Guest post by Steven Goddard
Several people keep asking why am I focused on winter snow extent. This seems fairly obvious, but I will review here:
- Snow falls in the winter, in places where it is cold. Snow does not generally fall in the summer, because it is too warm.
- Winter snow extent is a good proxy for winter snowfall. Snow has to fall before it can cover the ground.
So what about summer snow cover? Summer snow cover declined significantly (from the 1970s ice age scare) during the 1980s, but minimums have not changed much since then. As you can see in the graph below, the overall annual trend since 1989 has been slightly upwards.
Data from Rutgers University Global Snow Lab
Note in the image above that there has been almost no change in the summer minimum snow extent since 1989, and that the winter maximums have increased significantly as seen below.
Summer snow cover is affected by many factors, but probably the most important one is soot, as Dr. Hansen has stated.
The effects of soot in changing the climate are more than most scientists acknowledge, two US researchers say. In the Proceedings of the National Academy of Sciences, they say reducing atmospheric soot levels could help to slow global warming relatively simply. They believe soot is twice as potent as carbon dioxide, a main greenhouse gas, in raising surface air temperatures. … The researchers are Dr James Hansen and Larissa Nazarenko, both of the Goddard Institute for Space Studies, part of the US space agency Nasa, and Columbia University Earth Institute.
http://news.bbc.co.uk/2/hi/science/nature/3333493.stm
The global warming debate has until now focused almost entirely on carbon dioxide and other greenhouse gas emissions, but scientists at the University of California – Irvine, suggest that a lesser-known problem – dirty snow – could explain the Arctic warming attributed to greenhouse gases….The effect is more conspicuous in Arctic areas, where Zender believes that more than 90 percent of the warming could be attributed to dirty snow.
http://www.scienceagogo.com/news/20070506202633data_trunc_sys.shtml
In summary, winter snowfall is increasing and currently at record levels, and summer snow extent is not changing much. Earlier changes in summer snow extent were likely due primarily to soot – not CO2.
Why Is Winter Snow Extent Interesting?
Several people keep asking why am I focused on winter snow extent. This seems fairly obvious, but I will review here:
1. Snow falls in the winter, in places where it is cold. Snow does not generally fall in the summer, because it is too warm.
2. Winter snow extent is a good proxy for winter snowfall. Snow has to fall before it can cover the ground.
So what about summer snow cover? Summer snow cover declined significantly (from the 1970s ice age scare) during the 1980s, but minimums have not changed much since then. As you can see in the graph below, the overall annual trend since 1989 has been slightly upwards.
Data from Rutgers University Global Snow Lab
Note in the image above that there has been almost no change in the summer minimum snow extent since 1989, and that the winter maximums have increased significantly as seen below.
Summer snow cover is affected by many factors, but probably the most important one is soot, as Dr. Hansen has stated.
The effects of soot in changing the climate are more than most scientists acknowledge, two US researchers say. In the Proceedings of the National Academy of Sciences, they say reducing atmospheric soot levels could help to slow global warming relatively simply. They believe soot is twice as potent as carbon dioxide, a main greenhouse gas, in raising surface air temperatures. … The researchers are Dr James Hansen and Larissa Nazarenko, both of the Goddard Institute for Space Studies, part of the US space agency Nasa, and Columbia University Earth Institute.
http://news.bbc.co.uk/2/hi/science/nature/3333493.stm
The global warming debate has until now focused almost entirely on carbon dioxide and other greenhouse gas emissions, but scientists at the University of California – Irvine, suggest that a lesser-known problem – dirty snow – could explain the Arctic warming attributed to greenhouse gases….The effect is more conspicuous in Arctic areas, where Zender believes that more than 90 percent of the warming could be attributed to dirty snow.
http://www.scienceagogo.com/news/20070506202633data_trunc_sys.shtml
In summary, winter snowfall is increasing and currently at record levels, and summer snow extent is not changing much. Earlier changes in summer snow extent were likely due primarily to soot – not CO2.
I’d also point out that with an ever growing percentage of thermometers at Airports (where snow is typically cleared away so that the airport can function) there is a bias in the temperature record due to this. While there may not be many take off / landing events during snow season, especially at smaller airports, the tarmac never leaves….
So “snow extent” tells you more about where snow has actually stuck to the ground (and implicitly how warm that ground is – the melt line of 32 F / 0 C) while the temperatures may just reflect the temperatures of a black asphalt patch in the sun on a clear day… with 2 feet of snow in the woods a few miles away…
Put more bluntly: If a fine dusting of soot can melt snow, just think what acres of tarmac in the sun can do to a thermometer…
Leif,
What equation are you using to calculate R^2 in your example? I have a feeling something is wrong, since the R^2 should be very similar in all three of those cases. A good illustration of what R^2 shows can be found here http://mathworld.wolfram.com/CorrelationCoefficient.html As R^2 -> 1, the points being fit lie closer and closer to the fit line.
