SPM4 Eve

What will I be looking for in the SPM4? There’s not much fun in trying to predict their temperature estimate when they’ve already leaked that it’s 2-4.5 deg C by 2100. So here are some things that I’m going to be looking for.

1. First – and I realize that it’s far down the list for the world at large – but, if you’ll forgive me a little self-indulgence, I’ll check to confirm that “warmest in 1300 years” or “hottest in 1300 years” made it into the SPM. It would be fun if a spaghetti graph made it up the food chain, but that would be a pleasant surprise

2. Second, I’ll see if a “battalion of intergalactic smoking missiles” has arrived in Paris, as Andrew Weaver has told us. Since this document is supposed to a Summary of the WG1 Report, which itself was a literature review, it’s hard to see how even resourceful IPCC couriers could have smuggled an “intergalactic smoking missile” through security into Paris for presentation as new evidence tomorrow – it won’t be like one of the old Russian May Day parades. If IPCC council changes a probability rating of something from likely to very likely, that is not something that I would regard as an intergalactic smoking missile, although maybe this is a big deal in Team-world and to the BBC. Do I expect any new evidence in the SPM? No.

3. Third, I’ll cross-check the SPM4 to the TAR SPM (SPM3). My guess is that some of the statements in the two documents are going to be surprisingly similar. For example, SPM3 said: “…There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.” I suspect that SPM4 will also say “…There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.” However, it seems to me that most of the evidence available today – whatever its merit – was equally in play in 2001. So it will be interesting to see whether they specify what the “new and stronger” !$r evidence is.

4. Antarctica seems to be a bit of a battleground issue between IPCC factions. TAR said that Antarctic was projected to gain mass in the 21st century. The WG1 text said that precipitation over Antarctica would increase and that the resulting accumulation on the continent would have a negative impact on sea levels. Obviously some factions want to project melting in Antarctica and a positive contribution to sea levels. So let’s watch what happens. Will they mention “polar amplification”? Given recent cooling over Antarctic, my guess is that the term will not be used.

5. I think that we’ll hear a lot more in SPM4 than SPM3 about the Four Horsemen of the New Apocalypse: Drought, Hurricanes, Sea Level Rise and you-pick-it (Sea Ice Decline, Heat Waves, even old-fashioned Pestilence, although it is more a WG2 interest). The Horsemen of the Apocalypse only had bit roles in TAR WG1. Here I’ll be looking for language. Drought is particularly interesting as the WG1 paleoclimate chapter says that there is proxy evidence for much more extensive historic droughts than modern droughts and the model projections chapter reports moister monsoons under global warming. However, one suspects that they will try to saddle up Drought on a pale horse.

6. It sounds like they’re going to take a swipe at solar and promote the low variability view of Wang et al 2005. I get the impression that Wang et al 2005 is very speculative and not the sort of thing that should be incorporated into a mainstream poilcy position at this point. However, this will be amusing if they do, since the low variability Wang solar theory is inconsistent with solar irradiance in all the millennium paleoclimate simulations.

7. In one press story, they said the following:

11 of the past 12 years rank among the warmest since humans began taking accurate temperature measurements in the 1850s, a record of extremes so pronounced it is unlikely to be due to chance.

The WG1 report does not include the last phrase. Was this inserted in the press story or the leaked SPM? It would be delicious if it were in the SPM, since this introduces a statistical opinion on long-term persistence that seems outside the mandate of the SPM authors. Will they add this phraseology back into the AR4 to make it “consistent” with the SPM? Or just ignore the inconsistency?

