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A warming pause?

Filed under: — stefan @ 6 October 2009 - (Español)

The blogosphere (and not only that) has been full of the “global warming is taking a break” meme lately. Although we have discussed this topic repeatedly, it is perhaps worthwhile reiterating two key points about the alleged pause here.

(1) This discussion focuses on just a short time period – starting 1998 or later – covering at most 11 years. Even under conditions of anthropogenic global warming (which would contribute a temperature rise of about 0.2 ºC over this period) a flat period or even cooling trend over such a short time span is nothing special and has happened repeatedly before (see 1987-1996). That simply is due to the fact that short-term natural variability has a similar magnitude (i.e. ~0.2 ºC) and can thus compensate for the anthropogenic effects. Of course, the warming trend keeps going up whilst natural variability just oscillates irregularly up and down, so over longer periods the warming trend wins and natural variability cancels out.

(2) It is highly questionable whether this “pause” is even real. It does show up to some extent (no cooling, but reduced 10-year warming trend) in the Hadley Center data, but it does not show in the GISS data, see Figure 1. There, the past ten 10-year trends (i.e. 1990-1999, 1991-2000 and so on) have all been between 0.17 and 0.34 ºC per decade, close to or above the expected anthropogenic trend, with the most recent one (1999-2008) equal to 0.19 ºC per decade – just as predicted by IPCC as response to anthropogenic forcing.

GISS temperature trends

Figure 1. Global temperature according to NASA GISS data since 1980. The red line shows annual data, the larger red square a preliminary value for 2009, based on January-August. The green line shows the 25-year linear trend (0.19 ºC per decade). The blue lines show the two most recent ten-year trends (0.18 ºC per decade for 1998-2007, 0.19 ºC per decade for 1999-2008) and illustrate that these recent decadal trends are entirely consistent with the long-term trend and IPCC predictions. Even the highly “cherry-picked” 11-year period starting with the warm 1998 and ending with the cold 2008 still shows a warming trend of 0.11 ºC per decade (which may surprise some lay people who tend to connect the end points, rather than include all ten data points into a proper trend calculation).


Why do these two surface temperature data sets differ over recent years? We analysed this a while ago here, and the reason is the “hole in the Arctic” in the Hadley data, just where recent warming has been greatest.

Mean temperature difference between the periods  2004-2008 and 1999-2003
Figure 2. The animated graph shows the temperature difference between the two 5-year periods 1999-2003 and 2004-2008. The largest warming has occurred over the Arctic in the past decade and is missing in the Hadley data.

If we want to relate global temperature to global forcings like greenhouse gases, we’d better not have a “hole” in our data set. That’s because global temperature follows a simple planetary heat budget, determined by the balance of what comes in and what goes out. But if data coverage is not really global, the heat budget is not closed. One would have to account for the heat flow across the boundary of the “hole”, i.e. in and out of the Arctic, and the whole thing becomes ill-determined (because we don’t know how much that is). Hence the GISS data are clearly more useful in this respect, and the supposed pause in warming turns out to be just an artifact of the “Arctic hole” in the Hadley data – we don’t even need to refer to natural variability to explain it.

Imagine you want to check whether the balance in your accounts is consistent with your income and spendings – and you find your bank accounts contain less money than you expected, so there is a puzzling shortfall. But then you realise you forgot one of your bank accounts when doing the sums – and voila, that is where the missing money is, so there is no shortfall after all. That missing bank account in the Hadley data is the Arctic – and we’ve shown that this is where the “missing warming” actually is, which is why there is no shortfall in the GISS data, and it is pointless to look for explanations for a warming pause.

