While some other bloggers and journalists insist that recent winter snows are proof of global warming effects, they miss the fact that models have been predicting less snow in the norther hemisphere. See this 2005 peer reviewed paper:
Frei, A. and G. Gong, 2005. Decadal to Century Scale Trends in North American Snow Extent in Coupled Atmosphere-Ocean General Circulation Models. Geophysical Research Letters, 32:L18502, doi: 10.1029/2005GL023394.
It says exactly the opposite of what some are saying now. – Anthony
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Guest post by Steven Goddard
A 2005 Columbia University study titled “WILL CLIMATE CHANGE AFFECT SNOW COVER OVER NORTH AMERICA?” ran nine climate models used by the IPCC, and all nine predicted that North American winter snow cover would decline significantly, starting in about 1990.
In this study, current and future decadal trends in winter North American SCE (NA-SCE) are investigated, using nine general circulation models (GCMs) of the global atmosphere-ocean system participating in the upcoming Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC-AR4)…
all nine models exhibit a clear and statistically significant decreasing trend in 21st century NA-SCE
Some of the models predicted a significant decline in winter snow cover between 1990 and 2010.
Climate Model predictions of Snow Cover Decline
As we know, winter snow cover has actually increased about 5% since it bottomed in 1989, and is now close to a record maximum.
Below is another interesting graph. It shows the number of top 100 snow extent weeks by decade. I took the top 100 weekly snow extents (out of 2227) from the Rutgers record and sorted them by decade. The past decade has been at least as snowy as the 1970s.
The past decade has had the most weeks in the top 100 since 1966.
Above are images from NASA showing snow extent from 2001 to 2004. Below is an image from 2010, showing snow cover in all 48 states.
NOAA Image – February 12, 2010
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UPDATE: Here is a new graph of north American winter trend produced by Steve at the request of commenters:
So far, the climate models have the wrong polarity on their predictions of winter snow cover changes.
Leif,
Your graphs don’t change anything and you seem to have forgotten that there are several weeks left in 2010 which will probably score in the top 100.
Why all the nitpicking? If you see something fundamentally wrong with the conclusions, fine. I’m not seeing that in your posts.
“Save the whales!”
Too late.
I already have the whole set.
2 Questions
1) Why do you plot Dec-Feb when the model and paper only referred to January NA-SCE ?
2) Why does your plot start in 1989 when the Rutgers data goes back to 1967?
Robert,
The trend for winter snow in the Northern Hemisphere since 1999 is +220,000 km2/yr with rsq = 3.13 – culminating in the second greatest extent on record last week.
Your claim that there is no 21st century trend is patently absurd.
I’d guess that we have snow cover in all 50 states. Mauna Kea observatory is up at 4200 meters, so that should bring Hawaii in, too.
The models don’t seem to catch the 30 year half cycles of warming and cooling. Probably because the modelers aren’t old enough to remember the last half cycle.
Johnc,
I’ve answered the same question about three dozen times now. 1989 was the year when the trend started upwards. Prior to that, snow extent was declining. It makes no sense to do a linear fit across two legs of a cyclical pattern.
Want January? Even better. Trend = 102,000 km2/year rsq = 3.12
https://spreadsheets.google.com/oimg?key=0AnKz9p_7fMvBdHFzTFVnTlVrYnV0bEpxLWt5aXE2UEE&oid=3&v=1266604809333
johnc,
Also the models forecast a decline starting about 20 years ago.
John R. Judge (08:05:38) :
When the pundits and politicians say that the current snow storms are not “proof”, they are correct. When they say that they are not “evidence”, as many of them do, they are blowing smoke. Rising graphs may have ups and downs. They don’t have 100+ year records.
I believe there are 100+ year records for individual sites, but they are not in the form that is currently being discussed. You will find historical records in places where ordinary people kept track of 1st snow, last snow, last snow on ground, etc.
The sad thing about the models is that they cannot account for increases, i.e. – they are uni-directional.
Steve Goddard (10:17:55) :
Your graphs don’t change anything and you seem to have forgotten that there are several weeks left in 2010 which will probably score in the top 100.
My graphs show how careful one has to be. You did not comment on the smallness of the 1960s on your graph. Did you multiply by 2.5 to compensate for the decade only having data a quarter of the decade? If not, your graph is sloppy work.
The winter Dec-Feb 2010 does not have ‘several’ weeks to go. The Rudgers data go though week 7 of 2010.
In a frivolous note the 02/12/10 snow map, misses the snow that covered South Carolina the afternoon and evening of 02/12/09. By midnight most of the coastal region had snow on the ground.