It sounds to me like you’re just applying statistical measures with no understanding of their significance or purpose…
JonesII (12:28:07) :
…not to mention that Birkeland current in the Andromeda Nasa picture.
There is no Birkeland current visible in that picture. C.P.Snow was lamenting the schism between ‘the two cultures’. Other people have proposed that a ‘third culture’ exists http://www.edge.org/3rd_culture/
Your post and others of the same ilk show that there is a fourth culture out there of science illiterates. This is a dangerous situation in an age where we depend more and more on science and the scientific approach. This is a new Dark Age arising.
With snow it seems like you have two things at war. Snow does increase albedo tending to perpetuate cold conditions, but on the other hand it also insulates the ground preventing deep penetrating cold. I have to think these kinds of “warring” things tend to make climate an inherently unstable weatherlike kind of thing.
Being a farmer I really do think we could use a little global warming to guarantee our crops against fluky one or two hundred year frosts. A frost that might come about if you had an early winter hard freeze with no snow cover followed by a deep extensive snow. I can’t, for sure, say that this would translate into a June frost but it certainly would make it more difficult to get the crop planted in a timely fashion. By the way, there is still a good deal (maybe 5%) of corn standing unharvested in Northern Illinois due to last years cool summer, difficult fall harvest, and snowy winter conditions. That much corn unharvested is UNPRECEDENTED – not to coin a phrase.
John A (12:21:26) :
“I’m sorry Steve Goddard, but I think that the conclusion is largely cherry-picked from the time series and the trend is likely to be spurious. Yes 2010 appears to be a large extension of winter snowfall, but its one season.
As Leif points out, the low R2 of the points says that most of the apparent trend is scatter and not significant. …”
I think I have an alternate explanation. Some time ago I offered to co-integrate my lifetime data set series with my WOC (woman of choice). The WOC lifetime data set series has now been co-integrated with my own for 30 years. As a direct consequence of co-integration, several children (C) were formed. The C elements as stand alone were highly unstable from the start, but over time began forming unstable relationships with Others (O) of opposite polarity. These were also unstable for the most part with frequent discarding of one O in favour of another. Eventually however some of the CO relationships stabilized, producing an additional O with close bonds to both the C and the O. The unit as a whole is referred to as CO2. At time of writing, no CO3 has yet emerged.
I graphed Ti (total income) against Te (total expenses) to get Tr (total retained) and determined an inverse correlation with Tr to amount of C supported. The trend tailed off after CO stabilization, but with a HUGE downward inflection at WC (wedding ceremony). I conclude therefore, that Tr is inversely proportional to frequency of C, but that increases in CO2 instigate a major negative short term fluctuation with no long term trends following.
However, as to the current snowfall and cold weather, I must advise that my WOC recently requested an analysis regarding “dress” and “perception of fat”. My analysis was poorly presented, resulting in outright rejection and a pronounced cooling trend in the immediate vicinity. Until reading this post I had no idea the effects were so wide spread. I have ordered large quantities of S (sparklies) and F (flowers) and having oberved the cyclical nature of this particular type of cooling trend in the past, am predicting a warming trend in the coming weeks for the northern hemisphere at a minimum.
Matt (12:52:57) :
I have a feeling something is wrong, since the R^2 should be very similar in all three of those cases.
Certainly not. Try to do as I did. Generate y = sin(x) + a*x
and use your favorite formula to calculate R^2.
The one you cite will do fine:
A good illustration of what R^2 shows can be found here…
It sounds to me like you’re just applying statistical measures with no understanding of their significance or purpose…
Revisit this statement after you have completed the above assignment.
An important thing to note is that the US started installing scrubbers in coal plant smokestacks in the early 70’s, and 86 was around the time that China started expanding their energy infrastructure significantly, all coal plants with zero scrubbers…
Has anybody bothered to see what the published literature actually says about snowfall predictions?
I haven’t had time to get into this topic, but the one paper I have on hand is observational, not modeling. Changnon, Changnon and Karl, 2006.
They observed maybe an *increase* in snowstorms vs time in the US, over the entire last century, but the data is really really noisy.
Broken down by region, it’s even noisier.
This backs up what Leif is insisting on, when looking for the strength of the correlation. Snowfall data is very noisy, and you can fool yourself into seeing a trend where there’s just noise.
In that context, I’m not sure if anything would surprise me, out of a single winter. Snowfall is truly weather.
Tom_R (09:12:23) :
Hmm, as I write this I realize that the photon changes direction, but doesn’t lose energy since the wavelength doesn’t change. How is energy conserved when the air molecule gains kinetic energy but the photon energy remains the same?>
My recollection is that a photon has no mass so can’t transfer any kinetic energy?
