From the Rockies all the way to the Cascades, springtime snowpack has declined by about 10 percent over the past 50 years in the western U.S. That’s according to Philip Mote, director of the Oregon Climate Change Research Institute at Oregon State University. Dr. Mote is an expert on snowpack – snow that accumulates in forests, valleys, and mountains – in the western United States. He told EarthSky:
It’s a combination of less accumulation and more melt. The snow is melting earlier in the spring. So when you get to the late summer when most of the snow has melted and it’s not raining yet, the stream flow can be quite low in some places.
Much of the agriculture in the western U.S. is grown in fairly arid climates and the irrigation water, in large part, comes from snow melt. So we have to watch very closely what’s happening with snow.
Photo credit: andrusdevelopment
Less snowmelt meas less available water for irrigation. Dr. Mote said that this snowpack melt is a consequence of our warming climate. He added that, since climate warming is expected to continue, water managers in the western U.S. are figuring out ways to depend less on water from snow.
It’s not so much new sources as smarter use of water, covering or lining canals to reduce leakage or evaporation, using drip irrigation instead of sprinklers, moving away from large green lawns in areas where water supply is a problem.
In the Pacific Northwest, the situation is most apparent. Springtime snowpack has decreased by as much as 25%, said Mote.
The swath of largest impact of warming on western snowpack extends from the Sierra Nevada mountains of California up through Oregon, Washington, and into southern British Columbia. These are locations where there’s fairly wet winter climate, fairly frequent snowstorms, but the temperatures are fairly mild, so a little bit of warming can really change the amount of snow on the ground in the spring.
He explained that, historically, the date for measuring snowpack has been April 1st of any given year. That’s the date on which – again, historically – the most snowpack has accumulated, with little having melted. Dr. Mote talked about the visible decline in snowpack outside his hometown of Corvallis, Oregon.
There’s a peak about 4100 feet – Mary’s Peak – one of the hills in the coast range of Oregon, and the only location in Oregon where U.S. government snowpack measurements go back. It used to be fairly common for the April 1st survey on Mary’s Peak to have quite a bit of snow. By the 1980′s it was getting common to have no snow on April 1st.
Now it’s quite rare to have no snow on the 1st. Philip Mote explained how colleagues in California, led by climatologist David Pierce of the Scripps Institution of Oceanography, were able to determine, using climate models, that the snowpack melt his own team had observed in the western United States was due to the warming temperature caused by our own greenhouse gas emissions. Snowpack melt is expected to accelerate, he added.
Since flooding in Western states is caused by snow melt and Nashville went through a terrific flood, I question Philip Mote assertion of declining snow melt.
Nashville? Hey buddy, check out a map! Tennessee is one of them there southern states, where evolution and global warming doesn’t happen.
50 years is a very short time to form a conclusion when the earth is billions of years old. It’s like walking outside on a grey day and concluding that the sky is always grey.
What should the earth’s thermostat be set on? Who gets to decide what is the right temperature? If we could control the temperature, do we change it to benefit the most people even if others may die as a result of the tinkering?
Mountain snow fields act as natural reservoirs for many western water-supply systems, storing precipitation from the cool season, when most precipitation falls and forms snowpacks, until the warm season when most or all snowpacks melt and release water into rivers. As much as 75 percent of water supplies in the western United States are derived from snowmelt.
The Sierra is getting a huge pile of snow this year. I submit the whole deal is a result of cycles in weather.
The snowpack in California is two times normal. This should help the situation. It is the normal cyclical nature of things. No human intervention necessary.
If fifty years is a short time, then this season is I suspect one/fiftieth of a short time. What happens this season with weather is not climate. Never confuse weather and climate. Read Archer;s The Great Thaw and then determine for yourself the evidence. Mote’s findings are certainly in keeping with the abrupt events associated with a substantial increase in carbon dioxide in the air and oceans in fifty years. BTW, the isotopic analysis shows this carbon’s source is combustion — pure and simple isotopic evidence has the human fingerprints all over the nuclei! See Gavin Schmidt. The loss of snow by end of March should make water conservation a national priority, our food and electricity depend on it.
