Open Mind

Heavy snow (job)

December 20, 2008 · 73 Comments

We’ve got quite a bit of snow here in New England, and we’re expecting even more. Of course the denialosphere expects us to believe that a week’s worth of large snowfall over an area less than 2% of the globe somehow negates decades of global warming caused by centuries of human-caused greenhouse gas emissions. Certainly a lot of people — those who don’t know much about the science and know even less about the difference between long-term trends and short-term fluctuations — will be fooled by the heavy “snow job.”


What does snow cover really tell us about climate change? We’ve looked at this before, but in light of all the hoopla about snowfall, let’s take another look at northern hemisphere snow cover data from Rutgers University Global Snow Lab. By the way, most of the world’s snow cover is in the northern hemisphere because most of the world’s land is in the northern hemisphere.

A graph of snow cover data shows an obvious annual pattern, with more snow in winter and less in summer:

snowdata

We can remove the average annual pattern to compute snow cover anomaly:

snowanom

I’ve added a smoothed curve, which indicates that snow cover has decreased over the decades it’s been tracked by satellites. We can confirm the decline by fitting a trend line to the data:

snowtrend

This indicates that on average, for the last four decades snow cover has declined by about 45,000 km^2 per year. In fact the average northern hemisphere snow cover has declined during this time interval by about 2 million km^2. And yes, that decline is statistically significant.

But we can look closer by isolating snow cover during the different seasons of the year. I’ll use the standard climatological definitions of the seasons, Dec-Jan-Feb for winter, Mar-Apr-May for spring, Jun-Jul-Aug for summer, and Sep-Oct-Nov for fall. If we look at winter snow cover, we don’t see any obvious trend, and in fact a regression indicates that there’s no significant change in winter snow cover:

winter

It’s really not a surprise that there’s no trend in winter snow cover. Warmer temperature tends to melt snow, but also causes more water vapor in the air, so there’s more possibility of snow. And as long as it’s still cold enough to snow (which it still is during winter), we shouldn’t be surprised by no change in snow cover.

Springtime snow cover tells a different story:

spring

This time there is a statistically significant trend, snow cover declining at about 68,000 km^2/yr. This is due to higher temperature causing earlier, and greater, springtime snowmelt.

The trend is even stronger in summer:

summer

Average summer snow cover has declined at a whopping 99,000 km^2/yr. Again, higher temperature is the reason. The lowest average summer snow cover yet recorded was for 2008; the 2nd-lowest was 2007.

Autumn shows signs of a decline, but the decrease is not statistically significant:

fall

So, autumn snow cover might be declining, but then again, it might not.

The seasonal pattern of snow cover shows that there’s been no noticeable decline during fall and winter, so we shouldn’t be the least bit surprised by the large snowfall over the U.S. this past week. We can also plainly see that snow cover exhibits extremely large fluctuations, so again last week’s snowfall is no surprise whatever, and no harbinger of any reversal of global warming. But the rapid decline of springtime snow cover over the last four decades, and the even more rapid decline of summer snow cover, show the mark of global warming unambiguously. And despite what some like to shout, the statistically strong trends are what’s important, not the statistically normal noise.

But I don’t expect any of this to reduce the noise we’ll hear from denialist blogs.

Categories: Global Warming
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73 responses so far ↓

  • David B. Benson // December 21, 2008 at 12:15 am

    I’d comment, but I have to go out and shovel.

    :-)

  • dhogaza // December 21, 2008 at 12:38 am

    We’ll have to shovel in the morning …

    Meanwhile, it snowed slightly in madrid the week before this, and now, here I am in PDX, and we’re getting unusually heavy snow.

    While Madrid is now “proving” global warming to be true with unseasonably balmy weather in the 60s!

  • hengav // December 21, 2008 at 1:12 am

    Wonderful use of linear trend analysis. Now try a sinusoid with a period of 60 years…

    [Response: Why would I do that?

    The linear fit isn't meant to suggest that the change over time is linear; it's used to establish that there's a trend (there is), and that it's downward (it is). It also provides a very rough estimate of the total decline, a little under 2 million km^2.

    A better estimate of the total decline is given by the lowess fit, which indicates a decrease of over 3 million km^2.

    A 60-yr periodic waveform also indicates a decline over the observed time span. But since it's not as good a model as the linear fit (about the same residual variance but with more parameters), and not nearly as good as the lowess fit, there's no justification for using such a model to estimate the decline. Add the fact that there's only 42 years of data, and there's no validity to any claim that it actually models the pattern of change; it's ludicrous to claim that these data support that behavior. It also contradicts the sharp downtrend in the last 13 years; the sinusoidal model turns back upward but the data since 1996 alone show a statistically significant downtrend.

