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Those pesky scientific facts…

Filed under: — gavin @ 5 March 2006

We would be remiss in not bringing today’s Doonesbury cartoon to a wider audience.

Hat Tip: Pharyngula and Hank Roberts.


88 Responses to “Those pesky scientific facts…”

  1. 51
    Hank Roberts says:

    Richard — yes. That’s explained — with examples and much more — on the site where that link took you (the collection there is maintained by one of our RC hosts).

  2. 52
    Deech56 says:

    Re #36, #38 and #50. Thank you both for posting a couple of important links related to “impending ice age” that seems to be the big bugaboo among the skeptics. I have been following the contrarian comments to George Musser’s blog post in SciAm Observations, in which he asked skeptics to state which aspects of climate change they don’t accept, why they don’t accept it and what information they would like to see to convince them.

    http://blog.sciam.com/index.php?p=151&more=1&c=1&tb=1&pb=1#more151

    Many of the points that are brought up have been answered in the posts here and on other sites (Pew Center for Climate Change, UCS). What struck me are three points that are repeatedly brought up:

    1. Climate change science is driven by environmentalists.

    2. Scientists have been wrong before, especially when warning the public (here is where the ’70s ice age argument comes up).

    3. Climatology is driven by anti-capitalism.

    I have been reading about what George Lakoff has written about framing, and (as I have found out when arguing about science to laypeople) arguments that carry great weight with scientists, like appeals to the peer-review literature, mean little to the general public. What is termed “common sense” carries more weight for them. that is why Crichton gets such a wide audience. He spouts off the “scientists have been alarmist and have been wrong before argument”, provides a few distorted examples and when people start nodding in agreement to his “common sense” agruments, brings up his “and the global warming scare is just like the other times scientists have been wrong” schtick.

  3. 53
    Richard Ordway says:

    Nice Summation: “1. Climate change science is driven by environmentalists.

    2. Scientists have been wrong before, especially when warning the public (here is where the ’70s ice age argument comes up).

    3. Climatology is driven by anti-capitalism.”

    You want to know which of these “pesky little scientific facts” scares me the most… and it should every reader who cares about their children. It is something the “contrarian” skeptics cannot address.

    We are running an experiment. It is an indisputable experiment on the Earth. We do not know the outcome. It is the changing of the atmosphere the most in 400,000 years by adding 30% more carbon dioxide into the air. This is indisputable even by them.

    To ignore this, one of the most basic facts, is to be irresponsible to our children and to our country. You simply have to take this issue seriously and not make up lies about it. We do not know the results of this experiment. We simply do not know. But they will.

  4. 54
    David B. Benson says:

    Re #52 — Thank you for the link. Informative!

  5. 55
    Urs Neu says:

    Comment to response to 34:

    Ray, Coby, just something to think about:

    One reason of the temperature decrease from 1940-1970 theoretically might also be multidecadal internal climate variability. However, the evidence up to now is weak:

    From the research I know it seems not clear if there is something like an internal climate oscillation on a multidecadal time-scale with a distinct physical process behind it, as is e.g. El Nino on the interannual time-scale. We find such multidecadal variability in observational data, like PDO or AMO with periods in the order of about 50-70 years. Eric pointed out in his response to #1 in http://www.realclimate.org/index.php?p=267 that until now there is little evidence for a physical process producing the AMO. The same is true for the PDO. However, there are several model studies, that show AMO-like patterns as a response to variability of the Thermohaline Circulation (e.g. Vellinga and Wu 2004, Knight et al. 2005). In principle an internal multidecadal oscillation of the THC doesn’t seem unplausible physically, although for yet unknown reasons. However, there remain open questions:

