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A Swift Kick in the Ice

Posted on 19 February 2011 by Rob Honeycutt

Commenting in the trenches of the climate change blogosphere I find a large number of people who lack very basic understanding about Arctic Ice.  While I'm not an expert in the field I have managed to learn a few things with regards to why Arctic ice is an important issue.  There are a few misconceptions that require a "swift kick in the ice."

When learning about these issues myself I came upon a question that I could not immediately answer.  We know that water vapor is a strong greenhouse gas.  We know that warmer air holds more moisture than cold air, in fact, to the point where the Antarctic is one of the driest deserts on the planet.  So, how does this jibe with the idea of polar amplification, the idea that the poles will warm faster than the rest of the planet on average?  The climate models tell us that the poles will warm faster, and the model results are proving true now. Why would the poles warm faster if there is so little water vapor in the air?

Fig 1  -  Surface Temperature Map for Jan 2011 (Source: GISS)

The first answer comes by way of looking at a surface temperature map (Fig 1).  What we find is that the north and south poles are not warming equally.  In fact, the term "polar amplification" is better described by saying "Arctic amplification."  If we look out to the end of the century there is anticipated to be amplification in the south as well but most of the warming will take place in the north.

But that still leaves us with, why?  The Arctic gets cold too, therefore is drier than the equator.  Why would the equator not warm faster?  

Fig 2  -  Orbital tilt through the year

Pretty much everyone knows that these basic very important facts about the north pole:

  1. The ice at the pole is covering the Arctic ocean.  It's sea ice.
  2. Both poles are mostly dark half the year and mostly light half the year.

These two very basic aspects of the Arctic make it special in terms of climate change form the reason why Arctic Amplification is happens and is so important.

Each year the ice of the Arctic thaws back to a minimum extent during the late summer, usually some time in September.  Then it freezes back each winter.  This is obviously because summer months are warmer and winter months are colder.  

The Battle of Albedo

Now I'll beat you up with the concept of "albedo."  Albedo is the effect where light colored surfaces reflect light and dark colored surfaces absorb light. Think of it as white pavement or black pavement.  Black pavement is always going to scorch your bare feet more than white pavement in the noontime sun.  Dark surfaces absorb more heat from the sun.  Light surfaces reflect more light away and absorb less heat.  

Fig 3  -  Albedo effects (source: wikipedia)

As you can see from Figure 3, the albedo of fresh snow is dramatically different from water - it's much more reflective.

In the winter the Arctic sea is almost completely frozen over but this doesn't matter a lot because there is little sun shine for half the winter and even no sun shine at all for several months of the year.  There is no albedo effect at all during this part of the year.

In the summer months, though, the story is the opposite.  If the Arctic Sea is covered with ice in the summer - as it has been dating back perhaps thousands, to millions of years - the incoming sunlight is mostly reflected back to space without adding any heat to the Earth.  But, as ice melts back, as is happening today, the summer sun is absorbed by the darker open sea exposed by the disappearing ice.  

The open water absorbs more and more heat during the extended daylight of the summer months until winter comes again, when the Arctic Sea freezes.  But because of warming the ice is also losing its capacity to freeze back to previous levels.  This is what is meant by a feedback.  Less ice makes warmer water, which makes thinner ice, which melts easier, which makes warmer water… and so on.

 Fig 4  -  2007 Summer sea ice minimum (source: NSIDC)

This also points out why the sea ice in the Antarctic is less important and generates less warming.  The Antarctic is a land mass 1.5 times the size of the United States.  Each winter sea ice develops around the Antarctic continent but thaws back mostly to the coast each summer.  There it can go no further.  The continent is almost completely covered in snow year round so the south pole maintains its high reflectivity during the summer months.

Something to be wary of is people who point to very select years or short time periods to say the ice is not melting.  You have to look at all the data to see the full picture.  The full picture of the Arctic clearly shows a rapid decline of ice both in extent (area) and volume (total ice).  Some people will also tell you that ice is growing in Antarctica.  That's true and false.  Winter sea ice extent is increasing slightly, but the land based ice, on the whole, is melting.  And as we understand above, winter sea ice extent is not going to have any effect because there is little or no sun in the winter.

When you take a moment to step back from the dusty battle taking place on climate issues sometimes you gain a little perspective.  I've actually learned quite a lot doing battle in the blogosphere trenches.  On occasion I get a boot on the derriere that forces me to try to better understand the arguments on both sides of the issue and learn more about what scientists are trying to tell us. 

