Guest Post by Willis Eschenbach
I got to thinking about snow the other day. It was occasioned by my look at the correlation (both positive and negative) of temperature and albedo. Albedo is a measure of how much sunlight is reflected from the clouds and the surface. The greater the albedo, the more sunlight is reflected. Here’s the graph that set me pondering:
Figure 1. Correlation between surface temperature and albedo. Negative correlation (blue and green) means the albedo goes down (less reflected sunlight) as the surface warms. Positive correlation (red and orange) means the albedo goes up (more reflection) as the surface warms. Gray line shows zero value.
In the red and orange areas, which are mainly in the tropics, the albedo goes up as temperatures rise. This is generally because clouds form as temperatures rise, reflecting more sunlight and cooling the earth. In the blue and green areas, on the other hand, the albedo goes down as temperatures rise. Over the extratropical land, much of this change is from snow and ice. As the land warms, snow melts and the albedo goes down. And as the land cools, snow falls and the albedo goes up. This is a positive feedback, with warming leading to increased solar energy, and cooling leading to less solar energy.
One thing that is highlighted by this map is that the positive feedback from the changes in sea ice are much smaller than the feedback from the changes in snow and ice on land, for several reasons.
The first one is the small area of the sea ice variations. Note that the feedback is only in the areas that are seasonally uncovered and covered by sea ice—permanently ice-covered areas don’t have much albedo change. Net annual variation in Arctic sea ice is about ± 5 million square kilometres. This is only about 1% of the area of the globe.
Another reason the changes on land are larger is that when snow melts, it exposes soil and plants, both of which have low albedos. But when sea ice melts, it reveals ocean … and the albedo of the ocean at low sun angles is already pretty high. As a result, the melting of the ice doesn’t change the albedo as much as the melting of the snow.
Another reason the land varies more is that snow extends much closer to the equator than sea ice. As a result, the sun rises much higher over snow than sea ice, and thus the snow intercepts more sunlight than the same area of ice up near the poles.
Another reason is that as you can see from Figure 1, the negative correlation of the albedo and temperature is greater over northern lands than northern oceans.
All of this has made the snow-covered areas of the northern hemisphere the main suspects in the onset of the ice ages. The generally accepted theory is that the so-called “Milankovitch” variations in the earth’s orbit change the amount of sunshine hitting the northern hemisphere. When the northern hemisphere summer sunshine gets weak enough, the snow on the northern land doesn’t melt back as far. This residual snow reflects more sunlight, which leads to cooler temperatures, which leads to more snow, which leads to more reflected energy … I’m sure you can see the end of this story, glaciers a mile thick covering Chicago.
Now, people seem to have a strange need to believe in some kind of existential threat hanging over our heads. There appears to be a desire to worry about something, as long as it is dire and a couple of decades away. In the past we’ve filled this need by worrying about the “population bomb”, or the “ecological footprint”, or the dreaded arrival of “peak oil”. Nowadays, it seems like “global warming” is taking over the role of the scourge du jour.
Me, I prefer to only concern myself with real possibilities of real harm. We’ve seen a couple of degrees warming since the Little Ice Age, and overall the effects have been beneficial to humans, plants and animals. I have no concern about the fabled Thermageddon of a couple degrees more warming—the effects are not grave, will likely be beneficial, and I have strong doubts that it will happen this century.
Another ice age, on the other hand, seems to be both inevitable and very destructive. And to raise the stakes, near as scientists can tell the next ice age either due or overdue … this is already the longest of the “interglacials”, the historical periods in between the ice ages.
So I would suggest that we keep a fairly close watch on the snow cover of the northern hemisphere. Because when the apparently inevitable ice age comes ’round again, it seems to me that the first sign will be an increase in the snow cover in North America and Eurasia.