It is noteworthy in this context that despite the record low in the brightness of the sun over the past three years (it’s been at its faintest since beginning of satellite measurements in the 1970s), a number of warming records have been broken during this time. March 2008 saw the warmest global land temperature of any March ever recorded in the past 130 years. June and August 2009 saw the warmest land and ocean temperatures in the Southern Hemisphere ever recorded for those months. The global ocean surface temperatures in 2009 broke all previous records for three consecutive months: June, July and August. The years 2007, 2008 and 2009 had the lowest summer Arctic sea ice cover ever recorded, and in 2008 for the first time in living memory the Northwest Passage and the Northeast Passage were simultaneously ice-free. This feat was repeated in 2009. Every single year of this century (2001-2008) has been warmer than all years of the 20th Century except 1998 (which sticks out well above the trend line due to a strong El Niño event).

The bottom line is: the observed warming over the last decade is 100% consistent with the expected anthropogenic warming trend of 0.2 ºC per decade, superimposed with short-term natural variability. It is no different in this respect from the two decades before. And with an El Niño developing in the Pacific right now, we wouldn’t be surprised if more temperature records were to be broken over the coming year or so.

Update: We were told there is a new paper by Simmons et al. in press with JGR that supports our analysis about the Hadley vs GISS trends (sorry, access to subscribers only).

Update: AP has just published an interesting story titled Statisticians reject global cooling, for which they “gave temperature data to four independent statisticians and asked them to look for trends, without telling them what the numbers represented”.


456 Responses to “A warming pause?”

  1. 251
    tamino says:

    Re: #236 (Llewelly)

    The file GLB.Ts.txt is an average based on meteorological station data only. Stefan’s graph is from the global average based on both meteorological stations and sea surface temperatures; it corresponds to the file GLB.Ts+SST.txt.

  2. 252
    Hank Roberts says:

    Karst, look at an introductory statistics book. You haven’t understood how noisy data are worked with. How probable is the detection of a trend, either up or down? See Grumbine’s explanation at the high school level. Or this:
    http://www.stat.columbia.edu/~cook/movabletype/archives/2009/09/whats_the_diffe.html#comment-927483

    What you want is the ability to argue like a scientist, without doing the math.

  3. 253
    Hank Roberts says:

    RodB, you’re trying to use logic.
    In the real situation that would get you killed.
    This is a wonderful read, recommended:

    http://forums.steves-digicams.com/landscape-photos/139226-high-arctic-eskimo.html

    “If that wind ever shifts, to south strong wind, we have to run like heck to get out of here a.s.a.p. that means everything, everybody, off the ice. it takes 8 hours to set up that whaling camp correctly, It takes just 20 minutes to “Killigvuk” EVACUATE,… RUN…One huge mass panic of over 600 people… run for your lives because it is that sudden. Ice is headed our way and it will run right over everything in its path. This advancing ice will pile up into gigantic piles.”

    At least, look at the one picture: http://majikimaje.com/images/ICE.jpg

  4. 254
    Mark says:

    “Mark:

    You seem to be saying that one dimension (depth) is more important than the other two (area).”

    You seem to believe that depth doesn’t exist.

    Without depth, the volume of ANY surface is zero.

  5. 255
    Mark says:

    “In general, ice volume varies with ice extent”

    In general, ice volume varies with depth.

    Thousands of experiments have shown this.

    So why do you ignore it?

  6. 256
    Mark says:

    You know, this ignorance of the variation of ice volume with ice depth is an astounding contrast to the complaints from many people made about how tree growth depends on lots of other things and so why is it assumed that it varies with CO2.

    Strange how those people aren’t complaining at Bob bob’s and Karst’s avoidance that volume depends on depth.

  7. 257
    chris says:

    re #113 and your comments:

    “We have gathered an immense body of solar data, but still the consensus was that this year we would witness one of the greatest sunspot years. But now we see we are in a major minimum approaching the Dalton and Maunder, and the observations completely contradict the scientific consensus.”