It's not a pretty battle, and you have to bust ice to really get down to the truth.

-  -  -  -  -  -  

For the most up to date and accurate information about snow and ice issues you can visit the NSIDC, the National Snow and Ice Data Center.

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Comments 101 to 150 out of 155:

  1. RW1 @97, from further up the thread.
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  2. RW1:

    The 1922 ice extent low can be seen in the Walsh data graph. That was above 10 million sq km; the low extent last year was 4.8 million sq km. How do you think your seals felt about that?
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  3. RW1 @100, the formulae can be found here along with a variant version of the chart using different units. It is, however, transparently obvious that the chart includes the effects of angles of incidence for if it did not it would not show zero insolation during winter at the poles.

    As this discussion has degenerated to the point where your sole argument is to simply disbelieve any contrary data, I see no real point in continuing it.
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  4. #58 Tom Curtis

    You posted the PIOMAS graph for arctic ice volume that shows a steep decline in recent years. I was researching this a bit. You do realize that this graph is based upon some calculations and not based on empirical measurements of ice volume?

    From their site: "PIOMAS is a numerical model with components for sea ice and ocean and the capacity for assimilating observations. For the Ice Volume simulations shown here, sea ice concentration information from the NSIDC near-real time product are assimilated into the model to improve ice thickness estimates. Atmospheric information to drive the model, specifically wind, surface air temperature, and cloud cover to compute solar and long wave radiation are specified from the NCEP/NCAR reanalysis. The Pan-Arctic ocean model is forced with input from a global ocean model at its open boundaries."

    It seems another version disagrees with this one. PIP2 from the Navy show a totally different view of arctic ice volume.

    Two models for Arctic ice volume, which one is correct or are either of them right?.
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  5. My point, RW1, is that you're refusing to be skeptical of a newspaper article, which sounds to be entirely based on anecdotal evidence, & covers just a *single year*-whilst being hugely skeptical of mountains of data covering several *decades*-more than enough to smooth out year to year variability. Indeed, current ice extent is lower than the average plus *two standard deviations*-so very much outside of natural variability for the last 10 years. That's not skepticism, that is *denial* of the *facts*.
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  6. Norman,
    A picture is worth a thousand words; a video must be worth a thousand pictures. Here's a link to an ice reconstruction video (originally posted here), which shows the age of the ice in color. Old ice (orange and red) is thicker than new ice (blue). And there's a lot less old ice.

    Riddle me this: What mechanism would produce one year old ice that is thicker than older ice? What mechanism would produce thickening ice at the same time as ice extent is so rapidly decreasing?
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  7. Tom (RE: 103),

    It is, however, transparently obvious that the chart includes the effects of angles of incidence for if it did not it would not show zero insolation during winter at the poles."

    Angle relative to what? The spherical shape of the Earth or the angle of the tilt? Regardless, I guess since the solar constant is about 1366 W/m^2 and the maximum in the chart is only about 550 W/m^2, that would indicate that angle incidence is factored in.
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  8. Tom (RE: 103),

    You're first chart in post 55 didn't give quantifications of the insolation, which is why it was unclear to me. The one on Wikipedia does. I wrongly assumed the brightest color was the equivalent of maximum insolation (or 1366 W/m^2).

    So I'm conceding that my point about reduced insolation as you get closer and closer to the poles was/is incorrect.
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  9. Marcus,

    "My point, RW1, is that you're refusing to be skeptical of a newspaper article, which sounds to be entirely based on anecdotal evidence, & covers just a *single year*-whilst being hugely skeptical of mountains of data covering several *decades*-more than enough to smooth out year to year variability. Indeed, current ice extent is lower than the average plus *two standard deviations*-so very much outside of natural variability for the last 10 years. That's not skepticism, that is *denial* of the *facts*."

    You're misunderstanding the context and implications of that quote I posted. I make no claim that it proves anything - only that it's suggestive of large variability in the Arctic. I'm not denying any facts either, and I'm well aware of the record as it is. I'm simply saying 30 years isn't enough data to know whether the downward trend is anything unusual, or more importantly if it's even the result of global warming, let alone CO2 induced anthropogenic global warming.
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  10. No one has answered my question: If 'global warming' is causing the Artic sea ice to melt, why isn't the Antarctic sea ice decreasing as well? Why has it even expanded in recent years?
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  11. Norman @104, PIP2 does not disagree with PIOMAS, rather an analysis of PIP2 based on pixel counts purports to disagree with PIOMAS. In fact, however, it does not (whatever the text says).