8. I guess that we already know that their temperature projection to 2100 is 2-4.5 deg C (as opposed to 1.4-5.8 deg C in 2001). A story says that the report says “Large uncertainties remain about how clouds might respond to global climate change”. I’ll check to see. Im sure that they’ll say that “models are improving”. Just to demonstrate the remarkable progress in understanding over only one generation, the Charney Report in 1979, an interesting commissioned report by a NAS panel on 2xCO2 by eminent scientists, estimated the effect of 2x CO2 to be 1.5-4.5 deg C, said that the biggest problem with models and the biggest contribution to uncertainty was clouds, but that models are improving. Ten years earlier, Joni Mitchell said it better:

Rows and floes of angel hair
And ice cream castles in the air
And feather canyons ev’rywhere
I’ve looked at clouds that way

But now they only block the sun
They rain and snow on ev’ryone
So many things I would have done
But clouds got in my way
I’ve looked at clouds from both sides now
From up and down, and still somehow
It’s cloud illusions I recall
I really don’t know clouds at all

Here are some URLs to news stories about the preview that readers have sent in or that I’ve noticed.

CNN http://www.cnn.com/2007/TECH/science/01/23/climate.report.ap/index.html This isn’t a smoking gun; climate is a batallion of intergalactic smoking missiles.”


MSNBC http://www.msnbc.msn.com/id/16760730/ S

Telegraph http://www.telegraph.co.uk/opinion/main.jhtml?xml=/opinion/2007/01/27/do2701.xml

Reuters http://news.yahoo.com/s/nm/20070124/sc_nm/climate_security_dc

http://www.msnbc.msn.com/id/16884620/ clouds a puzzle



Yahoo http://www.cnn.com/2007/TECH/science/01/23/climate.report.ap/index.html http://news.yahoo.com/s/nm/20070124/sc_nm/climate_security_dc

AP http://hosted.ap.org/dynamic/stories/C/CLIMATE_REPORT?SITE=FLPAP&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2007-01-28-17-40-08

Observer http://observer.guardian.co.uk/world/story/0,,2000533,00.html

IHT http://www.iht.com/articles/ap/2007/01/28/america/NA-FEA-GEN-US-Climate-Report.php



  1. Spence_UK
    Posted Feb 1, 2007 at 4:59 PM | Permalink



    That Stefan chap gets about a bit doesn’t he? The most recent stories definitely have an “Oh my gosh it is even worse than we thought it was” feel to them. Pushing the idea that recent observations are at the top of the range of predictions made by the models.

  2. Pat Frank
    Posted Feb 1, 2007 at 5:00 PM | Permalink

    Ten years earlier, Joni Mitchell said it better” — Judy Collins did it better. 🙂

    Steve, it appears you have a copy of the WG1 in its pristine form. Is there any convenient way that you could compare WG1(pure) against the eventual WG1(SPM’ed – pronounced spammed) to see what they’ve done to the text?

  3. Steve McIntyre
    Posted Feb 1, 2007 at 5:07 PM | Permalink

    Here’s another SPM eve story discussed at RC. It seems that the US delegation is haggling about hurricane language. I wonder if they have any idea just how fragile and trumped up the hurricane statistics are.

  4. Reid
    Posted Feb 1, 2007 at 5:16 PM | Permalink

    Pat Frank comments: “Steve, it appears you have a copy of the WG1 in its pristine form.”


    If you do have a copy would you consider posting it on the net to coincide with tomorrows release?

  5. Jean S
    Posted Feb 1, 2007 at 5:34 PM | Permalink

    Steve, thanks for the Charney Report link, that’s a real treasure!

  6. jae
    Posted Feb 1, 2007 at 5:41 PM | Permalink

    The link says:

    “Transparency should be increased and aspects of previous assessments should be dissected to examine how the assessing scientists weighed and balanced the evidence, and arrived at their judgments,” Oppenheimer said.