I love reading responses to scientific claims! Such a poetic mix of ignorance and seriousness! Isotopes?! Iso-what? You think yer boy in Nashville cares about Isotopes? How about “snowpack two times normal” dude? No waaayyy man! Oh my. Looking at these posts as a microcosm of democracy, its obvious why we need a philosopher-king!
I wanted to call your attention to a study by former IPCC lead author and climatologist Dr. John R. Christy and Justin J. Hnilo (Christy et al 2010).
He created one of the most complete reconstructions of snowfall in the Southern Sierra. The conclusion of the abstract is as follows:
The full abstract is available from the Western Institute for Study of the Environment here.
I’ve also been looking at other snowfall datasets across the United States as this has become a hot topic. Some go back to the mid and late 1800′s and mostly agree with Christy et al with some degree of regional variability. I don’t doubt that we’ve been seeing earlier melts as that is consistent with the temperature record in the 1980′s through the 1990′s and I understand the issue of lower stream flow by summer as a result. But, given the record snowfalls of the past several years, and particularly this year, and plateaued temperatures since 2000, can we expect to see a recovery in the snowmelt numbers?
[...] According to Phil Mote of OSU, [...]
Hank,
The Christy paper was sent to Energy & Environment – a science journal in name only. Only ~25 libraries worldwide subscribe to it. And not a single Big10 or Pac10 library deems it worth the price of a subscription. It is not part of the ISI citation index and has a poor track record of competent review. In short, scientists don’t use it or read it.
Christy’s work may be correct, but choosing to publish in a rubber-stamp magazine that lacks the expertise for a serious review weakens his conclusions. It ensures that hydrologists and others studying snowpack will not see it. The intended audience seems to be the blogosphere rather than practicing scientists.
Jay,
I’m not sure where you get your information from. E&E is indeed listed in the Social Sciences Citation index of the ISI – where it belongs – also the Thompson Master Journal List, Scopus, and EBSCO database.
Lets get a little balance going. E&E published the high profile and widely read M&M paper that pointed out the principal component analysis problems with the Mann et al “Hockey Stick” paper that became the poster graphic of CAGW. To date, the M&M paper stands as a valid criticism of Mann’s paper.
Odd that you should mention the blogosphere. It was Dr. Gavin Schmidt’s scathing criticism of E&E on his web site and appealing to the blogosphere that got the whole meme of the E&E being a sub rate journal started. Schmidt was a contributor to Mann’s work. I see his now widely publicized criticism as a case of sour grapes and damage control. You seem to be offering up Schmidt’s criticism almost verbatim.
Almost every important scientist involved in the atmospheric sciences is mulling over and offering commentary on M&M’s paper in E&E. Your assertion that “scientists don’t use it or read it” seems rather contradictory.
BTW: If you do a search on Scopus and Google Scholar you’ll find E&E’s ranking on par with other energy and policy journals. I agree that Christy’s paper isn’t monumental enough to get published in the likes of NJS but inferring his work can’t be taken seriously because it wasn’t is a red herring.
This is another cherry pick by Mote who is tthe cherrypicking champion.
Starting in the snowy cold middle 1900s and ending in the early 2000s gives a false trend.
This last winter set records for reasons and represents a new trend that will eventually cost Mote his job. For the northern hemisphere, 4 of the top 5 snowiest winters in the northern hemisphere occured in the last decade, 3 in the last 4 years. Why? Because we are back in the same cycle phase we were in the 1950s and 1960s with a cold Pacific and more La Ninas. This summer they were skiing in July in the western mounttains. A sign of things to come for the next few decades. By starting in the 1950 time frame, when snow records were set in the west and ending at the end of the El Nino favored warm PDO, you were bound to see a decline.
Taylor and Albright, superior climatologists, have shown by extending analysis back to the early 1900s shows the cyclical nature of the snow and cold.
I rarely create remarks, but i did some searching and wound up here this blog name. And I actually do have some questions for you if it’s allright. Is it just me or does it give the impression like some of the comments look like coming from brain dead folks? :-P And, if you are writing at other places, I would like to follow anything new you have to post. Could you make a list of every one of your public sites like your twitter feed, Facebook page or linkedin profile?