Global Sea Ice Trend Since 1979 – surprising

Much importance has been ascribed to tracking the change in Arctic sea ice, but what about the global trend? That doesn’t seem to get much press. However there is some important information that needs to be presented related to the global trend of sea ice as measured by satellite since 1979. The results are surprising. – Anthony

global-sea-ice-from-aqua
Source: NASA’s Aqua satellite – click for larger image


A guest post by Jeff Id, from The Air Vent

2nd Update 12/24/08  It turns out that an error in documentation at NSIDC is the cause, see this new post for a full explanation.

Update and correction:

To my readers, Anthony Watts received a comment from our friend Tamino on the ice data I used for the area analysis. Unfortunately for me he is right this time. It appears that a correction to the data is required prior to 1987 which will create an approximate negative trend of 0.88 million sq kilometers per 30 years. It is a fairly small trend in the scheme of a 20million sq kilometer signal, but understand this mistake is entirely mine and is unrelated to Anthony Watts excellent blog.

Unfortunately the change makes the Area signal difficult to determine prior to 1988 because the percent fill is unknown. Anthony cannot check every detail of a post which took me days of research and he simply requested if he could copy it here.

The link to my corrections is:

http://noconsensus.wordpress.com/2008/12/16/sea-ice-decreases-despite-the-air-vent/

My apologies.
Jeff Id


I calculated a true global sea ice anomaly in this post using the National Snow Ice Data Center data. What would you say if I told you that over the last 30 years the sea ice area has stayed flat or even trended — Up!!!???

This isn’t a small deal. We have been told, well screamed at really, that CO2 is causing unprecedented rise of temperature on a global scale. We hear constantly that the ice is melting and the result will be dramatic flooding of the earth; movies have even been made. Those of us who pay attention to the scientists have heard that the most significant warming will be at the poles (according to the computer models). We also hear that the Antarctic has added ice during the same time the Arctic lost sea ice. This is explained in that the Antarctic ice increase is a local situation and the Arctic ice loss is a result of global warming. A unique form of cherry picking but should be treated with an open mind.

If you’ve been paying attention, you have heard that the net ice level is going down. The Antarctic gain cannot compensate for the Arctic loss. Well, I set out to see how bad the situation is.

First, anthropogenic global warming scientists use two measures, extent and area.

Extent looks at all the square Kilometers (Km^2) with more than 15% ice in them and adds them up.

Area looks at all the square Kilometers (Km^2) with more than 15% ice in them and adds them up but multiplies the Km^2 by the amount of ice in the square kilometer. i.e -(if you have 1 Km^2 of sea filled 15%, ice- extent counts it as 1Km^2 while area counts it as 15% of 1Km^2 or 0.15Km^2)

This post deals with the amount of sea ice so I used Area. In the future Iwill do it with extent. The NSIDC uses two algorithms for calculation of sea ice, nasateam and bootstrap. We will look at both here.

Without modification the NSIDC data for bootstrap runs from 1978-Dec. 2006 and the nasateam runs from 1978-Dec 2007, these near 30 year trends comply close enough with current science which states (conveniently) that climate requires a 30 year trend to see the result.

This is a graph of the global sea ice area from the nasateam algorithm.

global-sea-ice-nasateam-algorithm-area

The red line is the slope of the global sea ice data from nasateam in its raw format. The slope is negative by only 6803 Km^2/year and the mean is 18,290,000 km^2.

We should look at sea ice anomaly to be the most accurate for trend. To calculate sea ice anomaly I took the average shape of the annual signal and subtracted it from the curve above.

The average ice variation globally looks like this on an annual basis.

global-30-year-average-nasateam-algorithm-area

I subtracted this curve above to get the sea ice anomaly.

global-sea-ice-area-anomaly-nasateam-algorithm2

The downward slope of this graph is more extreme but the scale is highly magnified. The net downslope in 30 years of global warming is – 10173Km^2/year. Over 29 years of data this means that we have lost 302025 Km^2 of ice. This is a 1.65 percent drop in global ice level in 30 years. Remember though that this data ended on an extraordinary high melt year of 2007, the ice level can be seen recovering in dec 07 leading into 2008. This shows as a slight change in slope of the very tip of the first graph (a subtle, difficult to see effect).

Well NSIDC recommends using the Bootstrap algorithm for research instead of Nasateam because of certain errors which have been corrected for.

The bootstrap algorithm plot for global data looks like this.

global-sea-ice-area-bootstrap-algorithm

The red line is slope again, and this time it is positive, indicating an increase in ice level from 1978-Dec 2006. The slope of the red line is plus 6341 km^2 per year indicating that the earth in 28 years has added 177,000 sq kilometers of ice with a mean ice level of 20.42 million Km^2.

The anomaly is better for calculating trends because it cleans up the end points making the slope insensitive to the start and stop point of the annual cycle.

global-sea-ice-area-anomaly-bootstrap-algorithm

The up trend for the anomaly in sea ice from 1978 to end 2006 is 804Km^2 per year. Which in our timeframe the preferred bootstrap algorithm says the earth ADDED 22,000 Km^2 of ice area!!

Here are the anomalies rescaled to actual by adding the mean of the original data back in.

global-sea-ice-area-variation-nasateam-algorithm

global-sea-ice-area-variation-bootstrap-algorithm1

Obviously people cannot make the claim that sea ice is being lost. It isn’t. The data shows that our trend is basically flat during this time of unprecedented temperatures. It’s clear that there has been no significant change in sea ice area.

This is almost enough to make me turn in my Skeptic union card, but increased CO2 warming the earth makes some sense to me, the magnitude is in question. The fact that polar sea ice not melting is not an insignificant point. It is also important to realize that the changes are too small to fit with IPCC statements about the trend. Unlike trees, ice does make a good thermometer. I can’t say this strongly enough— This is a strong indication of substantial errors in the computer models and temperature data which needs to be addressed before we throw what’s left of our global economy to the wind. How would Earth’s total sea ice ignore such substantial warming? It’s a good question which deserves an answer.

I will update this when new data becomes available and will also attempt to demonstrate that the net slopes we see are within the margin of error for the measurement in a future post. In the meantime, lets let the world know the truth. We aren’t going to drown any time soon!

————————

I had a request for description of the difference between the bootstrap and nasateam algorithms. It is a bit complex but it seems well documented on the NSIDC here are a few links and descriptions from that site. From FAQ section.

2. What is the difference between the NASA Team algorithm and the Bootstrap algorithm?

For general analyses or creation of simple images, either algorithm will suffice. The Bootstrap sea ice concentration data set is believed to be more useful for modeling and process studies in the polar regions because it is generally free of residual errors that could not be removed by conventional techniques. A temporally more consistent time series of sea ice concentrations is provided, offering improved accuracy over the ice concentration maps created from the original Bootstrap algorithm.

More interesting to me was the table provided which shows the strenghts and weaknesses of each process. The original table is at the link above.

bootstrap-vs-nasateam-table

For more details and complete descriptions NSIDC provides two links Bootstrap and Nasateam

HERE is a link to the R code to make the above graphs.

Data sources:

ftp://sidads.colorado.edu/pub/DATASETS/seaice/polar-stereo/


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138 thoughts on “Global Sea Ice Trend Since 1979 – surprising

  1. An area of ice the size of the United States melts and re-freezes each year. This is an important article. Thank you Jeff

  2. The raw theory that increasing CO2 will “show up” at the poles makes sense: The AGW extremists know that at the poles the air is both extremely cold AND extremely dry (on average) so CO2 (at the same percentage as in warmer, more humid areas (ie, the rest of the planet!) makes up a significantly greater amount of the total greenhouse gasses present.

    If CO2 increases, then (reasonably) there will be a significantly greater percentage increase in greenhouse gasses at the poles than in the rest of the plant.

    Therefore, since (in their minds) CO2 is the great evil, and since there are no other GHG than Co2, the poles MUST melt first. So, every thought in their minds since Hansen’s 1988 presentation to Congress has focused on the “proving” that the poles will melt. (And then kill us all.)

    [Notice how the common Mercator projection in every classroom that exaggerates Greenland’s area helps this fear: When Greenland is projected as nearly twice the size as Australia, and when Greenland is displayed as about the same size as Brazil or Africa, then (when) that “huge area” melts, obviously the earth “must get” catastrophically flooded … And the politicians play on this fear – as Gore so recently did.

    ——

    Notice too that even ONE YEAR of “normal ice re-freezing throws out every real piece of the scare tactics: The ice that must melt in say 2010 is what was left over from 2009 into 2010. What was melted in summer 2007 (and then re-froze in winter 2008-2009) doesn’t matter at the edges of the ice pack.

    True a long-term trend would matter – But from these graphs there is no long-term trend of costantly melting ice.

    Yet the politicans, and their budget-linked members of the “science” community don’t care.

    Fear sells.
    Truth shows previous lies as the lies that they are.

  3. So, even with the big melt in 2007, we still see an average increase in sea ice anomaly trend with bootstrap. In that case, if you ignore the 2007 data (just for the fun of it) I bet we would see a much greater slope upwards in the 30-year trend. 2007 looks like an anomalous year, which may be influencing the statistics too much and masking a more realistic climatic trend. Just like the 1998 El Nino temperature-anomaly spike doesn’t seem to help the calculation of its long term trend, but only to increase its statistical fluctuations.

  4. I’m puzzled, why the 15% rule for the area? Why not adding everything?

    In computing extent I understand the need for a cut-off like this, but even then an indication should be added with the size of the regions with let’s say 15% +- errors from instrument sensitivity. I’d like to have an idea of the biases that come from simple truncation.

