Editor’s pickSnow and water: The U.S. West may soon be facing even more water troubles

22-02-2018

Image credit: Natural Resources Conservation Service

An early winter snow drought coupled with months of abnormally warm weather around most of the United States (U.S.) West have left record-low levels of snowpack in regions of the Central and Southern Rockies, leading to concerns regarding water shortages and resulting economic damage, according to Inside Climate News.

In the region, the lion’s share of the water cycle begins when thick layers of mountain snow piled up through the winter slowly melt in the spring. And if the snows do not come, there is no water to recharge the reservoirs.

And earlier this month, drought was rampant across large swaths of the Western regions, with storms earlier this year only making up a small percentage of the water deficit. Presently, runoff generated by melting snow is expected to be at less than 50 per cent of the average.

Recently, a series of studies have focused on how vulnerable snowpack is to rising global temperatures, and how economic costs that come from the decreasing snowpack could rise into hundreds of billions of dollars.

At the beginning of 2018, snowpack at Central and Southern Colorado, along with the Southern states of Arizona, New Mexico, and Utah were either at record or near-record lows. And at many sites the Natural Resources Conservation Service surveyed, the snowpack was at less than 50 per cent of average. In Arizona and New Mexico, the snowpack hovered between zero and six per cent of average.

Moreover, California, which originally rebounded from its most intense and longest drought on record lasting from 2011 to 2016, has found that it was returned to being hot and dry. Last year, October and November were the warmest recorded in Southern California, and the snowpack was a mere 44 per cent of the average by the end of December, according to Inside Climate News.

Research in the southern Sierra Nevada by Keith Musselman, a hydrologist from the University of Colorado, has shown just how sensitive mountain snowpack is to global warming. By analysing an extensive dataset taken from the western flank of the Sierra, he found that for every one degree Celsius the earth warms, the snowpack accordingly shrinks by ten per cent. And as winter rain storms increase in frequency due to rising global temperatures alongside melting snow accumulated over the winter may raise flood risks.

Climate scientists have stated that snow seasons much like the one the West is currently in the grip of will likely become more common over the coming few decades. If there are no winter snows, the melting snows will not revitalise the reservoirs, and Los Angeles, Las Vegas, and Phoenix may face the same issues Cape Town in Africa is currently facing.

But according to Philip Mote, a climate scientist from Oregon State University, these changes may even come sooner than anticipated, when a study in November 2017 showed how the snowline quickly moved as much as 236 vertical feet (71 vertical meters) a year between 2008 and 2017 – the warmed decade ever observed in the Earth’s climate history. And if the same trend continues unabated, water managers all over the world would have to begin extensive, as well as expensive, adjustments to distribution of water as well as water storage.

Moreover, the availability of water would also affect agriculture and entire municipalities,  with economic losses stemming from the shrinking snowpack potentially hitting US$575 billion per year.

 

Source: Inside Climate News