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2008 temperature summaries and spin

Filed under: — gavin @ 16 December 2008 - (Italian)

The great thing about complex data is that one can basically come up with any number of headlines describing it – all of which can be literally true – but that give very different impressions. Thus we are sure that you will soon read that 2008 was warmer than any year in the 20th Century (with the exception of 1998), that is was the coolest year this century (starting from 2001), and that 7 or 8 of the 9 warmest years have occurred since 2000. There will undoubtedly also be a number of claims made that aren’t true; 2008 is not the coolest year this decade (that was 2000), global warming hasn’t ‘stopped’, CO2 continues to be a greenhouse gas, and such variability is indeed predicted by climate models. Today’s post is therefore dedicated to cutting through the hype and looking at the bigger picture.

As is usual, today marks the release of the ‘meteorological year’ averages for the surface temperature records (GISTEMP, HadCRU, NCDC). This time period runs from December last year through to the end of November this year and is so-called because of the fact that it is easier to dice into seasons than the calendar year. That is, the met year consists of the average of the DJF (winter), MAM (spring), JJA (summer) and SON (autumn) periods (using the standard shorthand for the month names). This makes a little more sense than including the JF from one winter and the D from another as you do in the calendar year calculation. But since the correlation between the D-N and J-D averages is very high (r=0.997), it makes little practical difference. Annual numbers are a little more useful than monthly anomalies for determining long term trends, but are still quite noisy.

The bottom line: In the GISTEMP, HadCRU and NCDC analyses D-N 2008 were at 0.43, 0.42 and 0.47ºC above the 1951-1980 baseline (respectively). In GISTEMP both October and November came in quite warm (0.58ºC), the former edging up slightly on last month’s estimate as more data came in. This puts 2008 at #9 (or #8) in the yearly rankings, but given the uncertainty in the estimates, the real ranking could be anywhere between #6 or #15. More robustly, the most recent 5-year averages are all significantly higher than any in the last century. The last decade is by far the warmest decade globally in the record. These big picture conclusions are the same if you look at any of the data sets, though the actual numbers are slightly different (relating principally to the data extrapolation – particularly in the Arctic).

So what to make of the latest year’s data? First off, we expect that there will be oscillations in the global mean temperature. No climate model has ever shown a year-on-year increase in temperatures because of the currently expected amount of global warming. A big factor in those oscillations is ENSO – whether there is a a warm El Niño event, or a cool La Niña event makes an appreciable difference in the global mean anomalies – about 0.1 to 0.2ºC for significant events. There was a significant La Niña at the beginning of this year (and that is fully included in the D-N annual mean), and that undoubtedly played a role in this year’s relative coolness. It’s worth pointing out that 2000 also had a similarly sized La Niña but was notably cooler than this last year.

While ENSO is one factor in the annual variability, it is not the only one. There are both other sources of internal variability and external forcings. The other internal variations can be a little difficult to characterise (it isn’t as simple as just a super-position of all the climate acronyms you ever heard of NAO+SAM+PDO+AMO+MJO etc.), but the external (natural) forcings are a little easier. The two main ones are volcanic variability and solar forcing. There have been no climatically significant volcanoes since 1991, and so that is not a factor. However, we are at a solar minimum. The impacts of the solar cycle on the surface temperature record are somewhat disputed, but it might be as large as 0.1ºC from solar min to solar max, with a lag of a year or two. Thus for 2008, one might expect a deviation below trend (the difference between mean solar and solar min, and expecting the impact to not yet be fully felt) of up to 0.05ºC. Not a very big signal, and not one that would shift the rankings significantly.

There were a number of rather overheated claims earlier this year that ‘all the global warming had been erased’ by the La Niña-related anomaly. This was always ridiculous, and now that most of that anomaly has passed, we aren’t holding our breath waiting for the ‘global warming is now back’ headlines from the same sources.

Taking a longer perspective, the 30 year mean trends aren’t greatly affected by a single year (GISTEMP: 1978-2007 0.17+/-0.04ºC/dec; 1979-2008 0.16+/-0.04 – OLS trends, annual data, 95% CI, no correction for auto-correlation; identical for HadCRU); they are still solidly upwards. The match of the Hansen et al 1988 scenario B projections are similarly little affected (GISTEMP 1984-2008 0.19+/-0.05 (LO-index) 0.22+/-0.07 (Met-station index); HansenB 1984-2008 0.25+/-0.05 ºC/dec) – the projections run slightly warmer as one would expect given the slightly greater (~10%) forcing in the projection then occurred in reality. This year’s data then don’t really change our expectations much.