    Consider the graph of October 1 ice extents by ice depth based on the pixel count:



    Consider the comparison of 1st Oct, 2007 with 1st Oct, 2010. The first thing to notice is that the total extent of sea ice that is 3 meters thick or thicker is greater in 2007 than in 2010. What is more, nearly half that ice is over 4 meters thick, and a quarter over 4.5 meters thick in 2007, while in 2010 only a third of the equivalent ice (and one ninth of the total) is over 4 meters thick, and virtually none is over 4.5 meters thick. Consequently, even though 2011 has a greater extent of 2 to 2.5 meter ice, we would expect on the PIP2 data for 2010 to have less ice.

    The author creates an opposite impression by concentrating initially on the Dec 31st data, while ignoring the strong rebound in the PIOMAS data to that date.

    The author thinks he can make a more telling analysis than this with his graph of volumes. However, that graph is based first on pixel counts on a plane projection of the pole, which underestimates the area of the thickest ice relative to the thinest, and the more so the greater the ice extent.

    He also, of necessity assumes that the contours mark sharp steps in ice thickness. He assumes that, for example, a change from a blue to a green shading is a change from (at minimum) 2 to 2.5 meters of ice thickness, where as it may have been a change from 2.45 to 2.52 meters thickness. The necessary approximation in this process means his method is to crude for any but the coarsest comparison. You should read his graphs as having error bars of plus or minus 50%, and allowing for that possible error, PIOMAS falls well within the range of his calculations.

    Of course, there is a directly measured product for ice volume available, that produced by Icesat:



    PIOMAS has been compared to it, and performs well:



    As you can see, when compared to measured data, PIOMAS, if anything, over estimates ice volume.

    So I guess it all depends on how you want to verify your data - actual observations, or pixel counts and pub coaster arithmetic.
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  12. RW1: See this thread for Antarctic ice mass loss.

    Answers to your question here, here and here. Really, these aren't that hard to find on your own, if you would just look.
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  13. RW1 @110: It's #9 on the list of most used skeptic arguments (the chart on the left). Maybe you should check there.
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  14. Tom (RE: 41),

    "Of course, the figure you quoted is that derived from models which are underestimating the extent of sea ice loss in the arctic. Based on observation, the net forcing for the ice and snow loss to date is 0.62 w/m^2, and we have not yet experienced a full degree of global warming. That suggests the total effect could result in 7 to 10% additional warming, or up to an additional degree centigrade by the end of the century."

    I see, to the extent that models are underestimating observed Arctic sea ice melting, the models are likely wrong. To the extent that the models are overestimating warming, the models are still likely correct?

    That aside, how about we split the difference? Let's say each 1 degree C of warming will result in about +0.4 W/m^ from Arctic ice loss. That still leaves you way short. You need +16.6 W/m^2 at the surface for a 3 C rise. Assuming 2xCO2 gives you 1 C or about 5.6 W/m^2, where is the additional 11 W/m^2 coming from?

    Don't forget that the Antarctic sea ice is remaining stable or even increasing a little in recent years, and the albedo is remaining fairly stable or has even increased a little.

    In short, where is all the energy coming from that is supposed to be causing the warming - specifically the 3 C rise?
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  15. Tom @83
    You don't get the same outgoing radiation over water that you do over land (terrestrial). Last I checked, the Arctic was an ocean. CO2 or no CO2, you will get the same result if the Arctic Ocean is clear of ice. Solar radiation places it's energy deep in the water and it stays there until it escapes mainly by evaporation. Land is much better at converting insolation into outgoing IR.

    When interpreting the graph you present it is important to remember that the total longwave energy leaving must be reduced by the cosine of the latitude. Your graph is in units of power per unit area. It has to be integrrate over the area of the planet at each latitude. So a strip of the planet 1 degree wide at the equator receives and emits 40% more energy that a strip at 45 degrees. At 60 degrees it is 100% greater.

    In addition, if the polar region is snow covered with a high albedo the re-radiated energy is going to be shorter wavelengths up to UV. If the polar region is ice-free there simply isn't going to be a lot of longwave because the energy is deposited in the water and stays there. And 32 F water is not going to emit longwave like 80F water at the equator. So any effects of CO2 will be minimal compared to areas south of 45 degrees.
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  16. muoncounter (RE: 112),

    "See this thread for Antarctic ice mass loss.

    Answers to your question here, here and here. Really, these aren't that hard to find on your own, if you would just look."