    Duh. Maybe they could release the details along with (or even before) the Summary…

  7. Posted Feb 1, 2007 at 6:57 PM | Permalink

    Regarding the 2-5°C temperature rise over 100 years. Yes I know these are based on the incredibly thorough and reliable climate models, however here is the problem I have:
    – over the past 100 years we had a temperature rise of 0.6 degrees Celsius, ignoring likely errors in measurements and trusting the scientist in charge (although we have no way of knowing since they will not allow an audit).
    – Carbon dioxide output grew exponentially over this time. The response to increasing carbon dioxide is approximately logarithmic which gives us an approximate linear rate of temperature change. Great, wonderful.
    – I think it has now been acknowledged that the Sun has had some effect. I think I have heard estimates thrown around like 1/4 of the warming that occurred last century.
    – who knows when peak oil will occur, but probably it will occur sometime within the next 100 years. Say 2030-2050.
    – population growth over the last 100 years was exponential but is expected to level off around 2030 or so.
    – temperatures did not rise as much last century as predicted. Antarctica is not behaving as predicted. The troposphere is not behaving as predicted. In short the models have a questionable track record.

    It seems pretty obvious to me (although I have committed I’m not using a high powered model running on a supercomputer to come to these conclusions) that the rate of increase in CO2 will decrease (peak oil, population stabilization), the models did not do a very good job of predicting so far, the rate of increase in temperature over the last century was less than 0.6°C due to carbon dioxide ( taking out some amount for solar input). Temperature sensitivities are logarithmic with respect to CO2.

    So how does one go from a 0.6°C change over last century combined with the above observations to a possible 5°C change next century? It’s preposterous.

  8. Gary
    Posted Feb 1, 2007 at 7:32 PM | Permalink

    U.S. National Public Radio had a pre-release report today saying that the major difference between this and the 2001 report is that the uncertainties have been reduced, not that the conclusions have changed.

  9. Gerald Browning
    Posted Feb 1, 2007 at 9:08 PM | Permalink

    Steve M.,

    The claim that climate models are improving doesn’t wash given that the models can’t predict reality for more than a day (see BAMS article by Dave Williamson et al. mentioned in my initial post under modeling and the article cited in the comments on that post that the climate models can’t even compute the climate for a year). And although NCAR is going to build a new supercomputer center in Wyoming (because Wyoming has money to spare from the oil and gas industry – how ironic), more computing power will not help as mentioned in my
    first post under Solar Proxies and to be detailed in my coming discussion. The association between hurricanes and AGW has been shown to be questionable. The plots Chris has made seem to indicate a much stronger solar connection than previously acknowledged. IMO, the IPCC should bea bit embarrassed, but do not appear to be?

  10. Dieter Riedel
    Posted Feb 1, 2007 at 9:11 PM | Permalink

    Leading up to the inevitable, there have been the stories linking global warming/human-induced climate change with the coming death of billions due to floods and starvation, increased suicide rates due to warming and a never-ending common cold season.

    Somehow I doubt these will all make it into this latest volume, but there are more to come.

  11. Posted Feb 1, 2007 at 10:03 PM | Permalink

    #10 where do they come up with this stuff? (never ending cold season for example). I’m not that young, but young enough that this is the first (well other than the whole terrorist thing) social hysteria phenomena that I get to experience — and in painful slow motion too since it could take years before it’s obvious how ridiculous most (all?) of this hysteria really is. Remember the “certainty” of WMDs. The more passionately and confidently one argues without true evidence (filling the gap with anecdotes, models, scenarios, and sparse noisy data), the more wary we need to be.

  12. Steve McIntyre
    Posted Feb 1, 2007 at 11:05 PM | Permalink

    I might add that in terms of my own scientific interests I was far more interested in the NAS panel report than in the SPM4. I do not expect the SPM to do anything other than mention proxies in passing. I hope that they will carry on with HSticks but I doubt that we will be so lucky. Most of the active issues are in other specialties and it’s impossible for me to keep up with proxies. I’m taking a look at it because it’s in the news but may not keep doing so.