Finally, as we’ve discussed before, what climate models did or did not predict is available for all to see. Despite many cautions about using short-term changes to imply something about the long-term trend, these comparisons will still be made. So just for fun, here is a comparison of the observations with the model projections from 1999 to 2008 using 1999 as a baseline. The answer might be surprising for some:

1999-2008 model and data trends

You can get slightly different pictures if you pick the start year differently, and so this isn’t something profound. Picking any single year as a starting point is somewhat subjective and causes the visual aspect to vary – looking at the trends is more robust. However, this figure does show that in models, as in data, some years will be above trend, and some will be below trend. Anyone who expresses shock at this is either naive or … well, you know.

As for the next few years, our expectations are not much changed. This coming winter is predicted to be ENSO neutral, so on that basis one would expect a warmer year next year than this year (though probably not quite record breaking). Barring any large volcanic eruption, I don’t see any reason for the decadal trends to depart much from the anticipated ~0.2ºC/decade.

Update: Just FYI, the same figure as above baselined to 1990, and 1979.


393 Responses to “2008 temperature summaries and spin”

  1. 101
    JW says:

    Gavin – thanks for your responses to me, above. In an article cautioning about “spin”, I can see it would be difficult for you not to engage in a little spin of your own.

    Quote from your article: “Thus we are sure that you will soon read that 2008 was warmer than any year in the 20th Century (with the exception of 1998), that is was the coolest year this century (starting from 2001), and that 7 or 8 of the 9 warmest years have occurred since 2000. There will undoubtedly also be a number of claims made that aren’t true; 2008 is not the coolest year this decade (that was 2000),…”

    So, the phrase “was the coolest year this century” is correct, but the phrase “2008 is not the coolest year this decade” is not correct? If “This century” is from 2001 on, then in order to be consistent, “this decade” should also be from 2001 on. If 2008 was the coolest year this century, then it is also the coolest this decade. Or, they both should be relating to the last 100 years or last 10 years, respectively. It’s your site, it’s your spin.

    I understand your reluctance last year to have predicted 2008 would be cooler than 2007.

    Regards,
    JW

    [Response: With all due respect, this is kind of tedious. A decade is ten years. 2008 is not the coldest year this decade. Enough already. - gavin]

  2. 102

    #98–”The problem is this whole ranking of individual years, which is not a good way to think about climate.”

    Well, it’s not the most sophisticated. But it is a useful way to get at trends when talking with folks without a statistical background. For a lot of people, the statement that “every year from 2001 forward falls in the list of the 10 warmest years of all time,” is a powerful corrective to the “it’s been cooling since 1998″ meme. Many people have trouble seeing why you shouldn’t just make that obvious point-to-point comparison.

  3. 103
    jorge kafkazar says:

    # jcbmack Says:
    16 December 2008 at 3:55 PM

    “Gavin, good presentation as always, but this one in particular shows why global warming is still happening and why it will not just go away.”

    I agree. The graphs themselves are particularly impressive examples of intermodel concurrency. Although the scatter may appear at first glance seem quite extensive, it’s readily obvious to the eye that, despite broad swings of the various models, the actual data record trendlines stays well within the +/- 1 sigma envelope, very similar to the way it would have if random numbers had been used instead of the GC models. Perhaps not profound, but very interesting and very illustrative nonetheless.

  4. 104
    S2 says:

    If global warming hasn’t “stopped”, then why isn’t it getting warmer? Your 1999 figure shows 2008 almost returning to 1999 levels. Do we see any reason to expect an upturn in 2009?

    If 2009 turns out to be cooler than 2008, then that would probably put it below the warmest ten years seen to date.

    It’s not impossible, but this hasn’t happened since 1992.

    I would bet money on 2009 being warmer than 2008.

  5. 105
    John Millett says:

    Gavin’s response to #72 warned of the greater uncertainty of 19th century data. Statistical analysis reveals in the more recent 1959 – 2005 period, that when emissions increased relative to trend, temperatures fell relative to trend; and vice versa. The science says that emissions are linked to temperature via atmospheric concentration of CO2. During this period, when emissions increased relative to trend, concentration fell relative to trend; and vice versa. The corollaries of this counter-intuitive finding are: atmospheric CO2 concentration must be responding to something other than emissions; controlling emissions won’t control concentration; and if, as protagonists claim, concentration controls temperature, policies to control emissions would fail to achieve their objective.

    Over the period 1959-2007 direct correlation between concentration and temperature implies that changes in the former explain about half the changes in the latter. However, correlation does not necessarily denote causation; concentration and temperature could both be responding independently to a third climate agent, as two features of the climate system suggest is likely. Given that the atmosphere does not mix across the equator and that most emissions of CO2 are generated in the northern hemisphere, how do they become uniformly distributed in the atmosphere? And how does uniformly distributed CO2 concentration cause the northern hemisphere to warm faster than the southern one? While the atmosphere keeps to its side of the equator, ocean currents, with which the atmosphere exchanges CO2, range across it. There is here a strong suggestion that the oceans, not emissions, are feeding the atmosphere with CO2. Not only do the oceans range more widely than the atmosphere but they constitute an infinitely greater heat sink with commensurately greater potential to affect surface temperatures around the globe. Oceans could be the third climate agent affecting both concentration and temperature, rendering spurious the observed correlation between them. Add the inverse correlation between emissions and concentration and severe doubt emerges about man’s ability to control temperature by controlling emissions.