Wouldn’t that R^2 only be meaningful if you had a long enough time series to cover several complete cycles?
The Rutgers snow extent data only goes back to 1966. If the climate follows a ~60-yr cycle tied to the PDO and/or ENSO, 1966-2009 wouldn’t even cover one full cycle. Wouldn’t a linear or secular trend derived from such a short time series be spurious?
If I draw a linear trend-line through less than one full cycle of a sin wave with no underlying secular trend, I get an R^2 of 0.88…
Sin Wave 1906-1913
U know what i am afraid of?
That they will push full throtle on the weather machine HAARP and give us hellish high temps in the summer of 2010 on some big locations..
They use the olympics too for convincing us that global warming is real.. If the olympics cant continue then there must be global warming!!
Or is mother Earth more powerfull? Which i hope..
So the logic is that with a slight larger area covered in the summer and more so in the winter is due to soot for the summer cover, but only for the summer cover and only back in the day when the summer cover wasn’t as wide as today.
Come again?
There is a total media blackout on the snowfall in America in the Netherlands.
They mentioned it 2 or 3 times in the news and then went on to the order of the new world..
War, theft, murder, lies and cheating.. Thats all we ever get to see on the television.. Since i started to see through the lies of commercials and stuff, i seem to want to wake more people up.. Show them that the global warming scare is one big conspiracy and helps only 2 goals.. Estabecialing a NWO government and filling in the gap between truth and fiction! Truth: CO2 is not dangerous and needed, fiction: CO2 is a polution and very bad for our planet..
But u know what the answer is of most people i speak to?
I cannot change anyting about it, it doesnt help me if i know, so i just sit here and do nothing.. 🙁
They wanna help the planet, but not by believing in “conspiracies”.. The movies told them so…
Steve Goddard (08:42:01) :
“We have been told over and over again since Hansen spoke to Congress in 1989, that winter snow is declining”
Please provide a link to this statement or publication from Hansen. I’m not familiar with it.
Leif: “This is a new Dark Age arising”
Do you mean the one where most people no longer trust scientists because “Climate Scientists” are no more trustworthy than MSM “Journalists”.
Who caused that? Which profession kept their mouths shut? Who were too afraid to speak out because they kept getting called deniers?
Peer Review is now just another code word for either:
1) Cronies slapping you on the back
or
2) Enemies delibererately shutting out anyone threatening their flow of cash.
HankHenry;
Snow does increase albedo tending to perpetuate cold conditions, but on the other hand it also insulates the ground preventing deep penetrating cold>
Grew up on the farm Hank and your comment gave me an aha! moment. I remember all those years that there wasn’t much snow and so it melted pretty quick and everyone got hopefull for an early planting season. But then it seemed that spring just couldn’t quite get started and winter would just hang on by its finger nails for the longest time. I’m thinking your post is why, but it would be interesting to see if memory is playing tricks on me and compare snow extent to full seeding to see if the correlation is real.
Robert (09:24:32) : But that corrctive action continues to be drastically reducing burning carbon compounds for energy.
Ah, the smell of agenda driven conclusions….
How about we just put soot trap oxidizers on the billions of dollars of power plants and vehicles we use? Fast, fairly easy, and much much cheaper… You know, like we’ve already done for Diesels in the USA and Europe?
So the more accurate conclusion would be:
Have the 3rd worlders stop burning down the rain forests, and bring them to modernity so they can use natural gas to cook instead of trees (see the travesty in Madagascar and the denuded landscape in Haiti as examples of doing it wrong. See “Gobar Gas” in India as an example of how to do it right.)
Get the “newly developing economies” to put trap oxidizers and precipitators on factory smokestacks instead of running wide open.
Problem solved. Everyone living happier, healthier, and more PRODUCTIVE lives with wealth creation and modernity.
The alternative path (energy starvation) ends in economic collapse and subsistence living. That ( again, see Haiti and Madagascar – and Sudan and… ) leads to a denuded landscape as the forests are pillaged and burned to survive.
The USA has MORE forest / woodlands cover now than a generation or two ago, not less. We don’t need to burn trees any more and we produce more food than we can eat (and sell) on the farm land we do have, so more has been allowed to revert to scrub and forest. The direct result of using fossil fuels instead of biomass as done in traditional economies.
So before you run off to cause a global economic collapse, throw away a few $Trillion of total capital stock, condemn a few Billion people to death and starvation (NOT an overstatement. Shut down the tractors and trucks and see what happens…) and generally force everyone who survives to take an axe to the nearest trees to stay warm and cook: Think about the lowly ‘trap oxidizer’, the electrostatic precipitator, and the natural gas stove… “KISS” principle, please.