    I know all this. None of it answers my question. I'm talking about the Antarctic sea ice increasing trend. Even if the Antarctic land mass is losing ice, the continent is never going to melt, unless you wait a few 10s or 100s of millions of years for it to move from it's current location.
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    Moderator Response: [Daniel Bailey] Actually, the Antarctic Sea Ice trend is currently negative: With a long-term decline in evidence: Further reading here.
  17. RW1,

    See An overview of Antarctic ice. No one is expecting the continent to melt; the attic of your house may be on fire, but the food in your basement freezer will still be cold.
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  18. muoncounter (RE: 117),

    Seriously, if I'm to believe that complex of a series of factors is likely causing the Antarctic sea ice to grow inspite of 'global warming', why should I not believe that an equally numerous and complex series of factors, and not primarily 'global warming, is what's causing the Artic sea ice to melt?

    (*BTW, I don't doubt the reasons for the Antarctic increasing sea ice extent are numerous and complex, nor do I doubt that many of the listed mechanisms could very well be playing a role.).
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  19. "I'm simply saying 30 years isn't enough data to know whether the downward trend is anything unusual". It is when the previous 100 years of observed ice extent show no significant change. Funny that this sudden change just "happens" to coincide with the period of most rapid warming ever observed.
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  20. muoncounter (RE:RE: 116),

    "Actually, the Antarctic Sea Ice trend is currently negative:"

    The trend is nearly even or slightly positive. The past year is slightly below the average.

    "With a long-term decline in evidence:"

    Does that look like reliable data to you with all those straight lines for such long periods?
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    Moderator Response: [DB] If you had even bothered to peruse the link I gave you for your edification you would have found an answer to your "straight lines" question, among others. That indicates you're not even trying to learn, but obfuscate.
  21. RW1, No, that's what I came up as a quick analogy to your nonsensical notion that anyone expects the Antarctic continent to melt. An analogy is not a technical answer.

    Did you read the overview? It poses at least two answers to your 'question.'

    "if I'm to believe that complex of a series of factors is likely causing the Antarctic sea ice to grow ... why should I not believe that an equally numerous and complex series of factors ... is what's causing the Artic sea ice to melt?"

    So now we are supposed to have two 'complex series of factors'; one causing melting, the other freezing. Each unexplained, undocumented and apparently unknowable. Science marches on, I suppose.

    What you choose to believe is your own lookout. But perhaps the reasons lie in the fact that the oceanographic, atmospheric and physiographic settings of the Arctic and Antarctic are completely different? One has much less ozone than the other? One is in the hemisphere with most of the sources of CO2, the other isn't? One is land completely surrounded by open water, the other is water surrounded by land?
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  22. Marcus (RE: 119),

    "It is when the previous 100 years of observed ice extent show no significant change."

    "observed" in what way? I tend to only trust the satellite data on this.

    "Funny that this sudden change just "happens" to coincide with the period of most rapid warming ever observed."

    3 or 4 tenths of degree warming in 30 years is the most rapid warming ever observed?
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  23. muoncounter (RE: 121)

    "Did you read the overview?"

    Yes I did.
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  24. "observed" in what way? I tend to only trust the satellite data on this.

    Typical straw-man argument-exactly what I expect from a card-carrying denialist. We only have 30-odd years of satellite data but-in spite of its greater accuracy-it does *not* invalidate the decades of direct observation & measurement that occurred in the decades prior to satellite. You just deny the evidence in front of your own eyes, & use the old canard of "30-years is insufficient" argument to cover yourself-because you know there is no real come-back if you refuse to accept other valid data. Yet funny how you denialists will rant, rave & scream that "global warming has stopped" if even a *single* year-or even a single *month* is colder than expected.

    "3 or 4 tenths of degree warming in 30 years is the most rapid warming ever observed"

    Try closer to almost +0.5 degrees of warming in a 30 year period (over 0.16 degrees per decade), which is actually around 3 times faster than the warming we saw in the first half of the 20th century-you know, when solar activity was rising rapidly. This warming we've seen lately has occurred against the backdrop of falling solar activity, & higher than normal volcanic activity (especially over 1990-2010). It's about 10 times as fast as the warming believed to have occurred during the MWP (which saw a total of +0.6 degrees of warming over a span of SIX HUNDRED YEARS). So yep, the fastest warming ever recorded, & without the usual causes to explain even a slower rate of warming.
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  25. RW1. In statistical circles, 30 years of data *is* considered sufficient to arrive at a reasonable *average* state of affairs. Remember that ice loss isn't just below this average, its more than 2 standard deviations below this average. That makes this ice loss *incredibly* unusual & ongoing. Oh, but its not anecdotal evidence from an article in a newspaper, so how could you *possibly* be accurate?