Fortunately, the good folks at Rutgers University have a dataset showing the weekly area of the extent of the snow in the northern hemisphere that goes back forty years or so. Here’s that data:
Figure 2. Rutgers University snow extent data. Note the missing data prior to 1972. Data Source: Rutgers Snow Extent Data
So … how is the extent of the snow trending over time? Well, if we look at the complete data, which extends from 1972 to present, here’s how that breaks down:
Figure 3. Decomposition of Rutgers snow extent data. Top row is observations. Second row shows the trend in the 52-week mean. Third row is the regular seasonal variations. Bottom row is the residual variation once the seasonal and overall trends are removed. Note the different scales on all four rows.
The second row in Figure 3, entitled “trend”, shows the changes in the mean value over time. The snow area generally dropped during the first half of the record. Subsequently, it first rose and then remained level in the second half. So the good news is that we don’t appear to be started into an ice age. The other good news is that we also don’t seem to be headed for a time when our children won’t recognize snow … overall, like most climate records, not a whole lot going on. However, that is unlikely to last forever.
Finally, some speculation. I have long held that the main two ways that we affect local climate are through land use, and also via airborne soot (or “black carbon”) and “brown carbon”. Brown carbon is the airborne carbon from inefficient combustion of wood, coal and other fuels. In addition to coming from forest fires, brown carbon mainly comes from billions of cheap stoves and open cooking and heating fires in the developing world. Because of the prevailing winds, a goodly amount of the soot and brown carbon produced in the northern hemisphere falls on the northern snow and ice. And because the carbon compounds are dark in color, they are warmed by the sun. This leads to a more rapid melting of the snow. It has been suggested that this is the reason for the retreat of the European glaciers since the 1800s.
Now, humans have been dumping large quantities of soot into the atmosphere for quite some time now, ever since we managed to tame fire. And presumably, for all that time that soot has helped to melt the northern hemisphere snows and glaciers, so they didn’t start lingering further and further into summer. So … would it not be truly ironic if pollution, in the form of soot and brown carbon, were all that has been holding off another ice age? And wouldn’t it be a cosmic joke if our efforts to clean up soot and brown carbon pollution were the straw that broke the back of the Holocene, and ushered in the new ice age?
Do I think that’s the case, that soot is all that is keeping the next ice age at bay? Y’know … I truly don’t have a clue whether that’s true or not. That’s one beauty of climate science, that there are so many mysteries.
I’m just saying, I’m keeping an eye on the snow extent …
w.
DATA AND CODE:
I’ve posted up a .csv file containing the Rutgers data here, and the R code to read it is here.
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Poptech says:
October 18, 2013 at 7:01 pm
Phase 3 initiated.
Anthony, considering how far across the line he went last time, if this post from Poptech isn’t enough to earn a permanent ban, what will it take?
milodonharlani says:
October 19, 2013 at 9:44 am
The oldest Greenland Ice Sheet core found dates to ~150 Ka, during the glaciation preceding the Eemian interglacial:
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Now I am not a big fan of Ice Core proxies, especially those extracted from the Greenland glaciers. And my reason for saying so is that I personally believe that both the “age” of the ice core layers and the calculated atmospheric CO2 ppm quantities based on the quantity of CO2 entrapped within said ice layers …. are both highly questionable to say the least.
Now in reference to “dating glacial ice cores” I submit thee following:
Post-glacial sea level rise
The last glacial maximum was like 22,000 years BP (before present). Global temperatures started rising at around 21,000 years BP and the glacial ice began to melt ….. but then global temperatures began to surge at around 19,000 BP which caused an increase in melting of the ice. And then at 15,000 BP the temperatures must have surged again and the melting really exacerbated and continued until around 8,000 years BP which resulted in the current ocean levels which are 130 meters or 450 feet higher than they were during said glacial maximum.
Reference graph – sea level proxies: http://schools-wikipedia.org/images/439/43917.png
—————–
Given the above said we have to assume that near-surface air temperatures were extremely warm and rising up until 8,000 years BP.
And just how warm were those near-surface air temperatures post-8,000 years BP?
