Hadley Climate Center HadAT2 Data shows global cooling in the last year

Overall long term trend remains positive in lower troposphere.

Most often on this forum we have looked at either surface temperature data from surface observations or lower tropospheric temperature data derived from satellite sounders. Today I’d like to point out a short scale trend in global radiosonde data showing cooling in the last year, as well as examine the record back to 1958.

The HadAT2 dataset from the Hadley Climate Center takes in balloon radiosonde measurements taken twice daily from hundreds of points around the globe and compiles it. Here is how they describe it:

HadAT consists of temperature anomaly timeseries on 9 standard reporting pressure levels (850hPa to 30hPa). The data is also available as equivalent measures to the broad MSU satellite weighting functions. The gridded product is derived from 676 individual radiosonde stations with long-term records. Because of the criteria of data longevity the resulting dataset is limited to land areas and primarily Northern Hemisphere locations. Radiosondes are single launch instruments and there have been many changes in instruments and observing practices with time. HadAT has used a neighbour-based approach to attempt to adjust for these effects and produce a homogeneous product suitable for climate applications.

They also go on to add a cautionary note about data uncertainty:

It is important to note that significant uncertainty exists in radiosonde datasets reflecting the large number of choices available to researchers in their construction and the many heterogeneities in the data.

And they go on to suggest alternate data sets for “robustness”. For now, we’ll just stick to HadAT2, but if readers want to do comparisons against the other datasets I’ll post results here. Just visit the HadAT2 page for links.

Here is the plot of all the pressure altitude levels of temperature data since 1958:


Click for a larger image

The source data set in ASCII text is available here

In the graph above, the warmer (redder) colors represent lower tropospheric data closer to the surface (850mb for example) while the cooler blues (cyans) are the high altitude data (100, 50, and 30mb). You can see in the 850mb data, the familiar signature of the 1998 Super El Nino that raised temperatures globally.

You can also see the slow upward trend in temperature in the lower troposphere data since 1958, about 0.6°C.

To give laymen readers an idea of the vertical scope of the plot above, here is a graphic showing pressure versus atmospheric altitude.


Graphic Source: PhysicalGeography.net

Now what is interesting is when we zoom the data plotted above down to a five year level, as shown in the graph below.


Click for a larger image

Note that while preceding years have been relatively flat for trend, during the last 12-18 months, there has been a noticeable downward trend in all atmospheric levels except 50mb and 30mb, while 100mb appears to remain flat. The 50mb and 30mb levels don’t appear to have much of a positive trend in the last 12-18 months that differentiate it from the last 5 years.

For those who will immediately jump on the standard gripe of “cherry picking” let me say that I’m only using the zoomed 5 year time period above to better visually illustrate the change in the last 12-18 months. As I mentioned above, the overall long term trend since 1958 in the lower troposphere is still positive.

But whatever has happened globally in the last 12-18 months, the temperature downturn we see makes for interesting discussion.

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84 thoughts on “Hadley Climate Center HadAT2 Data shows global cooling in the last year

  1. Anthony,

    You don’t mention the blue color peaks in the long term record. Looks like St. Helens, El Chi, & Pina are all represented.

    Could the blue peaks, then declines in the early years be tied to nuc tests going underground (US & USSR last above ground tests in 1962-63)?

  2. If the atmosphere is cooling short-term, and the seas are cooling short-term, warmists can call it short term variation, but they still need to answer the question: How and why is heat leaving the system?

    It seems to me that under the “persistent forcing” view of things, the total heat in the system should be steadily increasing as CO2 levels increase.

  3. Doesn’t this also show quite significant stratospheric cooling? Judging from your altitude/pressure graph, I reckon the 50hPa line is at 25km altitude, in the lower stratosphere. The corresponding line on the temperature graph shows significant cooling – upwards of 2 degrees in 50 years. Isn’t this one of the models’ predictions for greenhouse warming? (I’ll grant you, of course, that the other more publicized one – the upper tropospheric “hotspot” – isn’t there.)

  4. OT Epilogue to Polarstern thread from August 8-08:

    Science Daily offers the story today, in a comprehensive translation:

    http://www.sciencedaily.com/releases/2008/08/080811092458.htm

    Again, the best way to monitor Arctic Sea Ice conditions day by day is the excellent overview offered here, as posted by several contributors in the past – one can enter any two dates for comparison:

    http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=14&fy=2005&sm=08&sd=14&sy=2008

    Right now, the obvious anomaly is a great deal of open water in the Beaufort Sea (creating sufficient fetch for wave build-up, making current oceanographic and seismic research more difficult). Three years ago, the open water was in the Chukchi and Laptev Seas – this illustrates circulation and wind patterns…

    It will be interesting to observe what the next three weeks will bring.

    For perspective, please check this outrageously flippant column by Thomas Friedman in the International Herald Tribune (I posted it before):

    http://www.iht.com/articles/2008/08/06/opinion/edfriedman.php

    his words: “Remember: Climate change means ‘global weirding,’ not just global warming.”

    we’ll see – Mr. Celebrity Columnist.

    If I had time, I would research Traditional Ecological Knowledge, talking to Inuit Elders about the warm spells of the 20s and 30s, among others – anybody knows of any oral history accounts?

  5. It would be interesting to see the trends for the 850mb-500mb thickness values. The last 12 months trend is interesting. It does illustrate the signifigance of ENSO on our global temperatures.

  6. Also, what caused the huge decline in 1972-74 @ 30mb? It doesn’t look like there’s been any change to note of since then at 30mb.

  7. Anthony,

    I would be interested in the algorithm used in the adjustment of the values. What caught my interest was the statement “neighbour-based approach” for the adjustment of error. Most of the radiosonde reporting stations in the US are hundreds of miles apart. I am very suspicious of adjustments made with such distant samples. The adjustments would have to account for significant differences in geography and current weather conditions requiring a very dynamic and analytical evaluation of each observation performed. Something I would have to have shown to me as being taken into account. Yes I am skeptical, there was once a time when that was a good quality, but when it concerns climate it is now a bad word.

    REPLY: I suspect it is much like the GISS homogenization routine, perhaps even identical.

  8. One of the signals of global warming is cooling in the upper stratosphere. The theory is that additional GHGs in the lower atmosphere intercept IR photons from the surface before they reach the stratosphere.

    While there has certainly been a reduction in temps in the stratosphere since 1958, as Gary in Olympia posted, it appears that the 3 major volcanic events, Agung in 1962, El Chichon in 1982 and Pinatubo in 1991 are the major drivers of these swings.