  6. 106
    steve says:

    I have to admit I’m a bit confused on why a changing current does not effect the energy budget when they are known to effect the temperature. Wouldn’t the albedo of the earth change depending on how severe winters were and the location where most storm fronts occurred. Could anyone point me to a paper on this I hate to waste everyone’s time answering someone out of their field. thanks

  7. 107
    Aaron Rury says:

    One of the major policy pushes in reference to AGW is to systematically reduce the amount of carbon that is emitted into the atmosphere. Since we are exactly sure what the impact of carbon emitted into the atmosphere, besides its effect on overall absorption of light, is it too naive to think that just reducing the amount of carbon emitted into the atmosphere will reduce the temperature? Is there a way to a priori determine whether or not the atmosphere with exhibit a hysteresis between CO2 concentration and temperature as we reduce carbon emission? I have tried to find some publication that research this idea, but have not found anything on the topic. Any directions would be much appreciated. Thanks.

  8. 108
    David B. Benson says:

    John Millett (105) — I disagree with central points in your analysis, but I’ll just mention that CO2 is well-mixed in the atmosphere with a mixing time of about 2 years; air does cross the ITCZ.

    And of course the southern hemisphere, being mostly ocean, warms more slowly than the northern hemisphere.

    Oh yes. You might also care to look at the great changes in atmospherin methane over the interval of interest to you.

  9. 109
    David B. Benson says:

    Aaron Rury (107) — Even if human-caused emission ceased today, the world would continue to warm for centuries as the oceans slowly respond to the extra warmth. There are many papers, but I suggest you read David Archer’s “The Long Thaw” as a place to begin.

  10. 110
    Jim Eager says:

    Re Red Etin @62: “Looks at the facts of sea ice cover, not the waving and frothing of alarmists:
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg

    Which tells us only that the Arctic still refreezes each winter but tells us nothing about the age or volume of that ice.

    What was that you were saying about waving and frothing?

  11. 111
    Ray Ladbury says:

    John Millett, Great. Now go design a climate model that explains everything in terms of your idea, figure out exactly by what mysterious mechanism ocean currents are controlling everything and you can get famous and go on Oprah! Go ahead. We’ll wait.

  12. 112
    S. Molnar says:

    OT: I have grown to expect RC to cover the Fall AGU meeting. Is a post planned? Even if we can’t have the incomparable liveblogging of raypierre this year, a quick summary of potentially interesting developments would be welcome.

  13. 113
    Ike Solem says:

    RE#33

    Quote: “What we don’t have is a word for what happens over periods from a few weeks to few decades.”

    That’s likely mostly ocean variability, plus random events like large volcanic explosions. Pinatubo, for example. Here’s a worthwhile post with comments from 2006 on that, interesting in hindsight (since the 2005 estimates of cooling ocean surface waters were based on flawed data):

    http://www.realclimate.org/index.php/archives/2006/08/ocean-heat-content-latest-numbers/

    For the published report, see Robock:
    http://climate.envsci.rutgers.edu/pdf/VEAChapter1_Robocknew.pdf

    The ocean is where many of the greatest uncertainties lie, but those are mostly of the week-to-decade variety, as far as long-term temperature trends due to atmospheric CO2 forcing go…. Spreading ocean hypoxia might be a bigger concern than ocean acidification, actually – but with such limited data, it’s hard to tell. We do know that large hypoxic zones are now a regular part of the seasonal regime of many ocean areas, from the Pacific NW to the Gulf of Mexico. We don’t really seem to have a good idea of how major ocean circulation patterns will change as the planet warms, either. The El Nino/Southern Oscillation is an example of internal variability, but it’s also an example of changes in the heat/water vapor exchange between ocean and atmosphere brought on by atmospheric and oceanic circulation changes, and all that will itself be influenced by warming waters and land bodies.

    As far as abrupt climate change, the first examples might be transitions to permanent drought regimes, with global warming-induced changes in atmospheric circulation over the oceans playing a role. “Abrupt” here means over a 30-year period or so, as in sub-Saharan Africa.

    1. http://www.newscientist.com/article/dn9229-global-warming-stretches-subtropical-boundaries.html

    2. Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North America, Seager et. al 2007

    3. Widening of the tropical belt in a changing climate, Siedel et. al 2008

  14. 114
  15. 115
    Ron Durda says:

    Gavin,
    Re: your response to JW in post 101 (Dec. 18, 5pm).

    With all due respect there seems to be two plausible interpretations to your statement that, “A decade is ten years. 2008 is not the coldest year this decade”.