    That’s simply wrong on several levels Jim Steele. What “consensus” about solar cycle sunspots are you talking about!? There are very few groups that make solar cycle predictions, and by and large they produce a broad range of forecasts since this is a poorly predictable phenomenon. Here’s the NOAA prediction for solar cycle 24 from 2007, for example:

    http://www.swpc.noaa.gov/SolarCycle/SC24/index.html

    They didn’t predicted that “we would witness one of the greatest sunspot years” at all. The high prediction was similar to solar cycle 23 which was actually a relatively low sunspot cycle in the context of the last 50-odd years; the low prediction was somewhat lower. The updated prediction (May 2009) forecasts a solar cycle near the low prediction of 2007.

    We’re not “in a major minimum approaching the Dalton and Maunder” at all. What lends you to think so?

    Let’s say anyway, that we were to go into a “Maunder minimum” solar state. The “immense body of solar data” that you speak of indicates that this will produce something like 0.2 oC of cooling relative to a more “normal” evolution of solar cycles (e.g. that we’ve had during the last couple of hundred years):

    e.g. see Y.-M. Wang, J. L. Lean and N. R. Sheeley, Jr. (2005)Modeling the Sun’s Magnetic Field and Irradiance since 1713 Astrophysical J. 625 522-538

    http://www.iop.org/EJ/abstract/0004-637X/625/1/522

    and: Lean, J. L., and D. H. Rind (2008), How natural and anthropogenic influences alter global and regional surface temperatures: 1889 to 2006 Geophys. Res. Lett., 35, L18701

    http://www.agu.org/pubs/crossref/2008/2008GL034864.shtml

  8. 258
    G. Karst says:

    Hank Roberts #252

    So your definition for flat Ts is: Gosh darn, there ain’t no such thang.

    Interesting, especially as it is the subject under discussion.

  9. 259
    John Mashey says:

    re: #226 CTG
    Thanks. If RC doesn’t want it, maybe Grumbine would?

  10. 260
    Arthur Smith says:

    CTG (#226) – I’d be happy to host also – apsmith at altenergyaction.org

  11. 261
    Patrick 027 says:

    I’ll repeat my OT comment:

    OT but … I wanted to send a friend the web address for the “FAQ on climate models” parts I and II; I found part II but part I is missing – there is this website:
    http://www.realclimate.org/index.php/archives/2008/11/faq-on-climate-models/
    but it is not what it should be. Where did it go?

    Please, help. Thank you.

  12. 262
    llewelly says:

    Thank you, tamino. I feel like I should have known that.

  13. 263
    Mark says:

    “So your definition for flat Ts is: Gosh darn, there ain’t no such thang.”
    Yup.

    Show me something flat.

    Anything.

    But it has to be absolutely flat.

    Find one thing flat.

  14. 264
    Sekerob says:

    Patrick027 #261

    The link your provide IS part 1. without the number in the title or?

  15. 265
    Chris Colose says:

    Since people have been talking a bit about sensitivity and feedbacks, I just finished a post on the subject. I tried to treat the topic somewhat comprehensively while still keeping it within the limits of blog post length. Hopefully it will re-iterate or expand upon Patrick’s and other posting or clarify some matters.

  16. 266
    Patrick 027 says:

    Re 264 – thanks; the link I gave is the link given to the previous post (part I, though it may not have been called part I before there was a part II) at the part II post (or put another way, within the part II there is a link to part I; that is the link). It looks like the comments may be the comments to the original, but the post itself is just a few words in what I’m guessing is a Scandinavian language, with a link to another website that I’m guessing is in the same language. I remember the original post – it was very good, and I wish I could find it.

  17. 267
    CTG says:

    Thanks John, and the others who have offered. Bob Grumbine is kindly going to put it on his blog, so we’ll add a link when it is up.