    Seriously, this kind of nonsense might work with your mates over at Watts Up With That, but we have a slightly higher standard of *evidence* here.
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  26. RW1 In the Arctic, its more like >0.8 degrees in 30 years.



    0.3 degrees per decade is a Northern Hemisphere norm these days. See the Northern hemisphere warming thread.
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  27. According to NASA's Earth Observatory, warming in Antarctica is closer to +0.1 degrees *per year* between 1981 & 2007, which amounts to around +2.6 degrees of warming. I'd call that *very* rapid.
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  28. muoncounter (RE: 121),

    "So now we are supposed to have two 'complex series of factors'; one causing melting, the other freezing. Each unexplained, undocumented and apparently unknowable. Science marches on, I suppose."

    No, the point is it's very likely the confluence of factors are just as numerous and complex for both, and assuming anthropogenic CO2 induced warming is what's primarily causing the Artic ice to melt while also assuming a confluence of complex factors, completely unrelated to anthropogenic CO2 induced warming, is what's primarily causing the Antarctic sea ice to expand, is awfully convenient.
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  29. Okay, correction. Some areas of Antarctica are warming at +0.1 degrees per year (especially around the peninsulas) the rest of Antarctica is warming at closer to a rate of 0.03 to 0.05 degrees per year-which still makes it significantly faster than average warming for the same period.
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  30. RW1. In the Southern Hemisphere, we've seen a significant rise in temperatures in the Southern Ocean. This has caused rain-making systems to shift southwards towards Antarctica. At low altitudes, this increased precipitation is causing increased calving & ice loss along the peninsulas, whilst at high altitudes its-surprise, surprise-falling as *snow* & *ice*. So when you look at the total ice extent for Antarctica, you're seeing both the increased ice extent on the higher altitude Eastern side of the continent (from increased, warming-induced precipitation) & the declining ice extent on the Western side of the Continent (caused by the same warming-induced precipitation increases).
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  31. RW1 "Antarctic sea ice to expand, is awfully convenient"

    Typical Denialist-speak I'm afraid. You've been outed mate. I'd suggest you'd do much, much better at WUWT, because your claims won't be held up to nearly as much scrutiny as they are here.
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  32. Marcus (RE: 124)

    "Typical straw-man argument-exactly what I expect from a card-carrying denialist. We only have 30-odd years of satellite data but-in spite of its greater accuracy-it does *not* invalidate the decades of direct observation & measurement that occurred in the decades prior to satellite. You just deny the evidence in front of your own eyes, & use the old canard of "30-years is insufficient" argument to cover yourself-because you know there is no real come-back if you refuse to accept other valid data."

    Sorry, I have a hard time believing non-satellite data on Artic sea ice extents is reliable. You should be a little more skeptical of such data yourself.

    Yet funny how you denialists will rant, rave & scream that "global warming has stopped" if even a *single* year-or even a single *month* is colder than expected."

    I don't do this.

    "Try closer to almost +0.5 degrees of warming in a 30 year period (over 0.16 degrees per decade), which is actually around 3 times faster than the warming we saw in the first half of the 20th century-you know, when solar activity was rising rapidly. This warming we've seen lately has occurred against the backdrop of falling solar activity, & higher than normal volcanic activity (especially over 1990-2010). It's about 10 times as fast as the warming believed to have occurred during the MWP (which saw a total of +0.6 degrees of warming over a span of SIX HUNDRED YEARS). So yep, the fastest warming ever recorded, & without the usual causes to explain even a slower rate of warming."

    Given that the amount of fluctuation from year to year is frequently as much as 0.4 to 0.5 C, I'm hardly shaking in my boots. The last 30 years could be easily wiped out in just a couple years.
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  33. Funny how this thread has come to resemble the Denominator thread...

    The Yooper
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  34. Marcus (RE: 125),

    "In statistical circles, 30 years of data *is* considered sufficient to arrive at a reasonable *average* state of affairs."

    What statistical circles? I don't think it's nearly enough. I would think at least a 100 years would be needed to get an accurate picture - perhaps even longer.

    What about the 30 years of statistical cooling between about 1940 and 1970? If that happened to be the period as the base for the '*average* state of affairs', you'd have concluded it was cooling (or at least that it wasn't warming).