    Similar contradictions arise from attempting to fit a 60-yr periodic waveform to the seasonal data. This is especially true for the summer-season data, which have declined by about 4 million km^2.

    In short, your suggestion is nonsense. I suspect it's motivated by an attempt to tie snow cover decline to some oceanic oscillation like PDO. The data don't support that idea.]

  • Horatio Algeranon // December 21, 2008 at 1:49 am

    “But I don’t expect any of this to reduce the noise we’ll hear from denialist blogs.”

    Would that be (infer) red noise? Or (take-a) shot noise?

    To celebrate the snow (and inevitable snow job), comin’ as it does just a few days before Christmas, Horatio proposes a slight variation of the classic…

    I’m dreaming of a Watt Christmas,
    just like the ones I used to know
    Where the folks go fishin’, forever wishin’
    For downward trends in every snow.

    I’m dreaming of a Watt Christmas,
    with every blogpost that I write
    May your data be cherries and whatnot
    and may all your Christmases be Watt

    PS, Horatio knows it’s “Watts”, but that don’t rhyme with “white” (not even close*), so Horatio has made use of his poetic license** (not the first time and surely not the last).

    *Yes, Horatio understands that neither does “Watt”, really, but to pick nits on this would not really be in the Christmas spirit, at any rate.

    **Some would undoubtedly argue that Horatio should have his poetic license revoked altogether, but that is a different topic and one that really should be taken up with the proper authorities.

  • TCOisbanned? // December 21, 2008 at 3:08 am

    a. You’re contesting an argument that hasn’t been made yet.

    [Response: No I'm not. I use the "tag surfer" to track wordpress posts about global warming, and there have been a *lot* of posts about how the heavy snowfall shows what a crock global warming is. So many ... that's why I did this post.]

    b. You’re probably right that they will.

    c. I (of course) agree with the silliness of said behavior.

    d. The warmers (or warmer supporters) do it too (cf. pictures of the Gulf with Katrina in it on magazines and TV programs about GW.)

    e. Stand by for a vehement (and trivial and boring) argument about who does it more. Cue Dhog in 4-3-2-1!

    P.s. I’ll see you one Vincenthaven and raise you two Jae’s.

  • dhogaza // December 21, 2008 at 4:47 am

    e. Stand by for a vehement (and trivial and boring) argument about who does it more. Cue Dhog in 4-3-2-1!

    My vehement and trivial and boring observation is that magazines and TV programs don’t pretend to doing science.

    While those on your “team” are claiming to be doing über science, so good that it trumps the work of actual scientists.

    You probably see no difference.

    [edit]

  • Hank Roberts // December 21, 2008 at 5:25 am

    http://www.noaa.gov

    * Fourth Warmest November for Globe
    This year is on track to be one of the 10 warmest years on record for the globe, based on the combined worldwide land and ocean surface average temperatures, according to a preliminary analysis by NOAA’s National Climatic Data Center in Asheville, N.C.

    * November Warmer Than Average in U.S.
    The November 2008 temperature for the contiguous United States was warmer than the long-term average, according to NOAA’s National Climatic Data Center in Asheville, N.C.

  • John Surname // December 21, 2008 at 6:33 am

    This argument is made all the time.

  • nanny_govt_sucks // December 21, 2008 at 7:40 am

    Hooray! Less snow!

    Were you hoping for more snow?

  • Sekerob // December 21, 2008 at 9:08 am

    I’m missing discussion of Eurasia v NA (minus Greenland). Rutgers data provides segmented monthly data.

    Totally agree Tamino. It’s an another total crock going around about there being snow in abundance this moment as a sign of anything and seen enough of them already. In Europe, incl. Russia, there’s still shortfall much shortfall. After a few days have passed Rutgers daily shows a long band, but already a third the size it was over the USA.

    Flip between day 345 and 355. The red where it should be:

    http://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2008&ui_day=345&ui_set=2

    http://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2008&ui_day=355&ui_set=2

  • dhogaza // December 21, 2008 at 2:44 pm

    Were you hoping for more snow?

    In western Oregon, we wring our hands in anguish when snow levels are too low.

    Because our cities, and towns, and farms get most of their water from in summer from runoff from the snowpack in the Cascade mountains.

  • S2 // December 21, 2008 at 2:59 pm

    I’m actually quite surprised at the lack of winter and autumn trends.

    In Northern Scotland we’ve seen a 25% reduction in the number of winter days of snow cover (from 1961 to 2004), despite a 69% increase in total precipitation.

    The autumn decline is an even more dramatic 70%.

    But then Scotland is a very small part of the hemisphere.

    Figures from
    A handbook of climate trends across Scotland

  • Steven Earl Salmony // December 21, 2008 at 3:34 pm

    Yes, definitely yes, some of the darkest of dark days are passing into history……finally. The future is about to begin…….mercifully.