    Temps increase temporarily by 1.0 to 1.5C from the volcanoes followed by a cooling of 1.25C to 1.75C within two years and the stratosphere temperatures seem to stabilize and do not change at all afterward.

    There has been no real change in stratosphere temps since 1994.

    [Personal opinion here – Of course, I can’t really buy the argument that global warming will lead to stratosphere cooling. There must eventually be a balance between the radiation coming to Earth with that leaving the Earth. Global warming could be thought of as a delay in the average time it takes for a photon from the Sun to escape the Earth. On everage, the delay is about 45 days (which leads to Greenhouse warming of 33C.) If global warming increases that delay by 1 day, then we will have 34C of warming. In this sense the stratosphere should not be cooling, it should be a steady temp reflecting the loss of energy required to keep in Earth in balance.]

    Global warming theory has not adequately explained the impact of volcanoes on the stratosphere (and how these are the main drivers) nor why the stratosphere should continue cooling in the theory.

  9. Sorry to be off topic, but I’ve just noted that the BBC are planning a definitive History of Climate Change programme this autumn: http://www.bbc.co.uk/pressoffice/pressreleases/stories/2008/07_july/10/bbctwo4.shtml#history refers.

    I wonder if anyone reading this blog has been contacted? Thought not. Perhaps someone should try to get the hockey-stick story over to them, at least, if not the surface stations fiasco…

    REPLY: They’ve already asked about the surfacestations, and I provided photos. But yes, perhaps sending over the hockey stick fiasco would be a good idea -Anthony

  10. AustinS asks… “Doesn’t this also show quite significant stratospheric cooling? …the temperature graph shows significant cooling – upwards of 2 degrees in 50 years. Isn’t this one of the models’ predictions for greenhouse warming? (I’ll grant you, of course, that the other more publicized one – the upper tropospheric “hotspot” – isn’t there.)”

    Let me also indicate interest in having this question answered in some detail. AGW does postulate that the CO2 warms the troposphere while cooling the stratosphere (the CO2 greenhouse effect traps the heat near the surface instead of leting it escape thus cooling the stratosphere), so how is this altitude cooling data not some indication that the AGW hypothethis has some validity? Enquiring minds like this non-ideological skeptic want to know!

  11. Seems to me the increase in low altitude temps since 1958 could be related to UHI (Urban Heat Island) growth. Since these sites represent northern hemisphere land for the most part, and many are next to sources of urban heat, the increase cause due to UHI is plausable. As I eyeball the altitude chart the low 850mb altitude is a mile or so or less. Anyone who’s been in a light plane at those altitudes above a city has experienced bumps from the heat rising.

  12. While digesting the info presented in the graphs, I found I kept having to ‘translate’ the key. As displayed, the key seems to be counterintuitive — when viewing the key and reading it from top to bottom it’s actually displaying data in reverse, from low altitude at the top and on up as working down the key. I’d suggest that the top of the key should start at 30mb and progress down to 850mb.

    Everyone’s a critic…

  13. How does the number of plots for 50MB & 30MB stack up with the lower levels? Balloon
    failures are quite frequent above 100MB.

  14. counters:
    You must remember, for a decade we’ve been lectured that CO2 and other greenhouse gases overwhelm other “natural” climate forcings. Things like ENSO, solar variations, etc… are driven or at least are secondary to the build up of GHGs. Esteemed scientists like Hansen have repeatedly stated that we have less than a decade to act, that we are ever so close to the “tipping point” and the danger of endless positive feedback loops. Other than that, I agree with you; 12-18 months worth of data may be interesting but not necessairily earth shaking. But don’t blame Anthony. Dr Hansen et. als. started this train.

  15. dreamin (03:10:35) :
    ‘If the atmosphere is cooling short-term, and the seas are cooling short-term, warmists can call it short term variation, but they still need to answer the question: How and why is heat leaving the system?
    It seems to me that under the “persistent forcing” view of things, the total heat in the system should be steadily increasing as CO2 levels increase.’
    Didn’t you get the memo? The CO2 ampification effect (2.5) went on vacation and will be back in 2015.

  16. I made a mistake in my earlier post with respect to 1972-74. The steep dropoff at 30mb i’m questioning is in 1992-1994, which i assume would correspond to pinatubo. But then , why doesn’t it equalize like it typically did after the other eruptions? What caused it to reset to the lower value (~-1.5) and stay there?

    My first thought is an instrumentation shift…

  17. and also Micheal don’t forget the increase in lower level heat trapping clouds that we have in times of low sunspot activity…adds up to me. but at the end of the day its the whole system, from the bottom of the oceans to the edges of the atmosphere, we can plot trends at specific points, but need to understand the whole picture.

  18. Austin S says: “The corresponding line on the temperature graph shows significant cooling – upwards of 2 degrees in 50 years. Isn’t this one of the models’ predictions for greenhouse warming? (I’ll grant you, of course, that the other more publicized one – the upper tropospheric “hotspot” – isn’t there.)”

    The two predictions are not really equivalent. The prediction of the upper tropospheric hotspot is a general prediction by the models (and basic theoretical considerations) of how warming in the tropics should occur independent of the mechanism causing the warming. I.e., it should be there for GHG warming but also warming due to increased solar luminosity or due to fluctuations.

    The prediction of cooling in the stratosphere, by contrast, is a prediction specific to the mechanism of GHGs. An increase in solar luminosity, for example, is not expected to produce such cooling.

    JP says: “You must remember, for a decade we’ve been lectured that CO2 and other greenhouse gases overwhelm other “natural” climate forcings. Things like ENSO, solar variations, etc… are driven or at least are secondary to the build up of GHGs.”

    We don’t have to remember it because it simply isn’t true! You are mischaracterizing the scientific claims. The claim has been that the general climate trends over periods of decades are now dominated by the greenhouse gas forcings (although they weren’t, say, 50 years ago). However, there has never been a claim that on shorter timescales of a few years there wouldn’t be the normal ups and downs due to internal variability (such as ENSO). In fact, individual runs of climate models themselves show such variability, not a monotonic increase in global temperatures from year-to-year. See, e.g., here: http://www.realclimate.org/index.php/archives/2008/05/what-the-ipcc-models-really-say/langswitch_lang/sk

  19. “You must remember, for a decade we’ve been lectured that CO2 and other greenhouse gases overwhelm other “natural” climate forcings over multi-decadal, long periods of time.”

    That bolded part I added in is much more important than the first part. As a matter of fact, the first part is false except in the context of the bolded addition.