  13. PHE
    Posted Feb 2, 2007 at 1:49 AM | Permalink

    The Hadley centre is already re-writing history in Orwellian style, showing the current temperature rise started in 1945 rather than 1976 (I know a similar re-hash was already been mentioned on this site recently):


    And the BBC do a classic distortion. Alongisde a photo of flooded homes, they state: ‘Climatic changes seen around the world are “very likely” to have a human cause, the Intergovernmental Panel on Climate Change (IPCC) will conclude.’
    Thus clearly implying that its the weather events themselves that are ‘very likely’ to be human caused. But reading the rest of the article, it turns out only that mean observed temperature rises are close to the upper preductions of TAR. They also state the temperature rise was 0.33degC between 1990 and 2006. Its very difficult to achieve this value without being very selective with the data! It certainly doesn’t represent the rise in the mean .


    And we’re going to see many more photos of polar bears standing on melting ice. As if they never did this before! Like every spring.

    But like most good ‘science’ and ‘environment’ correspondents, the author is only relying on the press release he’s fed. No point in making your own balanced judgment.

  14. Hans Erren
    Posted Feb 2, 2007 at 2:04 AM | Permalink

    In Holland the claim is made that AR4 is “conservative” and that the new more extreme results that Al Gore advocates (in particular re: sea level rise) didn’t make it to the report.

  15. ian
    Posted Feb 2, 2007 at 2:45 AM | Permalink

    Is it possible to reconcile the tenp chart on the BBC site referenced above:


    With this one:


  16. Jim Barrett
    Posted Feb 2, 2007 at 3:04 AM | Permalink

    Steve: you haven’t replied to Reid’s posting 4. Do you want to give him a lesson in common ethics or shall I?

  17. PHE
    Posted Feb 2, 2007 at 3:29 AM | Permalink

    The BBC article linked has now removed the graphs mentioned, and (through a slip I believe), they suggest temperature has risen 0.33 degC since 2001 and not 1990! But this type of slip easily goes unnoticed if you are expecting drama. If they more accurately mentioned a rise of 0.11 since 1990 or 0.002 degC since 2001, then bells might have rung.

  18. John Baltutis
    Posted Feb 2, 2007 at 4:03 AM | Permalink

    Re: #16

    Why don’t you do it since you think you’re qualified to do so. And, when you’re finished composing the lesson, why don’t you pass it on to all the individuals and organizations that have leaked information and made public comments the past few weeks about the contents of the SPM4 document?

  19. Hans Erren
    Posted Feb 2, 2007 at 4:05 AM | Permalink

    its here

    Click to access 02_02_07_climatereport.pdf

    Climate Change 2007: The Physical Science Basis

    Summary for Policymakers

    Contribution of Working Group I to the Fourth Assessment Report of the
    Intergovernmental Panel on Climate Change

    This Summary for Policymakers was formally approved at the 10th Session
    of Working Group I of the IPCC, Paris, February 2007.

  20. Willis Eschenbach
    Posted Feb 2, 2007 at 4:23 AM | Permalink

    Well, the media barrage has begun. Science Express has an article by Stefan Ramstorf, James Hansen, and the usual suspects, which purports to compare the changes since 1990 to the differences in the IPCC TAR scenarios. Here are their results:

    Original Caption Fig. 1. Changes in key global climate parameters since 1973, compared to the scenarios of the IPCC [shown as dashed lines (A1FI, light blue; A1B, purple; A1T, blue; A2, red; B1, yellow; and B2, green) and gray ranges in all panels].

    (a) Monthly carbon dioxide concentration and its trend line at Mauna Loa, Hawaii (blue) up to January 2007, from Scripps in collaboration with NOAA.

    (b) Annual global-mean land and ocean combined surface temperature from GISS (red) and the Hadley Centre / Climatic Research Unit (blue) up to 2006, with their trends.

    c) Sea-level data based primarily on tide gauges (annual, red) and from satellite altimeter (3-month data spacing, blue, up to mid-2006) and their trends. All trends are non-linear trend lines and are computed with an embedding period of 11 years and a minimum roughness criterion at the end (see ref. 6), except for the satellite altimeter where a linear trend was used because of the shortness of the series. For temperature and sea level, data are shown as deviations from the trend-line value in 1990, the base year of the IPCC scenarios.