    An unnecessary and unjustifiable war at a cost of three trillion dollars; a crashing economy at a cost of trillions more; a degraded environment, a dissipated Earth…….priceless.

    And people responsible for these nightmares want their 2008 bonuses……predictable.

  • Wayne // December 21, 2008 at 5:12 pm

    Were you hoping for more snow?

    Actually, the post isn’t about snow, it’s about snow cover. That’s the area of land covered by snow. One posible reason for the springtime decline is that there’s less snow. Another is that the temperatures are higher, so the same amount of snow melts sooner or quicker in the spring. It’s complex. Reducing it to a whine that snow is a pain to shovel, so we should all want less, is short-sighted. Understanding the issues and the science is hard and takes time, but it’s necessary to manage our impact on the climate.

  • John // December 21, 2008 at 5:16 pm

    You just prove the point that everything causes global warming and global warming causes everything. It’s getting boring and ridiculous. The world is warming because it is supposed to. It’s happened before and it will again after the period of cooling we’re currently experiencing. Adapt and live your life.

  • dhogaza // December 21, 2008 at 6:08 pm

    You just prove the point that everything causes global warming and global warming causes everything. It’s getting boring and ridiculous.

    Huh, I simply see a statistical analysis of snow cover that says it’s declining significantly.

    Exactly how is this ridiculous?

    The world is warming because it is supposed to.

    It’s supposed to? God’s will? Fate?

    Or because science tells us that adding GHGs to the atmosphere will cause warming?

  • elspi // December 21, 2008 at 6:21 pm

    Tamio
    Please ban the troll-john. He isn’t even snark-worthy.

  • Ray Ladbury // December 21, 2008 at 7:52 pm

    Little Johnny is only 14 years old. He makes one understand the W. C. Fields school of child rearing.

  • Holly Stick // December 21, 2008 at 10:51 pm

    I certainly recall how, 40 years ago, spring melting could go on for weeks in the farming area northeast of Calgary, with flooded ditches and sometimes flooded roads and the sound of running water everywhere. Now what snow there is seems to disappear overnight without a sound.

    I presume the winter snow levels in the northern hemisphere haven’t changed because even if it’s warmer in winter, it’s still not warm enough for long enough to melt the snow.

  • TCOisbanned? // December 21, 2008 at 11:07 pm

    aenocdotal evidence shows nothing.

  • Holly Stick // December 22, 2008 at 2:38 am

    This anecdotal evidence appears to be supported by the data as presented and analyzed; and it appears to corroborate the analysis. Is there anything wrong with that?

  • TCOisbanned? // December 22, 2008 at 3:26 am

    Yup. The data with appropriate numbers and statistics and such is the relavent thing. The anecdote tells nothing and can be (and often is) countered by denier anecdotes.

  • Richard Steckis // December 22, 2008 at 4:40 am

    Hank Roberts: “November Warmer Than Average in U.S.”

    November much cooler than average in Western Australia and December looking to go the same way.

    Weather, weather, weather.

  • nanny_govt_sucks // December 22, 2008 at 7:04 am

    In western Oregon, we wring our hands in anguish when snow levels are too low.

    Then you should be happy to hear that there is virtually no winter trend.

  • nanny_govt_sucks // December 22, 2008 at 7:10 am

    Seriously, reduced snow cover in spring (while winter snow cover shows no trend) is a bad thing?

    Seems like you get your usual winter snow but plants have more time and space to grow come spring. I don’t see the downside.

  • ozydingo // December 22, 2008 at 7:15 am

    I’m curious about some of the details on the statistical analysis, primarily for my own education on other statistical methods (I’m really just getting to learn the details of some of this stuff). Your typical plug-and-play regression, if I’m not mistaken, requires samples to be independent for computing the probability of false rejection (i.e. declaring statistical significance.) Surely snow-coverage samples within the same year are not necessarily independent samples of the process? It certainly wouldn’t surprise me that there might be also more elaborate probabilistic models that can go into the analysis that makes reasonable assumptions about yearly weather to attempt to take this into account. Can you comment to this effect, on what may have been done in the presented analysis and/or more general methods / pointers thereto?

    [Response: There are a number of posts on the topic, including here, here, and here.]

  • Paolo Morelli // December 22, 2008 at 8:07 am

    We experienced exceptionally heavy and early snowfall here in northern Italy this autumn and, off course, we did also have a lot of those absurd claims about the end of global warming in the blogosfere and on mainstream media. We are in desperate need of a local Tamino…

  • Armchair Climate Expert // December 22, 2008 at 9:30 am

    Global warming? Here in Brisbane Australia we have five times as much snow as normal for this time of year. And its summer.