    REPLY: Actually no I don’t think it is false. Here is why I think that. By the theory presented, the supposedly larger CO2 forcing would eventually dampen and “swallow up” smaller forcings, so that they are not as pronounced. There has been quite a bit of conjecture that this has already occurred. Hansen I believe wrote something on it a couple of years ago, though I don’t have the citation at my finger tips.

    An analogy would be to think of the effect like a toy balloon. If the total forcing represents the inflation volume of the balloon, then when the balloon is empty, a small amount of air (the lesser forcings) would make a visibly noticeable change in diameter. However, when the balloon is well inflated, representing the expected larger forcing of CO2, the same addition or subtraction of air volume into the balloon would not be nearly as noticeable, because the smaller volume is “swamped” by the existing larger volume. Granted this is not a perfect analogy, but it does illustrate the concept.

    Another way to look at it would be a radio receiver. A strong signal tends to “swamp” the receiver and make weaker distant signals on the same frequency disappear.

    The fact that we can still observe such changes, that are of significant magnitude, such as the 0.6C drop in satellite derived temperature in the past 18 months, or the radiosonde data above, tells me that the postulated CO2 forcings are still not in primary control of the atmosphere.

  20. But Counters, without weather patterns, climate change would not be happening at all. Not going up, not going down. It wouldn’t exist. Weather patterns, stacked up over the long term, are EXACTLY what makes climate change. There are weather patterns for CO2, water vapor, jet streams, water droplets, volcanoes, urban heat, fire storms, pollution, mountains, oceans, ozone, seasons, latitudes, Earth tilt and rotation. These patterns MUST be a significant part of climate change discussions. Anything less and we are back to demagoguery and pet theories instead of scientific discussions of observed phenomena.

  21. There are some interesting charts at the Hadley site linked to by Anthony.

    This one is supposed to be the MSU satellite-equivalent temps for stratosphere, mid-atmosphere and lower troposhere back to 1958.

  22. How does the number of plots for 50MB & 30MB stack up with the lower levels? Balloon
    failures are quite frequent above 100MB.

    I was wondering the same thing as I read through the post. As someone who conducted research with the use of sounding data, I have the impression the data are frequently missing at higher altitudes/lower pressure. I was forced to eliminate a number of cases in my research because data were missing. Oh, and I was only looking between the surface and 700mb.

  23. so how is this altitude cooling data not some indication that the AGW hypothethis has some validity? Enquiring minds like this non-ideological skeptic want to know!

    Couldn’t it just as easily be a signal of less stratospheric heating by the mechanisms of the Sun?

  24. Re: Temperature adjustments:

    I’ve been retired a long time now, but radiosonde temperature elements used to be individually calibrated — with the calibration record attached to each element. Additionally, the instrument on which the element was mounted was then adjusted to match the outside air temperature at launch.

    I believe these temperature readings were extremely accurate and should not require any adjustment whatsoever.

  25. What about the recent talk about how there really is a heat bubble in the UT? The data here doesn’t seem to show it.

  26. Pierre Gosselin (03:45:29) :

    ” That’s pretty darn good forecasting!”

    Are you serious? The average was 0.44, and the average forecast error 0.07, for an average forecast error of 16%. More than that, the standard deviation of the annual average was just 0.02, so the average forecast error was well outside even 3 standard deviations! A naive forecast of no change would have done better: in 2001, the average was .381, and the highest since was 0.432 in 2005, for a difference of .051. Maybe that 0.07 is something else, because if it is really the average error of their annual forecast, it isn’t very good.

  27. ‘The fact that we can still observe such changes, that are of significant magnitude, such as the 0.6C drop in satellite derived temperature in the past 18 months, or the radiosonde data above, tells me that the postulated CO2 forcings are still not in primary control of the atmosphere.’

    In other words CO2 forcing in lost in the noises.
    No wonder we don’t have CO2 induced climate control systems in our homes.

  28. Looking at a few past La Ninas, I’m not sure I see anything significant in the low levels temperatures, so this blog entry seems to rate a big yawn.

    OTOH, I’m sure I buy the argument that volcanos are responsible for the cooling of the stratosphere, I haven’t matched the dates of the peaks, but if the peaks match eruptions, then it seems to me that the trend without them is still going down.

    Nor am I clear about a link between warming Earth vs. cooling stratosphere. E.g. more lowlevel clouds increase albedo and sunlight photons generally don’t get stopped in the stratosphere. So it seems to me both levels could cool down simultaneously.

    Medium wave IR vs CO2 might be interesting, but given the saturation of the CO2 band, perhaps there just isn’t enough of that reaching the stratosphere to prop up stratospheric temps. [Caution – I’m pushing beyond my level of competance….]

    Another thing to go off and learn about. Good pointers appreciated.

  29. Anthony is right. The GHG warming theory says, as GHG (CO2) concentrations increase so does the size of their effect, relative to other forcings. Hence, the relative effect of the other forcings on the temperature record decreases over time.

    In simple terms, we should see progressively less ‘natural’ variation and progressively more GHG forcing. Which makes the natural variation argument to explain the recent cooling somewhat disengenous, because the GHG warming theory predicts natural variation should be decreasing (relatively).

    Again in simple terms, if natural variation is as large as it appears (needs) to be to explain the recent cooling, then that is evidence against GHG warming being the primary climate driver, irrespective of any contribution (or not) by GHGs to temperature increases.

    This may seem a somewhat arcane argument, but its an important prediction of GHG warming theory and makes the current cooling particularly problematic for the Warmers.

  30. Pofarmer says: “Couldn’t it just as easily be a signal of less stratospheric heating by the mechanisms of the Sun?”

    The problem is that a change in solar luminosity is expected to cause the same sign change in the temperature of both the stratosphere and the troposphere, i.e., that they would both go up if it is increasing or both go down if they are decreasing.

    Anthony Watts says: “The fact that we can still observe such changes, that are of significant magnitude, such as the 0.6C drop in satellite derived temperature in the past 18 months, or the radiosonde data above, tells me that the postulated CO2 forcings are still not in primary control of the atmosphere.”

    No, it just tells you that different things control the changes over different timescales. After all, if you looked at the weekly weather here in Rochester, you would find that even in the fall there would be weeks where the temperature trend would be up even though we are going from summer toward winter. Does this disprove the seasonal cycle as being in primary control of the weather here? I think not.

    old construction worker says: “In other words CO2 forcing in lost in the noises. No wonder we don’t have CO2 induced climate control systems in our homes.”

    Well, it may be lost in the noise on short timescales…but that doesn’t mean it is not a very important effect over a longer timescale, just as the fact that the seasonal cycle in the weather here in Rochester is lost in the noise over short timescales but is nonetheless very important.