  5. An interesting check to my results is at this link.

    The university of Illinois is using a slightly different dataset. I wrote for the data but haven’t received a reply. You can see from the graph that the shape of the curves I calculated is accurate. UIUC data has a ‘slightly’ stronger negative slope for some reason.

  6. A really inconvenient truth — it seems that total polar sea ice is essentially stable, notwithstanding Mr. Gore’s panic attack prediction.

  7. The truth is full of (strike(good news) bad news.
    I see a 3-4 year downward trend (2003-2007) also it appears we are starting into an upward trend. the agw crowd will cherry pick this as “proof” of ice loss. I see the beginnings of a cold trend as the Antarctic remains frozen and the arctic begins to freeze up more. less food can grow in the cold. longer winters. more clouds.

    what would be interesting would be to subtract the two variations ( bottom two grafts) and see the error ( noise ). because that is what they (agw promoters use) to twist the data around.

    Good job Jeff

  8. RE: David Ball (19:11:49):

    Anthony: How come we don’t drown via sea level rise each Arctic summer (assuming Antarctica doesn’t freeze as much ice as melts in the Arctic)? Is it because most of the ice that melts in the Arctic is floating ice?

    REPLY: Yes, try the ice cubes in a glass filled to nearly the top with water experiment. They float, they melt, but the glass does not overflow.

    Greenland ice is an entirely different issue, since it is land bound. – Anthony

  9. Jeff Id,
    May I ask some questions concerning the difference of the two methods.
    The nasateam data extend closer to present day than the bootstrap data. Does nasateam use a running mean taken over previous data, while bootstrap uses a mean including forward data as well?
    When looking at the two anomaly curves, they show a similar peak structure. But subtracting the two curves will not generate white noise?
    Maybe, when you put in a certain time shift between the two curves?

  10. I love how you say cherry prick, you take only sat photos, completely ignore all other data such actual physical investigations of the caps.

    Studies which have physicly found that the Perma-ice has lower denisity and is now honeycombed with airpockets.

    If you can provide me with data that shows that hundred of thousands of years old ice which used to be known as completely solid but which has now lost a good majority of its internal volume is normal.. or the data is all made up.

    I might actually believe our planet isnt as screwed up as they say.

  11. The shape of the 30 year average sea ice area is also very interesting. Assuming that the Day of Year axis represents a normal western calender, the areal extent of sea ice seems to fall to a minimum during the Antarctic summer, with a much smaller dip during the Arctic summer. That suggests that there is a lot more sea ice around the perimeter of Antarctica than in the Arctic region, contrary to my expectations.

  12. Lamont: SST for the Southern Ocean stopped its rise more than 20 years ago and has been on a sharp decline for more than 10 years.

    With respect to your realclimate link, they searched and found a few reports that discussed very specific climate models of the Antarctic and the Southern Ocean to illustrate that “A cold Antarctica and Southern Ocean do not contradict our models of global warming. For a long time the models have predicted just that.”

    But what do other models say? Look at the two graphics of GISS equilibrium runs used by realclimate in another discussion, the first two figures in the following.

    http://www.realclimate.org/index.php/archives/2007/12/tropical-troposphere-trends

    There is NO cooling in the lower troposphere of the Antarctic in either illustration. While the high latitudes in the Southern Hemisphere do not warm as greatly as they do in the North, they still show warming,

    Climate models contradict one another, so some will be consistent with reality while others will not. What value do they have then?

  13. @phoynix

    “Studies which have physicly found that the Perma-ice has lower denisity and is now honeycombed with airpockets.”

    Can you give us a reference to any of these?

    “If you can provide me with data that shows that hundred of thousands of years old ice which used to be known as completely solid but which has now lost a good majority of its internal volume is normal.. or the data is all made up.”

    Not sure what this means, but if you are looking for data on ice mass then I know that there are gravity-based estimates of ice mass, which would automatically correct for cavities in the ice.

    “I might actually believe our planet isnt as screwed up as they say…”

    I don’t think ANY planet can be a screwed up as ‘they’ say…..

  14. Lamont: You wrote, “The northern hemisphere has more people, more CO2 emissions, and more water to moderate the effects of AGW.”

    First, CO2 is a “well-mixed greenhouse gas”, so that part of your statement has little substance. Second, oceans cover approximately 60% of the Northern Hemisphere, and for the Southern, they cover about 80%, so that part of your statement is wrong.

  15. Lamont (00:08:06)
    ‘The northern hemisphere has more people, more CO2 emissions, and more water to moderate the effects of AGW. The Antarctic and the southern hemisphere was predicted to lag behind the northern hemisphere in its response to AGW:’
    Your statment, like the co2 theory, doesn’t make sense. …to moderate?
    And all this time I thought co2 was ‘well mixed’ in the upper troposphere.

  16. The trouble is it has always changed and always will especially with a live volcanoe under the ice ,If you look at history it clearly shows everytime the c02 is high the earth has been cooler not warmer ,the tree rings show that c02 in high amounts make eveything grow 75%faster ,at the end of the day no one can predict in 100yrs or conttrol it ,that is impossible ,this is a scam thats why there is no quantified equasion to predict anything exisists because its impossible .Ethanol reduces c02 slightly but burns with a lot more polluting solids as found by testing recently ,it also clogs motors and catalyic converters and produces nitros oxide which is a lot worse and that is smog ,more lies ,c02 is essential for every living thing on the planet not a pollutant .

  17. Lamont,

    Do I understand you to be suggesting that the increasing ice around the Antarctic is because the alleged AGW has not yet caused the ice to melt, but that I must believe you when you say it will melt, eventually?

    You also state that more people, more CO2 emissions, and more water moderate the effects of AGW. What do you mean by “moderate”? Do you mean to “lessen” the effects of AGW, so that the Arctic ice will increase or do you mean “potentiate” the effects of AGW, so that the Arctic ice reduces?

    I am directed to point out that the Arctic and Antarctic ice is increasing in both extent and area.

  18. Is anyone losing the will to live?

    I’m not a conspiracy theorist, but I’m starting to wonder how so many smart people can be so stupid for so long. When I hear a politician putting `Climate Change’ in his top three problems that need to be solved and then browse either here or Steve McIntyre’s website, I’m literally gob-smacked at the unbelievable stupidity of the whole warming thing.

    Do we sceptics all think about this problem with a different region of the brain to the warmists? The fallacy of CO2 based anthropogenic global warming is so self-evident, I’m wondering if such a difference in perceptual capabilities might explain it. Either that or the policy based evidence making is just that: we must stop sending trillions of dollars out of our economies to pay for oil and gas and here’s a good way to move people away from it.

    Either way my (and public) trust in science is set to take a nose-dive. It’s a profoundly depressing situation.

  19. “If you look at history it clearly shows everytime the c02 is high the earth has been cooler not warmer ,the tree rings show that c02 in high amounts make eveything grow 75% faster”

    Look that, please:

    “Abstract

    The writers investigated the effect of CO2 emission on the temperature of atmosphere. Computations based on the adiabatic theory of greenhouse effect show that increasing CO2 concentration in the atmosphere results in cooling rather than warming of the Earth’s atmosphere.”

    In Cooling of Atmosphere Due to CO2 Emission, by Authors: G. V. Chilingar; L. F. Khilyuk; O. G. Sorokhtin.

    http://www.informaworld.com/smpp/content~content=a788582859~db=all

  20. phoynix,

    “I love how you say cherry prick, you take only sat photos, completely ignore all other data such actual physical investigations of the caps.”

    There has been no selection of one data set over another. I used this data because it had a long timespan, it was well documented and was available.

    I separated the NH and SH out in previous posts. Some here have already seen them but I think they show a lack of selective plotting.
    NH

    http://noconsensus.wordpress.com/2008/12/13/sea-ice-area-or-anomaly/

    SH

    http://noconsensus.wordpress.com/2008/12/14/sh-sea-ice-data-and-anomaly/

    Lamont,

    I think others have already addressed your points (thanks to Bob T and the Geezer) but on the Air Vent it is my policy to not accept real climate references as valid.

    Consider that they will not accept dissenting opinion and also consider that they not only accept but embrace the Mann papers. Papers which are so mathematically and data flawed that you couldn’t push them through an undergrad stats class. They are well informed so you can learn things from them but they ceased to be scientists long ago.

  21. Werner Weber,

    “Does nasateam use a running mean taken over previous data, while bootstrap uses a mean including forward data as well?”

    It’s a good question, I don’t think this is being done but I don’t know. I just assumed the government was a bit slow in updating the web. There are some verification processes involved in releasing the data which may have something to do with it. I will look into it more over the coming weeks.

    Subtracting these curves will show a difference in method but since the data came from the same sensors I don’t know what we would learn.

  22. Exotic Electron (01:09:51) :

    Area does not equal mass. Very deceptive data mining.

    Area is easier to measure than volume. At the beginning of 2008’s melt season, official ice watchers pointed out that while ice area recovered well during the winter, there was so much thin first year ice that the melt would proceed quickly and there would be more melting than in 2007.

    We wound up with 9% more ice at the low point than in 2007 – evidence that supports an injection of warm water into the Arctic Basin had melted ice from below and that the 2007 melt was anomalous.

    Except for the warm water event, any discussion about the 2007 melt and its aftermath may be very deceptive data mining.

    What’s the difference between an exotic electron and a boring one? Is one really a positron or muon?