    :D

  • less // December 22, 2008 at 12:05 pm

    S2, indeed, Scotland is but a small part of the globe - one that’s strongly affected by the North Atlantic Oscillation. The NAO was at its most negative values in the early sixties and has generally been on the upswing since then, so the trends in winter precipitation that you’re describing are probably a result of that. Positive NAO = Warmer, wetter winters for Europe.

  • lowlander // December 22, 2008 at 3:39 pm

    Less:
    I think you may have not read the document linked by S2 with due attention. Period of analisis covers almost 100 years of records in Scotland since 1914.
    In summary:
    An increase in the average temperature of 2 Celsius
    A increase in average precipitation of 200 mm/year
    There is significant east/west difference of the country on how these variables are behaving.
    The baseline comparison is a standard climatic period of 30 years designed precicely to smooth the statistical noise out of the climatic data such as NAO.
    The question posed by S2 is actually quite interesting considering the analysis presented by Tamino.
    The report mentions with little surprise that average amount of snow cover days has decreased over Scotland but it mentions as well that most of the difference is Spring AND Autumn.

    I think that in the case of Scotland one must bear in mind that there are no glaciers. Snow cover is a seasonal event as Scotland is a peri-arctic nation with a strong influence from the Gulf current in it’s climate, which means that in terms of type of precipitation, Scotland is a border region.
    The winter process of maintenance of snow cover that Tamino describes (i.e. increased precipitation in the form of snow during the winter due to increased water vapour in the air) can only occur in regions where the increase in ambient temperature does not cause the fusion/freezing temperature range to be crossed during the Winter time as this is a physical tipping point for the type of precipitation that you will observe.
    I would venture to guess therefore that probably, regions such as Scotland are not covered by Tamino’s analysis. He may have something to add here.

  • Hank Roberts // December 22, 2008 at 3:53 pm

    It’s the presence of snow cover in the spring that provides slow, steady, meltwater that soaks in, rather than springtime floods. Lookumup.

    Some agricultural areas depend on an accumulation of snow during winter that will melt gradually in spring, providing water for crop growth. …
    en.wikipedia.org/wiki/Snow

    Observed change in spring snow-cover duration 1970–2004
    http://dataservice.eea.europa.eu/atlas/viewdata/viewmap.asp?id=3707

  • ozydingo // December 22, 2008 at 4:13 pm

    Thanks for the replies above! The Hurst parameter post is exactly what I was looking for.

  • dhogaza // December 22, 2008 at 5:23 pm

    Seriously, reduced snow cover in spring (while winter snow cover shows no trend) is a bad thing?

    Ignoring the fact that the fact that there’s no overall trend in winter snow cover doesn’t imply that there’s no downward trend in places like western oregon (you’d be mistaken to place faith in that assumption of yours) …

    Timing as well as amount of snow cover is extremely important in areas that depend on mountain snowpack for water. Decreased spring snowpack while winter snowpack is the same would, if true (and again, don’t hold your breath for western Oregon) imply a lot of late winter/early spring melt.

    At a time when we’re getting a lot of rain.

    Which means reservoir storage capacity gets totally used up earlier in the year than we want. The reservoir systems are planned with knowledge of the timing and amounts of spring rains, winter snowpack, spring melt and runoff, etc.

    You can change the timing of all that and simply pull a statement out of your ass proclaiming “I can’t see any downside!”

  • cletus // December 22, 2008 at 6:10 pm

    NGS–the downside is that for climates in the Western US, the snow is most of the water for the year so an early spring melt means increased drought stress in the fall. Also as far as farming goes, an earlier spring melt can mean challenges for irrigation…i.e., if the water flows down the stream in april rather than june, it’s not in the stream when you need it.

    Pooh-pooh it if you want, but it’s not trivial to have less snow in the spring.

  • Harold Brooks // December 22, 2008 at 6:15 pm

    Seriously, reduced snow cover in spring (while winter snow cover shows no trend) is a bad thing?

    Seems like you get your usual winter snow but plants have more time and space to grow come spring. I don’t see the downside.

    Much of the western US depends on snowpack for water supplies. Earlier snowmelt (or less available to melt) means less water available in the spring and summer.

  • Jim Eager // December 22, 2008 at 6:23 pm

    nanny imagines, incorrectly, that “cover” = “volume.”

    nanny also ignores the fact that faster melt = less absorption and replenishment of ground water.

    nanny imagines and ignores much.

  • Ian Forrester // December 22, 2008 at 8:09 pm

    NGS, do you ever get out and about and look at the world around you?

    Perhaps, along with the elementary subjects I suggested you upgrade on another thread, you may take time and drive around a bit and observe what happens under differing climate conditions.

    As well as providing soil moisture snow cover prevents the loss of soil by wind erosion, especially on the prairies.