  18. 268
    Brian Dodge says:

    re the various comments on CO2 versus time – I downloaded data on CO2 from the following 2 sites

    ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/
    http://chartsgraphs.wordpress.com/2009/08/13/excel-chart-misrepresents-co2-temperature-relationship/

    plugged it into a spreadsheet (Appleworks – kinda primitive, but presented in the spirit of open data & code)
    and (X-Y) plotted the data. The results (CO2 over 500, 2000, and 10k years) can be seen at
    http://www.imagenerd.com/uploads/co2vstime-hbg1b.jpg

    Regardless of the advent of the industrial revolution fueled consumption of fossil fuels, atmospheric CO2 concentrations didn’t really take off ’til after 1800.

  19. 269
    Hank Roberts says:

    Applause to John Mashey for wishing out loud, CTG for encoding the wish, and Robert Grumbine for hosting. Wonderful idea.

    I hope you also send it to the MIT climate people: http://web.mit.edu/globalchange/www/climate.html

    You could add a “create long flat stretches” for Karst — nah, too wishful.

  20. 270
    Jim Steele says:

    Chris #257. Your comments suggest that you are most likely a newbie to to looking at solar cycles. And if my my use of the word “consensus” bothers you then your beef is with the panel that releases a statement they all the “CONSENSUS STATEMENT OF THE SOLAR CYCLE 24 PREDICTION PANEL”

    My assertion was simply that despite our knowledge about the sun we in fact no very little, and therefore calculations about changes in solar output should have very low confidence levels. Granted the predictions vary quite a bit, I never said otherwise. But that diversity of predictions simply supports my contention that we still know very little. If some one predicted the final score of a baseball game before the game started but then changed their prediction each inning as the game progressed, you probably would not put much stock in the robustness of their predictive skills. Yet that is exactly what has the panel does. And no solar scientist I know (I am sure there may be a few) feels comfortable with their understanding to predict sunspots further out than the next cycle.

    Granted it was not the consensus prediction but NASA released the following statement suggesting an above average cycle 24. I will call 2006 the first inning of the game:

    “March 10, 2006: It’s official: Solar minimum has arrived. Sunspots have all but vanished. Solar flares are nonexistent. The sun is utterly quiet. Like the quiet before a storm. This week researchers announced that a storm is coming–the most intense solar maximum in fifty years. The prediction comes from a team led by Mausumi Dikpati of the National Center for Atmospheric Research (NCAR). “The next sunspot cycle will be 30% to 50% stronger than the previous one,” she says. If correct, the years ahead could produce a burst of solar activity second only to the historic Solar Max of 1958.
    “History shows that big sunspot cycles ‘ramp up’ faster than small ones,” he says. “I expect to see the first sunspots of the next cycle appear in late 2006 or 2007—and Solar Max to be underway by 2010 or 2011.” ”

    http://science.nasa.gov/headlines/y2006/10mar_stormwarning.htm?list791008

    Notice the prediction that solar max will occur in 2010-2011. Then check whatever source makes you happy and you will realize we are still in a minimum. Although predictions varied about the strength of the cycle, every prediction I read thought max would happen around 2010-2011.

    As the game progressed the panel then issued

    CONSENSUS STATEMENT OF THE SOLAR CYCLE 24 PREDICTION PANEL
    March 20, 2007
    The Solar Cycle 24 Prediction Panel anticipates the solar minimum marking the onset of Cycle 24 will occur in March, 2008 (±6 months). The panel reached this conclusion due to the absence of expected signatures of minimum-like conditions on the Sun at the time of the panel meeting in March, 2007:

    http://www.swpc.noaa.gov/SolarCycle/SC24/Statement_01.html

    So if you found anything in my statement confusing again your beef would be with the panel or NASA. In May 2006 they said minimum was “officially” here. Now in 2007 they predict minimum will occur in March 2008 =/- 6 months. Well minimum is still here in late 2009.