  23. Graeme Rodaughan (19:55:36) :

    “I’m shocked – that poor fellow Pugh paddled all the way to the north pole for nothing…”

    He actually gave up hundreds of miles short of the pole. The reason? Too much ice. And too much cold.

  24. We need to be careful focussing upon ‘trends’ – it can lead to serious errors of context – and this underlies the entire ‘global warming’ thesis which relies upon computer models with entirely false (i.e. non-natural) notions of an equilibrium starting point and calculations of trend – this conveniently ignores cycles, and it has to because a) there are several non-orbital cycles in motion (8-10 yr, 11, 22, 60, 70, 80, 400 and 1000-1500) depending on ocean basic, hemisphere and global view – all interacting via ‘teleconnection’ of those ocean basins , some clearly timed by solar cycles, some peaking together; b) because the cycles are not exact, you cannot tell in any one decade where you are in the longer cycles. Thirty years is far too short to encompass a cycle for the Arctic sea ice where the major cycle is at least 70 years – the best cycle context for this I have found is represented in the State of the Arctic Report or the work of Igor Polyarkov at IARC Fairbanks – looking at Surface Air Temperature trends for the whole Arctic – 60-90N, for the century you can see two peaks in 1940 and 2005 with a trough in the mid-80s (if anyone can tell me how to copy in a jpg I could put one in here!).

    Thus, whatever is happening now in the Arctic, if it is air-temperature related, then something similar happened then – but instrumental records were different. If you read E. Hanna et al in the Arctic Report Card 2007 (www.arctic-noaa.gov/reportcard/ArcticReportCard_full_report.pdf):

    “Over the past century, years in Greenland that register as abnormally warm, 1929, 1932, 1941, 1947, and 1960 are outstanding, having temperatures warmer than observed recently. Increases in GrIS melt and runoff during this past century warm period must have been significant and were probably even larger than that of the most recent last decade (1995-2006).”

    However, despite this, the team reckon to have perhaps isolated a ‘global warming’ signal in the accelerated run off of the Greenland Ice Mass – but only just, because the runoff at the edges is balanced by increasing central mass – again, they focus upon recent trends – a net loss of about 22 cubic kilometres in total ice mass per year which they regard as statistically not significant – to find the ‘signal’, and a contradiction to their ealier context of air temperature cycles.

    Anyone reading the Report Card can choose to focus upon the recent ‘trend’ and call it global warming, or the 70 year cycle.

    Even if the recent cycle (of which there is evidence of a turning through 2006-2008 with run-off slowing in Greenland and the 2008 summer sea-ice melt 9% up on 2007), is different from the previous in terms of the overall pattern – as some argue, this can just as easily be the effect of the 400 year cycle – recovery from the Little Ice Age, upon which the current 70 year cycle piggbacks. See the essay by recently retired director of the International Arctic Research Centre – Dr Syun-Ichi Akasofu (www.people.iarc.uaf.edu/~sakasofu/pdf/recovery_little_ice_age.pdf). So then, given that we are at a peak of the 400 year cycle and the LIA was a trough, we need to go to the previous peak – 800 years give or take a bit (and remember there is a lower frequency cycle below this one, probably due to ocean overturning) and we are in Viking settlement times on Greenland and legends of the circumnavigating Chinese fleet sailing home via the Arctic Ocean!

    For a useful critique of model-starting-points which bear no relation to the real-world, see: D. Koutsoyiannis et al (2008) ‘On the credibility of climate predictions’ in Hydrological Sciences 53(4) August 2008 671-684, who conclude that the GCM models defy normal assessments of validity and should not be relied upon to predict future climate change.

    And with regard to Antarctic ‘trends’ – virtually all the action is on the Peninsula region and the Western Ice Sheet (about 15% of the area) – with no significant trend for the other 85% of the continent. And it is known that the southern polar regions ‘see-saws’ with the northern – so when the north polar is on the up cycle – the south polar in on a downer (Bob Tisdale’s graph of the southern ocean SSTs shows this clearly for the ‘global warming’ period of 1980-2005 – and the Peninsula Region just catches a flow-in from warmer seas to the north).

  25. Re: Lamont (00:08:06)

    The same reasoning applies to Ozone yet somehow it seems to have ‘drifted’ mostly to the south pole. I guess the air currents were such that they moved ozone but not CO2?

  26. “This is a strong indication of substantial errors in the computer models and temperature data which needs to be addressed before we throw what’s left of our global economy to the wind. ”

    What errors would these be, then? Have you even looked at what the models say–especially about Southern hemisphere ice extent? How can you make such a bold statement without even consulting the literature?

  27. The key number is neither extent nor area, but VOLUME.

    That is: area*thickness.

    I know that thickness has declined significantly in the arctic, but have we had accurate measurement of ice thickness long enough to make any meaningful interpretations?

    Particularly in the Antarctic, where this may have a major impact on overall data…….

    Look forward to hearing from the pros on this…..

  28. In relation to the questions about ice thickness, I understand why the question is being asked, truly, but I don’t believe it is a relevent question for this topic. I believe this for two reasons;

    1) The research is based on ice area, not mass

    2) As we are dealing with ice area, it is logical that the primary driver of area will be to do with ocean ice. Given the annual cycle of melting and refreezing for the majority of sea ice, thickness is not relevent as it would dissapear and re-appear annually.

    Also, looking at Cryosphere Today, I don’t see a lot of difference in the thickness of the ice, only that it has moved around. (Darker Purple = Thicker)

    http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=12&fd=01&fy=1979&sm=12&sd=01&sy=2008

    Correct me if I’m wrong, it’s only a laymans (mine) thought process…

  29. there is a recent article where the geographical distribution of the warming was analyzed in detail
    (by Dr. John Christy, a professor of atmospheric science and director of the Earth System Science Center (ESSC) at The University of Alabama in Huntsville.)

    see e.g. for summary

    http://www.physorg.com/news148239677.html

    I think it is pretty clear why ice in south will grow as it has been cooling down durint the last 30 years !!

  30. Boris,

    You are right that I shouldn’t editorialize without reference, however lack of reference doesn’t imply lack of consultation. I assume that you know these models have been ‘updated’ over the years to show a different result. Most predictions I’ve seen show a net warming at the poles after all it is the antarctic land based ice which will eventually flood the earth.

    Rhys Jaggar,

    If you can show me a reputable volume data set for both poles I will plot that also. In the meantime ask yourself, how would a substantial change in volume have no effect on area and does the alternative explanation seem likely?

  31. Mass/Volume only seem to be relevant when someone points out that total area hasn’t declined. When pointed out that, in the Antarctic, there are many places where there is increased ice pack over the last few decades, even if some shelf here or there falls into the ocean, we are told that the mass isn’t as important as the area.

    Now, we see that neither mass nor area in the Antarctic has not perished, and area is making a comeback in the north.

    This is very inconvenient, so the logical thing to do is tell us that mass in the north is really what’s important.

    In my line of work, I end up throwing out models and stats at least as often as I actually use them. It never ceases to amaze me that a simple application of common sense more often than not gets you the right answer.

    And common sense says that we have long since passed the point of common sense being applied in the climate change arena. Imagine the good we could actually do if we simply stopped wasting time, energy, and resources on this non-existent problem.

  32. I’m still staring at the AMSR-E sea Ice extent graph, which right on cue with Al Gore’s proclamation that the Artic ice would be gone in five years (so give Al money now!), the line for 2008 began indicating that the Artic ice is decreasing.

    right.

    Who pays for that graph?

  33. @Robinson

    “Is anyone losing the will to live?”

    OK. Don’t let the bastards ruin what time you have during this fascinating voyage.

    Shake your head at their folly. It’s always been so with most of our species.

    Then enjoy the mystery, the timeless cycles. The sun (diminished as it is) rising.

    Time will throw the necessary light on this silly, misguided foolishness.

  34. Global Sea Ice as calculated is an irrelevant statistic.
    The Antarctic sea ice is one year ice. It melts every year. The winter ice is unimportant to the earth’s albedo because the sun hardly shines on it.
    The Antarctic sea ice in winter is increasing, but it doesn’t have any impact on global warming.

    The summer ice area is the thing to look at, and it is decreasing in the Arctic and more and more ice is one year ice.

    It seems to me that this blog has the effect of diverting attention from the important summer Arctic Sea Ice trend which has gone downward sharply in the past few years.

  35. Jeff ID

    The answer to you question on changein volume vs no change in area (or little change) presumably is that the area won’t change if the ice is 10cm vs 10 metres.

    At the very margins, this doesn’t matter, what does matter is where ice is retained all summer but a lot of the top ice melts off, so the area doesn’t change but the volume does.

    That’s what I’m thinking. It won’t change at the poles probably, but at the periphary of the permanent ice.

    My view is this: it’s easier for scientists to measure area than volume, so they measure area.

    I don’t know the reliability of the techniques, but aren’t there guys at UCL in London who’ve used satellites to measure thickness recently?

  36. Jeff Id: Good Job….fantastic

    Eduardo Ferreyra;
    Hudson Bay: game over

    http://saf.met.no/p/ice/nh/conc/conc.shtml

    Pamela:
    NOAA
    Niño 3-4…..12/08/2008….-0,5ºC
    Niño 3-4…..12/15/2008….-0,7ºC
    open count;
    NOAA:
    “A majority of ENSO forecasts indicate slightly below average SSTs in the central equatorial Pacific through Northern Hemisphere Summer 2009. Several models suggest weak La Niña conditions during December 2008-March 2009.”
    FM

  37. Eric, they said themselves, “As noted in earlier entries, persistent high pressure over the central Arctic Ocean led to fairly clear skies for the most of the summer, promoting melt.”

