Shawn Vestal: Researchers forecast a hard-to-imagine West – one without snow

If you ever lived on a farm, or in a farming community, the idea of praying for snow won’t be unfamiliar to you.

It’s different than praying for snow to ski on or wishing for a white Christmas. It’s deeper, connected more profoundly to your fortunes in the coming year. On a farm, you live in perfect clarity about the link connecting the seasons – from winter snowpack to summer growth to autumn harvest.

That cycle is obviously not limited to agriculture. In the West, snowpack is crucial for a range of warm-weather necessities, from drinking water to salmon runs. Unfortunately, if we don’t change our trajectory on carbon emissions, the Mountain West can expect a lot more praying and a lot less snow in the years to come, according to a new study.

The title of the paper, published in October in Nature Reviews, is ominous all by itself: “A low-to-no snow future and its impacts on water resources in the western United States.”

Without a change in carbon emissions, the West will reach a period of frequent snowlessness in the next 35 to 60 years, according to projections of the team of authors, many of whom work for the Department of Energy’s Berkeley Lab. We could go for years under the worst-case scenarios with no snow at all, offset by years in which a much-diminished snowpack melts much more quickly.

Imagine a time where a white Christmas is a rarity of cicada-like proportions. A Mountain West without snow would simply be – culturally, economically, socially, historically, essentially – a different kind of place entirely. But that’s where we’re headed, based on the current trajectory of climate change and our insufficient response to it.

The paper attempts to model potential changes in the future, but the dwindling snowpack is not a hypothetical, possible outcome. It’s already happening.

The authors say that snowpack in the West has declined about 20% since the 1950s, due to the warming climate. The effects of this change, in combination with persistent drought, have been disastrous with regard to fire season.

In a different journal article from last summer, scientists calculated that lower snowpacks have expanded the region’s “fire territory” – demonstrating that as snowpacks shrink and hold less snow for less time, wildfires are burning higher into the mountains, reaching regions where it used to stay too cool and wet to burn.

That study, published in May in the Proceedings of the National Academy of Sciences, showed dramatic fire-season changes at the highest altitudes in the West. Researchers analyzed all fires larger than 1,000 acres in the region between 1984 and 2017. They found that while acreage burned increased at every altitude, it rose the most dramatically above 8,200 feet – where it more than tripled.

The new paper focuses on water supply, and the need for communities to develop new strategies based on a future of lower snowpacks, rather than relying on historical snow levels to continue.

This has serious implications in the West, where snowpack is the key supplier for water systems that help communities make it through the dry summers – systems that supply drinking water, irrigation for agriculture, and other needs.

“The potential for persistent low-to-no snow to disrupt the (Western U.S.) water system is substantial, potentially even catastrophic,” the authors wrote.

In addition to smaller snowpacks, mountain snow is melting earlier in the year and expected to continue moving in that direction. Such melting undermines the entire system; the authors note that although California did not have a low snow year last year, much less water reached reservoirs because of an unusually warm spring.

Also, “atmospheric rivers” – corridors of concentrated moisture in the atmosphere that produce precipitation – are producing more rain than snow, raising the risk for flooding.

The exact nature and degree of future snow patterns is uncertain, and depends on a variety of factors – not least of which is whether we put down the fiddle and get more serious about greenhouse gas emissions.

But periods of low snow are projected, for five to 10 years at a time, under different models in the study. By the end of the century, between 78% and 94% of winters in the West will be completely snowless, under one projection.

And that’s a terrible vision for a Western future – on the farm and everywhere else.