    Dry winter winds soon remove snow and expose the underlying soil to wind erosion if the cover is too light.

  • Dave A // December 22, 2008 at 10:23 pm

    Just a question. How does the Rutgers Global Snow Lab collect its information and how accurate is it?

    From a couple of the comments here about Scotland it does not seem to offer comprehensive coverage.

    [Response: From their website:

    In 1966, NOAA began to map the snow and ice areas in the Northern Hemisphere on a weekly basis. That effort continues today, and remains the only such hemispheric product. NOAA maps are based on a visual interpretation of photographic copies of shortwave imagery by trained meteorologists. Up to 1972, the subpoint resolution of the meteorological satellites commonly used was around 4 km. Beginning in October 1972, the Very High Resolution Radiometer (VHRR) provided imagery with a spatial resolution of 1.0 km, which in November 1978, with the launching of the Advanced VHRR (AVHRR), was reduced slightly to 1.1 km. Maps show boundaries on the last day that the surface in a given region is seen. Since May 1982, dates when a region was last observed have been placed on the maps. An examination of these dates shows the maps to be most representative of the fifth day of the week.

    It is recognized that in early years the snow extent was underestimated on the NOAA maps, especially during Fall. Mapping improved considerably in 1972 with the deployment of the VHRR sensor, and since then mapping accuracy is such that this product is considered suitable for continental-scale climate studies.

    Despite the shortwave limitations mentioned earlier, the NOAA maps are quite reliable at many times and in many regions. These include regions where, 1) skies are frequently clear, commonly in Spring near the snowline, 2) solar zenith angles are relatively low and illumination is high, 3) the snow cover is reasonably stable or changes slowly, and 4) pronounced local and regional signatures are present owing to the distribution of vegetation, lakes and rivers. Under these conditions, the satellite-derived product will be superior to maps of snow extent gleaned from station data, particularly in mountainous and sparsely inhabited regions. Another advantage of the NOAA snow maps is their portrayal of regionally-representative snow extent, whereas maps based on ground station reports may be biased, due to the preferred position of weather stations in valleys and in places affected by urban heat islands, such as airports.

    The NOAA maps are digitized on a weekly basis using the National Meteorological Center Limited-Area Fine Mesh grid. This is an 89 x 89 cell Northern Hemisphere grid, with cell resolution ranging from 16,000 sq. km to 42,000 sq. km. If a cell is interpreted to be at least fifty percent snow covered it is considered to be completely covered, otherwise it is considered to be snowfree.

    ]

  • luminous beauty // December 22, 2008 at 10:41 pm

    Nags,

    <a href=”http://en.wikipedia.org/wiki/Summer_2008_California_wildfires” ¡Ya Basta!

  • luminous beauty // December 22, 2008 at 10:44 pm

    ¡Ay, Caramba!

  • David B. Benson // December 22, 2008 at 11:07 pm

    Here the farmers want snow to cover the soft white winter wheat to lessen frost damage.

    And incidently, the only month in which snow has not fallen here some year in the past 38 years is July. Last June was unusual in having about 3 cm of wet, heavy snow one day.

  • Dana // December 23, 2008 at 12:12 am

    “a. You’re contesting an argument that hasn’t been made yet.”

    Tamino is correct here. After the Las Vegas snow event there was a period of several days during which up to 50% of the questions in the Yahoo Answers Global Warming section suggested that because of this weather event, global warming is a myth.

    The argument has been made many times since late fall.

    This entry was a really interesting analysis of the snowcover trends. Nice job as always, Tamino.

  • TCOisbanned? // December 23, 2008 at 3:33 am

    I didn’t see Tammy citing or linking to the complainers. He also used future tense in his last sentence. I had the impression he was making the argument in advance.

  • Richard Steckis // December 23, 2008 at 3:37 am

    Given that the snow cover seems to important for agriculture in the western US, it would be pertinent to see if such declines in the spring and summer snow area has led to a concomitant decline in agricultural yield.

    Also a comparison with stream flows would be interesting.

  • nanny_govt_sucks // December 23, 2008 at 3:43 am

    Which means reservoir storage capacity gets totally used up earlier in the year than we want. The reservoir systems are planned with knowledge of the timing and amounts of spring rains, winter snowpack, spring melt and runoff, etc.

    And do these planners not have access to the data Tamino used above?

    NGS–the downside is that for climates in the Western US, the snow is most of the water for the year so an early spring melt means increased drought stress in the fall.

    … but also an earlier start to irrigating in the spring, I imagine. And aren’t increased CO2 concentrations and precipitation supposed to help ameliorate drought stress to a certain degree?

    And so far the reactions to my post seem to be about crops, not about the ecosystem as a whole. I’ve read studies showing that the planet is greening and that the growing season is longer, coinciding with recent warming. So something is going right.