    Now in 2009 just 3 years after NASA released the statement (see above) predicting “the most intense solar maximum in fifty years.” the are now predicting “he lowest of any cycle since 1928″

    May 29, 2009: An international panel of experts led by NOAA and sponsored by NASA has released a new prediction for the next solar cycle. Solar Cycle 24 will peak, they say, in May 2013 with a below-average number of sunspots.
    “If our prediction is correct, Solar Cycle 24 will have a peak sunspot number of 90, the lowest of any cycle since 1928 when Solar Cycle 16 peaked at 78,” says panel chairman Doug Biesecker of the NOAA Space Weather Prediction Center.

    So Chris I have to use your words that your response is “wrong on so many levels”.

    So I will restate that science does not know enough to robustly predict and calculate the effect of changes in solar cycles and their effects on the climate. So until our skill improves historical correlations suggest extended solar minimums produce several decades of cooling.

  21. 271
    Mark says:

    “My assertion was simply that despite our knowledge about the sun we in fact no very little, and therefore calculations about changes in solar output should have very low confidence levels”

    However, the solar cycle can’t be too different from what we see since we have instruments that measure the solar output.

    Again we have someone say “we know very little” when we know quite a lot:

    Its age
    Its weight
    Its composition
    Its size
    Its position in the galaxy
    Its heliopause, heliosheath etc
    How it will die
    Its power output
    Its past power output
    Its variability in power
    Its magnetic strength

    and so on

    Actually, we know very little about you.

    This doesn’t mean you don’t exist and it doesn’t mean that the climate models, not knowing a lot about you, therefore must be wrong.

  22. 272

    Mark:

    Find one thing flat.

    Beer left on a table with the cap off?

  23. 273

    Jim Steele, your many words are pretty much wasted: chris said that solar events are “poorly predictable,” and you’ve really said no more than that.

    Well, that is, up until your last paragraph, where you abruptly change the subject to the effects of solar cycle changes on climate. Then, without support, you assert the insufficiency of our knowledge.

    But we are not, in fact, limited to “historical correlations.” (And a good thing, too, since the “historical atmosphere” no longer exists, having been replaced by a new higher GHG model.)

  24. 274
    Ray Ladbury says:

    Jim Steele,
    You are discussing solar conditions as if they were normal, when the last solar minimum was the longest in ~100 years. The “consensus” you refer to was quite weak and was hardly a consensus in the scientific sense. I think you are attributing a level of accuracy to solar forecasting that just isn’t there yet. This isn’t too surprising, given the Sun is a magnetohydrodynamic mystery. We don’t even have 4-pi steradian coverage of our great plasmic meatball in the sky, and helioseismology–which probably offers the best hope we have for illuminating solar dynamics==is a technique in its infancy.
    This is largely irrelevant to long-term climate dynamics, as even the most intense deviations of solar behavior from the mean last decades, and the contributions of CO2 last centuries to millennia.

  25. 275
    Martin Vermeer says:

    Jim Steele #270, you may restate the same misconception as often as you like, it still is a misconception.
    Yes, the predictors of Solar activity update their predictions as time moves forward — just like weather predictors do, and for pretty much the same reason: it is an inherenty ill-predictable thing. That doesn’t mean that the physics is not understood. To the contrary: it’s the physics that tells us that it’s ill predictable…
    I asked you if you knew how deep the cooling was during the Little Ice Age / Maunder minimum. Assuming (debatable) that this was caused by the quiet Sun, it would give you an upper bound on the cooling to be expected. The number is the same 0.2C chris quotes above from the literature — little comfort when CO2 is piling up that same amount every decade.

  26. 276
    dhogaza says:

    My assertion was simply that despite our knowledge about the sun we in fact no very little, and therefore calculations about changes in solar output should have very low confidence levels. Granted the predictions vary quite a bit, I never said otherwise. But that diversity of predictions simply supports my contention that we still know very little.

    Don’t conflate the problem of not being able to accurately predict the end of the current solar cycle (for instance) with the problem of being able to predict the range of TSI variance due to solar cycles.