    Webster’s New World Dictionary, Third College Edition, provides two definitions that are germane to this issue. A-“a group of ten“, and B “ …officially, a ten year period beginning with the year 1, as 1921-1930…etc. [and in] common usage, a ten year period beginning with a year 0, as 1920-1929…etc.”

    Thinking of def. “A”, your claim about the coldness of 2008 could be paraphrased 2008 is not the coldest year IN THE PAST TEN YEARS, while with def. “B”, the paraphrasing would be that 2008 is not the coldest year SO FAR this decade (either officially or in common usage).

    This ambiguity could be resolved if you would give an actual starting date for your decade…or did I miss it?

    Thank You,
    Ron.

  16. 116
    Dave Werth says:

    Gavin, in #100 you said “…temperatures reaching from the surface to 10km, …”. Is that 10km above the surface regardless of the elevation of 10km above sea level?

    [Response: Actually it varies as a function of surface type. Closer to 10km above the surface than above sea-level though. - gavin]

  17. 117

    #62 Red Etin says:

    Looks at the facts of sea ice cover, not the waving and frothing of alarmists:

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg

    I looked at that, thank you. With neither waving nor frothing, I observed that the minimum summer sea ice extent dropped from 5.5Mkm2 to 3Mkm2 over the period graphed, a decrease of 45%. Is that what you wanted us to pay attention to? Or were you hoping that sneering would frighten us off from checking the facts?

    We have a recent prediction from a large study that the Arctic will be ice free by 2015, a big advance on the previous surprise prediction of 2030.

    Purely looking at ice extent misses another important variable, ice thickness. As ice becomes thinner because more of it is fresh since last summer (here’s a reference with a more complete analysis), sea ice extent can fall of very fast in summer.

  18. 118
    rando says:

    Re 117: I’m willing to bet you 1 million dollars that the Arctic will not be ice free by 2015.

    [Response: You'd be better off finding someone who predicted that (if anyone) - gavin]

  19. 119
    Hank Roberts says:

    Rando, the bets so far are about summertime ice, is that what you mean?
    See Stoat for details.

    S.Molnar, re blogging from the ACU, I agree, I’d been hoping to hear more from those attending this year. There are some out there:

    http://www.google.com/search?q=2008+AGU+%22San+Francisco%22+blogging

  20. 120

    Rando (#118): Of course I meant summer ice (#117), not the whole year.

    It’s kind of silly to score points on a narrow nitpick. The world climate does not depend on my (or any one elses) ability to express myself clearly.

  21. 121
    Mark says:

    re #118. Do you even HAVE a million?

    OK, I bet a bajillion squillion dollars.

  22. 122
    Mark says:

    Aaron, 107, it will stop getting worse quicker. That’s all that will be certain of happening. Depending on how MUCH we reduce output, the CO2 may start reducing fairly quickly, though the results of this may be unwelcome (acidic waters, for example). The inertia of the system may still continue but the length of time for that change to get noticed depends on how much CO2 is reduced.

    Maybe the reason why you find nothing is because it’s not a question that needs to be answered.

    After all, if your doctor tells you to stop smoking because of the cancer risk, you stop. This may not stop a cancer that has already started growing but if there is one, it is easier to treat.

  23. 123
    Andrew says:

    Re #106 Steve;

    This paper describes trends in snow cover extent.

    http://www.unep.org/geo/geo_ice/PDF/GEO_C4_LowRes.pdf

    Notice; snow cover extent in the Northern Hemisphere shows a decline except for the months of November and December. Since there is little sun shine during those months, the albedo feedback are minimal.

    In contrast, reduction in snow cover extent is greatest during the spring when albedo feedback is more significant.

    The increased amount of winter snow cover has many people wondering about global warming. However, it is happening because global warming is also leading to increased precipitation, especialy in the winter.

    Re # 115 Rando;

    Could we agree that an ice free arctic corresponds to less than 0.1 Mkm^2 of sea ice and on a definition of a climatically significant volcanic eruption?

  24. 124
    Nick Gotts says:

    As scientific men we should set up a common set of parameters for verification. – Anon

    All you women, don’t you bother your pretty little heads about climate change any more, you hear?

  25. 125
    Ray Ladbury says:

    Mark and Rando: In the interest of keeping the bet fair, I volunteer to hold the money while we wait for the outcome. ;-)

  26. 126
    ldavidcooke says:

    Gavin,

    One quick question, what happens to the trend line if you base it on the mean of the entire population of all the various records, rather then on start year or a specific representative sample year? In short, my thoughts are that comparing data against the entire population values with trend lines for peaks, valleys and averages should provide some interesting fodder for conversation.

    Thanks,
    Dave Cooke

  27. 127
    Ike Solem says:

    Don’t forget that most of the warming is going into the oceans. That’s the essential reason why the long-term trend is robust – there will be many fluctuations in surface temperature, but the warming signal in the oceans is just as strong.