    1. observations cover hardly two cycles. They show a quite regular behaviour, but this might also be by accident (see below). And it is hard to find some obvious regular behaviour in reconstructions (e.g. Gray et al. 2004, http://wwwpaztcn.wr.usgs.gov/julio_pdf/Gray_ea_AMO.pdf).
    2. the fact alone, that models show an oscillation of a frequency in the same order of magnitude than the AMO is not convincing at all. Looking at Figure 2 in Gray et al. you can find “oscillations” with frequencies of about 100 years or 200 years, while the 70 year cycle, which seem apparent in the observational period, doesn’t show up at all. And the first peak is out of order anyway (at least the amplitude). I for my part can’t see any regular pattern. It looks very much like noise.
    3. quasi-oscillations in time-series can occur by accident. Let’s take the example of global temperature: Let’s suppose there is only little forcing until about 1905, then we have a forcing by increasing solar activity and for a small part rising GHG’s until about 1940, then the solar forcing stops, we have increasing aerosol forcing, volcanism, and decreasing solar activity (all cooling), which balance the increasing GHG forcing until about 1975 and afterwards strongly increasing GHG forcing, with the other factors more or less constant. This leads to a nice step-like pattern just through the accidental superposition of several irregular forcings. If you detrend this data (as is done for the calculation of the AMO), you end up with a very nice oscillation with a 70-year period. And this oscillation shows striking similarites to the AMO (same period, same phase, similar features, similar amplitude (0.3 vs. 0.4 K)…
    4. Gray et al. note, that the AMO shows up on the hemispheric and even global scale. This does not necessarily mean that there is a physical process in the Atlantic which influences global climate: the similarity of the AMO and the (detrended) global temperature pattern could also mean that the AMO is only the expression of the global variability caused by external forcings (somewhat altered by regional influences and feedbacks). Not easy to decide in view of the numerous interactions…

    However, the possibility that there is an internal oscillation of the THC superposed on the effect of external forcing, as suggested by the models, still remains. Maybe it accidentally just fits more ore less the “fake” oscillation of other forcings – not very likely, but possible, if the simulated THC oscillation is real.

    In summary, the AMO pattern of the 20th century might be the result of an internal multidecadal oscillation of the THC as well as just the result of the sum of external forcings (solar, volcanism, aerosols, GHG), or also a mixture of both. The possibility of AMO (or THC, respectively) influence on the1940-1970 cooling remains open.

    Moreover, in this context it’s not evident to attribute the increase of the AMO (and the corresponding increase of Atlantic SSTs) during the last two decades exclusively to a natural cyle. It might also – at least partly – just represent the warming due to GHG’s, as explained above. Which weakens the arguments for the advocates of a “natural” increase of Atlantic hurricanes…

  6. 56
    Pat Neuman says:

    re 55. 42.

    Warmer late 1920s to 1930s due to surge in SOLAR.
    Warmer 1940s to mid 50s due to frequent EL NINOs.
    Cooler mid 1950s to mid 1970s due frequent LA NINAs.
    Warmer late 1970s to current due to accumulation of GHGs.

    http://www.grida.no/climate/ipcc_tar/wg1/449.htm
    http://www.pmel.noaa.gov/~kessler/ENSO/soi-shade-ncep-b.gif
    http://www.realclimate.org/index.php?p=220 .. comments 117, 141
    http://www.grida.no/climate/ipcc_tar/wg1/figspm-3.htm
    http://www.giss.nasa.gov/data/simodel/
    http://pg.photos.yahoo.com/ph/patneuman2000/my_photos

  7. 57
    Lawrence McLean says:

    Re #48
    Pat,

    I started to realise that the climate was getting warmer sometime in the early 1980′s. The changes that I mention in #39 figured in my thinking bringing me to the opinion that the rise in Carbon dioxide must be starting to have an affect. I did a degree in Chemical Engineering and in that course I learned how CO2 acts as a greenhouse gas, that is, it is tranparent to short wavelength infrared radition but reflects long wavelength infrared (just like glass). I also appreciated that although CO2′s greenhouse affect is much weaker than H2O, it does not have H2Os self limiting effect, H2O condenses into liquid when its concentration exceeds its physical maximum vapour concentration, that is, clouds form, reflecting the short wave infrared. CO2 however has no maximum concentration and always remains transparent to short wavelength infrared. I figured this out myself. Another contributing factor, came from a very old Aunt, who told me in the early 1980′s that she remembered it snowed twice when she was a child in Wollongong (before 1910). If you go to your atlas and look carefully where Wollongong is (about 34 degrees South, and on the coast, check out: http://www.bom.gov.au/climate/averages/tables/cw_068188.shtml) you will realise it is inconcievable such a thing happening now.

    If any skeptic looks at the climate link I have just given, sees the record minimum of -0.5 degrees celsius (June) and jumps to the conclusion that snow should be not unusual. Then they are wrong. I can guarantee that temperature would have occured on a still, dry and very clear Winters night. When it is cloudy in winter in Wollongong now, you would be lucky for the temperature to be less than 10 degrees C.

    As far as rapid change, I have not really thought of it in those terms until very recently. I live in Canberra now and it is really obvious that the weather is getting warmer. There is less and less snow every winter, hills that used to be snow covered don’t get any now. Summers are getting hotter and longer. Air conditioning was rare in Canberra, very common now. It goes on and on.