To answer that question we have to acknowledge the finding of the following peer reviewed study, to wit:
Holocene Treeline History and Climate Change Across Northern Eurasia
Radiocarbon-dated macrofossils are used to document Holocene treeline history across northern Russia (including Siberia). Boreal forest development in this region commenced by 10,000 yr B.P. Over most of Russia, forest advanced to or near the current arctic coastline between 9000 and 7000 yr B.P. and retreated to its present position by between 4000 and 3000 yr B.P. Forest establishment and retreat was roughly synchronous across most of northern Russia.
During the period of maximum forest extension, the mean July temperatures along the northern coastline of Russia may have been 2.5° to 7.0°C warmer than modern. The development of forest and expansion of treeline likely reflects a number of complimentary environmental conditions, including heightened summer insolation, the demise of Eurasian ice sheets, reduced sea-ice cover, greater continentality with eustatically lower sea level, and extreme Arctic penetration of warm North Atlantic waters. The late Holocene retreat of Eurasian treeline coincides with declining summer insolation, cooling arctic waters, and neoglaciation.
Exerted from: http://www.sciencedirect.com/science/article/pii/S0033589499921233
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Now the above study confirms those extremely warm temperatures post-8,000 years BP. It also confirms said temperatures remained extremely warm for like +-4,000 years between the stated 9,000 BP and 3,000 BP time frame …… otherwise the growth of those forests would never have “advanced to or near the current arctic coastline”.
And if those extremely warm temperatures (2.5° to 7.0°C warmer than modern) across all of northern Russia and the Arctic Ocean persisted for like +-4,000 years then surely those past accumulations of “yearly” surface layers of ice on the glaciers on Greenland were melting …. like they were going out of style.
Reference map: http://www.worldpress.org/images/maps/world_600w.jpg
So the BIG question is, …. how many “yearly” surface layers of ice “melted away” during said +-4,000 years? Are they not now claiming that the Greenland glaciers are melting and it has only been moderately warm in comparison for the past 100 years?
Samuel C Cogar says:
October 20, 2013 at 1:31 pm
Good questions. It also appears that up to a third of the GIS might have melted during the Eemian, which was even warmer & lasted longer than the Holocene. What effect this mass loss might have had at the high elevations & latitudes of the core samples, I don’t know.
However, there likely would have been less melting atop the GIS domes than near sea level farther south, as along the Siberian tree line. Whether there are whole years missing from the core record during the Holocene Climatic Optimum, I also don’t know, but suspect not.
IMO it’s clear that Earth has been in a long-term cooling trend for over 3000 years. And that there were probably thousands of summers during the Optimum in which the Arctic Ocean was effectively sea ice free.
Sorry, I meant ANDREW KHAN is Poptech, blog author of Popular Technology. Did I spell your name right this time?
Poptech, if you were so smart you would not keep repeating that your name is NOT ANDREW KHAN. You would remain silent and let others think that it is. Stay calm and think hard for once Andy.
Samuel C Cogar quotes:
“During the period of maximum forest extension, the mean July temperatures along the northern coastline of Russia may have been 2.5° to 7.0°C warmer than modern. The development of forest and expansion of treeline likely reflects a number of complimentary environmental conditions, including heightened summer insolation, the demise of Eurasian ice sheets, reduced sea-ice cover, greater continentality with eustatically lower sea level, and extreme Arctic penetration of warm North Atlantic waters.”
Reduced sea-ice cover and extreme Arctic penetration of warm North Atlantic waters takes negative Arctic and North Atlantic Oscillation conditions, the opposite of what would happen in the warmest periods.
Poptech says:
October 19, 2013 at 7:15 pm
Jimbo, my name is not Andres Khan despite your ignorance of all things Internet related. I am only electronically dangerous to people wish me to be banned.
================
Don’t want to see you banned.
You enliven the discussion.
I mean it is a discussion, within this blogs policies.
There are other blogs where you can say anything you want.
