing factors such as higher evapotranspiration, altered vegetation composition and changes in wildfire behaviour in a warmer world.”

“These changes undermine conventional WUS water management practices, but through proactive implementation of soft and hard adaptation strategies, there is potential to build resilience to extreme, episodic and, eventually, persistent low-to-no snow conditions.”

“Federal investments offer a timely opportunity to address these vulnerabilities, but they require a concerted portfolio of activities that cross historically siloed physical and disciplinary boundaries.

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FLASHBACK TO 2015: Drought on the West Coast – A New Reality?

Western North America may be crossing an invisible threshold into a different hydro-meteorological regime. Communities can no longer count on a predictable snowpack and reliable precipitation to maintain a healthy water balance in their watersheds. It has been difficult even for experts to grasp the extent of what the loss of relative hydrological stability means. Last year, in an online poll conducted by CBC News, the public chose the drought as British Columbia’s “Top Story of 2015”.

Understand the Relationship between Land and Water

“Communities in southwest BC dodged a bullet in 2015. The clock is ticking. Communities need to leverage this teachable year and seize opportunities to change how the water resource is viewed and managed. This starts with an understanding of the relationship between land and water,” emphasizes Kim Stephens, Executive Director, Partnership for Water Sustainability in BC.

“Restoring the absorbency of the urban landscape would stretch the seasonal population-support capacities of water storage reservoirs – by reducing demand for landscape irrigation water – and sustain environmental flows during droughts. It would also reduce stream erosion in wet weather.”

”Too often people think of land and water as being independent – almost like silos. But what we do on the land, and whether we treat the land with respect, has direct implications and consequences for water use. The Water Sustainability Act connects these dots,” concludes Kim Stephens.

To Learn More:

Read Context for BC’s 2015 Drought: “Yes, We Need Rain, But We Also Need Snow,” wrote Pauline Holdsworth in The Tyee

Read Reflections on the 2015 Drought: “In engineering terms, in BC we have small margins of safety for water storage and therefore limited resiliency to adapt to a changing climate,” says the Partnership for Water Sustainability’s Kim Stephens