    "Remember that ice loss isn't just below this average, its more than 2 standard deviations below this average. That makes this ice loss *incredibly* unusual & ongoing. Oh, but its not anecdotal evidence from an article in a newspaper, so how could you *possibly* be accurate?"

    But the average used for the standard deviation is from 1979-2000 and not 1979-2010. Did you catch that? The record low extent didn't occur until 2007. These are some of the kinds of issues that can skew the trend analysis when only such a short period of time is availble.
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  35. "Given that the amount of fluctuation from year to year is frequently as much as 0.4 to 0.5 C, I'm hardly shaking in my boots. The last 30 years could be easily wiped out in just a couple years. "

    Another typical denialist cult argument, RW1. You clearly haven't even got a *clue* how the temperature anomalies work-or the warming trend-or you wouldn't make such a blindingly ignorant comment. In fact there are no 0.4 to 0.5 degree fluctuations in temperatures, as you claim. Average year-to-year fluctuations are more on a scale of 0.05 to 0.2 degrees. Also, the minimum & maximum anomaly in each decade continues to increase. So in the 1980's, the minimum anomaly was +0.05 degrees & the maximum was +0.31 (in 1988 alone)-with the most common maximum being +0.26. In the 1990's, the minimum anomaly was +0.13 degrees, & the maximum was +0.57 degrees (in 1998 alone), with the most common anomaly for the decade being around +0.35. In the 2000's, the minimum anomaly was +0.32 degrees & the maximum was +0.62 degrees-with the next most common anomaly being around +0.55 to +0.6 degrees. You see a *pattern* emerging?
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  36. "What statistical circles? I don't think it's nearly enough. I would think at least a 100 years would be needed to get an accurate picture - perhaps even longer."

    Yet another typical Denialist Argument. Even if we had 100 years of satellite data, you'd still say it wasn't enough-you & your denialist mates keep shifting the goal-posts of what constitutes evidence, so that you can maintain your denial-yet you'll leap on the smallest amount of data to "prove" your point. As a *scientist* myself, I have a very good understanding of what amount of data is accepted as statistically significant-you, on the other hand, have *no clue* about statistical significance.


    "What about the 30 years of statistical cooling between about 1940 and 1970? If that happened to be the period as the base for the '*average* state of affairs', you'd have concluded it was cooling (or at least that it wasn't warming)."

    There is so much *noise* in that data that its not actually statistically significant-largely because the time series you use marks the end of the solar induced warming of the first half of the 20th century (1900-1945), & the brief cooling that followed it. It also represents the usual cherry-picking I've equally come to expect from the Denialist Cult. If I take 1945-1975, for example, I get a modest warming trend (though, again, not statistically significant). By contrast, if you take 1950-2010 or 1980 to 2010, you get a very statistically significant warming trend. Anyway, why are you talking about 1940-1970? I thought you only trusted satellite data?

    "But the average used for the standard deviation is from 1979-2000 and not 1979-2010. Did you catch that? The record low extent didn't occur until 2007. These are some of the kinds of issues that can skew the trend analysis when only such a short period of time is available."

    Oh, that's too hilarious RW1. Yes, 1979-2000, a period in which the majority of the experts believe that ice loss was already underway (& had been for about a decade). Yet all the ice coverage for 2001-2010 has been below even *this* average. You denialists do have an uncanny knack of shooting yourselves in the foot.
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  37. The point, RW1, is that your reliance on all the tried-&-true Denialist myths exposes you as yet another resident of the Denialist Cult. As such, I really don't think there's any point in people trying to further address your "concerns"-given that everyone has already been sufficiently patient in the face of your increasingly ludicrous claims. Maybe you should go hang out with your mates Anthony Watts & PopTech, as they have about the same weak grasp on reality as you do.
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  38. Marcus (RE: 135),

    "Another typical denialist cult argument, RW1. You clearly haven't even got a *clue* how the temperature anomalies work-or the warming trend-or you wouldn't make such a blindingly ignorant comment. In fact there are no 0.4 to 0.5 degree fluctuations in temperatures, as you claim. Average year-to-year fluctuations are more on a scale of 0.05 to 0.2 degrees."