    Is there any evidence that persistent high pressure over the central Arctic Ocean is unique, or new in some way? They use the word “extreme” a lot, but I doubt they have significant historical data over the last few millennia to substantiate such a claim.

  38. Eric,

    Now that’s serious cherry pickin. If the summer ice is downward trending in the arctic, other ice must be compensating for it right, or the net would be downward????

    Don’t pay attention to the man behind the curtain.

    Rhys Jaggar,

    I concede that volume is a more direct measurement, the belief that volume is independent of extent is a major stretch, especially when you consider larger magnitude changes. Also consider the current AGW science regularly presents this data (arctic only) as evidence of coming doom.

    This really was an eye opener for me who has tried to remain skeptical but undecided. I fully expected a very boring series of posts showing the magnitude of the downtrend. In my experience physics has a way of taking your strongest held beliefs and turning them right on their head.

  39. “The summer ice area is the thing to look at, and it is decreasing in the Arctic and more and more ice is one year ice. ”

    More correctly, it “was” decreasing, and more and more ice “was” one year ice. The pesky summer of 2008 didn’t go as planned, and thus there is now more 2+ year ice this winter than last winter. When we see 2009 ice increase from 2008, then that will mean there is more 2+ year ice than in the previous couple years.

    Just like the cooling trend in place at the moment that gets dismissed as a short-term aberration, I wonder how many years if increasing levels on the summer trough will have to now occur before AGW proponents will move on to the next argument and ignore the trend reversal.

    And yes, despite the one data point, I do believe we’ve seen a reversal. The temps in the Arctic have declined now for a few years and it had warmed enough that it makes perfect sense that we would see a lag in the reformation of ice.

  40. Well one thing we can conclude definitely: Global Warming is actually Anthropocentric. It’s our narrow view of time and space which forces us to see shallow pulses in the ziljoen year timespan as monumental pulses in our lifespan. AGW does exist, but thankfully only in our heads.

  41. Jeff ID

    I’m also a open-minded skeptic, but that’s why I’m asking whether the measurements have been done.

    I have no axe to grind, but my view is that sudden drops in ice extent are more explainable if a large area at the edges thins over several years, thus allowing a big chunk of melting. I have no data to support that, but it seems intuitively reasonable.

    Otherwise, you’d expect a uniform increase or decrease in ice extent over multi-decadal cycles.

    Wouldn’t you?

    Any links you can pass me to which examine this issue?

  42. In some western Alaska villages, heating oil is going up to $11 per gallon this winter.

    Why?

    When thick ice clogged the slough into Napaskiak, forcing the barge carrying a winter’s worth of heating oil to turn back in October, people panicked.

    “The houses were running cold and the businesses were closing their doors,” said Phillip Nicholai, general manager of the village corporation. “It was kind of a disaster.”

    BLOCKED BARGES

    On the day the fuel barge was supposed to arrive in Emmonak, around Oct. 20, Agathluk was flying home to the village from Hooper Bay.

    “I could see the Bering coast was frozen from Scammon Bay all the way past the Yukon river,” he said.

    The freezeup came earlier than usual …

    Yes, I know one winter doth not a trend make, but this sort of story makes it increasingly difficult to lay awake nights worrying about Arctic ice melting.

  43. Graeme Rodaughan (19:55:36) :

    “I’m shocked – that poor fellow Pugh paddled all the way to the north pole for nothing…”

    Ahem. Fridjof Nansen the Norwegian explorer got 4 degrees further north than Pugh ever did, and that was back in 1893 in a much larger boat, the Fram.
    Expedition route here: http://www.fram.museum.no/en/default.asp?page=142
    Design of the Fram here: http://en.wikipedia.org/wiki/Fram

    Didn’t Pugh turn back at around 80.5 degrees Latitude? Nine and a half degrees of latitude short of target? That’s not even close.

  44. Re: Mark (05:52:35),

    Opps, I meant CFC’s. That’s what I get for reading this great site first thing in the morning…

  45. Jeff Id said,
    “Eric,

    Now that’s serious cherry pickin. If the summer ice is downward trending in the arctic, other ice must be compensating for it right, or the net would be downward????

    Don’t pay attention to the man behind the curtain.”

    The problem with your graph is that you are adding summer ice in the Arctic to winter ice in the Antarctic in your graphs. As I mentioned the winter ice in the Antarctic can increase as much as it wants without affecting the earth’s albedo.

    It seems obvious that this is why scientists look at the two regions separately.

    The right way to do this is to offset the Antarctic and Arctic statistics by 6 months if you want to look at winter versus summer trends on one graph by year.

    Expressing contempt is not a scientific argument even though it plays well on this web site.

  46. Can you provide data about ice volume versus area? As sea ice thins, it can get pushed out by the mass of land ice, so you end up with ice over a larger area even though there’s less of it.

  47. Eric,
    Sorry. That was for Jeff Id.
    Jeff Id,
    Do you know what the trend for thaw and re-freeze of summer ice is?

  48. Eric
    “As I mentioned the winter ice in the Antarctic can increase as much as it wants without affecting the earth’s albedo.”

    That must be one of the absurd arguments i’ve ever read. This would be true only if the ice never reached north of the arctic circle and froze/melted instantly upon the appearance/disappearance of the sun. Actually the winter ice reaches maximum about the autumn equniox, when sunlight reaches the South Pole, and the sea ice nowhere extends south of 78 degrees (because there is no sea there).
    Actually the argument makes more sense applied to the arctic sea ice – both in winter and summer, since it is at a much higher average latitude and therefore affects albedo much less.

  49. Eric (10:42:39) :

    “The problem with your graph is that you are adding summer ice in the Arctic to winter ice in the Antarctic in your graphs. As I mentioned the winter ice in the Antarctic can increase as much as it wants without affecting the earth’s albedo.”

    So the Antarctic never gets a summer?

    DaveE.

  50. Eric,

    I see we aren’t going to agree on this, there are several points in your post I have issues with.

    “As I mentioned the winter ice in the Antarctic can increase as much as it wants without affecting the earth’s albedo. ”

    The ice still has to melt requiring energy input, during that time the albedo in the area changes. So I don’t believe you can make this statement.

    Energy in is energy in and percent reflection from a largely Lambertian diffuser (snow and ice) doesn’t change much with angle. The total energy required to melt the ice from winter to summer with either ice albedo or seawater albedo should be relatively independent of season.

    “The right way to do this is ….”
    I wanted to look at the overall trend not winter vs summer.

    “It seems obvious that this is why scientists look at the two regions separately.”

    I can think of another reason that arctic summer ice is the talking point for AGW. I bet most of the people on this blog can think of another reason too.

    Whether summer ice is an example of political expedience or it is scientifically valid, the politics of AGW do exist and do pollute the science – see previous Gore post. We cannot simply pretend it doesn’t exist. This means that every claim needs to be scrutinized and assumptions need to be confirmed.

    I understand the concept of summer to winter variation being a global warming response but the net change should be negative – and its not! So I would ask, does that mean the summer/winter trend you want to discuss is not a result of global warming?

  51. Eric says:

    The problem with your graph is that you are adding summer ice in the Arctic to winter ice in the Antarctic in your graphs. As I mentioned the winter ice in the Antarctic can increase as much as it wants without affecting the earth’s albedo.

    Well, it really depends on what you are trying to understand. If you are trying to understand the total amount of ice on the planet and whether or not it is static, increasing or decreasing, I would suggest to you that you need to add them together for the same time period.

    If you are trying to understand the annual albedo contribution of the ice then you might do a season-based comparison.

    How much albedo do the poles contribute anyway, compared to other factors? I suspect a red herring.

  52. Your entire analysis is invalid. You should have read the documentation more closely.

    There’s a discontinuity in area data in 1987 because there’s a “hole” in the observed area which is smaller for the SSM/I satellite than for SMMR, hence area data after the switch from one satellite to another are larger — not because ice area was greater, but simply because the area which is “not counted” is smaller:

    Sea ice concentrations are assumed to be 100 percent around a circular sector centered over the Northern Hemisphere pole (known as the pole hole) which is never measured due to orbit inclination. The Southern Hemisphere also has a pole hole; however, it does not affect this sea ice data set; since only land is under this hole. For SMMR, the hole is 611 km in radius and is located poleward of 84.5 degrees north. For SSM/I, the hole is 310 km in radius and is located poleward of 87 degrees north.

    This is better explained in the documentation given for monthly averages:

    Important Note: The “extent” column includes the area near the pole not imaged by the sensor. It is assumed to be entirely ice covered with at least 15% concentration. However, the “area” column excludes the area not imaged by the sensor. This area is 1.19 million square kilometers for SMMR (from the beginning of the series through June 1987) and 0.31 million square kilometers for SSM/I (from July 1987 to present). Therefore, there is a discontinuity in the “area” data values in this file at the June/July 1987 boundary.

    Hence there’s an artificial “jump” in sea ice area data of about 0.88 million km^2. Without compensating for that discontinuity, any trend analysis of the data (including this one) has no validity.

    If you correct for the discontinuity in the way area is measured, it’s undeniable that global sea ice has trended down over the time span monitored by satellites.

  53. It seems to me that the lag in atmospheric temperature min/max with respect to winter/summer solstices indicates that the oceans’ overall surface temperature is a predominate factor in determining seasonal average air temperatures. Has someone modeled the thermal characteristics of the oceans + solar heat input and would that help explain recent trends in global temperatures?

