500 Year Low in Sierra Snowpack

Multi-Century Evaluation of Sierra Nevada Snowpack

Comparison photos of Sierra Nevada snowpack in 2010 and 2015

These images captured by NASA’s Aqua satellite show the difference between snow cover in 2010—the last year with average winter snowfall in the region—and 2015 across the Sierra Nevada Mountains. Credit: NASA/MODIS

The 2015 record low snowpack level in California’s Sierra Nevada mountain range is unprecedented in comparison to the past 500 years, according to a new paper published in Nature Climate Change(link is external). In their examination of paleoclimate tree-ring based records dating back to 1500, scientists from the University of Arizona, University of Arkansas, and NCEI’s Paleoclimatology Program expect that the current snowpack low has a strong likelihood of occurring only once every 500 years and only once every 1,000 years below 7,000 feet. Such an exceptional low level poses significant challenges to California, which receives over 30% of its yearly water supply from Sierra Nevada snowpack.


Snowpack Outlook Grim for Water Needs

There’s a reason Climate Change is the biggest ‘tag’ on this blog (see Tags in right column.)  It is the biggest concern we should all have. Bigger than who the president is.  Way bigger than who the General slept with. [I am reminded of John Goodman’s line in Flight when he comes to see his buddy Denzel Washington, in the hospital with grievous wounds:  Hey, I brought you some stroke magazines!]  The world as we know it is en-route to the biggest changes in the shortest time Homo Sapiens has ever been around for.  No kidding.

David Perlman, as he has so often, contributes a column that should be pasted over every Californian’s kitchen sink.

Calif. snowpack outlook grim for water

The future of water for drinking and irrigation looks increasingly bleak throughout California and the world’s northern regions as the changing global climate shrinks mountain snowpacks and speeds early runoffs, Stanford researchers forecast.

Decreases in winter snowpacks are likely to be most noticeable during the next 30 years and will continue to shrink through the century, according to an analysis of future climate trends by a team of specialists led by Noah Diffenbaugh at Stanford’s Department of Environmental Earth System Science.

“One clear result is that western North America shows the most rapid and largest response to the continued emissions of greenhouse gases when it comes to early snowmelt and spring runoff,” Diffenbaugh said.

The result, he and his colleagues say, will be less runoff water for irrigation during the season when California’s high-value crops need it most for growing, and also more early springtime flooding that can strain dams and reservoirs before the water reaches lowland cities.

Read all:

You could also watch Discovery Channel’s “On Thin Ice,” with David Attenbourough at both poles, showing what climate change is doing to ice, snow and water there.

The Wilkins Ice Shelf, a 200-meter thick sheet of floating fresh water ice larger than Jamaica, started to break up in 2008.

On the Dry Side of Wet

We in northern California felt the rain of the last week or so might have made up for the abnormally dry winter.  Some days it felt like the great dam in the sky was doing an enormous spillway release to save itself.  But wet as we got it’s still been a very dry year.  As of April 1 the snow pack in the northern Sierras is only at 55% and in the south, worse, at 39%.

…the state will probably deliver just half of the 4 million acre-feet of water requested by members of the state water project this year, after an unusually wet 2011 helped fill up the state’s reservoir storage. An acre-foot is 325,851 gallons of water – enough water to supply one to two households for a year.

SF Gate:  and The Executive Summary at California Department of Water Resources