    What data are you looking at specifically?
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  39. RW1 (Re:138) GISS global temperature anomalies. Maybe you should check out the data before you go running off at the mouth-especially when you consider that this represents the average anomaly for the entire globe. Its worth noting that the +0.6 degrees of warming over the span of the *entire* Medieval Warm Period was sufficient to wipe out 3 major civilizations (The Anasazi, the Mayans & the Khmer Empire)-so yes there is something to be concerned about.
    The other point is that, as the data shows, regardless of what the year to year fluctuations are, the minimum & maximum anomalies are shifting up-by around +0.1 degrees-per decade. i.e. year to year fluctuations have yet to even bring the planet's temperatures back to the averages of the 1990's, let alone the averages of 30 years ago.
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  40. Marcus (RE: 139),

    "GISS global temperature anomalies. Maybe you should check out the data before you go running off at the mouth-especially when you consider that this represents the average anomaly for the entire globe."

    I'm looking at UAH and RSS. Both show year to year fluctuations up to 0.5 C. Now the temperature departures from the average don't show this much variation but that's to be expected.
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  41. Oh &, before you ask-RSS (satellite) data shows similar year to year fluctuations in the temperature anomalies-with the sole exception of 1997-1998, & 1998-1999 (a change of +/-0.45 respectively). You see, what you clearly fail to understand about year to year fluctuations is that they're usually *corrected*, but still the underlying minima & maxima continue to rise (so for the 1980's, its -0.25 & +0.09; for the 1990's its -0.18 & +0.55-for 1998 only-though its most commonly +0.15; for the 2000's, its +0.08 to +0.55-though its most commonly +0.3 degrees. Again, notice the *trend*).
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  42. "I'm looking at UAH and RSS. Both show year to year fluctuations up to 0.5 C. Now the temperature departures from the average don't show this much variation but that's to be expected."

    You're totally full of it RW1. I've got the RSS data right in front of me &-with the exception of the strong El Nino year of 1998-1999, there was never a year-to-year fluctuation of more than 0.3-& even the 0.3 degree fluctuations are rare. Most of them are closer to 0.1 to 0.2 as I already said. All of which deliberately ignores the fact that the baseline anomaly for each decade is climbing by around 0.1 degree per decade. Hardly something that can be easily ignored.

    Still, I was wondering how long it would take for you to resort to outright fabrication to make your point.
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  43. Marcus (RE: 139),

    "The other point is that, as the data shows, regardless of what the year to year fluctuations are, the minimum & maximum anomalies are shifting up-by around +0.1 degrees-per decade."

    Actually, the data I'm looking at is showing more like +0.15 C per decade.

    "i.e. year to year fluctuations have yet to even bring the planet's temperatures back to the averages of the 1990's, let alone the averages of 30 years ago."

    According to UAH, January of this year came back down to -0.01 C below the 30 year average. You're making a mountain out of mole hill with this data. The temperatures don't do anything but go up and down from year to year.
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  44. So, to further make my point-according to the RSS data, the only time you get a year to year fluctuation of *more* than 0.3 degrees is 1997-1998 (where it went from +0.10 degrees to +0.55 degrees-a change of +0.55 degrees-a change of 0.45) followed by 1998-1999 (where it went from +0.55 to +0.09-a change of 0.46 degrees). So no there are no changes of "up to 0.5 degrees"-only a *single* change of 0.45 degrees. The rest are closer up to 0.2 degrees per year, with the occasional 0.3 degrees per year (usually corrected the following year) as I've already said.
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  45. Marcus,

    "So, to further make my point-according to the RSS data, the only time you get a year to year fluctuation of *more* than 0.3 degrees is 1997-1998 (where it went from +0.10 degrees to +0.55 degrees-a change of +0.55 degrees-a change of 0.45) followed by 1998-1999 (where it went from +0.55 to +0.09-a change of 0.46 degrees). So no there are no changes of "up to 0.5 degrees"-only a *single* change of 0.45 degrees. The rest are closer up to 0.2 degrees per year, with the occasional 0.3 degrees per year (usually corrected the following year) as I've already said."

    You appear to be referring to deviation from the average. I'm referring to actual changes in temperature from year to year.
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  46. "According to UAH, January of this year came back down to -0.01 C below the 30 year average. You're making a mountain out of mole hill with this data. The temperatures don't do anything but go up and down from year to year."

    LOL. What was I saying about you denialists leaping on even the most insignificant pieces of data to "prove" their point? Thanks for shooting yourself in the foot again RW1.You claim 30 years isn't sufficient data, but apparently a single month is?!?! So what if the UAH data is showing January sitting at around the 1979-2000 average? despite your increasingly ignorant claims, the temperatures don't just simply "go up & down from year to year". They're actually *trending upwards*. The average temperature anomaly for the 1980's is -0.06 degrees, the average temp anomaly for the 1990's is +0.08 degrees (a difference of 0.14 degrees) & the average temp anomaly for the 2000's is +0.53 degrees ( a difference of 0.45 degrees). So its a clearly *accelerating* warming trend.