  31. I don’t see why CO2 forcings should “swallow up” natural forcings. If the different forcings are purely additive, then it should be possible to separate out the different forcings from the (e.g. temperature) data.

    On that basis, I currently suspect that there has been a *small-ish* temperature increase over the last several decades due to (man made) CO2, but that the majority (>>50%) of the increases are due to other things (such as cloud variation due to changes in the solar wind).

  32. For stratospheric cooling, but tropospheric heating no greater than at the surface, does this make sense as a possible explanation:

    It has been suggested (and shown to be possible) that increased solar activity -> reduced cosmic rays -> reduced cloud cover -> less sunlight reflected away -> higher temperatures.

    *WHAT IF* it is mainly high-level clouds that are reduced? In that case lower-level clouds would still trap heat as usual (allowing temp to increased from increased sunlight), but without so many high-level clouds the stratosphere would not trap as much heat (and thus temp would reduce). This is well beyond my expertise, so I would appreciate feedback from any climate experts here.

  33. Just an anecdote….

    Here on the Front Range of Colorado, the temperature is currently 51 degrees at noon, with a light rain. The normal high temperature is 87 today. Denver is forecast to reach a high of 59. If that occurs, it will smash the record low high of 68 for the date. Tomorrow’s record low high of 63 is also in jeopardy.

  34. Mr. Watts, your analogies are appropriate for if we were discussing burps of CO2 being injected over a short period of time. However, that’s not the case here whatsoever. Notice that both of your analogies deal with the absolute magnitude of the “forcing” being introduced to the system.

    Here’s the appropriate way to think about it: imagine that each oscillation and trend is a distinct signal which can be plotted on a rectangular coordinate plane. The expected trend over a given period of time, then, becomes the sum of each signal at each timestep over the interval of time in question. Essentially, it’s the law of superposition; each signal’s amplitude must be added together in order to determine the signal at each point in time.

    With this analogy, it’s much easier to illustrate several things. First, let me illustrate why one would not expect CO2 to drown out other forcings: for starters, over 12-18 months ,what will the net change in CO2 concentration in the atmosphere be? If you look at the Keeling curve, you could guesstimate that it would actually be close to zero due to the seasonal oscillation of the biosphere. However, there is still most likely a overall trend of perhaps 1 ppm at the max. Now, reference my above posts with SOI and PDOI values; you see a dramatic shift over a 12-18 month period. Now, which would you expect to effect the weather (not the climate, since we’re talking about a 1 year trend) the most: a 1 ppm increase in CO2, or a shift of the warm waters in the Pacific from the center of the ocean all the way to the coast of South America? It’s not a trick question.

    HOwever, this analogy (or “model”) let’s us also clear up a common misconception about the anticipated 10 year “flat-line” of the AGW trend. It has been estimated that we will enter a strong phase of hte PDO oscillation, which will essentially mitigate a rapid upward trend in temperature for a short while. What does this mean on our signal-graph analogy? The PDO would be dipping very low, like a damped sine wave; if you have a roughly positive trend coming from overall AGW added to a severely negative trend? What do you get? An artificial period of either reduced warming or even possibly cooling.

    I appreciate your time in deducing analogies for your explanations, but they’re just not appropriate for what we’re discussing here. My analogy is closer to the one you’d find if you sat through a University course on climate trends. If you wish for me to elaborate on it further, let me know, and I’ll try to write an entry to my own blog which could address some nuances in it.

    Pamela: You’re a bit confused here. For starters, climate is not equal to the sum of the weather conditions over a period of time; climate is the de facto “stable” or standard state of the atmosphere after you remove the dramatic swings seen over short temporal or spatial frames. Many of hte things you talk about – such as volcanoes, urban heat, pollution, etc – are not “patterns.” Many of them introduce distinct forcings into the overall climate system. But the bottom line is that after decades of study, these forcings (for the most part) are pretty well understood and incorporated into models. Clouds and aerosols are really the only major forcing which is still an active area of intense research, although great strides occur each month.

    You’re right that patterns are a significant part of climate change. And the clear pattern is that global temperatures have been rising for the past century.

    REPLY: Hmm, interesting twist, but I’m unconvinced at this point. I’ll look into it further.

  35. Rod Smith:
    I believe these temperature readings were extremely accurate and should not require any adjustment whatsoever.

    Yes, the temperatures reported were probably highly accurate… but were the altitudes/pressures just as accurate?

    DaveK

  36. What the AGWers are unable to explain is the 10 year flat trend in global temps. With rising CO2 ongoing, why would temperatures stop rising over such a period? Give me an answer more substantial than the meanigless “decadal variation” or “noise”.

  37. <i.No, it just tells you that different things control the changes over different timescales.

    (Warning; rant coming) It disturbs and frustrates me that no one on the warming side of the debate seems to be able (more likely wants to) debate the facts on their merits. I call it the culture of deception, and it so pervades the warming side of the ‘debate’ that they appear to think it’s normal and natural.

    The point at issue is whether or not GHG are, or are not ,increasingly driving climate change (assuming it’s happening). And so to say, different things control the changes over different timescales is pure obfuscation.

  38. I think what’s happening is that as more CO2 is introduced to the atmosphere it is becoming saturated hence the effect is less and less… ergo no crisis as far as global warming is concerned. Some scientists have proposed this theory and it seems they might be right.

  39. “You must remember, for a decade we’ve been lectured that CO2 and other greenhouse gases overwhelm other “natural” climate forcings over multi-decadal, long periods of time.””

    Puleeze counters,
    There have been several “weather events” that’ve occured that’ve been tagged as proof of AGW. Here are just a few:

    The remarkably hot European summer of 2003, in which 35,000 died due to heat realted deaths.

    The 6 year Austrailian Drought.

    The Nov 2006-Feb 2007 period, in which NOAA highlighted was the warmest Nov-Feb in recorded history.

    The 1995-2005 uptick in North Atlantic Basin TCs.

    In each of these events (short term events), you can find a number of Climate Experts who cite AGW as the cause. Again, I will also mention Dr Hansen’s assertion that we have a decade or less to act in order to avoid an climatic tipping points. SInce Hansen has narrowed the interval to years, and Dr Hansen is one of the most respected Geoscienists, Anthony is well within his bounds to highlight a 12-18 month cross section of data.

    How about a truce: you get the “peer reivewed climate experts” to refrain from using short term “weather events” a proof of AGW, and maybe Anthony will do the same. How about we use non-MBH paleo reconstructions and up the debating interval to say 400 years (that would take into account a full cylce of the solar Gliessberg Oscillation). I imagine the debating hall would get awfully quiet.