After my last “on the spur of the moment’s” comment on October 18, 2013 at 6:26 pm, I have done some internet searching as I am quite certain that there is a very good reason as to why “more snow is falling and staying longer into the summertime, on a regular enough basis to bring on an “Ice Age”, that is – and so I asked my ‘search engine’: “ Is the Earth’s axial tilt increasing or is it decreasing?
Many clever answers were returned and I could only deduce that our planet is getting to be “more upright” and that the seasons will therefore change. – O K, so it is a very slow process but it must mean that during every summer (N&S), both Poles are pointing a little bit “less directly” at the Sun and therefore both Hemispheres may gradually cool. One question of course is: “Will the more upright tilt mean correspondingly warmer winters”? – Well, I doubt it will make up for the ‘Summer Chill’, also if “The Holocene Maximum” was 1 – 1.5 ºC warmer than it is at the present, or ‘half a degree of tilt ago’, then another 1.5 degrees of pointing away from the Sun, should mean a further cooling of, say 4.5 ºC, as a minimum. Which would gradually, during the next few thousand years, bring this planet back into, an other glaciation. – Oh and if we add in a bad Solar Minimum or two, i.e. the Little Ice Age (LIA) or the Roman Cold Period (RCP), or anything else you guys can think of, it may come a lot sooner than I think.
P.S.
Under: Axial tilt – Wikipedia, the free encyclopedia I read: “The Earth’s axial tilt is decreasing, but the change is very slow. The amount is 0.47 arcseconds per year. This means that the Tropic of Cancer and the Tropic of Capricorn are both moving towards the equator at the rate of about 15 metres per year, so you can see it’s not very much. The tilt varies over the range 22.1º to 24.5º over a period of 41,000 years.
http://en.wikipedia.org/wiki/Axial_tilt
On it’s own, change of axial tilt might not cause much climate change. But combined with the variation in the eccentricity of the Earth’s orbit and precession of the Earth’s axis, there is some correlation between the periods of these cycles and past climate change. See Milankovitch Cycles: http://en.wikipedia.org/wiki/Milankovitc…
At the end of reading that entire page, I also read a postscript: “This page was last modified on 17 October 2013 at 01:43.”
So, somebody is keeping ‘an eye on it’
In any case if the Earth began to come out of one of its many “Glaciations” some 20 – 15 thousand years ago when the ‘axial tilt’ was at it’s maximum, say 24º, then it seems reasonable to me that the beginning of the Holocene, or of any other ‘long lasting warm period, would be warmer than it becomes some 10 – 15 thousand years later – and they all do (the last 5 major interglacial periods) – or have done, as far as I can see.
And, – 150.000 years from now – our descendants will look at, and compare, the by then, new Greenland- and the Antarctic Ice-Core-Graphs and say: “This can’t be right, the ancient scriptures say – – – – – -.”
Jimbo, you never answered the question… how does it feel to be my puppet? I think I am going to create a list puppets like you that I now control.
[Reply: Stop it! — mod.]
It is only funny if you don’t know how to use Google and forget to use quotes.
[Reply: Stop it! — mod.] – please see Jimbo’s posts October 20, 2013 at 3:18 pm + 3:23 pm.
[Reply: OK then, both of you, Stop It! — mod.]
Once last thing, so there is no confusion, Willis’s peer-reviewed papers are still on my list and will never be removed unless they get retracted. Any new peer-reviewed papers of his will be added in future updates.
http://www.populartechnology.net/2009/10/peer-reviewed-papers-supporting.html
E.M.Smith (The Chiefio) also thinks we may be overdue for a severe bout of cooling. See http://chiefio.wordpress.com/2012/12/29/annoying-lead-time-graph/
Spectacularly OT – but most important nonetheless (at least, that’s what it is for me…):
Thanks a million times for your good advise on efficient [breathing], Willis.
At first I was a sceptical, when I read what you were proposing the other day, umm: Thread. But then I gave it a try, just out of curiosity – and experienced a truly SPECTACULR success.
i am a big, heavy guy – I am six feet, two inches tall, and my weight exceeds 300 ponds easily – but I am not only fat. In my younger years, I did lots of competitive Judo and weight-lifting, but failed to train down properly after I had to stop my sporting activities. So yes, under the fat there’s still lots of muscles which are greedy for oxygen,whenever I start to move.