    Now, from this you get an impression that graphs represent scenarios since 1990, and the gray range shows the full range of all of the climate model results. They also say:

    Although published in 2001, these model projections are essentially independent from the observed climate data since 1990: climate models are physics-based models developed over many years that are not “tuned” to reproduce the most recent temperatures, and global sea level data were not yet available at the time.

    However, the IPCC tell a very different story (emphasis mine):

    Since the SRES was not approved until 15 March 2000, it was too late for the modelling community to incorporate the final approved scenarios in their models and have the results available in time for this Third Assessment Report. However, draft scenarios were released to climate modellers earlier to facilitate their input to the Third Assessment Report, in accordance with a decision of the IPCC Bureau in 1998. At that time, one marker scenario was chosen from each of four of the scenario groups based directly on the storylines (A1B, A2, B1, and B2). The choice of the markers was based on which of the initial quantifications best reflected the storyline and features of specific models. Marker scenarios are no more or less likely than any other scenarios, but are considered illustrative of a particular storyline. Scenarios were also selected later to illustrate the other two scenario groups (A1FI and A1T) within the A1 family, which specifically explore alternative technology developments, holding the other driving forces constant. Hence there is an illustrative scenario for each of the six scenario groups, and all are equally plausible. Since the latter two illustrative scenarios were selected at a late stage in the process, the AOGCM modelling results presented in this report only use two of the four draft marker scenarios. At present, only scenarios A2 and B2 have been integrated by more than one AOGCM. The AOGCM results have been augmented by results from simple climate models that cover all six illustrative scenarios. The IS92a scenario is also presented in a number of cases to provide direct comparison with the results presented in the SAR.

    The final four marker scenarios contained in the SRES differ in minor ways from the draft scenarios used for the AOGCM experiments described in this report. In order to ascertain the likely effect of differences in the draft and final SRES scenarios, each of the four draft and final marker scenarios were studied using a simple climate model. For three of the four marker scenarios (A1B, A2, and B2) temperature change from the draft and marker scenarios are very similar. The primary difference is a change to the standardised values for 1990 to 2000, which is common to all these scenarios. This results in a higher forcing early in the period. There are further small differences in net forcing, but these decrease until, by 2100, differences in temperature change in the two versions of these scenarios are in the range 1 to 2%. For the B1 scenario, however, temperature change is significantly lower in the final version, leading to a difference in the temperature change in 2100 of almost 20%, as a result of generally lower emissions across the full range of greenhouse gases.

    Note that the scenarios do not start in 1990 as Rahmstorf et al. claim, the 1990 and 2000 values are “standardized values” which are identical for all models, with no information given about how the standardized values were chosen. To claim that they mean anything about how well the models did is simply not true. They are simply numbers which were picked by somebody. Not only that, they were later changed, so these “marker scenarios” are different (particularly in the early years) from the remainder of the scenarios used (presumably) for the gray areas in the graphs.

    Also, note that two of the scenarios used by Rahmstorf et al. weren’t even used in the TAR …

    Finally, notice something curious. Only two of their six results are from the AOGCMs … the other four are from “simple climate models”.

    So in reality, we only have five years of climate model results from AOGCMs, and these only cover two scenarios, the rest are just “simple climate models”. Hansen commented regarding his early models that

    Because of this chaotic variability, a 17-year period is too brief for precise assessment of model predictions, but distinction among scenarios and comparison with the real world will become clearer within a decade.

    So now, he’s trying to sell us on the idea that a 5 year period is plenty to determine how well the IPCC models are doing … I gotta admit, this is getting very, very old …


    PS – I also note that they have spliced two very different sea level trends together (Church and White, and TOPEX). In addition, they say:

    Note that the rate of rise for the last 20 years of the reconstructed sea level is 25% faster than the rate of rise in any 20 year period in the preceding 115 years.

    Since the “reconstructed sea level” they are using is a spliced dataset, this is both meaningless and a deliberate deception. The Church and White sea level they are using shows the following:

    Original Caption c) Linear trends in sea level from the reconstruction for overlapping 10 year periods. The trend for each period is plotted at the centre time of the period.