  40. Dean_1230 and others regarding stratosphere cooling:

    I have always contended that it is less man-made pollution over the course of the 20th century that is causing stratospheric cooling and tropospheric warming (less particles to cause dimming). Any particulate matter/aerosol in the upper troposphere/lower stratosphere will cause warming (and vice-versa). This is why the NH has had temperature increases over the past 30 years and the SH has not (85% of all sulfates originate in NH). Imagine how cold it would be (due to the quiet sun) if NA, Europe, and the former Soviet Union did not clean up their skies in the 70’s, 80’s, and 90’s (causing a warming microtrend). Why has it been cooling since 2001? Answer: the sun has gone quiet and the effect of reducing pollution on atmospheric temperature has reached a point of diminishing returns (China being the exception).

  41. DOHERTY: NEW SCIENTIFIC DATA JUSTIFIES REPEALING GLOBAL WARMING RESPONSE ACT

    URGES STATE TO HOLD OFF ON DAMAGING NEW REGULATIONS AS CLIMATE CHANGE THEORIES CLASH

    Responding to various new scientific reports questioning the concept of global warming, Assemblyman Michael Doherty today called on Governor Corzine to hold off on proposing any new regulations associated with the state’s Global Warming Response Act and urged the Legislature to repeal that act when it returns to legislative business after Labor Day.

  42. counters
    ‘if you have a roughly positive trend coming from overall AGW added to a severely negative trend? What do you get? An artificial period of either reduced warming or even possibly cooling.’
    An artificial period of either reduced warming or even possibly cooling?
    PDO
    I would call that a natural cooling or less warming which has a greater effect than all the total effect than CO2 forcing. Are you saying that PDO, La Nina, La Nino, cooling oceans water vapor not being the “positive feedback” is masking the 2.5 amplification of CO2?
    So, what has been that amplification number for the last 8 years?

  43. Counters: You write about the PDO as if it is the SST of the North Pacific. It is not. It is a statistically manufactured index that pulls the ENSO signal out of the North Pacific. This is a graph of North Pacific and Global SST anomalies.

  44. Jared: “What the AGWers are unable to explain is the 10 year flat trend in global temps. With rising CO2 ongoing, why would temperatures stop rising over such a period? Give me an answer more substantial than the meanigless ‘decadal variation’ or ‘noise’.”

    Well, if you consider the correct answer to be meaningless, there is little more that can be do to convince you. As has been clearly demonstrated, even individual runs of climate models that incorporate the increasing levels of CO2 show periods over which the temperature trends are essentially flat or negative. See here: http://www.realclimate.org/index.php/archives/2008/05/what-the-ipcc-models-really-say/langswitch_lang/sk

    Philip B says: “The point at issue is whether or not GHG are, or are not ,increasingly driving climate change (assuming it’s happening). And so to say, different things control the changes over different timescales is pure obfuscation.”

    It is not obfuscation to point out the obvious flaws in your logic. I even gave you a clear analogy: The fact that there are significant temperature variations from week-to-week (or, even if you wish, from day-to-night) that sometimes cause temperatures here in Rochester to go in the opposite direction from what is predicted on the basis of the seasonal cycle does not mean that the seasonal cycle isn’t happening and isn’t a very strong driver of the weather here. Do you disagree with this observation or think that this analogy is somehow invalid?

    JP says: “In each of these events (short term events), you can find a number of Climate Experts who cite AGW as the cause…How about a truce: you get the ‘peer reivewed climate experts’ to refrain from using short term ‘weather events’ a proof of AGW, and maybe Anthony will do the same. ”

    Well, I cannot vouch for everyone else talking about such events. However, the correct way to relate such events to AGW is to note that in a world where there is global warming (and possibly an accompanying increase in powerful hurricanes and an increase in droughts in some areas…), the sort of extreme events or record-breaking events that you mention become more likely…in some cases, significantly more likely. None of these events can be shown to be due to AGW specifically and none alone is proof of AGW. One has to do careful studies of the changes in the severity or frequency of extreme events or temperature records in order to draw rigorous conclusions.

    Sometimes, scientists tend to point to such extreme events as illustrative of the effects of AGW. When there is more serious research to back up the idea that these events are or are expected to become more likely, then I think there is nothing wrong with this as long as the scientists are careful to point out that no one event can be definitively pinned on AGW.

  45. Hadley normally updates the version at http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/monthly before the 12-month-per-row version at http://www.cru.uea.ac.uk/cru/data/temperature/hadcrut3gl.txt

    Please tell me I’m doing something wrong. The alternative is that Hadley has been GISS-iffied.

    I’m comparing the June grid (12 months in a row) with the July monthly version (1 month per row). I’ve converted both to my own “internal” format where…
    1850.083 = 1850/Jan
    1850.167 = 1850/Feb

    1850.833 = 1850/Oct
    1850.917 = 1850/Nov
    1851.000 = 1850/Dec (yeah, it looks weird)

    There were a few minor changes to recent data going from May to June. In a paranoid mode, I ran a diff on the June dataset versus the July dataset, and noticed quite a few changes. This time they go back to 1851. The early changes (1929 and earlier) seem to be mostly cooling, and the later changes (2007 onwards) seem to be mostly warming. Is this “manmade global warming” or what? Please tell me I’m doing something wrong.

    For those of you not familiar with the posix “diff” utility, entries flagged with “”.
    18c18
    1851.500, -0.268
    465c465
    1888.750, -0.256
    803c803
    1916.917, -0.610
    888c888
    1924.000, -0.072
    950c950
    1929.167, -0.676
    1892,1894c1892,1894
    < 2007.667, 0.362
    < 2007.750, 0.410
    2007.667, 0.370
    > 2007.750, 0.412
    > 2007.833, 0.370
    1896,1897c1896,1897
    < 2008.000, 0.212
    2008.000, 0.220
    > 2008.083, 0.050
    1900c1900
    2008.333, 0.267
    1902c1902,1903
    2008.500, 0.312
    > 2008.583, 0.403

  46. Gack!! WordPress seems to have treaded the angle brackets as HTML controls, and totally screwed up my post. Here is the data again, using “remove” and “insert” instead of angle brackets. Webboards suck. Bring back usenet.