Steve Goddard
You really stirred up a few folks.
When I get back from Colorado in September, I’ll be sure to let you know if my 20 plus years of observation of the snow-pack Around Monarch Pass fits with your increasing snow in NH in the winter. I really hope you are right.
What a great site. I’m sure everybody agrees except maybe Tom P.
If I said that it has warmed up since 6 AM, some people would complain that I am cherry picking. “Why didn’t I start my measurements at 3 PM yesterday?”
Winter snow extent (like everything in the climate) is cyclical. Prior to 1989 it was going down, and since 1989 it has been going up. It makes no sense to apply linear statistical techniques starting at a date on the other leg of the cycle. If snow extent was actually linear with time, we would either have no snow or complete snow cover of the entire planet. Obviously neither of those is the case.
The trend for the last twenty years is obvious. Don’t get confused by charlatans.
http://wattsupwiththat.files.wordpress.com/2010/02/dec-feb_snow_ext.png
Dr. Tim Ball was interviewed on the Tom Sullivan Show yesterday (16 Feb 2010) in regard to Tim’s views on global warming/climate change.
Dr. Ball proposed the anology of the red noise of an individual in a large stadium and the roar (white noise) heard outside the stadium with the IPCC’s conclusion that the individual (CO2) red noise is responsible for the white noise (global warming/climate change).
————————————————————-
Sunspots and Cosmic Radiation
Governments Plan for Warming Based On Corrupt IPCC Science
By Dr. Tim Ball Thursday, February 18, 2010
http://canadafreepress.com/index.php/article/20150
Do Nothing Than The Wrong Thing
The IPCC was deliberately focused on establishing human causes of climate change so it failed to consider major natural causes. Chief among these were changes in the Sun. It was also deliberately directed to proving CO2 and especially human CO2 was the cause of warming and climate change. This became the basis of all government’s energy and environmental policies, which assume warming is the only possibility. A real scientific investigation would establish natural climate variability and mechanisms first, which is further proof of the political exploitation of the issue. It is better to do nothing than do the wrong thing for the wrong reason.
Someone here suggested that they won’t trust a trend that is less than 200 years.
If snow extent increased at the current 10 year rate of 200km2/year for 200 years, that would cover all of the currently bare ares Asia, Europe and North America. i.e, an ice age.
Climate is cyclical – over the last two hundred years, snow cover has gone through many phases where it has increased and many where it has shrunk. People who insist on doing a a linear fit or linear analysis across different legs of a cycle, are just not thinking clearly.
Steve Goddard;
The trend for the last twenty years is obvious. Don’t get confused by charlatans.>
I’m a confirmed skeptic Steve, and I don’t dispute your data for a moment. That said, there is about 10 years of data on AMSU-A. Now 20 years is not enough data for a measure of climate, so the last 10 is even worse…. But, that data still shows a slight upward temperature trend over the last 10 years at sea surface, near surface, and lower atmosphere while snow extent is also rising. How do you reconcile these?
@ur momisugly Fred H. Haynie (12:19:57) :
‘Snow is not a perfect reflector. In fact, because of it’s structure, fresh snow acts as a black body. The high energy shortwave radiation from the sun rapidly melts the surface which freezes to form an ice crust that is more of a reflector. But even ice is transparent like glass and the fraction of the energy reflected back to space depends on the angle of incidence. It does radiate low energy longwaves as a function of surface temperature. Much of the outbound longwave radiation from the top of the atmosphere measured by satalites is frozen cloud tops.’
So there should be two factors working against the equator-ward extension of snow cover: the increasing effective radiation intensity (as the angle of incidence of the incoming radiation becomes progressively normal to the ground surface), and the increasing absorbtion of that radiation by the fallen snow/ice crust (as reflection decreases with increasing the angle of incidence). Though it will be more complex than this of course, due to atmospheric scattering of the incoming radiation.
Steven Goddard:
I think your article was great. Maybe a needed a tidbit deeper analysis and style according to some. Here’s a statistical curiosity.
Using your weekly global data, just analyze the period from first week of 1989 forward. The linear trend is basically flat. Assuming y is in sq.km, the upward slope is a positive 39 sq.km per week over that 21 year period. It is then factual that no decrease has occurred since 1988 and all of the decrease in snowfall occurred prior to 1989. During 1967 to 1988 the decrease was a negative 620 sq.km per week over that period. Wow.
That’s new news to me anyway, that the decrease in snowfall many tout and tie to AGW stopped long, long ago and has been a falsehood for two decades now.
(If you want good R^2 for some, annualize the data first. You get the same trend line, but many magnitudes of better R^2. However, I won’t go there, R^2 is meaningless in this context unless the data was supposed to be a dead straight line and you want to guage how close the data is to being linear in fact, then it could have meaning.)