    Note that ocean temperature changes can be much smaller, yet represent far greater amounts of energy change. If you take a cubic meter of ocean, and a cubic meter of dry air, the difference in the ability to store heat is over 3000-fold (4.186 J/cm^3-K vs. .0013 for air)

    Thus, if the oceans are warming, that will not be erased by any short-term fluctuations in atmospheric temperature. And yes, the oceans are warming:
    http://www.sciencemag.org/cgi/content/abstract/309/5732/284

    Penetration of Human-Induced Warming into the World’s Oceans,
    Tim P. Barnett,1* David W. Pierce,1 Krishna M. AchutaRao,2 Peter J. Gleckler,2 Benjamin D. Santer,2 Jonathan M. Gregory,3 Warren M. Washington4

    Science 8 July 2005:
    Vol. 309. no. 5732, pp. 284 – 287

    A warming signal has penetrated into the world’s oceans over the past 40 years. The signal is complex, with a vertical structure that varies widely by ocean; it cannot be explained by natural internal climate variability or solar and volcanic forcing, but is well simulated by two anthropogenically forced climate models. We conclude that it is of human origin, a conclusion robust to observational sampling and model differences. Changes in advection combine with surface forcing to give the overall warming pattern. The implications of this study suggest that society needs to seriously consider model predictions of future climate change.

    1 Climate Research Division, Scripps Institution of Oceanography, 0224, La Jolla, CA 92037, USA.
    2 Program for Climate Model Diagnoses and Intercomparison/Lawrence Livermore National Laboratory, Post Office Box 808, Livermore, CA 94550, USA.
    3 UK Met Office Hadley Centre and University of Reading, Reading RG6 6BB, UK.
    4 National Center for Atmospheric Research, Post Office Box 3000, Boulder, CO 80307, USA.

    There is no uncertainty about that. Nevertheless, world leaders continue to ignore the reality while making plans to continue with business-as-usual. It’s the Mbeki-Mugabe phenomenon (wrt HIV/AIDS) on a much larger scale – government leaders ignoring science in favor of their own peculiar beliefs – Mbeki appeared to truly believe that HIV did not cause AIDS, and that retroviral drugs were toxic.

    Mbeki ignored the science on HIV, Guardian UK, Dec 17 2008

    “Malicious or not, the former South African president’s Aids policy is responsible for hundreds of thousands of deaths.”

    The same can be said of many other world leaders, whose lack of action today and over the past few decades will also result in hundreds of thousands (if not millions) of deaths over the decades to come.

  28. 128
    reenactor says:

    Actually, I don’t think anyone with an 8th grade education would describe 2008 as the warmest year of the TWENTIETH century.

  29. 129
    William says:

    #113 Ike Solem
    You state: “We don’t really seem to have a good idea of how major ocean circulation patterns will change as the planet warms” If that’s the case then the there must not be a good understanding of ocean circulation patterns i.e. the science is not settled.

    You State: “As far as abrupt climate change, the first examples might be transitions to permanent drought regimes” Either it will or will not, when you say something “might” happen it’s uncertain therefore the science on that is unsettled.

    You state: “That’s likely mostly ocean variability, plus random events like large volcanic explosions”. Which is it? Not knowing is uncertainty i.e. the science is not settled.

    It was my understanding that the science was settled on climate change. Anything might happen. If your premise is that the GCM’s are certain about what will happen then there is no need to qualify your statements and predictions. Otherwise let’s all agree to the statement GCM’s might be right or they might be wrong and remove all this reference about the science being settled.
    Thanks
    William

    [Response: Now this is tendentious twaddle. Perhaps you would care to point out anywhere on this site, or in anything any of us have written that declares that 'the science' (whatever that means) 'is settled'? This is simply a false binary distinction (settled/unsettled) foisted on a much more complex situation where there are large gradations in what is understood, done purely to imply that if something is unsettled, we can say nothing. Well, that is BS. (Sorry to be harsh, but really!). - gavin]

  30. 130
    Hank Roberts says:

    reenactor; you “don’t think anyone … would” — no one has said anything like what you’re mocking. Did you misread the original post?

  31. 131
    snorbert zangox says:

    Gavin,

    I am not sure that you (in your discussion of incommensurate satellite data) are not merely talking about a different, albeit more complex, physical model needed to get from signal strength to temperature. Every means of measuring temperature requires application of mathematics based on physical theory to convert a signal to a temperature. Liquid in glass thermometers require a different set of physical theory and mathematics than do thermocouples.

    Would you say that data from those two methods are incommensurate?