    The skeptics have a grip on the mainstream media here in Australia and I just could not believe what they were saying, as it did not correspond to what I and every one I know was observing first hand. That is why I looked for and found this website.

    As far as my own effots to reduce GHG: I ride my pushbike as much as possible. I own a 4 cylinder (2 litre) car, which gets about 7 litres per 100 kilometers, I buy so called green energy, which is a way of subsidising the development of wind generators. I try and buy things that last and are made locally (rather than transported long distances), I recycle. Within the context of the society I do my best.

    I tend to figure things out for myself (although, I am not arrogant and do not hesitate to seek out information from others, I am certainly aware of the limitations of my knowledge) and I am quite ruthless on ideas and theories when they do not match with objective reality. I sent the link of the cartoon in this thread to a friend of mine and his response was:
    “Hi Lawrence,

    I used to refer to “hate conditioning” but I suppose “fear and doubt conditioning” helps to convince us educated types.

    Ever since the second world war we’ve lived a virtual world where we see the world through the media rather experiencing it first hand and we need such experts to help draw the right conclusions from what we see.

    Before then the Sunday surmon tried to stop us from drifting too far off the correct analysis/interpretation track.

    Cheers,

    Mario”

  8. 58
    Deech56 says:

    Re #53: Thanks. Another point that comes up is that of causation vs. correlation of temperature and CO2 levels. Among the strongest evidence I have seen is in the 2001 IPCC Report comparing the models if natural or anthropogenic or both sets of forcings are considered. The fact that CO2 is a greenhouse gas is simple physics. Another talking point is that money that would go towards reducing greenhouse gases (according to them, only a possible problem) should be spent reducing third world poverty, malaria (known problems). I have seen this enough times I can only imagine that this point came from somewhere.

    I know that the scope RealClimate.org is scientific and not political, but the credibility of scientists is important. It’s those “pesky facts” vs. “common sense” again.

  9. 59
    llewelly says:

    Re 55, Urs Neu:

    Thank you for a long and informative post on temperature trends vs the AMO (Amplification of Mankind’s Output? :-) ). For some time, I’ve wondered how a climate scientist might go about determining how much of North America’s recent warming is attributable to AGW, how much is attributable to the AMO, and to what extent the AMO might itself be driven by AGW. (It seems to me that all natural cycles must be expressions of various forcings, such as solar insolation, GHGs, aerosols, etc, so I find it hard to see how any natural cycle would not be affected at least a little by AGW.) Not being a climate scientist myself, I hadn’t made much progress. Your post is quite helpful. I’m reminded of Dr. William Gray’s (the AGW denialist and hurricane season prognosticator, not the Gray in the paper you link to) focus on the AMO. He seems to think the AMO has a significant influence on global temperatures, and, whenever he trots out his prediction that ‘the earth will begin to cool’, I suspect it is due primarily to a belief that the AMO is the proximate cause of the recent global warming, and therefor, the warming will eventually peak, and global temperatures will thereafter decline. It would be ironic, if anthropogenic influences were in fact the primary cause of recent Atlantic SST variability, the appearance of oscillation being due to coal power’s output of aerosols which cause cooling, but are relatively short-lived, as well as CO2, which is longer-lived and causes warming. (That would also be quite worrisome, given the response of hurricane activity to Atlantic SSTs.) Even if AMO is a natural cycle in its own right, with a primary cause independent of AGW, it seems unlikely that the end of the AMO’s hot phase would result in more than a brief stall in warming.

  10. 60
    Gerald Machnee says:

    Re #59 – **I suspect it is due primarily to a belief that the AMO is the proximate cause of the recent global warming**
    You had to make this up – that is why there is such a misunderstanding of warming issues – too many rumours. Neither Dr. Gray nor any other reputable scientist have said that AMO causes GLOBAL warming. The AMO has been linked to higher Atlantic SST and a higher incidence of hurricances during that period.

  11. 61
    llewelly says:

    Re 60, Gerald Machnee:
    In retrospect, it was irresponsible of me to say that Dr. Gray believed that the AMO was the proximate cause of global warming.

    However … if you, or anyone else knows why he has forecast the earth will begin to cool, I’d like to hear it…

  12. 62
    Pat Neuman says:

    re 57.

