Guest Post by Willis Eschenbach
The abstract of a new study from Science Magazine entitled “The Unusual Nature of Recent Snowpack Declines in the North American Cordillera”, Gregory Pederson et al., 9 June 2011 (paywalled, all data available here, figures here, overview here) opens by saying:
In western North America snowpack has declined in recent decades, and further losses are projected through the 21st century.
The abstract goes on to describe their findings:
Over the past millennium, late-20th century snowpack reductions are almost unprecedented in magnitude across the northern Rocky Mountains, and in their north-south synchrony across the cordillera.
Figure 1. The future of skiing in the North American Rocky Mountains? Eric Lon, rock skiing
And the culprit, the Grinch stealing the white Christmas? Why, us fools who ate the fossil-fuel-fertilized apple and got ourselves thrown out of climate Eden, of course. Or in their words,
Both the snowpack declines and their synchrony result from unparalleled springtime warming due to positive reinforcement of the anthropogenic warming by decadal variability.
First, kudos to the authors for archiving their data and meta-data at the time of the publication of their work. This is an excellent example of providing the necessary information so that others can investigate their results.
Now, about those results …
I’ve mentioned that the first thing that I want to look at is the actual data. While they didn’t exactly provide that, they did provide the standardized data for the two regions that they studied, the “Northern Cordillera” and the “Southern Cordillera”. (To “standardize” data, it is adjusted so that the average is zero and the standard deviation is 1. This allows the comparison of dissimilar datasets.)
In this case, the data that they used was the April snow water equivalent, or SWE. The SWE is how many inches of water you get when you melt a column of snow. Use of the SWE avoids the problem that different kinds of snow have different thicknesses, as some are fluffy and light and others are wet and heavy. Figures 2 and 3 show their standardized SWE results.
Figure 2. Pederson 2011 individual and average April snow water equivalent (SWE) for the northern part of the Rocky Mountains. Data Source (Excel, worksheet “HUC6 Observed SWE”)
Figure 3. Pederson 2011 individual and average April snow water equivalent (SWE) for the southern part of the Rocky Mountains. Data Source (Excel, worksheet “HUC6 Observed SWE”)
Well … I looked at that and I thought “western North American snowpack has declined in recent decades”? Really? I thought “unprecedented reductions”?!?
I thought, well, maybe we’re not talking about the same thing. Maybe the actual snowpack records show something different, something unprecedented, some big decline in recent decades. So I went to the NRCS SNOTEL records and got the data for Colorado. I averaged it by year and month, and calculated the average April Colorado SWE data to compare with the Pederson 2011 Southern Cordillera data (where Colorado is located.) Figure 4 shows how well they match the Pederson data.
Figure 4. Comparison of the SWE records for Colorado (SNOTEL figures) and the Southern Cordillera (Pedersen 2011 figures).
So we are definitely talking about the same thing …
OK, I thought, that’s it. I’m blowing the whistle. According to both their figures and the SNOTEL figures, there’s no “late twentieth century decline” in snowfall in either the Northern or the Southern Cordillera. That’s hype, and their own data says so. This is particularly true when the more recent data is included (blue line). For unspecified reasons their data ends in 2006. Since then, the snowfalls have generally increased.
Once again, the AGW proponents haven’t even begun to show that anything out of the usual is occurring. Instead they’ve jumped directly to explaining the cause of something that they haven’t yet shown to exist.
In other words, another day, another alarmist exaggeration. Don’t you love how well peer review is working at Science Magazine for climate articles? Oh, well, I suppose the good news is that it results in a target-rich environment, makes my job easy … but the bad news is that we all lose when this kind of alarmism is published as though it were science.
w.
PS – There’s other issues in this. They say that they can reconstruct historical snowpack from tree rings … hmmmm, where have I heard something like that before? And if they can do such reconstructions, their results don’t show an unprecedented decline in the late 20th century. Instead, they show a decline starting about 1880 or so, and only in the more northern regions.
But that’s all raw meat for someone else to chew on … I’ve seen enough of this study.
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John Marshall says:
June 11, 2011 at 3:47 am
“The Innuit have, I think, 350 words for snow.”
Just for amusement… the number of “words” for snow is indefinite; they have a polysynthetic language.
“A polysynthetic language is a language in which words tend to consist
of several morphemes.