  • Richard Steckis // December 23, 2008 at 4:00 am

    Armchair. Snow in Brisbane? In summer?

    Methinks you jest!

  • nanny_govt_sucks // December 23, 2008 at 7:40 am

    At a time when we’re getting a lot of rain.

    Which means reservoir storage capacity gets totally used up earlier in the year than we want.

    Well, if you are getting more rain, then doesn’t that mean that there’s less need to pull water (for crops anyway) out of the reservoir? So maybe the reservoir water will last a bit longer into the fall and ameliorate potential late season drought.

  • sod // December 23, 2008 at 7:51 am

    … but also an earlier start to irrigating in the spring, I imagine. And aren’t increased CO2 concentrations and precipitation supposed to help ameliorate drought stress to a certain degree?

    i ll keep it simple:

    very fast and early melt: problematic. causing floods early and drought later in the year. not good news.

    slow melting: good. less floods, more water later when needed.

    more precipitation might help, or might not. this depends on timing. the extra rain might actually be more winter snow, melting early. this would simply INCREASE THE PROBLEMS, that outlined above.

    or it might fall as rain in autumn, too late for farmers.

    And so far the reactions to my post seem to be about crops, not about the ecosystem as a whole. I’ve read studies showing that the planet is greening and that the growing season is longer, coinciding with recent warming. So something is going right.

    the planet will survive. the question is, how will mankind (and some wildlife) hang on.

  • Lee // December 23, 2008 at 9:09 am

    nanny - Out here in the west, we don’t need to irrigate in the spring. It rains here in the the winter and spring.

    California agriculture is dependent on summer and fall irrigation. The rainfall between end of april and late october or november, is effectively zero inches for most of the relevant parts of the state. That is also the period when temperatures are high enough to grow stuff. Increased early melt and early runoff simply means that there is less snow in the mountains and less water in the streams in the summer and fall, when we need it most.

    We capture a lot - but far from all - of that water in reservoirs, which ameliorates the problem to an extent. But if the reservoirs fill up early in spring with melt, and then replenishing flows are reduced in the summer, that means that stream flow releases have to come from the storage pools for more of the year, meaning also less water available in summer and fall. Early melt means that more storage is necessary to meet teh same water needs - and out here in the west, that means more reservoirs - but we’ve used up all the good spots - or expanded pools in existing reservoirs, by rebuilding them and raising the pool elevation, none of which comes cheap in either money or environmental impacts.

    This is all exacerbated, in California, by a significant trend of decreased winter snowpack - not necessarily coverage area, but less water falling and being stored as snow, period.

    Western water planners are very, very worried by all this - and they know a hell of a lot more about the melt timing issues and impacts than you do, nags.

  • Lee // December 23, 2008 at 9:14 am

    “so far the reactions to my post seem to be about crops, not about the ecosystem as a whole.”

    Trees/forests/plant communities throughout the west are being increasingly water stressed by this. If snowpack at a given location melts off earlier, and doesn’t last as long into the summer then the water supply goes away earlier than it used to do - leaving a longer period of no water. Plants do not like this.

  • Ray Ladbury // December 23, 2008 at 1:26 pm

    Nanny reveals the key to all his thinking on climate science:

    “…I imagine…”

    Nanny, science isn’t about imagining. It’s about gathering information and seeing how it fits together. It’s not about looking around for studies that support your rosy view. It’s about looking at all the data and making a realistic assessment. Can ya try and do that for us? Please?

  • dhogaza // December 23, 2008 at 4:13 pm

    I’ve read studies showing that the planet is greening and that the growing season is longer, coinciding with recent warming. So something is going right.

    Forests throughout the west are drought-stressed and fire seasons have been growing longer with hotter weather. Pine bark beetles are expanding their range north, the trees they infect are especially vulnerable to fire.

    Past fire suppression efforts make fires burn hotter and more thoroughly, however the past is NOT responsible for the hotter and drier fire seasons we’re seeing. Climate change is the major driver.

    Ray’s got it right. Your thinking boils down to “…I imagine…”. Furthermore, your imaginative thinking is driven by one thing, and one thing only … the attitude towards government so accurately described by your handle.

    Sorry, your political beliefs are not going to change the physical reality of what’s happening out there in the hard, often cruel, world.

    However, I know that your inability to accept facts that run counter to your political beliefs is boundless. You’re another denialist who clearly falls into the bin labeled “uneducatable”.

  • Dano // December 23, 2008 at 4:58 pm

    And so far the reactions to my post seem to be about crops, not about the ecosystem as a whole. I’ve read studies showing that the planet is greening and that the growing season is longer, coinciding with recent warming. So something is going right.