    Lawrence, I’ll need a little more time to check out Wollongong. Your story was interesting, even motivating! Rather than say what my answers are to the questions I asked you yesterday, I’d like to ask you, and others at RC, to take a look and comment on the NYC indymedia article I posted today, link follows.

    Should we trust NWS flood predictions?
    http://nyc.indymedia.org/en/2006/03/66159.html

  13. 63
    Hank Roberts says:

    > “earth will begin to cool”
    Can you give us a reference/footnote/cite for this assertion? All Google is finding for me is the assertion without any source on “discussion” websites. I suspect people are getting it from some original source, but what is the source?

  14. 64
    llewelly says:

    Re 63, Hank Roberts, here is a link to his statement on the web site of the US Senate Committee on Environment and Public works:
    http://epw.senate.gov/hearing_statements.cfm?id=246768
    This is the document I was thinking of, but I have fumbled (or confused with a similar statement) the exact wording. Here’s the relevant sentence:

    I anticipate that the trend of the last few decades of global warming will come to an end, and in a few years we will start to see a weak cooling trend similar to that which occurred from the mid-1940s to the early 1970s.

    This seems roughly equivalent to me, but if someone else feels it is not, I appologize for any confusion.

    The article on http://julesandjames.blogspot.com/2005/09/bill-gray-bets-on-cooling.html
    uses the phrase ‘begin to cool’. I don’t have time (or sound on this computer) to listen to the linked audio to hear his precise words. I assume – until someone says differently – that in the audio file Dr. Gray does indeed say ‘begin to cool’, and that I misquoted his prepared statement because he said something slightly different in the spoken version, and I failed to double-check the document I was thinking of. The audio file is from the same September 28, 2005 committee hearing as the statement I link to above.

  15. 65
    Andrew Dodds says:

    Re: 58

    The idea that money would be better spend on things like providing clean water and preventing malaria in the third world comes from the Lomborg group, he of the Skeptical Environmentalist. It relies on economic models which are very strongly influenced by the initial assumptions – if you assume huge costs associated with AGW mitigation and assign large dollar benefit amounts to providing fresh water then your conclusion is pre ordained. The fact that the people involved in making and using these models have no apparent desire to provide money for any of the proposed actions anyway makes the whole excercise more of a way to generate debate points anyway.

  16. 66
    Deech56 says:

    RE: #65 Thanks. It’s hard enough keeping up with the scientific literature (but easier than in the past thanks to RealClimate) without trying to read up on all the contrarian ideas.

  17. 67
    Mikel Marinelarena says:

    Re #47 Michael: Thanks for correcting my reasoning. I was missing the forcing-warming lag in this particular prediction of Gavin’s.

    However, further up in the same thread he explains:

    “Even in the extremely unlikely event that there is no further growth in emissions, the current planetary energy imbalance (estimated to be almost 1W/m2) (due to the ocean thermal inertia) implies that there is around 0.5 C extra warming already in the pipeline that will be realised over the next 20 to 30 years. Any growth of emissions above that will lead to more warming.”

    So, again, just to compensate for the current energy imbalance in Gavin’s estimations we have a warming trend of about 0.2 C to keep up with in the next 2-3 decades. And we’re not quite there yet.

    Besides, as you said, we’re just talking about the most conservative and optimistic scenario here, with NO further emissions growth.

    So the essence of my proposition seems to hold. Am I right in saying that, allowing perhaps 5 years for the possibility of internal climate variability and absent any major negative forcing, we must start seeing a manifest acceleration of the current 0.18 C/decade trend (and hopefully a correction of the tropospheric inconsistency) in the near future for your models to get validated?

    Thanks.

    [Response: No relaxation process will cause an accelaration of warming after the forcing is stabilised - it would go slower and slower until the imbalance was negligible. However, the imbalance is currently growing and so the system is being pushed further out of equilibirum - that eventually will cause the temperature rises to accelarate. According to our projections the trend of around 0.2 deg C/decade or maybe a little more will continue for the next few decades (barring any large volcanic eruptions, or significant efforts to reduce emissions). -gavin ]

  18. 68
    Steve Sadlov says:

    Hmmmm …. my observations of real current conditions in California are being censored. Well, maybe this one will get by. Today, we have a wintry mix down to sea level, with the proper snow level at ~ 500 feet. A record outbreak in a number of ways, in particular, its lateness. Generally, in the past we’ve only gotten these between Dec 15 and Feb 15. Spring may well be disappearing from this part of the world.