  54. Phil (22:54:04) :

    RE: David Ball (19:11:49):

    Anthony: How come we don’t drown via sea level rise each Arctic summer (assuming Antarctica doesn’t freeze as much ice as melts in the Arctic)? Is it because most of the ice that melts in the Arctic is floating ice?

    REPLY: Yes, try the ice cubes in a glass filled to nearly the top with water experiment. They float, they melt, but the glass does not overflow.

    Archimedes approves. The volume of ice is greater (less dense) than the same mass of liquid water.

  55. @Chris Wright (04:57:21) :
    @Mister Jones (10:19:44) :

    I was jesting, I’m well aware of Pughs self promoting folly.

    It was the contrast b/w the “notion of an ice free artic that would allow for someone to Kayak all the way there” and “Jeff’s illumination of increasing global sea-ice” that I was driving at – all be it – from an abtuse angle.

    For the AGW Warmers – a relatively short time ago – loss of sea ice extent was all the rage as an indicator of Catastrophic Global Warming… The artic was the proverbial Canary in the Global Warming Coal mine that was twittering warnings of the demise of the world.

    Why has the argument moved from “ice extent” to “ice mass” – is the extent proxy no longer able to help support AGW – as it is no longer reducing and the artic is not playing ball.

    And you accuse sceptics of “cherry picking” data.

    I suggest that you look up “Cognitive Dissonance” on Wikipedia. Your little religion of global apocalypse is clouding your minds.

  56. “I can think of another reason that arctic summer ice is the talking point for AGW. I bet most of the people on this blog can think of another reason too. ”

    Ohhh, ohhhh, Mr Kotter, Mr Kotter…..

    Because the Antarctic ice is not cooperating with their “models.”

  57. Jeff Id, a point that may suggest further analysis.

    While much is made of summer sea ice melt, it’s irrelevant to the claimed increased greenhouse effect. The best, and arguably only, measure of global warming is winter maximum sea ice extent/area.

    This is because the winter maximum excludes any intra-annual effects, which cannot possibly be due to the cumulative effects of greenhouse gas warming over periods greater than a year.

    Note that while GHG warming may have intra-annual effects, these effects are of no relevance to climate change/global warming defined as changes over periods greater than a year.

    Also note that the GHG effect operates by decreasing cooling. An effect that should be at it’s maximum at night, which in the polar regions is synonomous with winter.

    In fact the GHG effect also decreases solar warming at the surface by blocking incoming solar radiation. So an increased GHG effect should manifest in the polar regions in a decrease in winter sea ice extent and a smaller increase in summer sea ice extent relative to the winter maximum extent (ie a smaller annual range in sea ice extent).

    I think you will find the exact opposite in all 3 sea ice metrics; winter maximum, summer minimum and annual range, at both poles. Compelling evidence that changes in sea ice extent/area have nothing to do with an increasing GHG effect.

  58. RE: Eric (10:42:39)
    The right way to do this is to offset the Antarctic and Arctic statistics by 6 months if you want to look at winter versus summer trends on one graph by year.

    Eric, are you sure that offsetting those 2 series will produce negative trend? Somehow I doubt that simple phase shift in 2 oscillating data series will suddenly produce trend where there was none before.
    I might be wrong, but you have to actually do it and prove it if you want me to believe you.

  59. The flatness is really impressive. Could it be that it is meaningful ? Is there any kind of explanation that could suggest that this is more than a coincidence ?

  60. Ben: your

    The flatness is really impressive. Could it be that it is meaningful ? Is there any kind of explanation that could suggest that this is more than a coincidence ?

    Pielke Sr has the melt seasons for the Arctic and Antarctic, using minimum and maximum ice dates, and these graphs are also remarkably flat.

    http://climatesci.org/2008/12/08/are-there-long-term-trends-in-the-start-of-freeze-up-and-melt-of-antarctic-sea-ice/

    http://climatesci.org/2008/12/04/are-there-long-term-trends-in-the-start-of-freeze-up-and-melt-of-arctic-sea-ice/

  61. I find the ice mass a potential red herring. Since ice can sublime and we know from the discussions on glaciers that they can grow or shrink with percipitation, simple mass would not be appropriate. Ice extent/area does appear to be the correct metric for our discussion. Since the water will turn to ice, as Jeff ID has pointed out as ice is a good temperature measurement. The atmospheric pressure does not change at sea level enough to change the freezing point of sea water that can be measured except in a most exacting laboratory experiment. Also, with the elevation changes in Antartica, there are known precipitation/elevation problems. Once again, the proper metric would be area/extent.

  62. Robinson (04:13:47) :
    I’m starting to wonder how so many smart people can be so stupid for so long.

    [...]
    Do we sceptics all think about this problem with a different region of the brain to the warmists? The fallacy of CO2 based anthropogenic global warming is so self-evident, I’m wondering if such a difference in perceptual capabilities might explain it.

    Get a copy of “Memoirs of Extraordinary Popular Delusions and the Madness of Crowds” by Charles Mackay. Would you pay the price of a house for a tulip bulb? People did during the tulip mania. Believe the computers of the world would halt on Y2K day?…

    It doesn’t have to do with the thinking part of the brain, it has to do with the emotional part. Intelligence is orthogonal. The witch burners of New England were fairly smart, but delusional (imho). The only thing I’ve seen is a somewhat higher emotional sensitivity in the AGW folks. Less self control.

    This mania is just one more in a very long string. There is something in the human nature that requires herd behaviour. Add to that the fact that folks LOVE to panic. Stir with some self interested greed and power lust on the part of a few ‘leaders’ and season with some mild self delusion on the part of a few ‘scientists’. Shake with media fear and pour yourself a tall one of madness.

    There are a few people, a small percentage, that doesn’t mind looking someone in the eye and saying “Pardon me sir, but you seem to be nuts.” Or “Thank you, but no, I don’t want a car with fins or a Neru Jacket or a Leisure Suit or short hair in ’50s or long hair in the ’70s or…” Very very few.

    They are derided during these manias. Sometimes killed as heretics. There are a few people who don’t get caught up in the emotional fervor. A broken emotional center? A good self discipline? Self confidence? It is hard to tell one from the other some times … (” I am not a number …”) Society desperately needs these folks, yet often despises them, until the mania ends.

    Thus we get the Tech Bubble. The Housing Bubble. Gold bubbles every decade or two. etc. etc. Hula Hoops and Pet Rocks. Jonestown. One of the hardest things to do in investing is to remember to “Be greedy when others are fearful and fearful when others are greedy.” Very few can move against the herd (and fewer still can do it at the right time…)

    Either way my (and public) trust in science is set to take a nose-dive. It’s a profoundly depressing situation.

    Yes. Made especially so by the fantasy that scientists are emotionally neutral and dispassionate searchers for truth. That they are often motivated by political needs, social rank seeking, money, fame, fear, greed, anger and spite, and all the other failings of humans comes, some how, as a shock.

    The king and queen have sex and go to the bathroom like everyone else; but we would be shocked to see it. The public is about to see a bunch of scientists having a brawl and food fight and flinging poo over who lied to them the most. They will not react well… But that is human nature.

    The best advice I can give is to find a nice seat a bit back from ringside, wear a rain slicker, stock up on the beverage of your choice, and enjoy the show. You can’t leave the theatre anyway…

  63. Great analysis Jeff,

    I think separating the impact between the hemispheres is also important and we should try to see if we can find natural variation that is not the result of global warming.

    I note the global warming models used to say that the Antarctic would be affected just as much as the Arctic by warming. When they saw that there was no warming happening in the Antarctic and they realised they couldn’t “adjust” the temperature records in the Antarctic (because they were carried out properly by scientists on-site) like they did in the Arctic, they changed the models to show less warming in the Antarctic (even though there is no logical reason for CO2 to impact the Antarctic less that Arctic.)

    We are heading into the Antarctic melt season and there will soon be more media hype about rapid Antarctic ice shelf collapse.

    The NSIDC has finally improved their website and there is a new section where one can view “really good” close-up satellite pics over the last several years for all the major Antarctic ice shelves. The current pics of the Wilkins’ ice shelf show the ribbon connecting to the (some) island will likely collapse completely this melt season and it will be cited as the final proof for global warming.

    http://nsidc.com/data/iceshelves_images/

    In case they start fooling around like the NSIDC seems to do occasionally, here is the FTP site where the Raw images are stored.

    ftp://sidads.colorado.edu/pub/DATASETS/ICESHELVES/

  64. Pamela Gray (06:03:17) :
    By the way, I know who took the ice from up North. Oregon. The new Arctic.
    BRRRRRRRRR!!!!!!!

    You are just jealous of the snow near Los Angeles! (Grapevine Interstate 5, and I15 between L.A. and Las Vegas closed due to snow at about 3000 feet, etc. etc.)

    So its snowing in the deserts of southern California, it just has to be due to Global Warm [ SLAP SLAP ], er, climate change…

    /sarcoff>

  65. Philip_B says:

    In fact the GHG effect also decreases solar warming at the surface by blocking incoming solar radiation. So an increased GHG effect should manifest in the polar regions in a decrease in winter sea ice extent and a smaller increase in summer sea ice extent relative to the winter maximum extent (ie a smaller annual range in sea ice extent). (Emhpasis added.)

    Are you sure about that. I though that the GHG in question was pretty poor at absorbing SWR (the incoming stuff) but pretty good at absorbing certain frequencies of LWR (the outgoing stuff) and re-radiating half of it back down, or warming N2 and O2 in the atmosphere.