Leif,
Do you have a fundamental objection to the conclusions?
Your analysis is flawed. If the first week in March is in the top 100, it goes in the graph. The graph represents weeks – not months.
Second, I included the entire Rutgers record in that graph. It would be sloppy to extrapolate data which does not exist. And at no time did I make any inference comparing vs. the 1960s. The comparison is vs, the 1970s – which is a complete record.
Leif Svalgaard (10:51:17) :
Steve Goddard (10:17:55) :
Your graphs don’t change anything and you seem to have forgotten that there are several weeks left in 2010 which will probably score in the top 100.
My graphs show how careful one has to be. You did not comment on the smallness of the 1960s on your graph. Did you multiply by 2.5 to compensate for the decade only having data a quarter of the decade? If not, your graph is sloppy work.
The winter Dec-Feb 2010 does not have ’several’ weeks to go. The Rudgers data go though week 7 of 2010.
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There are several weeks of winter left. Obviously, there will be no remaining Winter 2010 data, for Rutgers or anyone else, to show until those weeks have passed into Spring. Unless of course, you use one of those vaunted models that predict weather and climate with such accuracy! 😀
Frei, A. and G. Gong, 2005. Decadal to Century Scale Trends in North American Snow Extent in Coupled Atmosphere-Ocean General Circulation Models. Geophysical Research Letters, 32:L18502, doi: 10.1029/2005GL023394
The full paper:
http://www.geo.hunter.cuny.edu/people/fac/frei/frei_gong_2005_revised.pdf
Of course, more snow across the USA does not necessarily mean that the world as a whole is getting colder.
Roy Spencer has an interesting global temperature plot for January on his site here:
http://www.drroyspencer.com/wp-content/uploads/UAH_LT_2010_01_grid1.jpg
and the message seems to be that northern mid latitudes have been cooler than usual this year while other places have been warmer – in some cases like Greenland and Northern Canada a LOT warmer (of course warmer still means those places are below freezing so no lack of snow there either).
Roy suggests that this pattern may be associated with the current El Nino.
” Steve Goddard (10:30:29) :
Robert,
The trend for winter snow in the Northern Hemisphere since 1999 is +220,000 km2/yr with rsq = 3.13 – culminating in the second greatest extent on record last week.
Your claim that there is no 21st century trend is patently absurd.”
It’s your source, Mr. Goddard. I just went there and looked at the snow figures you were citing.
You are also misunderstanding the research if you think “change in the 21st” and “trend throughout the 21st century” mean the same thing. The climate is not changing linearly. We can expect more change at the end than at the beginning. The models themselves are extremely limited, as the paper acknowledges, which is why they confined themselves to talking to predicting the long-term trend (with many caveats.)
Your position is analogous to a person who goes to an action movie after being told fifty people will be shot, and leaves after five minutes because no one has been shot yet.
You are ignoring the significant decline in snow my almost every other measure (spring and summer extent, average extent, duration of snow cover) and are focused like a laser beam on a non-significant trend. 1999 was the lowest winter snow extent in the 15 years from 1985-1999. You’re cherry-picking your start date. An RSQ function is not a test of statistical significance as far as I know (feel free to educate me). What’s the p-value for your supposed positive trend?
@Anthony: My institution gives us an email for shared personal and professional use. I am not commenting on my institution’s time, or using their facilities, or in consultation with them. To avoid confusion, I’ve switched to another e-mail account.
very interesting post.
i suppose it is only a matter of time until some one says ‘ ah yes – but snow is not climate’
slightly off topic but – does anyone know where i could get monthly rainfall levels for med. north africa area.
it appears to have been raining for most of this year in southern spain, portugal, algeria, morocco etc.
in view of the recent IPCC scandal of ‘50% decline in food production’ in this area due to projected AGW lack of rain, it would be of interest to see what is really happening.
Another great post Steve, although I believed you the first time around. 🙂
Your thread is all about proving that the GCM’s used by the IPCC were completely wrong, and this you achieved. I don’t think that statistics and trends are important. Just eye-balling the numbers shows that snow levels have returned to what we experienced 30-40years ago. This was not predicted by the GCM’s.
Bearing in mind that the much of the alarmist twaddle from the IPCC relies on model predictions, what you’ve done by falsifying their prediction is a significant nail in the CAGW coffin.