    This logic presumes that the premise of ‘greening is good’ is correct, or that short time scales equal longer scales.

    Read further into these studies and see whether perennial woody plants are happy.

    That is: does the longer period of metabolism translate to more plant health? The early indications are that there is less OM and nutrients falling out of the tree (via leaves) and into the soil.

    IOW: so what. A little wisdom goes a long way, NaGS. The Google doesn’t have a wisdom button.

    Best,

    D

  • mauri pelto // December 23, 2008 at 6:27 pm

    In mountain regions of the Pacific Northwest in particular a key factor in changes in snowpack is the ratio of snow to rain. This has been called the snowpack-precipitation ration by Knowles, Dettinger and Cayan (2005) and Pelto (2006 and 2008) and snowpack storage efficiency by Mote et al. (2008). It is evident that this ratio is declining regardless of time interval observed. The amount of ppt require to yield the same snowpack must increase. Fortunately for the Pacific Northwest this has been a wet decade from 1999-2008, making up for the declining ratio. http://www.nichols.edu/departments/Glacier/snowpack_variations_in_the_north.htm

  • David B. Benson // December 23, 2008 at 8:02 pm

    sod // December 23, 2008 at 7:51 am — Actually, rain in the autumn is good for soil moisture for next year’s crops. Around here the only time rain is (most) unwelcome is during harvest, August into September.

  • dhogaza // December 23, 2008 at 8:47 pm

    So, how does Mauri, living in MA, end up spending more time in the North Cascades than I do, living here in PDX :)

    NGS - Mauri Peltois is an expert in the subject matter addressed in his post. Pay attention to what he says …

  • JCH // December 23, 2008 at 11:33 pm

    “Given that the snow cover seems to important for agriculture in the western US, it would be pertinent to see if such declines in the spring and summer snow area has led to a concomitant decline in agricultural yield. …”

    For whatever reason, where we farmed and ranched, when it was too warm to snow, it would rain.

  • P. Lewis // December 24, 2008 at 12:35 am

    NGS - Mauri Peltois is an expert in the subject matter addressed in his post. Pay attention to what he says …

    I’m not sure that appeals to authority work … more especially to the ineducable.

  • Hank Roberts // December 24, 2008 at 2:15 am

    http://www.cig.ensmp.fr/~iahs/hsj/360/hysj_36_06_0611.pdf

    Hydrological Sciences - Journal - des Sciences Hydrologiques, 36,6, 12/1991
    Rain-induced outflow from deep snowpacks
    in the central Sierra Nevada, California

    Abstract In many mountainous areas of the Pacific coast of North America, rainfall onto snowpacks causes massive floods….

  • nanny_govt_sucks // December 24, 2008 at 4:01 am

    Gotta go away for the rest of the week. Some quick comments. Floods aren’t bad news for topsoil. And fish. Western watter planners = government. Centralized government at that - I’d be worried regardless of snowfall amounts. A flexible, dynamic free society water distribution system would better meet the needs of farmers. Green IS good Dano. no matter how you try to twist it.

  • dhogaza // December 24, 2008 at 6:03 am

    I’m not sure that appeals to authority work … more especially to the ineducable.

    Well, sure, that’s sort of inherent in wide-spectrum science denialism.

    NGS reinforces our understanding with this:

    And fish. Western watter planners = government. Centralized government at that - I’d be worried regardless of snowfall amounts.

    See? Any problem with water is due to government.

    The Sahara would be a garden of Eden if it weren’t for the overly restrictive government agencies that refuse to let it rain there.

    A flexible, dynamic free society water distribution system would better meet the needs of farmers.

    Western water law was instituted because your “free society water distribution system” FAILED.

    This is called history, which of course I’m sure you reject as vehemently as you reject science (and sociology, and political science, and everything else ever written by other than Ayn Rand and Robert Heinlein).

    Green IS good Dano. no matter how you try to twist it.

    In other words, science is bogus, because NGS says so,.

    I shoulda dropped out of school at age 4, would’ve saved me a shitload of work, and I’d be just as informed and smart as NGS if I’d done so…

  • dhogaza // December 24, 2008 at 6:04 am

    Floods aren’t bad news for topsoil.

    This one is especially lovely :)

  • malcolm // December 24, 2008 at 7:51 am

    Tamino - didn’t you previously claim that the mid-1970s were a turning point for global temperatures? Your graphs above seem inconsistent with this. Care to comment?

  • storak // December 24, 2008 at 11:39 am

    Floods aren’t bad news for topsoil.

    i doubt that massive floods benefit farmers. this is a british report tackling “autumn floods”:

    http://www.publications.parliament.uk/pa/cm200001/cmselect/cmagric/172/17203.htm

    mankind is having a huge impact on water. apart from the climate change, we are sealing the ground, cutting woods and change rivers.
    and we use more and more surface area, increasing our vulnerability.