    18c18
    remove 1851.500, -0.269

    insert 1851.500, -0.268
    465c465
    remove 1888.750, -0.255

    insert 1888.750, -0.256
    803c803
    remove 1916.917, -0.609

    insert 1916.917, -0.610
    888c888
    remove 1924.000, -0.071

    insert 1924.000, -0.072
    950c950
    remove 1929.167, -0.675

    insert 1929.167, -0.676
    1892,1894c1892,1894
    remove 2007.667, 0.362
    remove 2007.750, 0.410
    remove 2007.833, 0.367

    insert 2007.667, 0.370
    insert 2007.750, 0.412
    insert 2007.833, 0.370
    1896,1897c1896,1897
    remove 2008.000, 0.212
    remove 2008.083, 0.054

    insert 2008.000, 0.220
    insert 2008.083, 0.050
    1900c1900
    remove 2008.333, 0.254

    insert 2008.333, 0.267
    1902c1902,1903
    remove 2008.500, 0.314

    insert 2008.500, 0.312
    insert 2008.583, 0.403

  47. Joel Shore (14:10:39)
    ‘Sometimes, scientists tend to point to such extreme events as illustrative of the effects of AGW. When there is more serious research to back up the idea that these events are or are expected to become more likely,’
    More likely than what? Bigger storms bigger drought since the CO2 drives the climate theory began than in all the history of mankind? There have not been enough hands on studies to use the term more likely, but yet you believe in forecasting models without using forecasting principles.

  48. Joel Shore…

    There should be scientific reason for “decadal variation”. What conditions changed that would cause the temperature trend to turn flat for this long, after rising steadily for 20 years? “Noise” or “decadal variation” offers no real explanation.

  49. In addition, Joel, you cannot claim that decade long absences of global warming were expected by the AGW community. Looking at statements by NASA, the IPCC and others, it is clear that they have expected the warming to continue.

    This is why GISS/NASA predicted that if an El Nino formed in 2006 or 2007, a new global temperature record surpassing 1998 would likely be set. The El Nino formed, but no new temperature record. Not even close, according to most metrics. In addition, the 2007 IPCC report predicted that half of the years between 2009 and 2015 would exceed 1998’s temperatures.

  50. It can clearly be seen that the volcanos are responsible for the temp drop in the stratosphere, so what is the mechanism. Is it possible that the SO2 acts as a nucleation centre causing an loss of water vapor from the stratosphere? Could volcanoes cause short term cooling but long term heating at the surface due to an increase in short wave caused by a decrease in clouds? I did read that the observed cloud decrease has resulted in an extra 6w/m2 reach earths surface, compared to all of 2.4w/m2 for CO2 doubling.
    Cheers

  51. counters (11:28:47):

    However, this analogy (or “model”) let’s us also clear up a common misconception about the anticipated 10 year “flat-line” of the AGW trend. It has been estimated that we will enter a strong phase of hte PDO oscillation, which will essentially mitigate a rapid upward trend in temperature for a short while. What does this mean on our signal-graph analogy?

    Hmm. Over the last ten years the PDO was negative for the first several years, then positive for several, then slid negative recently, see http://www.woodfortrees.org/plot/jisao-pdo/from:1998/mean:12
    Overall, it’s about a wash, so perhaps the PDO hasn’t had much of an impact until the past year or so. The last 10 years of temperature data has been pretty flat, so I’m having trouble seeing much of an AGW signature in
    http://www.woodfortrees.org/plot/jisao-pdo/from:1998/mean:12/plot/wti/from:1998/mean:12

    BTW, I may have missed it, all I recall are quotes from UN personnel, what’s the rationale behind the anticipated 10 year flatline?

  52. Being a little nostalgic here, but any old mets or vets remember using the GMD RAWIN system?(radiosonde tracking system)

    When I was in the service, I used it. That was a lot of work, until they switched to the MDS system, which was computerized. “Cutting” those charts from the recorder was intense and you had to be good. If the artillery was missing its target, they would call “bad met”, and you’d better have your ducks in a row when you evaluated the chart, and they start checking. No time the first time around to sit and make sure it was right before you sent the data to the Fire Direction Center.

    Here’s some pics of the old system.

    http://www.tpub.com/content/meteorology/TM-750-5-3/TM-750-5-30015.htm

    http://www.tpub.com/content/meteorology/TM-750-5-3/TM-750-5-30042.htm

    And before they came out with precalibrated sondes, which I used, you had to do that yourself with this.

    http://www.tpub.com/content/meteorology/TM-750-5-3/TM-750-5-30019.htm

    Not sure when the NWS switched to computerized system, but the Army didn’t until the late 80’s-early 90’s. And I’m sure the NWS had the time to go over their charts to make sure they evaluated them correctly.

    We did have a small computer with the GMD RAWIN system that printed out messages from the chart data, azimuth, and elevation angles we had to put into it, manually. It weighted the data for the artillery and also produced AWS messages, if needed. The computer would be able to send the info, encrypted, to the FDC.

    The precalibrated sondes had tags on them with info that would also get entered in the computer along with surface temp and humidity, derived from wet/dry bulb readings( the old hand whirl method, forgot the name of it) And with surface baro in MB’s.

    I was also involved in balloon testing. A company was trying out different materials to get the best consistency in burst altitudes. Results really varied depending on the batch and materials used. I’ve seen them go to 100,000ft+ many times, though( artillery didn’t need those heights, but the AWS did). And windy days really sucked when trying to launch. You need a BIG field on those days for your 100yard dash. LOL Balloon trains were 50ft long(to keep the wild swinging to a minimum) and that dumb balloon didn’t want to go up as fast as it did going forward. It would pass you up, and hopefully you didn’t get caught up in the train. Balloons were 8-10 high and 4-6ft in diameter, and we used hydrogen. You had to be grounded(because of static electricity) and NO SMOKING around that thing. A few thousand degree fireball would make for a bad day. It would be like having the Sun right next to you for a second. Melt your clothes/uniform right to you, and burn your hair off. Not good. Helium was too expensive, but we did use it sometimes, which I liked. Calcium Hydride charges sunk in water when in the field.(makes hydrogen)

  53. Joel Shore:

    “As has been clearly demonstrated, even individual runs of climate models that incorporate the increasing levels of CO2 show periods over which the temperature trends are essentially flat or negative.”

    Translation: even a broken clock is right twice a day.

  54. DaveK: Yes, the temperatures reported were probably highly accurate… but were the altitudes/pressures just as accurate?

    The pressures were also quite accurate even in my day. Altitudes were calculated, but I suspect (emphasis on suspect) that altitudes were not bad especially through 100mb or so.

    Do they use GPS altitudes now?

    Brian D: I first trained on the old Signal Corps “bedsprings” model. It was on a gun-mount affair with a sort of bicycle seat and hand cranks to train the “bedsprings” antenna. Our tracking device was a small telescope — really a bear right after launch. It was a tough job in bad weather too!