  66. Re: Sea Ice extent decreasing

    If you look at this comparison there does seem to be some reduction of sea ice near Russia (Siberia?) just near the Pacific entrance to the Bering Strait.

    That seems to be about all that is possible. It seems that Hudson Bay will be completely frozen over soon as well.

  67. MattN (13:03:55) :
    “I can think of another reason that arctic summer ice is the talking point for AGW. I bet most of the people on this blog can think of another reason too. ”
    Ohhh, ohhhh, Mr Kotter, Mr Kotter…..

    Me ME ME! Mr Kotter….

    Because it puts the problem 6 months further away before they have to admit it… hope springs eternal for another warm summer ???

  68. To my readers, Anthony Watts received a comment from our friend Tamino on the ice data I used for the area analysis. Unfortunately for me he is right this time. It appears that a correction to the data is required prior to 1987 which will create an approximate negative trend of 0.88 million sq kilometers per 30 years. It is a fairly small trend in the scheme of a 20million sq kilometer signal, but understand this mistake is entirely mine and is unrelated to Anthony Watts excellent blog.

    Unfortunately the change makes the Area signal difficult to determine prior to 1988 because the percent fill is unknown. Anthony cannot check every detail of a post which took me days of research and he simply requested if he could copy it here.

    The link to my corrections is:

    http://noconsensus.wordpress.com/2008/12/16/sea-ice-decreases-despite-the-air-vent/

    My apologies.
    Jeff Id

  69. Jeff Id:

    Don’t worry about Tamino. To paraphrase Bill Clinton: Tamino can’t be wrong all the time.

    He’s just wrong about his AGW/CO2/runaway globaloney theory.

    [Great post, BTW.]

  70. Richard Sharpe, GH gases, particularly CO2, do block some incoming solar radiation, although it is much less than the outgoing LWR blocked.

    I’m not the first to point out that we should see increasing minimum temps and a decreased diurnal range as the signature of GHG warming.

    However, I’m not aware that anyone else has pointed out that we should see the equivalent effect on sea ice extent/area – decreasing winter maximum extent, decreasing annual melt range and no increase or even a slight decrease in summer melt.

    Note the GHG diurnal effect is accentuated toward the poles where we have moreorless 6 months of daylight followed by 6 months of night.

    The pattern of sea ice melt bears no resemblance to what an increasing GHG effect should produce and therefore it cannot be the cause.

  71. I’ve been trying to think of a way to correct the post. Since we don’t know the percent area filled we can’t calculate the true slope. This applies to extent also but to a lesser degree.

    So far, I can’t think of anything except separation of the pre and post 1987 data and using them alone. Perhaps I can find a way to expand the satellite hole in the modern record to calculate a trend but that doesn’t sound too easy.

    My updated post has an exaggerated slope but by how much I don’t know. One other detail I really want to add is the 2008 data.

  72. I know that 20 years is a short time frame – but is there any discernable trend from 1988 to 2008?

    Mind you – short timeframes have never blunted the AGW movement.

  73. Philip_B (19:35:27) :
    Richard Sharpe, GH gases, particularly CO2, do block some incoming solar radiation, although it is much less than the outgoing LWR blocked.

    [...]
    Note the GHG diurnal effect is accentuated toward the poles where we have moreorless 6 months of daylight followed by 6 months of night.

    The pattern of sea ice melt bears no resemblance to what an increasing GHG effect should produce and therefore it cannot be the cause.

    Perhaps this:

    http://exp-studies.tor.ec.gc.ca/e/ozone/Curr_allmap_g.htm

    has some bearing? Notice that ozone is about -10% to -30% deviation in the north pole and up to (down to?) -40% deviation in the south pole on 2008/12/13.

    Given that O3 is a GHG and a significant % of GHGs … maybe the GHG folks are somewhat right. GHGs do matter, just not the way they think. The sun goes quiet, O3 plummets, the poles get really really cold and the rest of the planet starts to cool off fast?

    Just call it the Smith Solar O3 Pump Theory if anything ever comes of it ;-)

    Wouldn’t be the first time folks had the right idea but the wrong sign. Something very similar happened in the early ice age theory leading up to Milankovitch final theory.

  74. Perhaps the gracious response would be to thank Tamino and acknowledge that the people who study these things professionally seem to have it correct:-

    Arctic and Antarctic Sea Ice Extent, 1979-2007: Although Arctic sea ice extent underwent a strong decline from 1979 to 2007, Antarctic sea ice underwent a slight increase. The Antarctic ice extent increases were smaller in magnitude than the Arctic increases, and some regions of the Antarctic experienced strong declining trends in sea ice extent

    http://www.nsidc.colorado.edu/sotc/images/arc_antarc_1979_20

    http://www.nsidc.colorado.edu/sotc/sea_ice.html

    Oh, and the headline should be edited from ‘surprising’ to ‘unsurprising’

    ;-)

  75. One of the signs of bad science is when scientists make huge conclusions based on data that is either within, or just barely outside, the MOE.
    That. even with the correction made the trend is still basically flat, it is still clear that the AGW alarmists are the ones promoting bad science.
    What is surprising, and will remain so, is how a series of dubious measurements, either synthesized from out of the noise or barely above the noise, and in no way historically unsurprising, has made the world stand on its head and contemplate the idiocy demanded by Gore & co.

  76. Dodgy Geezer (14:00:33) :

    sven (23:44:02) :

    What’s this? Has the arctic ice been melting?! In december?!

    http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

    Yup. I saw that as well. But no one seems fussed about it. I’m surprised that Anthony hasn’t picked it up….

    If you look at the cryosphere animation, you can see the cold amoeba pulling back a bit. Some of the warmth we are getting at the south east of europe might be brushing up there? Volcanic activity? That would show up on a temperature map?

  77. Continuing my last observation, if you look at the animation ( bottom of the index) of the anomalies in the waters

    you will see hot spots on the south of Iceland starting around end of November. By 14th December it looks suspiciously like volcanic activity: localized.

  78. Ok, how does the trend look post-1987? Since that’s when we have the most accurate data without a correction. That’s 20 years of data….

  79. I think that playing spin the bottle is a very poor substitute for scientific observation and reporting. It reminds me of current news reporting. Nobody reports news anymore. Nobody reports what they observe out the door. They seem compelled to spin it. When Anthony started his surface station review, he didn’t study just a few in a short period of time and then spend the remainder of his time spinning his opinions. As far as I know, the final report has not been printed in public because not every last station has been surveyed. Now that is self control. Though I will grant that we are getting sneak previews of stations that just leave me speechless.

    If you find something interesting, state it as an observation, then try your best to prove it is not significant, or caused by some event. Everything is non-significant random events till proven otherwise and the research is repeated by others. Pay close attention to the ever present risk of possible mistakes. Send draft articles out for others to review before going public. And you should ALWAYS send a draft out to someone who is studying the same phenomena but from an opposing point of view. Their critique will be the most useful.

    Finally, don’t veil your article in subtle spinning. It stinks worse than obvious tones.

  80. Jeff, great article. whether the slope is positive or negative may not be as important as the fact that either are basically flat, meaning no great change,
    no great warming. Thank you

  81. Anyone ever seen the arctic ice extent completely flat-line for 4 days in December before? The data’s not been updated at nsidc.org over the w/e then it’s been upgraded with no increase in ice for four days.

    I find that quite surprising, in the absence of unusual climatic conditions.

    Are there any out there right now?

  82. For what it is worth – the latest “scientific” report from AP news.

    More than 2 trillion tons of land ice in Greenland, Antarctica and Alaska have melted since 2003, according to new NASA satellite data that show the latest signs of what scientists say is global warming.

    More than half of the loss of landlocked ice in the past five years has occurred in Greenland, based on measurements of ice weight by NASA’s GRACE satellite, said NASA geophysicist Scott Luthcke. The water melting from Greenland in the past five years would fill up about 11 Chesapeake Bays, he said, and the Greenland melt seems to be accelerating.

    NASA scientists planned to present their findings Thursday at the American Geophysical Union conference in San Francisco. Luthcke said Greenland figures for the summer of 2008 aren’t complete yet, but this year’s ice loss, while still significant, won’t be as severe as 2007.

    http://news.yahoo.com/s/ap/20081216/ap_on_sc/sci_arctic_ice

  83. From: http://news.yahoo.com/s/ap/20081216/ap_on_sc/sci_arctic_ice

    as described by previous post:

    ‘As sea ice melts, the Arctic waters absorb more heat in the summer, having lost the reflective powers of vast packs of white ice. That absorbed heat is released into the air in the fall. That has led to autumn temperatures in the last several years that are six to 10 degrees warmer than they were in the 1980s, said research scientist Julienne Stroeve at the National Snow and Ice Data Center in Boulder, Colo.’

    Just how rare are 6 – 10 degree variations? I seem to recall that PDO shifts can induce precisely that sort of change in pacific waters within a 12 – 18 month period around e.g. Alaska.

    Is there enough data to say that we know that the 1980s were ‘normal’ rather than a bit colder than average and that this change is permanent rather than transitory?

    These are questions, not doubts….

  84. Pamela Gray,

    “I think that playing spin the bottle is a very poor substitute for scientific observation and reporting.”

    I missed a single sentence in the middle of a huge pile of info which I read several times. The data was presented as a continuous time series adding to the confusion. Also adding the area back in creates an unrealistic jump in the time series so my corrected slope is exaggerated. I was tricked by it and it was my fault, but really the down slope is not as strong as my new post states. I have some ideas for correction now which should give a better view. You make it sound like scientists never make mistakes — ever read Mann08.