Yup’ik Inuit
tuntussuqatarniksaitengqiggtuq
‘He had not yet said again that he was going to hunt reindeer.’
”
found here:
http://dreamsongs.com/Files/RoadNotTaken.pdf
Do we have a way to distinguish the light, fluffy kind of Bad Science from the wetter, squishy kind? A sort of “Bad Science Equivalent”? Maybe just sniff it…
Of course, it makes a difference when you start and end the data. Start 20,000 years ago, and the losses are absolutely devastating! 🙂
Best,
Frank
Willis>
“There’s other issues in this. They say that they can reconstruct historical snowpack from tree rings …”
This is a bit like the cub reporter sent to cover a high-society wedding, who rang in to report that there was no story because the bride hadn’t turned up. We’ve been hearing for years about how it is possible to extract a (meaningful) temperature signal from tree-rings, because there are no other discernible factors which affect tree growth. Either tree-rings are a poor proxy for temperature, or they can’t be used as a proxy for snow depth: one or the other, not both.
Not only are they tipping their head to see hockey sticks, now they are standing on their heads to see declines. Eventually, these folks will have to turn in insurance claims for neck injuries and will be seen giving talks on climate change with neck braces strapped on.
lol, more mythological snow loss. I know our western snow pack is different, but the NH isn’t losing snow. It’s gaining, and has for twenty years………..http://suyts.files.wordpress.com/2011/06/image5.png
“almost unprecedented in magnitude”- so it’s not unprecedented then? Is this anything like “almost unique”?
“positive reinforcement of the anthropogenic warming by decadal variability” – I thought variability meant “both up and down”. Silly me – this is AGW variability – it always goes in the direction which suits your otherwise scantily-clad argument.
Richard Wakefield says:
June 11, 2011 at 5:58 am
“Can someone explain how tree rings can be a proxy for snow depth when trees arn’t growing in winter?”
It’s a negative correlation. Greater snow depth = longer time to melt = shorter growing season and later onset of growing season = thinner tree rings.
But then, everyone knows tree rings are a proxy for temperature. /sarc
Well if you draw a line from the 1952 peak to the 1999 valley you can get a nice declined line. Mind you that ignores the entire rest of the chart and the trends being shown there which don’t support their main contention. But if you draw the line on the graph as I mention you can claim that there was a decline in snow pack levels in the late 20th century. You have to end the line at the late 20th century for the claim to work but you can make the claim.
So they basically used creative license in their conclusions. Which is what Willis was wondering about and checked.
It’s about as ludicrous as the BBC news reporter standing in the rain and telling us how bad the drought was on the BBC news yesterday!
It rained all day here yesterday but it’s terrible drought apparently, maybe it’s code for, get ready to pay more for your water. Where have we seen tactics like that before?
You chew on their data and eschew their conclusions.
“nc says: Then we have the other side of the spectrum, http://www.cbc.ca/news/canada/edmonton/story/2009/06/15/edmonton-forest-fires-alberta-fire-bans.html
Alberta dry and one third of Slave Lake was destroyed.”
Well, yes indeed, part of Alberta is dry. Part is wet. The dry part, a band north and east of Edmonton, has had very unusual weather. First, exceptionally deep snow pack exceptionally late into the spring. Then the snow “left”, with little runoff and apparently not as much soil moisture as would be expected. Spent the month of May trying to fly my glider from my home club east of Edmonton. Day after day of winds from the south east and lots of moisture in the middle levels, and evenings in the bar discussing soil moisture and pasture performance with local ranchers.
So it was unusual. But what’s the point? The jet stream was further south, more loopy, than is typical for that time of year. The low pressure systems were passing south of Edmonton, when typically for May they have moved north of Edmonton.
So, nc, is this evidence of global climate disruption due to CO2 in the atmosphere, or simply something that happens once in a while? Hint: I have been flying from that field for 25 years, and as a glider pilot watch the weather patterns very closely. My opinion: this is something that happens once in a while. Cheers.
This was publised right? That means it was peer reveiwed right? So why didn’t they notice this rather obvious flaw?
Willis you missed the caveat… they did say LATE 20th century, meaning like 1975-1995, they want people to ignore all the other years. They also said ALMOST unprecedented (meaning its not unprecedented but we want to give the reader the impression it is). I’d say technically their article is correct.