    This was in what I now refer to as the “Bow and arrow” phase of our Air Force, and I worked with for years with dropsondes.

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  56. Rod Smith
    “Bow and arrow” would be appropriate for that set up. Never seen anything like that. The hardest tracking setup I dealt with was pilot balloon tracking using a theodolite. Near surface was extremely difficult to follow that darn thing. And then to do it at night with a small cluster of lights on the a short string under it was even more difficult. At some point, most everyone ended up tracking stars on a clear night when it had gotten some altitude.LOL We did have some guys that were really good at it though. It was a two man operation, with one guy tracking, and the other reading azimuth and elevation angles.

  57. Joel Shore,
    I’ve read all your replies, and I must say, I have rarely seen such arrogance. In every reply, you belittle the person you are replying to before you say “Oh, the Real Climate data already has incorporated everything that is happening, therefore I am right and AGW is the correct model”. You sound like David Hathaway who keeps extending his solar cycle 24 prediction because the sun refuses to obey his theories. David now says cycle 24 should start in March 2008 +- 6 months. Or was that +- 5 years so he can be right.

    Let’s wait a year and see what reality tells us about the winter of 2009.

  58. Dennis Sharp (14:09:39) :
    ‘Let’s wait a year and see what reality tells us about the winter of 2009.’
    Or you could pick up a copy of old farmers almanac, at least they are right 80% of the time.

  59. ric werme
    ‘BTW, I may have missed it, all I recall are quotes from UN personnel, what’s the rationale behind the anticipated 10 year flatline?’
    I remember that. They announced that aerosols was to blame for masking CO2 warming, except studies showed aerosols can warm as well as cool. According to the models, the cooling was to end in 2009.

  60. Dennis Sharp says: “I’ve read all your replies, and I must say, I have rarely seen such arrogance.”

    Dennis, I apologize if I sometimes come across as arrogant. However, I would ask you to consider who is truly more arrogant: (1) a person with little training or research background in a field who thinks that he or she knows more about a subject than most of the scientists who have spent years training and then researching these issues OR (2) a person who suggests that these scientists may actually know more than you do and tries to explain the ways in which you are deceiving yourself.

  61. I think I finally figured out this whole global warming thing. We caused it because we have been really, really bad. And when we start seeing evidence of it, we will all be very, very sorry that we didn’t believe in it, and change our evil ways. Of course, when it does comes back, it will be too late for us to be saved.

    Waiting in dread of the second coming of AGW,
    Mike Bryant

    PS I think I’ve been fed this line before.

  62. Jared says: “There should be scientific reason for ‘decadal variation’. What conditions changed that would cause the temperature trend to turn flat for this long, after rising steadily for 20 years? ‘Noise’ or ‘decadal variation’ offers no real explanation.”

    Jared, first of all, the temperature rise had not been “steady” when you look at it over timescales of several years…It is only when looked at over a sufficiently large time that the trend clearly emerges from the noise. (See, for example, the HADCRUT record here http://www.cru.uea.ac.uk/cru/info/warming/ ) Second, whether the trend has been flat for the last several years or not depends strongly on which temperature record one looks at and the exact number of years one looks over…further evidence of how trends over time periods of less than about 10 – 15 years can vary quite a bit.

    Jared says: “In addition, Joel, you cannot claim that decade long absences of global warming were expected by the AGW community. Looking at statements by NASA, the IPCC and others, it is clear that they have expected the warming to continue.”

    Again, that expectation is that the warming would continue when looked at over a long enough time period. As I have noted, the models that they are basing their predictions on clearly show large variations in shorter periods.

    Jared says: “This is why GISS/NASA predicted that if an El Nino formed in 2006 or 2007, a new global temperature record surpassing 1998 would likely be set. The El Nino formed, but no new temperature record. Not even close, according to most metrics.”

    Actually, the NASA GISS data itself does show that there was a new global temperature record, so by their own metric it was. HADCRUT and the satellites (which measure a somewhat different thing) do not show it to be a new record…but it was second in those records only to 1998.

    Jared says: “In addition, the 2007 IPCC report predicted that half of the years between 2009 and 2015 would exceed 1998’s temperatures.”

    Where in the IPCC report does it say this? (I am not saying it doesn’t, it well may…but I remember this as being a specific prediction made in one recent paper by the Hadley group.) At any rate, since we are still in 2008, I would say that we know very little about whether this prediction will turn out to be correct or not.

  63. counters — “HOwever, this analogy (or “model”) let’s us also clear up a common misconception about the anticipated 10 year “flat-line” of the AGW trend.”

    Not exactly. The model is merely an observation of what’s perceived as being past temperatures and then doing the software equivalent of casting goat entrails to peer into the future, except with scientific sounding terminology.

    Temps have warmed since the LIA. Past reconstructions of temperature show quick ups and downs (unless of course you perceive MBH99 as scientific, which makes you religious, not scientific.) These are seen as normal variation. There is nothing in the current rise of tems in the past 150 years to suggest that mankind is solely to blame for these. In fact, the work of Mr Watts et al tell us that the temp record is likely to be incorrect/improper/biased. Not by an evil Dr. Hansen, either; most of this is likely to be poorly understood effects based on land use.

    In truth nobody knows what the “average” global temperature ought to be nor what this was. GCM’s meanwhile are a poor tool. They are designed solely to model the effects of CO2 based on a myriad of SWAGs (assumptions) and unsurprisingly after a churning for days at petaflop speed they spit a result out that looks suspiciously similar to a linear trend based on fundamental GHG equations. This trend has an increasing first sigma error capability such that after 15 years the signal itself has no meaning. Then of course if the “strong PDO phase” kicks in and the temps later show up not as predicted (e.g. lower) but within the absurd first sigma range (error bars) then it’s pronounced as successful.

    And then of course we have the fact that neither the IPCC nor anyone else can give a straight and reliable answer to how long CO2 lives in the atmosphere. There are “estimates” which are merely more SWAGs, which seem to pile up aftar a while. For example the SWAGs of days gone by were explicit that the poles ought to be warming more than the rest of the globe. The south pole didn’t play right. It’s cooling. GCM’s were “updated” (different entrail mix, apparently) to make the model fit that particular data. Then, of course, the modelers claimed that the southern cooling was predicted all along. People like you regurgitate the line by claiming that “the science has moved on and improved.” Nonsense. The science was caught with its panties around its ankles so was recast with the claim that the real culprit was that there was a pentaflop shortage. “We have more horsepower now, so we can better model!” More nonsense, this time on the level of claiming that a Corvette really isn’t a rolling overpriced POS and is worth buying because it has more horsepower. It solves all. Rubbish! Brute force isn’t the problem and isn’t the answer. In the world of software this has never been the case. We use brute force only to save coding time.