    Note that, in stark contrast to their claim, the most recent trend in the Church and White record has been exceeded twice in the 20th century.

  21. Andre
    Posted Feb 2, 2007 at 5:14 AM | Permalink

    Average Northern Hemisphere temperatures during the second half of the 20th century were very likely higher than during any other 50-year period in the last 500 years and likely the highest in at least the past 1300 years. Some recent studies indicate greater variability in Northern Hemisphere temperatures than suggested in the TAR, particularly finding that cooler periods existed in the 12 to 14th, 17th, and 19th centuries. Warmer periods prior to the 20th century are within the uncertainty range given in the TAR.

    As the Medieval Warm Period was assisanted in the TAR, it is still considered death. Moreover about chances, wouldn’t that be a insult to Norths NAS verdict: ‘less confidence…” etc

    So how many studies appeared that counterbalanced the hundreds about the Medieval Warming Period with a peak around 950AD.

    I’ll update the list here eventually

  22. TAC
    Posted Feb 2, 2007 at 5:34 AM | Permalink

    #20 Willis, thanks for the analysis and graphics. I was wondering how global temperature data from the last five years (since IPCC TAR), which arguably show a downward trend, could be reconciled with model predictions. Now I know 😉

  23. Douglas Hoyt
    Posted Feb 2, 2007 at 6:46 AM | Permalink

    As the SPM comes out, it is -7F in Boulder with heavy snow. As of 3:53 AM, the temperature plummeted to -16F at Denver International Airport, tying the record low for February 2 set in 1996.


    1. 63 days…Nov 26, 1983 – Jan 27, 1984
    2. 60 days…Dec 1, 1913 – Jan 29, 1914
    3. 48 days…Dec 24, 1982 – Feb 9, 1983
    4. 45 days and counting…Dec 21, 2006 – Feb 2, 2007
    5. 43 days…Dec 19, 1973 – Jan 30, 1974

    As of yesterday, Denver Stapleton had 9″ of snow on the ground, so it is virtually certain that the present snow cover of greater than one inch will move into third place.

    I see some irony in this.

  24. David Smith
    Posted Feb 2, 2007 at 7:50 AM | Permalink

    Re #13

    The Inconvenient Cooling of 1945-1975 has now been purged from history (see graph ).

    My prediction is that the next purge of the records will remove that Inconvenient Hump, 1935-1945. I predict that we’ll begin to see articles questioning the validity of the 1935-1945 data due to the World War and see that period replaced by something like a gap or light dotted line or range.

    The Hadley article referenced several days ago mentioned that some of the records of what, and how, historical temperature data was adjusted has been lost. If they lose the records of what they adjusted this time, it may be impossible to ever undo the damage to the records.

  25. Hans Erren
    Posted Feb 2, 2007 at 8:19 AM | Permalink

    luckily we still have the raw dutch daily data

  26. Jean S
    Posted Feb 2, 2007 at 8:39 AM | Permalink

    re #24: You may find this article interesting:
    Robock, Alan, 1982: The Russian surface temperature data set. J. Appl. Meteorol., 21, 1781-1785.

  27. Douglas Hoyt
    Posted Feb 2, 2007 at 10:38 AM | Permalink

    Just to update my previous message 23:

    New record low for Feb 2:

    At 4:44 am the temperature at Denver International Airport fell to 18
    degrees below zero. This breaks the old record of 16 below zero set
    in 1996.

    NCAR is not too far away and the city of Boulder is suing the Fedreal government to make the climate cooler via reduced carbon dioxide emissions.

  28. jae
    Posted Feb 2, 2007 at 11:31 AM | Permalink

    21, Andre: Great list! Have you seen this one?

  29. David Smith
    Posted Feb 2, 2007 at 12:14 PM | Permalink

    RE #26 Thanks for the link.