Oliver K. Manuel (08:23:26) :
“Decades of filth and abuse of science by the National Academy of Sciences and all the research agencies whose budgets require NAS review (NASA, DOE, NOAA, etc) are concealed beneath the climategate iceberg, so you can expect negative comments from those with a vested interest in the flow of federal reserch funds.
This is what happens when government and big business control the purse string. I’m afraid that this CAGW cancer has also spread to many other main-stream areas of science and currently little progress is being made. Science which has no useful predictive power is in need of new paradigms.
OT – don’t know if you so this recent NASA article about the discovery of Fe in the suns corona seen during several eclipse?
Another great post Steve, although I believed you the first time around. 🙂
Your thread is all about proving that the GCM’s used by the IPCC were completely wrong, and this you achieved. I don’t think that statistics and trends are important. Just eye-balling the numbers shows that snow levels have returned to what we experienced 30-40years ago. This was not predicted by the GCM’s.
Bearing in mind that the much of the alarmist twaddle from the IPCC relies on model predictions, what you’ve done by falsifying their prediction is a significant nail in the CAGW coffin.
http://www.nasa.gov/centers/goddard/news/topstory/2010/aas-eclipse.html
Oliver K. Manuel (08:23:26) :
“Decades of filth and abuse of science by the National Academy of Sciences and all the research agencies whose budgets require NAS review (NASA, DOE, NOAA, etc) are concealed beneath the climategate iceberg, so you can expect negative comments from those with a vested interest in the flow of federal reserch funds.
This is what happens when government and big business control the purse string. I’m afraid that this CAGW cancer has also spread to many other main-stream areas of science and currently little progress is being made. Science which has no useful predictive power is in need of new paradigms.
OT – don’t know if you so this recent NASA article about the discovery of Fe in the suns corona seen during several eclipse?
@Anthony: “REPLY: It’s not a strawman.
http://www.time.com/time/health/article/0,8599,1962294,00.html
http://www.washingtonpost.com/wp-dyn/content/article/2010/01/28/AR2010012800041.html
http://www.nytimes.com/2010/02/11/science/earth/11climate.html”
I’m afraid none of those links feature ““bloggers and journalists [that] insist that recent winter snows are proof of global warming effects.” They include many statements to the effect that winter is not climate, and several references to the idea that more intense storms may be more common in a warming world. Nobody said the recent winter storms were proof of global warming.
Still looks like a straw man to me.
REPLY: Still looks like you only see what you want to me. – A
Tamino agrees. Obviously there’s a censorship issue here as well. The horror! Pay no attention to that man behind the curtain. I am the wizard who doesn’t have a college degree.
“Ordinarily, with 22 data points you’d only need the t-value to exceed plus or minus 2.09 to reach 95% confidence. But when cherry-picking the strongest trend from any point to the end, for a set of 44 data points, the necessary t-value for 95% confidence is much larger, 3.75. Goddard’s value, 2.91, isn’t even close, it doesn’t even reach significance at 90% confidence.
Goddard’s trend is not statistically significant and his emphasis on the recent extreme snow cover is nothing more than a weather report.”
Mike Edwards,
The plot is for the Northern Hemisphere, not the USA.
http://wattsupwiththat.files.wordpress.com/2010/02/dec-feb_snow_ext.png
Robert,
If you want statistics, how about doing a correlation of GCM predictions vs. actual for the first decade of the 21st century? The only reason I did rsq() was because other people wanted it.
The graph is clearly in disagreement with the GCM forecasts. Some web sites love using statistics to obfuscate. I have zero respect for those people.
Should be “weather is not climate.” Although winter is not climate either, I suppose.
Robert,
The change is in the wrong direction. If snow extent change accelerates as you predict, then we will be in for another ice age.
Physics Major (08:45:16) :
So anyone who claims that increased snow extent is consistent with CO2 induced global warming is what? A liar maybe?
Keep in mind that in AGWSpeak, “consistent with” in this context means not utterly impossible. 25-Sigma events would probably be considered consistent with AGW models.
From accuweather.com: Jan 19th (today)
“A train of storms is on the tracks in the Pacific Ocean, and it appears people in California and the Southwest will be waiting a long time for the caboose to pass.
The onslaught will begin this weekend as two moderate storms roll ashore.
In a singular sense, the storms will not have the power and the outcome of the storms in January. However, enough rain will fall to lead to urban flooding problems, mudslides and perhaps a few washouts.
Enough snow is in store to again grace the Sierra and other ranges in the Southwest with heavy snow and fresh powder.”
The train is loaded, it’s on it’s way in. Anyone want to wager what will happen when that train passes the Rockies?