  19. 69
    Dan says:

    re: 68

    So what? We just tied (and will likely break) today’s high temperature record here in my location in Virginia. But the much more important point is that specific local, short-term conditions have little bearing on the global or even regional averages over a year. Furthermore, even a location which ends up having a cooler than normal average yearly temperature is not inconsistent with global warming trends.

  20. 70
    Hank Roberts says:

    Steve, this was predicted, no surprise if you look for the info.
    http://www.cpc.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/churchill.html

  21. 71
    Don Baccus says:

    And it hasn’t rained in Phoenix in 141 days, kicking the old record of 101 days set in 2000 into the toilet. Must prove global warming! But, wait! Portland just had its first march snow in 55 years yesterday. Must prove global cooling!

    Steve … local weather events prove nothing. As I’m sure you know. It is an accepted fact, even among professional skeptics, that global warming is real.

  22. 72
    Stephen Berg says:

    Re: #64,

    The betting on the Earth cooling down is just a way for contrarians to inject some sort of questionability or doubt in the minds of the public and policymakers. In reality, the likelihood of a cooling such as from the 1940s to 1970s is so minimal that if one were to make such a bet, they would get very little in return, so it would be basically a waste of time.

    [Response: Gray has been offered a chance to bet on cooling but hasnt taken it - William]

  23. 73

    Re #67: What ‘tropospheric inconsistency’ are you talking about? This one http://www.realclimate.org/index.php?p=179 ?

    Because you are talking about a triumph of the big models, not a point of doubt. It turns out that the two independent streams of data showing no middle troposphere warming were probably wrong, and the models that failed to capture this behavior were right. This itself has been a major contribution of modeling efforts back to the observational branch. It’s a simple and compelling example of why the models are useful in advancing understanding.

    Now, you seem to be looking for some other way to falsify the models, quibbling about a difference in trend between 0.18C/decade and 0.2C/decade.

    You should understand that the observational trend is a crude and noisy statistic. The system has lots of internal wobble masking the trend, so the number cannot be measured precisely. The exact statistics to be used are not

    Similarly, no one claims that climate models are precisely right. One can only discuss whether some specific use of the model is correct or incorrect within some bounds.

    At present, nobody is asserting that the models predict the rate of increase of the rate of increase of global mean temperature to with 0.02 degrees C per decade per decade, nor that observations meaaningfully detect such a change.

    Another way to put is is that you would have to be watching the system for a long time for a signal like that to emerge from the noise. A five year observation just won’t be long enough to make that number meaningful.

    An instantaneous trend or an instantaneous trend of a trend (second derivative) are useful mathematical concepts, but in practice there is no direct measurement of the second derivative of global mean temperature that is meaningful in this context.

    You should look at the actual observations to clarify this. See http://en.wikipedia.org/wiki/Image:Satellite_Temperatures.png

  24. 74
    Lawrence McLean says:

    Pat,

    I am not familiar with the subject of the article, so I cannot judge it. A comment by a skeptic on this thread is interesting, Steve Sadlow #68. Here in New South Wales, Australia, we have just had our hottest summer on record (see: http://www.bom.gov.au/announcements/media_releases/nsw/20060301nsw.shtml). In neighboring Queensland it was so hot that cattle were dying from heat stress (not lack of water!). However south west Western Australia, which has a Mediterranean climate has just had one of its coolest summers (see: http://www.bom.gov.au/announcements/media_releases/wa/20060301b.shtml). It seems that it was so hot in central and eastern Australia that it reversed the normal wind direction in Perth. The reason SW Australia was so cool was because it rained so much. Is that pattern similar in other Mediterranean climates, the comment by Sadlow indicates that sort of behavior is also happening in California, are both their winters and summers wetter and cooler? If so, it may explain some of the skepticism from residents in those regions. They can get away with saying their rubbish without being ridiculed by their neighbors.

  25. 75
    Pat Neuman says:

    re 74.

    Lawrence wrote … They can get away with saying their rubbish without being ridiculed by their neighbors.

    Yes, I think that attitude is the main reason few people acknowledge climate change as a problem that’s already underway. Meteorologists and news anchors talk to the public daily about the same old roller coaster weather, not giving any acknowledgment to the fact that the roller coaster is starting at higher levels as years go by. The National Weather Service (NWS) has given strong support to the notion that nothing is happening, by saying nothing. NWS claimed climate change is too political and controversial, then said there’s no global warming problem. NWS has access to climate records that few others have and are in a position to inform the public about what’s happening but refuse. I was harassed by supervisors and coworkers at NWS for 5-6 years before NWS forced me out of federal service in July, 2005 after I had 29 years of public service in hydrologic modeling and flood prediction with NWS. I may seem bitter, but I don’t go to bed thinking I could have done more. I did everything I could but failed, which is a better feeling than not having tried anything and failed, for me anyway.