Now in my early Fifties, I was quite short on breath already, as soon as I started walking fast or, God forbid, running. But owing to you advise to EXHALE properly, instead of concentrating on breathing IN as much as I can, I have almost DOUBLED the distance I can walk/run/climb stairs until I finally run out of breath INSTANTLY.
This, in turn, means, that walking/running/climbing stairs for me finally is FUN again, and will help reduce my weight to sensible levels, now that i know how to breathe to not run out of breath the next moment, whenever I start moving.
Thanks again, Willis. Your advise helped improve my life 100 percent!
But why don’t they teach stuff like this at school…?
Ulric Lyons says:
October 20, 2013 at 3:37 pm
Reduced sea-ice cover and extreme Arctic penetration of warm North Atlantic waters takes negative Arctic and North Atlantic Oscillation conditions, the opposite of what would happen in the warmest periods.
————————————
Ulric, I was not learned in/on what said A&NA Oscallations were …. so I had to “read up” on said ……. and what I found is contrary to what you stated above, to wit:
————
Global Patterns – Arctic & North Atlantic Oscillations (AO & NAO)
The Arctic Oscillation (AO) is a climate index of the state of the atmospheric circulation over the Arctic. It consists of a positive phase, featuring below average geopotential heights , which are also referred to as negative geopotential height anomalies , and a negative phase in which the opposite is true.
In the negative phase, the polar low pressure system (also known as the polar vortex) over the Arctic is weaker, which results in weaker upper level winds (the westerlies). The result of the weaker westerlies is that cold, Arctic air is able to push farther south into the U.S., while the storm track also remains farther south.
The opposite is true when the AO is positive: the polar circulation is stronger which forces cold air and storms to remain farther north. The Arctic Oscillation often shares phase with the North Atlantic Oscillation (NAO) (discussed below), and its phases directly correlate with the phases of the NAO concerning implications on weather across the U.S
http://www.nc-climate.ncsu.edu/climate/patterns/NAO.html
In reference to what …………
O H Dahlsveen says:
October 20, 2013 at 6:51 pm
The following was exerted from: http://en.wikipedia.org/wiki/Tropic_of_Cancer
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Tropic of Cancer
The Tropic of Cancer currently (Epoch 2012) lies 23° 26′ 16″ [2] north of the Equator. Its position is not fixed, but varies in a complicated manner over time. It is presently drifting south at the rate of almost half a second (0.47″) of latitude per year (it was at exactly 23° 27′ in year 1917).
Carretera 83 (Vía Corta) Zaragoza-Victoria, Km 27+800. In all crossings of the Tropic of Cancer with Mexican federal highways, this is the only place where the latitude is marked with absolute precision and where the annual drift between 2005 and 2010 can be appreciated.
————————
Click link below to see photo of that “yearly drift” southward.
http://en.wikipedia.org/wiki/File:Tr%C3%B3pico_de_C%C3%A1ncer_en_M%C3%A9xico_-_Carretera_83_(V%C3%ADa_Corta)_Zaragoza-Victoria,_Km_27%2B800.jpg
@Samuel C Cogar
With negative AO/NAO conditions there are increased surface winds in the Arctic causing ice beak up and drift. And of course with a weaker vortex and incursions of Arctic air southwards, warmer air from the mid latitudes exchanges with it into the arctic. Nothing you quoted is contrary to what I said, though it is incomplete. And it is estimated that ~60% of increased sea ice loss is due “extreme Arctic penetration of warm North Atlantic waters”, that occurs consistently with negative Arctic and North Atlantic Oscillation conditions.