    [Response: Not unless you had good reasons to suspect that there was a problem there. But why can't you just accept that a weighting of temperature from the ground to 10km, varying as a function of location, is a different quantity than the surface temperature anomaly? Just because something is measured in the same unit, doesn't make it the same. Just for fun, look up what the mean MSU-TLT temperature is globally (not the anomaly, the absolute number), and then come back and tell me it's the same as the surface temperature. They are related, but they are not the same. - gavin]

    Moving on to a slightly different subject. Anthony Watt is at it again. He has plotted the 20th century temperature data as reported by USHCN to the same data as adjusted by GISS for a single station in Santa Rosa NM. (http://wattsupwiththat.com/2008/12/08/how-not-to-measure-temperature-part-79-would-you-could-you-with-a-boat/#more-4455). Mr. Watt demonstrates that 100% of the warming at this station during the 20th century occurred during the adjustment process. The folks over at Climate Skeptic repeated the exercise for the entire 20th century United States temperature record and found a similar result (http://www.climate-skeptic.com/2008/12/global-warming-is-caused-by-computers.html).

    Hmmm.

    To be fair, both sources acknowledge that there are legitimate reasons for making post-measurement adjustments to the raw temperature data, and I agree. I just find it peculiar that the raw temperature record would show little or no warming, but the adjusted data do show warming.

    My musing on all of this led me to an actual question, which is, “What physical data would induce you to reconsider your belief that anthropogenic carbon dioxide is causing the ongoing warming?”

    I know that I am waiting for the GCMs to make some accurate projections of climate conditions before I will reconsider my position. It often seems similar to Waiting for Godot.

    [Response: Well instead of waiting around aimlessly, I suggest you do some reading. Hansen et al 1992 for instance, or even Hansen et al 1988, or Legrande et al, 2006, or IPCC(1990) etc. For what is being claimed in the future, the models have already demonstrated skill. And as for CO2 not causing warming, try redoing the whole of the HITRAN database, showing that Tyndall (1867) and everyone who has followed was wrong, find another reason why the ice ages were as cold as they were, and then invalidate all of radiative transfer theory without undermining all of the existing satellite records. Let me know how that goes. - gavin]

  32. 132
    Peter K Miles says:

    Baselines:

    With temperature data being reported as anomalies relative to a baseline I am interested in knowing how the ‘standard’ baselines were selected. The most common one appears to be the 1961-1990 period, but I also see 1951-1980. I understand that 30 years appears to be the standard minimum for such climatic comparisons, but why not a longer baseline in a time period that is better compromise between accurate temperature recordings and limited green house gas forcing….say a 90 year period such as 1851 – 1940?

    [Response: You want a period long enough to average over interannual variability, but short enough so that you can see climate change. 30 years is the de-facto standard. - gavin]

  33. 133
    Aaron Rury says:

    Re: 122

    Mark, I don’t think that you understand my question possibly. In phase space, there are many different trajectories that would give increasing temperature, some with increasing CO2 concentration and some with decreasing CO2 concentrations. This is true of most thermodynamic systems. I was wondering if there were any papers on this issue in the frame of the climate as a thermodynamic system. It seems rather dismissive to claim that this question does not need an answer.

    As for your analogy, if I smoked in the past and stopped before cancer began to grow, I can still get cancer in the future due to my smoking. This is because my cells have a type of “memory” of my smoking. I think our climate system may also have this type of memory when it comes to CO2 or other gas concentrations. Please remember that these systems, like most, are not as simple as we might think.

  34. 134
    SecularAnimist says:

    Regarding “spin”, the blog at Washington Monthly highlights the following from CNN last night:

    Yesterday, CNN’s Lou Dobbs … told viewers that the weather has been “unbelievable,” because there are “unusual storms and a deep freeze across much of the country tonight.” Dobbs was particularly animated about snowfall in Las Vegas, Malibu, and Payson, Arizona. “So what are those folks talking about global warming?” Dobbs asked incredulously.

    To “discuss” the subject, Dobbs invited CNN meteorologist Chad Myers and Heartland Institute science director Jay Lehr onto the show.

    Not surprisingly, Lehr told Dobbs what he wanted to hear, starting with an anecdote about Lehr’s sky diving hobby.

    LEHR: “I have jumped out of a plane in Ohio every month for 31 years, and I track the weather constantly to find out if I can make it out of a plane. And I can tell you, the weather the last ten years hasn’t been significantly different than the ten years before that or the ten years before that. It has been — it is always changes what the weather is about. And to say that it has to do with global warming is really more of a joke than anything else. Why people are so alarmed about it, I have no clue.”

    DOBBS: “You know, that’s fascinating.”

    Before ending the segment, Lehr added that the sun, “not man,” warms the planet, and that “right now,” we’re “going in to cooling rather than warming.”

    … though Dobbs apparently forgot to mention it, the Heartland Institute is a conservative think tank subsidized by ExxonMobil, not an independent scientific organization, and Jay Lehr’s background is in “groundwater hydrology,” not climate science.

    … the bizarre commentary from CNN’s Chad Myers wasn’t much better. He argued that it’s “arrogant” to think that humans can affect the climate (“Mother nature is so big,” he said) and that people who accept global warming are only looking at “a hundred years worth of data, not millions of years that the world has been around.”