    Thanks to the rest for your support. I did send a thank you over to Tamino on his open thread for finding my error (we’ll see if it gets accepted).

    My impression is still that the down slope is pretty minor considering the rhetoric we hear. I will continue to work on this in the future. One thing we know for sure is we aren’t in the driver seat on this one right now. The ice will do what it does.

    I am looking for 07-08 SH area and extent data if anyone knows where to find it.

    Thanks again,
    Jeff

  85. “Continuing my last observation, if you look at the animation ( bottom of the index) of the anomalies in the waters

    you will see hot spots on the south of Iceland starting around end of November. By 14th December it looks suspiciously like volcanic activity: localized.

    Great observation, Anna!

  86. I have added an IUIC plot to my corrected page. It doesn’t look that different from my original post but still has some down slope.

    http://noconsensus.wordpress.com/2008/12/16/sea-ice-decreases-despite-the-air-vent/

    Ice area stays flat from 1978 to 2003 then drops. I had originally done a post on this graph Dec 9.

    http://noconsensus.wordpress.com/2008/12/09/global-sea-ice-extent-experienced-minimal-change/

    I should have put it in my statement at the top.

  87. Great article Jeff! Even considering the blooper, you owned up to it promptly. Good job. Interesting that Tamino caught the error. He reads the climate skeptics blogs huh? Heh.

    But I have to say, sea ice area or extent are not enough for me. Does any agency or group track sea ice volume, or can it be done? It seems to me that that is the sea ice metric that really matters.

    Concerning the two trillion tons of land ice that has melted since 2003, what percent of the total is this? I mean, if there was 10 quintillion tons to begin with, this could just be another example of “large number scaremongering”.

  88. I notice that the daily NSIDC daily extent graph today suddenly indicates a week of flat growth in extent or even a loss of sea ice extent. I follow it every day and that doesn’t seem to agree with the map of sea ice extent on the same webpage.

    What’s that all about?

  89. Keith Wooster, you do well to put “scientific” in quotes. The AP article looks to be a rehash of an old NASA press release from nearly 2 years ago.

    It,

    Confuses mass with weight.

    Confuses Greenland glacial ice with sea ice

    Doesn’t refer to net ice loss. All glaciers at all times lose ice at the margins and gain ice at their source.

    As far as I can determine in a cursory read, the satellite data measures land surface elevation, ie, tectonic rebound. A process that occurs over thousands of years after the ice melts. It is still occuring in the UK even though the last ice sheet melted at least 8,000 years ago.

    To portray this data, as the AP article does, as somehow reflective of what has happened recently is either profoundly ignorant or wildly deceptive.

  90. Lessee, I’m gonna try to answer one of my own questions. I hope I don’t screw this up.

    This site: http://www.johnstonsarchive.net/environment/waterworld.html
    says there is approx. 29,340,000 km^3 of grounded ice on the planet.

    This site:http://hypertextbook.com/facts/2000/AlexDallas.shtml
    says the density of ice is approx. 917,000,000 metric tons/km^3

    That would mean there would be approx. 26,905 trillion metric tons of grounded ice on the planet. (Somebody, please double check my cipherin’! Tamino?)

    That would mean that the two trillion ton ice melt amounted to 0.007% of our planets total grounded ice.

    Is that a big deal?

  91. Philip B

    The AP article is poor reporting, editing or deliberate misrepresentation. It is a headline grabbing number with no benchmark identifying whether it means anything.

    As the above charts demonstrate ice melts and reforms in varying cycles.

    Unfortunately, the AP article – like many others- will be picked up in dozens of outlets both print and non-print.

    Keith

  92. Negative CO2 feedback by Iceberg ocean fertilization. See:
    Bioavailable iron in the Southern Ocean: the significance of the iceberg conveyor belt Rob Raiswell
    Geochemical Transactions 2008, 9:7doi:10.1186/1467-4866-9-7

    We have shown that the present-day flux of glacial Fe oxyhydroxides to the Southern Ocean is sufficiently large that the dissolution of the tiny proportions of nanoparticulate Fe in this material may play a significant role in the delivery of bioavailable Fe; at least comparable to that from aeolian sources. A more comprehensive study of iceberg hosted sediment is now required to ascertain the extent to which Fe oxyhydroxide nanoparticulates are present in icebergs and their geographical distribution, and examine their bioavailability experimentally. Identifying icebergs
    as a significant source of bioavailable Fe may shed new light on how the oceans respond to periods of atmospheric warming. The iceberg delivery of sediment containing nanoparticulate Fe during the Last Glacial Maximum
    (18000–21000 years ago) may have been sufficient to fertilize the increase in productivity required to drawdown CO2 to the levels observed in ice cores [9]. We speculate that, if icebergs mitigated against climate warming in the
    past, they may have the capacity to do so in the near future.</blockquote

  93. Hey, Anthony, take a look at this BBC article and tell me what you think of it. I think it funny that the lady who did this research is stating that their research is in its “infancy” and that nobody knows where this all will go; the BBC science editors who edited this story are pretty determined to give it the worst possible spin.

    http://news.bbc.co.uk/2/hi/science/nature/7786910.stm

  94. To David Hagen:

    “A more comprehensive study of iceberg hosted sediment is now required to ascertain the extent to which Fe oxyhydroxide nanoparticulates are present in icebergs and their geographical distribution, and examine their bioavailability experimentally. Identifying icebergs
    as a significant source of bioavailable Fe may shed new light on how the oceans respond to periods of atmospheric warming.”

    In other words, “Our first study is finished. We found somthing we can related to global warming, but we spent all the money and wrote our paper. Send more money (now) so we can keep studying it some more and write another paper. Our research (funded by fears about global warming) needs more money so we can keep finding things we can charge to global warming studies” …..

  95. The key to that story, Richard Hegerty, is the statement ‘in the satellite age’.

    How can you say that the ice conditions today are unique when you’ve only got about 30 years of data?

    There’s various stories that in the 1880s, 1920s that ice levels were much, much lower than a few years previous. From Norwegians.

    I’d wait a while yet before being so unequivocal. And I really would scour historical records for evidence that this has happened before.

    Because my hunch is that is has.

  96. That story is a classic: ‘Give us a lot of grant money otherwise you might all die!’

    You’ll see similar ones about ‘curing cancer’ when they’ve identified a new protein that MIGHT be a drug target, against which drugs MIGHT be developed, which MIGHT or MIGHT NOT be better than current drugs and which will only come to market in 15 years.

  97. Rhys Jaggar (04:38:38) :

    That story is a classic: ‘Give us a lot of grant money otherwise you might all die!’

    You’ll see similar ones about ‘curing cancer’ when they’ve identified a new protein that MIGHT be a drug target, against which drugs MIGHT be developed, which MIGHT or MIGHT NOT be better than current drugs and which will only come to market in 15 years.

    Science has never operated in “wait until we understand everything before publishing” mode. By reporting the small steps along the way, that gives other people direction in their own research. It allows people to replicate the results and report back if they are unable to.

    Human medical research moves at an especially slow pace. Something about lawyers loving it when a human trial (or post trial) goes wrong. We don’t yet have good design tools to create drugs or enzymes that bind to these new proteins, but we do have some computer software that can test potential drugs’s fit with new proteins. I don’t know how well they work, but it is another step along the path.

    One of the differences between science and engineering is that you’re never quite sure where the science is heading. Fix that and then your concerns could be addressed.

  98. To David Hagen and other commentors on the Raiswell- Fe/Iceberg/Plankton study

    My understanding of this work is that a negative feedback loop is put into effect by the bio-available Fe providing an essential ingredient for stimulating the growth of plankton.

    See http://www.cesm.gatech.edu/faculty/fernandez/index.php
    Study of the Biogeochemical Cycling of Fe: Plankton plays a crucial role in the Earth’s life dynamics; this tiny organisms lie at the bottom of the aquatic food chain, and its fate is thus thought to have deep implications in global climate change. Iron, among other trace metals, is an indispensable nutrient for the production of plankton, the most abundant marine organism. Because iron is extremely scarce in surface seawater, it is thought to occur almost exclusively bound to complex ligands of biological origin.

    Also
    From the Planktos Institute
    “Fortunately the utility and efficacy of iron micro-nutrient ocean eco-restoration is near to hand and has benefitted from 20 years and $200 million in public research funds. Just a few weeks ago the Chief Scientist of the largest and best ocean iron micro-nutrient replenishment study performed aboard the German Alfred Wedgner Institutes research ship Polarstern announced that in their experiment they observed the following results. Within 30 days of adding iron (Fe) to enrich a patch of iron deplete Southern Ocean water to approximately 100 parts per trillion Fe a plankton bloom had fixed 50,000 tonnes of carbon (C) for each tonne of Fe applied. Given that biomass C was derived from CO2 that is a Fe:CO2 ratio of ~1:186,000 fixation. Further that scientist reported that 50% of that fixed carbon had sunk to or below the permanent thermocline in the same 30 day time frame.”

  99. Larry (22:15:03) :
    http://news.bbc.co.uk/2/hi/science/nature/7786910.stm

    If this process continues, it will extend the melting season for Arctic ice, delaying the onset of winter freezing and weakening further the whole system. These warming effects are not just restricted to the ocean, Dr Stroeve said. Circulation patterns could then move the warmth over land areas, she added. “The Arctic is really the air conditioner of the Northern Hemisphere, and as you lose that sea ice you change that air conditioner; and the rest of the system has to respond.