Also, why do the authors say “Over the past millennium” and then only show data for the past ~80 years? They are soooo tyring to hype something from nothing…. typical.
ignore the Over the past millennium comment by me… I spoke too soon – sorry. I see in their original article they do show more than the past 85 yrs.
Wasn’t another paper by Gregory Pederson of the USGS discussed here a while back? I think it might have involved species migration.
It doesn’t matter Willis ; we’re all going to drown anyway…or, NOT!
http://www.abc.net.au/local/audio/2011/06/09/3240161.htm
You are all missing the point. This is what the authors say:
“Of particular interest is the shift in the snowpacks’ response to natural variations in climate over the
tropical and northern Pacific, which occur on time scales of a few years to a few decades.
Typically, gains and losses of mountain snowpack seesaw between the northern and southern Rockies
with these natural swings in Pacific climate patterns, Pederson explains.
This feature stands out in the team’s data throughout the past millennium, with a couple of notable
exceptions around 1350 and the early 1400s, when warmer average temperatures reduced snowpack up
and down the length of the Rockies at the same time.
The seesaw still occurs to some extent. But since the 1980s, snowpacks again have been declining
along the entire length of North America’s geological spine, regardless of the state of these natural
climate swings.”
http://www.csmonitor.com/Environment/2011/0610/The-new-water-wars-Study-shows-broad-decline
-in-Rockies-snowpack.
So the graphs Willis produced are irrelevant. Take a look at the article figure 3 (linked by WE
at thetop oft the post:). Don’t you see the synchronicity (North-South) and overall trend in recent
decades?
“According to both their figures and the SNOTEL figures, there’s no ‘late twentieth century decline’ in snowfall in either the Northern or the Southern Cordillera. That’s hype, and their own data says so.”
“That’s hype…” Gotta admire the restraint – I would have called it something else!
When all that snow starts melting, the Warmers are going to say that AGW is causing unprecedented floods and that the flooding is causing unprecedented sea level rise.
Here is the article from the Edmonton Journal yesterday:
http://www.edmontonjournal.com/technology/Shrinking+snowpack+threatens+water+supply/4923408/story.html
I am not defending what they say, but here are two sentences:
“Luckman said the tree rings track the depth of the snowpack because some species such as the alpine larch tend not to grow well in heavy snowpack years because it takes so long for water to start flowing on mountaintops.
Trees such as Ponderosa pines at lower elevations thrive in years of heavy snowpack, resulting in thicker tree rings.”
The final paragraph says:
“This year’s La Nina episode has generated lots of snow in the Rockies in the northern U.S. and Canada and drought in the southwestern U.S. But the scientists say this year’s snowpack gains are a “small blip” on a long snowpack decline that they expect will put increasing strain on water supplies in the western United States and Canada in coming decades.”
Science is nothing more than a supermarket tabloid of science…the kind of rag you pick up at the check-out line to see fake photos of aliens and two-headed babies to titillate and frighten.
Here is the current Colorado snowpac numbeers (updated dailey), which is currently 277% of normal
http://snowpack.water-data.com/uppercolorado/index.php
Lake Powell reached one foot per day water level rise yesterday
http://lakepowell.water-data.com/
But AGW is supposed to cause more rain and snow, no?
This is why AGW enthusiast blogs have to post each day about bleeding heart issues of destruction and the evil ExxonMobile zombie deniers: so that their readers don’t stray on over here to see the actual content of the site.
Cutting recent data off is quite popular with IPCC authors:
http://i49.tinypic.com/mk8113.jpg
I don’t know much about their data, but I do know that four Tahoe area ski resorts are re-opening for Fourth of July weekend: Alpine Meadows, Kirkwood, Squaw Valley and Sugar Bowl. I’ll see you on the slopes.
Alcheson says:
June 11, 2011 at 10:38 am
“Willis you missed the caveat… they did say LATE 20th century, meaning like 1975-1995, they want people to ignore all the other years. They also said ALMOST unprecedented (meaning its not unprecedented but we want to give the reader the impression it is).”
Yeah, almost unprecedented… like “almost true” in Boolean logic… the warmists are really masters in communicating their science. Well, it’s almost science. Meaning, it’s not, but it produces papers and graphs.