“So … would it not be truly ironic if pollution, in the form of soot and brown carbon, were all that has been holding off another ice age?”
http://climal.com/previous-story-1.php
mogamboguru says:
October 21, 2013 at 6:41 am
Many thanks, mogamboguru. I put it out there and said it wouldn’t help some people, but others might just get the amazing benefits I got from it … and I’ve taken some stick out there on the intarwebs for doing so, people claiming I was out of line, or that I was doing it for some egotistical reason.
But I did it for a simple reason—I’d gotten huge benefit from it, and I thought others might as well.
So thank you kindly for letting me know that it has worked for you. I don’t know of anything I have to give away that’s more valuable than that, I’m stoked that you’ve gotten so much out of it.
Regards,
w.
Willis Eschenbach says: October 19, 2013 at 10:02 pm
I do not know why Poptech has taken such bitterness and enmity upon himself towards me. I’m sorry to see it, and if it is for some slight or humiliation that I’ve put upon him, he has my apologies…………………………….So I’m not opposed to Poptech agitating to correct what he sees as mis-statements. I don’t see them as that, but I’m not concerned about his doing it, I don’t see it as a problem. A google search on “willis eschenbach” brings up a quarter million pages, so it is going to be a long task.
__________________
I’m a nobody on this blog but I read here every day and occasionally post. I very much appreciate Willis and the WUWT community.
I’m not sure what the reasonings are for not banning Poptech. My inclination is to trust the judgment of WUWT…..frankly I wonder if Poptech’s threats have something to do with this. I bet I’m not alone in wondering if WUWT is intimidated by Poptech’s threats.
I freely assert that Poptech has a horrible, reprehensible reputation on the web. He’s revealed himself here to be a threatening stalker. His rep is worse……… EVERYWHERE. Google him and you will very quickly learn who and what he is as if his antics and threats here have not already convinced you. IMO he’s bad for skeptics and really no better than slayers or Dr. Mann. It’s past time to police our own and shun Poptech. Poptech has been banned and shunned all over the web…..It’s time to kick him to the curb here IMO unless or until he apologizes to Willis and the WUWT community.
[trimmed. Mod]
@ur momisugly Ulric Lyons
You sure confused me with this statement of …. “there are increased surface winds in the Arctic ……[snip]…… and incursions of Arctic air southwards, warmer air from the mid latitudes exchanges with it into the arctic.”
That sounds like you got the surface air going both directions at the same time.
Ulric, all I can say is, …. click this link and read the abstract yourself, to wit:
http://www.sciencedirect.com/science/article/pii/S0033589499921233
Samuel C Cogar says:
“That sounds like you got the surface air going both directions at the same time.”
Precisely, exchange of Arctic and Temperate air occurs with weak polar vortex conditions.
OK, thanks to the explanation at this link, to wit:
http://www.aer.com/science-research/climate-weather/climate-dynamics/polar-vortex-impact-winter-weather
I now understand what you are saying.
And I think it also explains an event that bedazzled me when it occurred some 40 years ago.
At the time I was living in upstate NY on top of a hill overlooking the City of Utica. I had a wood burning cook stove in the kitchen, against the wall, on the North end on the house which was used for both cooking and keeping that end of the house warm. In the winter time I would wake up at 1 or 2 am and stoke the fire up to keep it going.
One morning when it was like -10 F degrees outside I was doing my chore and just when that added firewood started burning good ….. “WHOOOOOSH”, ….. smoke started pouring out of every crack, crevice and opening in that stove and quickly filled up the kitchen area. I shut the air input and flue pipe dampers off but that that didn’t help much. Anyway, I was forced to open the door to the outside to get rid of the smoke knowing full well that at -10 F and a fairly strong wind blowing that it would “kick” my oil-fired furnace into high-gear to warm the house back up.
But, “WOW”, when I stepped outside to get a breath of fresh air is was like 45 F degrees and that strong wind was coming directly out of the South and across the top of my house. Now that explained the “down pressure” causing my stove to smoke like a heavy hauling coal fired RR locomotive going upgrade ……. but I never ever bothered to figure out what caused that Warm Front to push directly North.
Now I think I know.
Cheers, Sam C