    Someone needs to tell them that they left the AC on this year… we’ve had the onset of ‘winter freezing’ in fall when sometimes we didn’t get any at all.

    Last night the SF Bay Area had such things as freeze warnings (20F range) and yesterday the nightly news had film of kids playing in snow in Berkeley. (Though I suspect they had to work hard to find someplace upslope from the city to film…)

    These events are unusual even in the depths of winter. (In 30+ years here I don’t remember anything like it… but then again 25 yrs ago I wasn’t as interested in weather…)

  100. E.M.Smith said:

    These events are unusual even in the depths of winter. (In 30+ years here I don’t remember anything like it… but then again 25 yrs ago I wasn’t as interested in weather…)

    Oh pshaw, don’t you know that the behavior of the atmosphere to increasing CO2 is counter intuitive? At first, you get global warming, but after a while you get global cooling and then chaos!

  101. If you go to Cryosphere Today and click on the map that has the regional ice areas, you will see that for most of the Arctic, it is right on average for sea ice. It is only in one or two areas that ice is not forming (along Russia’s boarder). If you head out to the Bering Straight, the ice is actually above the mean. The Arctic ice area really should be examined in terms of smaller regional areas so that a more refined assessment can be done as to the cause of low sea ice production. If it is only in one or two areas and has a melted edge versus a growing jagged edge, a well defined warm water current is likely to blame. Strong wind may also play a factor in keeping sea ice up against an edge as opposed to growing out to sea, especially in the case of a warm current keeping the edge melted and soft.

  102. Ric Werme in response to my previous post:

    1. Yep I’m well aware about how to develop drugs and the computer aids available – it’s been part of my professional life!
    2. I’m all for scientists publishing data part of the way along: what I’m less happy with is ridiculous posturing in the media which befuddles non-scientists into unrealistic expectations of cures or, in the case of climate science, armageddon. Scientists should apply the same rigour to press stories they consent to as they do to their research. And sorry, boys and girls: you don’t. You’re like the rest of society: telling a few porkies for the printed word.
    3. Is ‘science’ three sets of scientists coming up with totally different predictions for the top amplitude of the next solar cycle? I don’t think so. It’s laying futures bets.
    4. It’s advisable to distinguish between ‘science’ and ‘star gazing’. If I read a paper describing changes in ice conditions over 15 years and then finding that miraculously extrapolotated over a century, I say: ‘you need to study the basis of making extrapolations and the likelihood that they are right’. What scientists write in that context is NOT science. It’s fantasising. It’s either going to get hotter or colder. Well big deal. I didn’t need my Govt to spend £1m of taxpayers’ money to tell me that. It’s friggin’ obvious!

    Merry Christmas!

  103. Can some one explain what is happening up there in the Arctic?
    The increasing recovery of ice has come to an end

  104. Watts up in the arctic?
    Well…either it is those socialist-plot-for-increased-reserch-funding-scientists that is manipulating the data to make the situation look worse that it is, IE more warming, you know(matter has been thoroughly examined on this site, I believe)…
    or…
    …there is wind or current patterns packing the ice. Remember: You do not need any more than 15% concentration of sea ice in a “grid cell” to be counted in the extent value. That will also be the explanation to why the area curve on CryosphereToday is growing, while the extent curve has gone flat: Packing the slush from 15% conc. to, say, 30% or more, would theoretically result in a decrease in “extent” but leave the “area” unaltered, as I understand the difference between those two figures…that leaves me with the conclusion that “area” is a better, more interesting and far more significant figure to put your interest in regarding the state of the sea ice…even more interesting to remember that the area-minimum of this year was equivalent to last year, and even more interesting than that it is to consider the actual volume of the sea ice, wich tells us how much ice there actually is up there, and some of those {snip} “warmers” are actually pointing out that there now actually is a rather small amount of arctic sea ice regarding the volume of the stuff…

    Strange, that…

  105. The whole concept of the biosphere as a greenhouse is incorrect to begin with. It does not behave like a greenhouse. It is a flawed idea from the start, at its roots, so all the arguing about whether or not there is global warming due to GHG’s is also flawed and pointless. This is also one reason that the computer models are complete failures – they are based on a false idea. The ONLY greenhouse type of effect occurs as a result of the effects of clouds, especially the large and reflective type which are generally cumulous (low) clouds and to some extent cirrus and stratos, but mostly the low clouds. More CO2 does not mean higher temperatures but only greater thermal “intertia” so that temperature variability is reduced, not temperature changed. As the atmosphere builds in energy content as a result of greater thermal mass it also builds in re-radiation into space as a result of a pretty constant absolute temperature, this increase in re-radiation away from the earth being in direct proportion to the increased energy concentration. If temperature does increase or decrease then energy re-radiation into space also increases or decreases in direct proportion BUT it also increases and decreases in proportion to the TOTAL available energy. Each extra CO2 molecule equates to an extra absorber AND an extra radiator. Putting aside the effects of clouds, the biosphere is not some kind of thermal “diode” that allows energy in but not as much out. If we are to understand the mechanisms behind global climatic temperature variability then it is absolutely essential to look at clouds as being the primary direct controller of variability and therefore we must understand how and why clouds form and what controls them. This is where Henrik Svensmark and his team of honest, non-politically biased work has been of such great importance.
    More CO2 has no effect on temperature average, only on temperature range (day to day, season to season, etc) just like the effect of atmospheric water. Moreover, the oceans have about 1000 times the thermal capacity of the atmosphere and to think that the atmosphere could so dramatically affect the oceans when it is apparent and obvious that the major portion of sunlight is absorbed by the oceans, the stmosphere being largely transparent to this, and therefore the oceans have the major controlling effect on temperature variability AND absolute temperature of the biosphere when combined with the effects of land on atmospheric temperature (apart from seismic or volcanic or other internal mechanism activity), to think the atmosphere has a major say in temperature control is incredibly scientifically ignorant or just an outright lie. It shows little if any true understanding of heat, temperature, thermal capacities, energy, radiation or any meaningful physical science relating to the subject in question. The main difference between H2O and CO2 (apart from the numerical differences of their specific physical properites such as degree of freedom, thermal capacity, physical mass, etc) in terms of their effects on the atmosphere is that water is capable of condensing into liquid to form clouds and readily and rapidly moves between surface and atmosphere, daily, seasonally, annually and on even greater time scales, but CO2 does not liquify in the biosphere and transfers over mostly long time periods between surface (primarily oceans, seas, etc) and the atmosphere.
    If you want to understand climate temperature trends you MUST study clouds, their formation, their causes, their dissipation, how pressure and temperature systems affect them but most importantly what seeds them. Clouds do not just appear when air and therein contained atmospheric water cools down. Every droplet in a cloud must be seeded on a particle of some kind, generally referred to as aerosols. Up until Svensmark’s work, there were inadequate explanations for some of the effects we have seen in terms of cloud variability and especially with its association with solar magnetic activity. I will not go into depth here but for anyone wanting some real and honest science rather than cult faith you should look into the whys and wherefores of clouds, and not just the work of Svensmark but all reputable scientific sources who do not have an agenda of self-interest (usually income or reputation based on past work – pride is a great influence on perception) with regards to the ever variable climate.

  106. Just a further comment – the so-called greenhouse effect is also the effect of temperature being raised as a result of the energy stored in the atmoshpere, due to that thermal resistance of the atmosphere acting on the infra-red emissions from the ground back out. Without an atmosphere the earth’s surface would be about -18 C (255 K) but the mean temperature of the atmosphere at sea level is in fact around +14 C (288 K), so this difference of +32 K is due to that atmospheric thermal resistance preventing the rush of infra-red into space with the heat being stored on its way out in the atmosphere’s thermal capacitance. However, you MUST remember that over 95% of this effect is due entirely to water vapour, and the remainder is due almost entirely to non-GHGs, with CO2 accounting for some tiny fraction of the order of 0.1%, and this is of the 32K difference and NOT the total absolute temperature of 288K. This is not measureable in the thermally noisy atmosphere let alone has it any noticeable effect on the mean temperature, even if all the CO2 were either removed or doubled.
    CLOUDS, folks, it’s the CLOUDS!!!!! These cover, typically, over 60% of the earth’s surface, a great fraction of that being low level and highly reflective clouds, this reflection keeping out a lot of sunlight in the day and having a cooling effect on the earth’s surface, especially with regards to the massive thermal storage capacity of the oceans which is about 1000 times that of the atmosphere. A mere 1% increase or decrease in average low cloud coverage will cause at least 0.3% decrease or increase in thermal energy input into the earth’s surface and thus ultimately into the lower troposphere. The cloud coverage changes by much more substantial amounts than a mere 1%. The night-time effect of trapping heat is no different to the same effect in the day-time but that is heat that would not be there in as great a quantity were there more clouds to begin with. More clouds both drastically reduce energy input from the sun and simply slow release of what energy there is trapped in the lower troposphere, but the long term effect would be a fall in average temperature because of the significantly reduced input power but the atmosphere’s ability to cool is aided by air current circulation whereby the warmer air rises above those low clouds and that infra-red is more easily re-emitted into space, whereby the low clouds now block that re-emission from hitting the ground again to any significant degree. The clouds just slow the cooling thus giving us the “balmy night” effect. CLOUDS control the average temperature offset level from the base (no-atmosphere) level of 255K. No clouds would result in drastically greater offset than +32K, all cloudy would result in a drastically lower offset than +32K. Study clouds, how and why they form, and you will be well on the way to understanding any of this recent climate change, and indeed climate change of past millenia.

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