    That leaves us with the following —

    Your analogy is utterly devoid of meaning because neither the GCM nor the best of SWAGs nor the IPCC nor the rest of the entire movement can possibly tell you that the last 100 years isn’t perfectly natural.

  64. Re cold outbreak in Australia. I live in the norther suburbs of Sydney and as I type it’s about 4C outside and it will get down to < 1C by morning, and just as it did today the temperature will rise again tomorrow to about 14C (57F) under clear skies and without much wind. This isn’t really very cold by North American standards but this is definitely below average for the Sydney region in late winter and it’s been pretty much this way since the start of July. Actually some days have struggled to exceed double figures.
    Today there was an avalanche in the Snowy Mts and a person unfortunately died. The cold weather has resulted in heavy snow in SE Australia and it been falling to as low as 300m (1000Ft) both here and in Victoria and down to sea level in Tasmania.
    Of course none of this has anything to do with global warming or global cooling but it’s of interest because it’s been nearly 20 years since we’ve had a winter like this even though this type of winter was perfectly normal in the 1960’s and 70’s. It will be interesting to sea how the Norther Hemisphere fares in about 4 month’s time just as it will be interesting to see if next winter is also like this again here in Australia.
    Whatever the cause, i’m going to take full advantage of this cold winter next weekend because I’m packing up and going cross coutry skiing for a few days in part of our alpine wilderness to the south. At the moment there’s about 2m (6ft) of virgin powder snow awaiting.

  65. Dodgy Geezer (06:57:45) :
    …BBC are planning a definitive History of Climate Change programme this autumn: http://www.bbc.co.uk/pressoffice/pressreleases/stories/2008/07_july/10/bbctwo4.shtml#history

    Do my eyes deceive me, it looks like beeb might change their tune…?

    REPLY: Possibly. They contacted me about the surfacestatiosn project, and I provided several photos. I’m pretty sure they’ll be showing the picture of the rooftop USHCN weather station in Baltimore.

    See it here:

    https://wattsupwiththat.wordpress.com/2008/01/23/how-not-to-measure-temperature-part-48-noaa-admits-to-error-with-baltimores-rooftop-ushcn-station/

  66. Joel-
    “Well, I cannot vouch for everyone else talking about such events.”
    “Sometimes, scientists tend to point to such extreme events as illustrative of the effects of AGW.”
    I take this at face value. However, I do not recall that ANY such scientists, nor indeed others advocating the AGW hypothesis, corrected the impressions left by Mr Gore’s film. I do not recall that they criticised the award of a Nobel Prize to that gentleman. So much uncontradicted rubbish has been spouted on the subject that you may forgive some (less than scientific comments) from those who consider the matter as completely undecided.
    I am not a scientist, but I can read. I can understand the papers and make judgements as to whether or not the methods are rigorous. I can follow the calculations, the statistics and so on. Please let’s not hear any of this “we scientists know better than you laymen” talk.
    At this point in time, AGW is an unproven theory which should be open to vigorous scientific scrutiny. Since there may be important changes in the world which I inhabit consequent upon government reaction to the theory, I am afraid you will also have to put up with non-scientific scrutiny.
    With others, I claim my right as a citizen to involve myself in the debate notwithstanding the greater knowledge of “experts”.
    On a lighter note, I am reminded of the old definition –
    ‘Expert’ (pronounced ex-spurt)
    ‘Ex’ – a has-been ‘spurt’ – a drip under pressure.
    (sorry bout that)

  67. randomengineer:

    …neither the GCM nor the best of SWAGs nor the IPCC nor the rest of the entire movement can possibly tell you that the last 100 years isn’t perfectly natural.

    Bingo.

  68. I’m a bit late to this, but –

    There seems to me to be a confusion further up the thread between the relative weight of forcings (yes, it’s true that if GHG forcings increase they will be proportionately more significant than others) and the absolute effect of internal variation.

    The ENSO effect, for example, is not an external radiative forcing. Regardless of the energy balance (and what that means in terms of rising or falling background temperatures), the extent of natural internal variation is not reduced proportionately.

    Of course, there are those who speculate that a changing energy balance may increase the range of natural internal variability, but that’s a wider issue.

  69. PDO

    heck, why stop there. PDO, AMO, NAO, AO, AAO, and IPO all flipped from cool to warm from 1977 to 2001.

    Then, the above all being in a warm phase already, the temperatures stopped going up.

    Now the PDO has gone cool, and posibly the AO (decades ahead of schedule). The NAO and AMO are still warm but looking shaky. Temperatures are off by half a degree C,

    What goes up may reasonably be expected to come down.

    (The “dead sun” is a legit but separate issue.)

  70. One has to do careful studies of the changes in the severity or frequency of extreme events or temperature records in order to draw rigorous conclusions.

    Well, so far as hurricanes go, accumulated cyclone energy (ACE) and numbers of storms seem to have decreased rather steadily over the last few decades.

    The Rev posted on this subject a while back.

  71. Ah, Joel is not so bad. I’ve seen much worse.

    I think I understand his main point (AGW is an underlying upward push that does not negate natural variation). I merely disagree (mostly). I think there has been some giveback from the LIA, and the recent (late 70s – 1998) increase is due to multidecadal ocean/atmospheric cycles flipping to warm.

    I think the Aqua satellite data is showing us that the positive feedback from CO2 may well be negative feedback leading to more low clouds, increased albedo and homeostasis.

    And now the cycles are beginning to go cool again.

  72. Please let’s not hear any of this “we scientists know better than you laymen” talk.

    Maybe they do; maybe they don’t. But it is the laymen who get to decide policy!

  73. Evan Jones – ‘maybe they do; maybe they don’t’.

    Yes. I’m prepared to accept that in relation to their sphere of expertise, indeed they do (know more than a layman). What I object to (gently) is the ‘I’m a scientist, trust me’ line – a layman with the requisite maths and science education can understand the papers and make cogent judgements. And so far as logic goes – that is for everyone, not just scientists.
    Of course, one needs to see a number of papers not just those from one point of view. But given that, I see no difficulty in engaging in rational analysis of the science.
    I take your point (to the effect that it is the laymen who decide). But if laymen can decide (and they do as you say), it follows that they can also agree and disagree ( or even agree to disagree.).

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