    Centralized government at that - I’d be worried regardless of snowfall amounts. A flexible, dynamic free society water distribution system would better meet the needs of farmers.

    this is total nonsense. this problems are typically handled at exactly the right level of “centralization”.
    it is completely impossible to solve a problem like this (water distribution along a river, for example) without some “centralization”.

    Green IS good Dano. no matter how you try to twist it.

    false again.

    look at the algae, plaguing the Mediterranean.

    http://query.nytimes.com/gst/fullpage.html?res=950DE5DE1539F935A2575BC0A96F948260&sec=&spon=&pagewanted=print

    caused by human waste, spilled into the sea, it is killing a lot of other life. (the color is rather brown, btw..)

  • Ray Ladbury // December 24, 2008 at 12:44 pm

    NGS says “Green IS good Dano. no matter how you try to twist it.”

    Nanny, I’ve got a loaf of bread that’s “good”. Wanna buy it?

  • Elery Fudge // December 24, 2008 at 3:45 pm

    Fall and winter snow cover has not changed much.

    Spring and summer snow cover has decreased.

    Rain precipitation has increased.

    What are the concrete, observed, adverse results?

    What are ideal conditions and when were they last observed?

    Elery

  • dhogaza // December 24, 2008 at 5:07 pm

    What are ideal conditions and when were they last observed?

    They were last observed in the Garden of Eden…

    (sorry, but some questions just can’t be taken seriously)

  • Lee // December 24, 2008 at 6:33 pm

    I am astounded at how little nanny knows, and how authoritatively he nonetheless pronounces his claims of knowledge.

    “Western watter planners = government. Centralized government at that”

    This is complete crap. My father was a planning engineer for the California Department of Water Resources, involved over the last decades of his career in several sets of allocation and storage negotiations. A typical negotiation involved dozens of entities, including several state departments (fish and game, water, budget, environmental), federal entities (reclamation, corp of engineers, EPA, forestry), each county affected, each city affected, private and quasi-public irrigation districts and ditch districts, private irrigator interests, public environmental and sportsman groups. No single agency had authorization authority - multiple agencies had veto power, and it was all subject to judicial oversight under the water laws and subject to superrceding public and private water rights.

    To claim, as nags does, that this is “centralized government” is to betray utter ignorance of the water planning processes that he is claiming to understand.

  • P. Lewis // December 24, 2008 at 7:47 pm

    n_g_s said:

    Gotta go away for the rest of the week.

    Just the rest of the week? Shame about that.

  • David B. Benson // December 24, 2008 at 8:33 pm

    P. Lewis // December 24, 2008 at 7:47 pm — What you just wrote.

  • guthrie // December 24, 2008 at 8:42 pm

    I read “The western Paradox”, a book of essays and such by Bernard de Voto. In it he makes it very clear how the “west” was ruined ecologically and socially by cattle barons and miners and loggers, and it wasn’t until the gvt intervened that things began to get better. All this happened back in the 30’s, 40’s and 50’s. NGS clearly hasn’t a clue about the history of the area.

  • dhogaza // December 24, 2008 at 10:01 pm

    This is what life on the open range was like before the state and federal governments stepped in:

    The range wars in Central and Eastern Oregon initially involved threats and scattered property damage. In the late 1890s and early 1900s, these incidents escalated to the burnings of sheep camps, and direct violence, including the clubbing, poisoning, and shooting of sheep. Violence perpetrated by groups of vigilante cattlemen reached a climax in the years 1904-1906. In April 1904, 2,300 sheep were killed in a single night in Lake County. In May 1904, a delegation of sheepmen from Antelope in eastern Wasco County traveled to Crook County in an effort to reach an agreement with the cattle ranchers of central Oregon. This attempt was unsuccessful and a few days later, 150 sheep were shot near Mitchell, located fifty miles southeast of Antelope. Additional incidents of sheep shooting occurred in Central Oregon that summer. The region’s sheepmen continued to advocate a non-violent resolution to the conflict, calling on state officials to act in order to stem the violence. In response, a group of cattlemen calling themselves the Crook County Sheep-Shooting Association urged the governor and state officials not to meddle in the affairs of “our province.”

    In addition to the above, there was at least one murder of an opponent to the Sheep-Shooting Associations. There’s another in Oregon’s Great Basin country that’s not been definitely pinned down to the cattle ranchers.

    I’ll take government, thank you.

  • David B. Benson // December 24, 2008 at 10:48 pm

    Elery Fudge // December 24, 2008 at 3:45 pm — I’ve posted again and again on actual adverse results of AGw, which has just barely started. On DotEarth.

    Do go read Mark Lynas’s “Six Degrees”.

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