    (I’m going to break this into parts because the spam filter hates me for some reason)

  27. 277
    dhogaza says:

    OK onwards oh spam filter:

    To user your baseball analogy, predicting who will win and by what score isn’t possible at the beginning of a game.

    However I can predict with 100% confidence that the two scores will each be >= 0 at the end of the game, and I can predict with 100% confidence that the sum of the two scores will be > 0.

  28. 278
    dhogaza says:

    And lastly (it probably thought my further discussion of the baseball analogy was gambling-related?)

    So until our skill improves historical correlations suggest extended solar minimums produce several decades of cooling.

    Yet the current minimum sees us with the warmest decade in the instrumental record …

  29. 279
    dhogaza says:

    Last try …

    Baseball: Most likely that sum (of the two scores) will fall on a normal distribution centered around “a few runs”.

    Since I’m not actually doing an analysis I won’t attempt to define “a few” more precisely, but with the data at hand one could, though the center of the distribution may be different year-to-year. For instance, the end of the dead-ball era led to higher scores.

    For climate predictions, being able to predict the exact start and end of solar cycles isn’t really important, it’s being able to pin down the range of variability of TSI over time.

  30. 280
    Jim Eager says:

    Brian Dodge @268 wrote: “atmospheric CO2 concentrations didn’t really take off ’til after 1800.”

    Which pretty much agrees with what I wrote @250, no?.

    But on your long scale 10k plot, note that post-glacial natural CO2 levels peak just under 270 ppmv ~8.5-8k ago, just before the Holocene Climate Optimum, and then begin a shallow 3000 year decline to ~260 ppmv as northern hemisphere summer solar insolation decreases, only to reverse and begin an even longer shallow 5000 year rise to ~280 ppmv at the beginning of the industrial revolution (1750, 1800+, or whenever you choose to mark it).

    William Ruddiman contends that this is the initial anthropogenic greenhouse signature produced by the development of agriculture, through land clearance and removal of a carbon sink and release of stored carbon by burning wood for cooking and heating fuel, and rice cultivation and an increase in methane emissions from paddies, which are engineered wetlands, with that CH4 oxidizing to CO2 in the atmosphere. Ruddiman’s hypothesis is that this anthropogenic forcing became strong enough to first offset and then reverse orbital insolation forcing as long as 5000-6000 years ago.

  31. 281
    Mark says:

    ” Find one thing flat.

    Beer left on a table with the cap off?”

    You’ll given him ideas.

    Anyway, the beer’s never flat.

    I drank it…

  32. 282
    RichardC says:

    Arctic ice could be part of the issue. “Extra” ice melt which reveals open water centers in the late summer and fall, when the sun is quickly declining. Yes, open water absorbs more heat from what little sun there is, but it also emits more heat to space. As open water remains further into winter, the energy budget changes towards cooling of the planet. This seems to be a natural “speed bump” which has to be overcome in order for warming to continue. Thus, it is possible that we’re just in a temporary and necessary period which will last until ice melt gets earlier in the season, enough to counteract this negative feedback. My guess is that once the multi-year ice is essentially gone, we’ll head down the far side of the speed bump and enter a warmer world.

  33. 283
    Rod B says:

    Mark, this is becoming surreal, though in an odd reverse sort of way I think you answered my question. No one has said that volume does not depend on depth. It most certainly does… along with Length and Width — the latter two (strangely???) directly tied to extent — of either butter or ice. No matter how pedantically you slice it, and ignoring the improbable freaks of nature, the greater the extent of sea ice, the greater the volume of the sea ice riding the extent. Though the volume grows faster than the extent because of the buildup of the thickness (depth — TA DA!) as you back away from the extent edge. (Though not always smoothly as Hank points out). That’s just how ice, which has no concept of butter knives and bread slices, forms. Also things can be proportional without having a specific and unique constant of proportionality.

    Jeeeze.