    Still, as you're a typical denialist who twists the facts to suit himself, I really don't see the point in dealing with you anymore. Congrats on your thread-jack though-another typical denialist strategy. Now go & hang out with your other denialists-unless you actually now have something remotely *intelligent* or *relevant* to say!
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  47. "You appear to be referring to deviation from the average. I'm referring to actual changes in temperature from year to year."

    Nope, that's just what you want to believe. I'm actually looking at comparing each 12-month period to the 12-month period that follows it &-guess what-it doesn't change by "up to 0.5 degrees" as you claim. Also, I notice you're relying on UAH data, which has already been proven to be the *least* accurate of all the temperature data (ground & land based). Its the preferred data-set of denialists, of course, because it shows the slowest rate of warming-surprise, surprise.

    As I said, though, nice little thread-jack.
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  48. Here's the point, RW1, if-as you claim-year to year fluctuations are sufficient to wipe out all the warming that's occurred since 1979, then why has the global temperature for the 2000's *never* been as cool as any of the years of the 1980's? Surely we should have had a whole year as "cold" as the 1980's given that solar activity for this decade has been at its lowest since the start of the 20th century.
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  49. Just one more point, though-you do realise that there has been channel data difficulties with the satellites since the start of this year? RSS has actually ceased data collection since the end of last year-& the main AMSU-A channel (channel 04) is currently off-line. So I'd like to know where you're getting that data for January 2011.
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  50. TOP @115:

    1) You aresimply wrong about outgoing radiation and the ocean.

    To quote from the first link:

    "The best up to date measurements of ocean emissivity in the 8-14 μm range are 0.98 – 0.99. The 8-14 μm range is well-known because of the intense focus on sea surface temperature measurements from satellite.

    From quite ancient data, the average emissivity of water across a very wide broadband range (1-100 μm) is 0.96 for water temperatures from 0-30°C.

    The values from the ocean when measured close to the vertical are independent of wind speed and sea surface roughness. As the angle of measurement moves from the vertical around to the horizon the measured emissivity drops and the wind speed affects the measurement significantly."

    An emissivity of 0.96 is higher than that of land, or land plants in the IR spectrum, so rather than ocean emitting less outgoing radiation than land, it emits more. I have seen this in IR cameras over the sea, with the sea surface being bright due to high emissivity while the land of nearby islands are dark due to a relatively lower emissivity and cooler night time temperatures.

    2) You wish to adjust the OLR radiation indicated on the graph for the lower unit area per degree latitude at the poles, but you have failed to notice that the scale is already adjusted to compensate for exactly that effect. I even made a note about it. Consequently no further adjustment is required, and the OLR from arctic areas is proven to be substantive by that graph (or more particularly, by the satellite observations summarized in that graph).

    3) Ignoring the fact that you repeat the error you discussed in point 1, you are also ignoring the fact that emissivity and absorptivity of different substances vary at different wavelengths. Snow and ice are very good reflectors of visible light. The may or may not reflect UV light well, but as you can become easily sun burnt while swimming, I suspect that they doe not. They certainly do not reflect IR radiation well, instead absorbing it almost completely. In consequence, they are also almost perfect emitters of IR radiation, having about the same emissivity as liquid water.

    Further, it is quite true that the impact of green house gases depends on the brightness temperature of the outgoing radiation. However, at the tropics, incoming solar radiation greatly excedes the Outgoing Longwave Radiation. The difference, the excess heat, is carried to the poles by air and water currents. Consequently, if GHG's trap 10% more of OLR, they trap less than 10% more of the incoming energy from the sun. If 1/3rd of the incoming energy is transported to the poles, than energy transport by OLR by 10% only results in a net forcing of 6.7% of the incoming solar radiation.

    In contrast, at the poles, the energy transported by OLR is much greater than that recieved from the Sun. If a third of the incoming energy at the poles is from surface heat transfer, then trapping an additional 10% of OLR energy transfer will trap an additional 15% of the energy incoming from the sun. That means adjusting the energy trapped by OLR is a more efficient driver of temperature at the poles than at the tropics.

    It really is that simple. But ignoring the actual mechanics involved, or adhering to simply non-physical theories about sea surface emissivity as you are doing will blind you to the fact.
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