  26. 76
    David B. Benson says:

    Pesky facts –

    At least the Scots are taking GW seriously. Yesterday I attended a talk by Mike Rivington, Macaulay Institute, Aberdeen, Scotland, entitled “Farm-Scale Modeling of Climate Change Impacts”. The study is government funded and will require many more months to conclude, intended to assist policy makers in the govenment and on the farm. He started with a regional modeling program from the Hadley Center and made necessary adjustments to calibrate it for scottish temperature and precipitation. His modeling was set for the year 2070.

    The first conclusion was that the variability in percipitation would make spring barley a risky crop, although it is now a scottish mainstay. The second was a big surprise: if livestock growers ‘extensify’ they will double their net income, given current govenment farm subsidies. Extensification means halving their herds and so their production costs. The third conclusion was that regional analysis was not sufficient. Since global economics matters to scottish farmers, global climate change matters as well. This was as much as he has simulated so far.

  27. 77
    David B. Benson says:

    Re #76 — This is a followup for Eachran and others interested
    in planning for climate change. This is not my specialty. In #76
    there are various names to try web trawling on. Using the search words ‘regional planning climate change’ produced oodles of hits.

  28. 78
    Pat Neuman says:

    Where are those pesky facts?

    Excerpts: March 12, 2006, THE MELTING OF MINNESOTA

    What’s driving the changes?

    The warming of the Earth is widely attributed to three things: natural, long-term climate variation; alterations to the landscape such as spreading cities and forest clearing, and a buildup of heat-trapping gases — primarily carbon dioxide, methane and water vapor, known as “greenhouse gases” — in the atmosphere.

    University of Minnesota Extension meteorologist and climatologist Mark Seeley said he objects to fixating on whether humans are completely to blame for warming. That distracts from discussions on what to do about it, he said.

    “Scientific nitpicking disguises the fact that our vulnerability is not going away,” Seeley told a group of farmers in southern Minnesota this month. “That vulnerability is almost a national agenda item. It’s of more economic consequence than ever.”

    The National Academy of Sciences, and Minnesota climate scientists such as Seeley, also say a warmer climate could bring benefits: lower heating costs and energy use, increased yields for some farmers and more time for summer recreation. Some evidence also suggests increased CO2 may actually enhance some plant life, trees in particular.

    http://www.startribune.com/127/story/300057.html

    re 74, 75: No comment by staff at local NWS office.

    Pesky facts at link below.
    NOAA/ESRL Global Monitoring Division, Boulder, CO
    http://www.cmdl.noaa.gov/infodata/faq_cat-3.html

  29. 79
    Mikel Marinelarena says:

    Re# 76 The “tropospheric inconsistency” I was referring to is essentially this:

    “In the tropics, the agreement between models and observations depends on the time scale considered. For month-to-month and year-to-year variations, models and observations both show amplification (i.e., the month-to-month and year-to-year variations are larger aloft than at the surface). The magnitude of this amplification is essentially the same in models and observations. On decadal and longer time scales, however, while almost all model simulations show greater warming aloft, most observations show greater warming at the surface.”
    USCCSP Executive Summary Nov 05
    http://www.climatescience.gov/Library/sap/sap1-1/public-review-draft/sap1-1prd-exsum-no-figs.pdf

    Of course I am not trying to falsify “the models”. I wish I had half the brains it would take to engage in such an attempt. All I’m doing, like many other laypeople interested in what’s happening to our planet, is trying to see if there is any way to ascertain the validity of those models and their dire predictions in the more or less near future (please excuse my not being a full believer yet). Speaking of which, I would rather see a more pedagogic and less militant attitude from experts like you towards the questions raised by simple observers.

    Now, going back to Gavin’s explicit predictions, if all the global warming we’re going to see in the next decades is that of the current trend (0.18 C/decade), or a bit more, by the year 2050 we’ll get a warming of around 0.8, or a bit more. Doesn’t sound like a lot. I don’t understand why Raypierre is trying to scare another poster about the disasters to come by 2050: http://www.realclimate.org/index.php?p=269#comment-9607

    However, I understand that the most likely scenario envisaged by climate scientists is one where CO2 emissions will continue to grow and the real warming will be larger than those minimum figures derived from the current imbalance. I guess that’s where those extreme figures of +5.8 C by the year 2100 (one of the IPCC scenarios) or some even higher estimates published in the scientific literature come from.