  34. 284
    Ray Ladbury says:

    Mark says, “Anyway, the beer’s never flat. I drank it…”

    Oh, that explains a lot…

  35. 285
    Ray Ladbury says:

    Jim Steele, You seem to be falling victim to the “we don’t know everything, so we know nothing” fallacy–a favorite of creationists, denialists and other anti-science types. Don’t go there. First, you need to understand what is unknown, but then you need to understand if it is relevant for the phenomena at hand.

  36. 286
    Phil. Felton says:

    Rod it is area rather than extent which important, for example a 12.5×12.5 km pixel which is deemed to be sea ice could have as little as 15% ice coverage whereas the area would be 23.5 compared with 156.25 (for 100% coverage). Also the ice thickness has been steadily decreasing so the same extent/area from year to year represents less ice than before.

  37. 287
    Mark says:

    “No one has said that volume does not depend on depth”

    You’ce consistently ignored it though.

    Area doesn’t give you volume.

    “along with Length and Width — the latter two (strangely???) ”

    But you are using area. not length and width.

    “Though the volume grows faster than the extent because of the buildup of the thickness (depth — TA DA!)”

    Nope. Not necessarily.

    Please prove.

    Here’s a very simple example: homogeneous ice can reduce its volume drastically by thinning. If the ice is a flat rectangular block like a domino, then the volume drop is more dependent on the thinness of the ice not its extent (it melts from the top, which reduces depth, not area).

    “That’s just how ice, which has no concept of butter knives and bread slices, forms.”

    No, wrong again. Prove that the sea ice has done this.

    Here’s how this is trivially wrong: when ice breaks up, there is more water per ice area. But as long as it is more than 15% ice, it remains counted as ice extent.

    You can easily therefore get a fivefold difference in ice extent without changing volume on iota.

    1) Shepherd all the ice together so that there is no gap between each lump of ice.

    Measure the extent.

    2) Cut each square meter of ice top surface up and place them so that there is one cube of ice in each 5m square area.

    Measure the extent.

    Both count as “ice extent” but #2 has a figure 5 times that of #1 yet no change in volume.

    Now when panice breaks up, what happens?

    Something like what happens in #2.

    So how can you have measured ice total when all you’ve measured is the ice extent?

    You cannot.

    Hence “try again”: your figures are not comparable since you have ignored depth.

    You can afford to miss depth out no more than you can afford to miss surface area. But in the graph pointed to, that isn’t what’s being measured.

    So it’s not even surface area you’re trying to make out to be ice volume.

    Please try again.

  38. 288
    Hank Roberts says:

    Rod, you’re using logic again, and it’s still failing you.

    You write
    > the volume grows faster than the extent … That’s just how ice … forms

    You can’t generalize like this unless your only aim is to prolong a digression for the amusement of whoever’s encouraging it. Please stop.

    Large expanse of open water in the fall, as freezing starts.
    Large amount of pancake ice, agglomerating into larger sheets with time.
    Typical extensive first year sheets of sea ice, all very thin.

    Seriously, man, go back ’round to the stables and count the teeth in the horse, don’t tell us what logic says must be the right number.

  39. 289
    Mark says:

    “Also things can be proportional without having a specific and unique constant of proportionality. ”

    It does have to be constant, though.

    If it changes, then it’s not a proportionality.

    So, has the depth remained unchanged over the years?

    No.

    Sheesh.

  40. 290
    Donald says:

    Hello,

    The BBC has just published a really dreadful article on this theme, full of errors, misrepresentations, sceptical voices given equal weight to mainstream science… the author seems to have picked most of it up from sceptical web sites on the internet.

    Any chance of somebody getting in touch with the BBC and tell them how dreadful the article is?

    http://news.bbc.co.uk/2/hi/science/nature/8299079.stm

  41. 291
    dhogaza says:

    No matter how pedantically you slice it, and ignoring the improbable freaks of nature, the greater the extent of sea ice, the greater the volume of the sea ice riding the extent.