    So this is the message, and these are the messengers, that the American public is hearing from “the most trusted source in news”.

    Suffice it to say that so-called “mainstream” media coverage of anthropogenic global warming and climate change still leaves much to be desired.

    [Response: Very odd. I've been on Dobbs' show twice and he, the reporter and the producer seemed to get it. Let's hope this was just an aberration. - gavin]

    [Response: Indeed, I was on Lou Dobb’s too (once w/ Gavin), and Lou didn’t even want to discuss the science, considering it ’settled’. He wanted to talk ’solutions’. This evident retrenchment is disappointing. I saw the segment yesterday. Chad Meyers appeared a bit stunned by Lou’s ambush, and came across as more dismissive then I believe he is. I think he was trying to say something we all know, that you can’t seen climate change in the day-to-day weather. You have to look at the longer-term trends. But he appeared flustered, and didn’t quite communicate that message. Coupled with CNN’s recent dismissal of Myles OBrien and his entire science and technology team, who had set the broadcast media gold standard for climate change coverage, this is a worrying development at CNN. - mike]

  35. 135
    Aaron Rury says:

    I actually found this article on this issue, but in a different context.

    http://www.nonlin-processes-geophys.net/15/541/2008/npg-15-541-2008.html

    It shows that going between states of all ice and all water on a global scale for a planet climate in a two-dimensional climate model, the temperature will show a history dependent temperature. They do not speculate why however.

    This is a very simplistic model, but it shows the point I was trying to make. These climate system are complicated enough (much more complicated than a simple two dimensional model) to show hysteresis with respect to many parameter changes. If there is any other work like this that someone knows of, please let me know. Thanks.

  36. 136
    Rod B says:

    Gavin (129), the gist of your argument is true, but (and this is admittedly a nit over a likely poor choice of words) to say the phrase “the science is settled” or its definitive equivalent has not been posted in RC tells me you’re in overload in managing RC — (and you probably really are and all greatly appreciate it!) Maybe not by folks you necessarily sanction, but it is all over the place.

    [Response: 99.99% of the time it is said it is to make the same lame contrarian point. The other 0.01% of the time it is usually an activist of some sort, and even then it is related purely to the standard consensus (as we defined it years ago). You can search but I challenge you to find one scientist saying any such thing about any of the secondary issues such as ocean circulation, or regional rainfall or hurricanes etc. - gavin]

  37. 137
    Steve Horstmeyer says:

    Lou Dobb’s show mentioned in #134 made businessandmedia.org here is the link:

    http://businessandmedia.org/printer/2008/20081218205953.aspx

  38. 138
    Mark says:

    Aaron, 133. There are many phase spaces that have no oxygen around you too. Yet you still fail to suffocate.

    People here know what phase spaces mean.

    Don’t think by using them you’ll flim-flam anyone.

    And you are incorrect about how cancer forms. The cells don’t “remember” squat. The single cancer cell can metastasize and live dormant. If you take treatment the cells die off and if you aren’t adding more by smoking, you won’t be adding cells that are cancerous to new places where they will not be picked up and removed.

  39. 139
    Joe Hunkins says:

    such variability is indeed predicted by climate models

    This sounds odd to me. Is the point that climate variability has consistently been falling within the ranges we’d expect from current models? Is an alternative even possible given the large number of factors that lead to year to year prediction uncertainties?

  40. 140
    Mark says:

    And further to the answer to 132, much less than 30 years and you’re looking at decadal patterns being left as signal rather than noise and if you use much more than 30 years, you’re looking at 100 years which means you’re unable to react within a lifetime. 30 years is about a generation of humans. You will personally be able to remember the days of your youth when you’re middle aged and will be able to extrapolate.

    If, on the 10,000 year scale the planet will cool, that doesn’t help us if our destruction is occurring on the century scale, does it.

    So it’s kind of pragmatic: things that take longer may take too long for us to be able to react to and much shorter and we KNOW we’re including things that will reverse.

  41. 141
    Mark says:

    Ray #125.

    Will you accept a cheque???

    :-P

  42. 142
    Falconsword says:

    … though Dobbs apparently forgot to mention it, the Heartland Institute is a conservative think tank subsidized by ExxonMobil, not an independent scientific organization, and Jay Lehr’s background is in “groundwater hydrology,” not climate science.
    ——————————————————————————————————-

    Yes, and most of the so called ‘climate scientists’ are being funded by government grants, and those grants are written by liberal politicians hoping to get a bigger piece of the pie from the ‘green energy boondoggle’ that Obama is going to ram through. So both sides show bias. The difference is you refuse to notice your own sides bias, instead you yell ‘debate is over’, or ‘consensus has spoken’. What scientist in his/her right mind uses concensus as a basis for solid scientific theory?! Lunacy!