    I know that I’m not going to get any expert to make short-term predictions but let’s put it this way: even for Gavin’s optimistic scenario (at least 0.5 C GW in the next 20-30 years and -I infer- 0.8 C by the year 2050) to realize, let alone for the more pessimistic ones, we couldn’t see anything like a reversal of the current trend lasting more than a few years from now on, absent major negative forcings. If such an attenuation of the trend took place, the chances of even Gavin’s moderate predictions for the next quarter of the century to come true would become rather unlikely (simple arithmetic). Then one could deduce that something in “the models” was wrong, hence we do have a possibility of assessing the models’ validity in the short-medium term.

    Where am I wrong now?

    [Response:You're failing to read what you've been repeatedly pointed at: the Aug 2005 Science papers: see http://www.realclimate.org/index.php?p=179 and http://www.realclimate.org/index.php?p=170. Why are you going round in circles? - William]

  30. 80
    Mikel Marinelarena says:

    William: you don’t stand any chance of convincing anyone who is not already in full agreement with you (which I have the impression is the only acceptable attitude you contemplate -here and elsewhere-, even for any newcomer to the GW debate!).

    Of course I have read those articles and of course nothing there contradicts the statement by the CCSP I gave above. Where is your point?

    Temperature observations of the troposphere used to show an obvious inconsistency with what models predicted (larger warming there than on the surface). Once Spencer and Christy’s satellite measurements were corrected, the newest models and observations “ceased to be inconsistent” (by means of the overlapping of the spread of those different models’ outputs and that of different observations, a way of solving inconsistencies that does not look very convincing to my eyes, but that’s another story). However, an inconsistency remains for the tropics, as clearly stated by the CCSP and either models fail to capture this behaviour or observations will need to be corrected further, in their own words.

    Do you not agree with this conclusion or did you get so carried away by S+C accepting the correction to their data that you still fail to see what the issues now are?

    As for the ONLY IMPORTANT point of my previous messages, I’m sure any neutral, non-militant observer will be able to see that it’s not quite me who’s going in circles. If the prediction is that we’ll see a warming of *at least* 0.5 C in the next 20 or 30 years but in the next 10 years we see a warming of less than 0.18 C (with no big negative forcing of the kind now contemplated in the models), it’s just not going to happen. What’s more, even if it were to finally happen by means of a rapid acceleration of the trend in the next decade, I don’t think that’d be something current models have an explanation for.

  31. 81

    Re #34 (comment)

    Raypierre,

    Sorry for the late reply, still a lot of work here, and only sporadic looking at RealClimate comments…
    About learning, I still learn everyday. Here and on other discussions and from literature. I admit that I am rather skeptical in accepting one’s comment, if the arguments are not very convincing. But I have no problems at all to accept what anybody says, if I made an error of any kind, or the science is clear to a reasonable extent.

    In the case of aerosols, there was no reaction at all on my detailed post on that subject, neither from RealClimate nor from the guest writers. Thus still in my opinion, I suppose that I have not made any substantial error in downplaying the effect of human-made sulfate aerosols.
    There may be a difference in scattering between (human made) tropospheric and (volcanic) stratospheric aerosols, but I haven’t found such a difference in the literature.
    What I have found is something (quite old) by Paul Crutzen and others, which even increases the doubt about the influence of anthropogenic sulfate aerosols: half of the anthropogenic SO2 drops out as dry deposit (which I suppose is not the case for stratospheric aerosols), and most of the rest doesn’t form new drops, but oxidizes in already existent cloud water droplets (and there are no, or very few clouds in the stratosphere).
    But even if the physical actions and properties were the same, that implies that only a very small direct influence of human made sulfate aerosols is possible.

    About regional influence in more detail: Scandinavia suffered from “acid rain”, only some 1,000-2,000 km from the main source (the English industry in that case), thus any direct effect should be detectable within that distance (even if this is in part leveled off by other more global influences). And the huge change in human emissions in Europe should give a detectable difference in trends between less and more polluted places in the main wind direction. Which I haven’t found in the relevant period for less polluted and downwind European places.
    In contrast, the abstract of the article by Tapio Schneider mentions localized cooling at the places with the highest sulfate load, but I have no access to the full article.