    Well, except NASA satellite observations support the following claim:

    Even in years when the overall extent of sea ice remains stable or grows slightly, the thickness and volume of the ice cover is continuing to decline

    This includes 2008 vs. 2007 – minimum extent was above the record 2007 level, yet 2000 cubic kilometers were lost.

  42. 292
    Krog says:

    #237 JPR
    Thank you for the info & URL. It is bookmarked.
    I that the CO2 problem will be on the way to solution when a consensus forms to tax oil, gas, & coal at the drillhead and mine. Then let the market do what it does best.

  43. 293
    David Horton says:

    #289 I have just put the following into the “contact us” section on the BBC web site. Other RCers might like to try their own versions.

    “The article by Paul Hudson”What happened to global warming?” is unworthy of the BBC. To answer Mr Hudson’s rhetorical question, it is getting worse. Can we expect further in the series of meaningless “balance”? “What happened to evolution?” “What happened to relativity?” “What happened to the germ theory of disease?” “What happened to atomic theory?” Does Mr Hudson want to try his hand at any of these? Come on, lift your game BBC, this rubbish could have appeared on any of the notorious denialist sites around the world. We expect better of you.”

  44. 294
    Tom Dayton says:

    Greenman3610 has created a video that starts with video of Latif speaking, and follows with Beck, Hannity, and so on’s wild distortions. Highly recommended! http://www.youtube.com/user/greenman3610#p/a

  45. 295
    Ray Ladbury says:

    Tom Dayton says, “Greenman3610 has created a video that starts with video of Latif speaking, and follows with Beck, Hannity, and so on’s wild distortions. Highly recommended!”

    You supplying the anti-emetics and the special glasses to protect us from the 3rd degree stupidity burns as we watch geniuses like this?

  46. 296
    Wolff says:

    From the BBC article.

    “Piers Corbyn….claims that solar charged particles impact us far more than is currently accepted, so much so he says that they are almost entirely responsible for what happens to global temperatures.

    He is so excited by what he has discovered that he plans to tell the international scientific community at a conference in London at the end of the month.

    If proved correct, this could revolutionise the whole subject.”

    Any thoughts on what this “discovery” could be?

    [Response: Corbyn has been hyping a supposed solar based forecasting system that he has never described for years. James Annan had a whole series of posts on how it doesn’t produce good forecasts, so this discovery is very unlikely to punt to anything. Significant black mark against the Beeb’s coverage. – gavin]

  47. 297

    #283 Rod Black

    In addition to Ray and Mark, and Hanks comments…

    It is clear in the observations that ice extent increases in width before the multiyear (thickness/volume) builds.

    I just added some new images (more to come). Some of these graphs may provide perspective:

    http://www.ossfoundation.us/projects/environment/global-warming/myths/images/arctic

    First, ice extent grows, then, if things stay cold enough, it is added to and 1st yr ice becomes 2nd year ice, and so on.

    If conditions don’t warrant multiyear ice growth, then the thickness does not build. The general (non linear) trend is down for ice mass/volume/thickness.

  48. 298
    Mark says:

    Thank you ray, for that meaningless, but heartfelt comment.

  49. 299
    dave p says:

    Will the cooling phase of the Pacific Oscillation be a big drag on the warming trend?

  50. 300
    RichardC says:

    291 dhogaza said, “NASA satellite observations support the following claim:
    Even in years when the overall extent of sea ice remains stable or grows slightly, the thickness and volume of the ice cover is continuing to decline
    This includes 2008 vs. 2007 – minimum extent was above the record 2007 level, yet 2000 cubic kilometers were lost.”

    Yes, but other data doesn’t always agree. According to the polar 5 survey, ice thickened somewhat. Now, polar 5 was a linear and limited survey, but its technique seems more reliable.
    http://www.sciencecentric.com/news/article.php?q=09050433-research-aircraft-polar-5-finishes-arctic-expedition


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