    [Response: Very odd. I’ve been on Dobbs’ show twice and he, the reporter and the producer seemed to get it. Let’s hope this was just an aberration. - gavin]

    [Response: Indeed, I was on Lou Dobb's too (once w/ Gavin), and Lou didn't even want to discuss the science, considering it 'settled'. He wanted to talk 'solutions'. This evident retrenchment is disappointing. I saw the segment yesterday. Chad Meyers appeared a bit stunned by Lou's ambush, and came across as more dismissive then I believe he is. I think he was trying to say something we all know, that you can't seen climate change in the day-to-day weather. You have to look at the longer-term trends. But he appeared flustered, and didn't quite communicate that message. Coupled with CNN's recent dismissal of Myles OBrien and his entire science and technology team, who had set the broadcast media gold standard for climate change coverage, this is a worrying development at CNN. - mike]

    By “getting it” we must assume slurping the AGW theory. I wonder how many people will die from hypothermia this winter before the average person starts to ‘get it’?

    [Response: So let's get this straight, the existence of winter precludes the possibility of anthropogenic climate change, and you think that NASA, NSF, NOAA, DOE and NIH research grants are allocated by politicians? Hmm. Let us know when you want to start talking about the real world. - gavin]

  43. 143

    #134, DWT’s not as measured by MSU…. Are very powerful tool in determining
    how cold this air, big freeze, contrarians are using to prop up their house of cards claims.
    Uptown NY state DWT last week from surface to tropopause: 260.6 Kelvin..
    Surface temperature on 12/12 +13.6 C. THis morning same station DWT to trop.
    256.06 K with a temp this morning of -2.1 C… 15.7 C of surface temperature difference = 4 Kelvin
    drop for the entire troposphere. The true measure of temperature change is found with the entire troposphere, comparable Decembers much show if really there is an incredible cooling, or simply one thing, winter……

  44. 144
    Hank Roberts says:

    From the AGU meeting:

    http://www.achangeinthewind.com/2008/12/we-have-to-tell-people-something-is-happening-with-the-permafrost.html

    _________________
    “eruption Intime”
    _________________
    Ever wonder if someone were to write software to let ReCaptcha assemble sentences or paragraphs, not just two words at a time, we might really be surprised?

  45. 145
    Matt says:

    Are you SURE about your ENSO-neutral forecast this winter? As Monty Python would say, “Here comes another one, here it comes again”…

    http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/weeklyenso/heat-last-year.gif

    [Response: It's not my field, but I'm happy to go with the consensus forecast as the best guess. - gavin]

  46. 146
    Mark says:

    Joe, 139. Is it just possible that within the errors attributed, the models are, y’know, actually RIGHT?

    Or is that impossible?

  47. 147
    dhogaza says:

    Yes, and most of the so called ‘climate scientists’ are being funded by government grants

    “so called”?

    Prediction – 99% of the people here stopped reading your post at that point, and having skimmed down to read your handle, won’t bother to read anything else you post here again.

  48. 148

    “Yes, and most of the so called ‘climate scientists’ are being funded by government grants, and those grants are written by liberal politicians hoping to get a bigger piece of the pie from the ‘green energy boondoggle’ that Obama is going to ram through.”

    Are these the same liberal politicians who tried to muzzle Hanson and other NASA personnel on the subject of AGW? Because I don’t think there have been too many ‘liberals’ in control on the federal side between 2000-2006.

    “The difference is you refuse to notice your own sides bias, instead you yell ‘debate is over’, or ‘consensus has spoken’. What scientist in his/her right mind uses concensus as a basis for solid scientific theory?! Lunacy!”

    Well, if punctuation is a guide, you’re the one doing the yelling. At the end of the day, the answer to your ‘concensus’ question is “all scientists.” Science is driven by evidence, but evidence can be accepted or not–as your post so aptly illustrates. Hopefully the valid evidence will be the most persuasive in the long run.

    Certainly the broad acceptance of AGW today is an example of an idea surviving on its merits in the face of decades of skepticism. The idea has thrived because the evidence keeps getting stronger. (If you are not familiar with this history already, see “The Discovery of Global Warming,” by Spencer Weart–it is linked in the sidebar to the right of each RC page. It is a fascinating and enlightening read.)

  49. 149
    SecularAnimist says:

    Falconsword wrote: “Yes, and most of the so called ‘climate scientists’ are being funded by government grants, and those grants are written by liberal politicians hoping to get a bigger piece of the pie from the ‘green energy boondoggle’ that Obama is going to ram through.”

    I guess that would be “so called climate scientists” as opposed to real climate scientists like Rush Limbaugh?

  50. 150
    Matt says:

    The mean of that IRI consensus is now -0.5C for DJF, or borderline La Nina. Last year’s subsurface data preceded the surface anomalies, so get ready for a La Nina surprise this winter…


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