    And the fact that far more human made aerosols are released in the NH (and stay there), while ocean heat content increase is substantially higher in the NH than in the SH (when corrected for surface), isn’t very convincing for aerosol cooling (maybe the other types of aerosols even overrule the sign, as rural India is warming faster than nearby Diego Garcia in the SH).

    Oh, about an alternative theory. Have a look at the experiment by Stott ea., where they increased (within the constraints of the Hadcm3 model) solar (10x) and volcanic influences (5x). If one increases the Hoyt & Schatten solar reconstruction with some factor 3-5 (at the cost of the GHG-aerosol combination), one has a near-fit of the 1945-1975 temperature. And as you may be convinced now (those pesky scientific facts): after two satellite measured cycles, there is a direct influence of the solar cycle (as TSI) on (low) cloud cover. Thus any variation in current (and likely past) solar irradiation is fortified by cloud cover changes…

    More about glaciers within a few days…

  32. 82
    Almuth Ernsting says:

    Re: 28 and 30 (old textbooks)

    I looked at the books when I went visiting so I don’t have them in front of me. The 1978 one which refers to Wally Broecker is “Earth” 2nd Edition, Front Press, MIT, by Raymund Siever.

    I am about 90% sure that the 1950s one I looked at was “Principles of Geochemistry”, Brian Mason, 1952-1958. It was far less specific than the other one.

    Interestingly, particularly in the 1978 book, there was some reference to increased albedo from oil on water (?) which sounds a bit strange, but certainly reference to the cooling effects of sulphour emissions probably offsetting the warming effects of increased CO2 emissions. Some information about the greenhouse effect in general and nothing about an imminent ice age.

    Almuth Ernsting

  33. 83
    Hank Roberts says:

    Mikel, you seem to be repeating, as your reason for questioning the models, the quote
    “model simulations show greater warming aloft, most observations show greater warming at the surface.”

    Did you have another reason for questioning the models? I wonder if you are basing your quoting of that just on the time stamp order of the dates of the publications? Or what else?

    If I understand this, the quote you repeat — “most observations show greater warming at the surface” — even as of its November 05 publication date was based on old info and the facts had been corrected by the Aug 2005 Science papers (I recall confirming followups in one of the November Science mag. issue letters columns as well).

  34. 84
    Steve Sadlov says:

    Siever is excellent. It was one of my baby steps as a Freshman.

  35. 85

    Protect Us From Facts
    Sometimes, it takes someone like Doonesbury to show us how we Democrats can be as happy as Republicans: forget about those silly facts. Click to enlarge via RealClimate…

  36. 86
    Hank Roberts says:

    Following up #70 (relevance? on the cusp where enough weather starts looking like climate, and NOAA’s predictive ability) — the prediction of a cold wet March for the California coast is holding up nicely so far. See the predictions, via the link at #70 — NOAA also predicted no more below-average weather for many months hereafter.

    I wonder if the local meteorologists “marveling” at the weather (quote below is from today’s SF Chronicle story) knew of the NOAA prediction for March?

    Quote:
    “An unusual meshwork of atmospheric highs and lows is parked over the Pacific, pummeling Hawaii for days on end while diverting the jet stream south. Meteorologists are marveling at the pattern’s persistence, but the result is buckets of moisture being dumped on the Bay Area.
    One more day of rain will tie the record, 23 days of rain, for San Francisco’s wettest March…
    End quote

  37. 87
    Steve Sadlov says:

    RE: 86. The most remarkable thing is that unlike the far more common “Pineapple Express” rainy pattern we get repeatedly during the course of most rainy seasons, the current particular pattern is not that one. It is, instead, a “Siberian Express” pattern of unprecedented duration. We’ve had it in place, with the exception of a short “Pineapple” interval for a couple of days, and a couple of short lived dirty ridges, ever since Mid Febrary. Today we were just above the triple point at my place and the precip was slush. I live at just under 1000 feet, quite near the coast, south of 40 N.

  38. 88
    Dano says:

    87:

    The trof axis is too close to the coast and the lo center too far south for a Pineapple Express & these years are usu. below normal for those unfavored for lo position. In years where the trof axis is so close to the shelf, you have to look at the position of the los for your PWs: too far N and weak fronts, too far S and you get your synoptic situation but Bay Area or Big Sur happy as in late 90s (further S as is usually a bit later and LA gets their precip), and the frequent big double-barreled los you’re getting make wobblies and who knows which county gets the precip. Looks like to me this next one is going to track ~ the same as last one did.

    Best,

    D


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