    The article shows the Russian data with a clear decline from 1945-1975. I also glanced at several of the references used in this 1982 paper and saw Hansen’s work with a global temperature decline and Angell’s radiosonde work with a temperature decline. I did not see Jones’ 1980 chart (no access).

    I wonder if they’ll purge these historical studies from the record, too.

  30. Hans Erren
    Posted Feb 2, 2007 at 3:44 PM | Permalink

    Steve M writes:

    their temperature projection to 2100 is 2-4.5 deg C

    That is not correct:
    SPM page 9 reads

    The equilibrium climate sensitivity is a measure of the climate system response to sustained radiative
    forcing. It is not a projection but is defined as the global average surface warming following a doubling of
    carbon dioxide concentrations. It is likely to be in the range 2 to 4.5°C with a best estimate of about 3°C,
    and is very unlikely to be less than 1.5°C. Values substantially higher than 4.5°C cannot be excluded, but
    agreement of models with observations is not as good for those values. Water vapour changes represent the
    largest feedback affecting climate sensitivity and are now better understood than in the TAR. Cloud
    feedbacks remain the largest source of uncertainty. {8.6, 9.6, Box 10.2}

    The waiving of the lower that 1.5 and emphasising over 4.5 values is telling. There are very good arguments in favour of a value of 1.3±0.4°:

  31. Dave Dardinger
    Posted Feb 2, 2007 at 5:13 PM | Permalink

    re: #30 Hans,

    Note that the 2-4.5 deg C is based on a doubling of CO2 concentration by 2100. I don’t know that that’s a slam dunk by any means. Certainly guessing how we’d be producing energy by 2000 in 1905 would likely be rather wrong. I know warmers want to cut back fossil produced energy use ASAP, but most skeptics agree that there will need to be a reduction in fossil energy use in any case. We’ll have to see which scenario pans out.

  32. Hans Erren
    Posted Feb 2, 2007 at 5:28 PM | Permalink

    Hi Dave

    Don’t confuse the scenario projections (page 21) with climate sensitivity!

    I think the current world is more a B1 than an A1 world (page 14), and combined with IMHO increasing instead of decreasing sinks we will never reach a CO2 doubling any way.

    The input scenarios are described here in TAR:

    here are all SRES tables

  33. Dave Dardinger
    Posted Feb 2, 2007 at 5:57 PM | Permalink

    re: #32

    I’m just following what you quoted; i.e. that 2-4.5 deg C is the doubling sensitivity. It may be that the IPCC projection according to some model is that this is also coincidentally the same as a doubling, and that that is what Steve was quoting, but if so, you might have said so. I glanced through the SPM, but I’m far from having memorized it. Anyway, I suppose I shouldn’t have used the word “scenario” as I wasn’t especially thinking about the IPCC scenarios, just the general scenarios concerning whether CO2 will ever double or not.

  34. Douglas Hoyt
    Posted Feb 20, 2007 at 3:41 PM | Permalink

    For the record, here is the official update from the NWS for message #23 above. This year finished in second place. They expect more snow in Denver next Saturday.



    63 DAYS………………………………NOVEMBER 26 1983 – JANUARY 27 1984
    61 DAYS …………………………….DECEMBER 21 2006 – FEBRUARY 19 2007 (FINAL)
    60 DAYS………………………………DECEMBER 1 1913 – JANUARY 29 1914
    48 DAYS………………………………DECEMBER 24 1982 – FEBRUARY 9 1983
    43 DAYS………………………………DECEMBER 19 1973 – JANUARY 30 1974
    39 DAYS………………………………NOVEMBER 21 1992 – DECEMBER 29 1992
    38 DAYS………………………………DECEMBER 24 1987 – JANUARY 30 1988
    35 DAYS………………………………JANUARY 2 1949 – FEBRUARY 5 1949
    33 DAYS………………………………DECEMBER 17 1918 – JANUARY 18 1919
    27 DAYS………………………………JANUARY 28 1989 – FEBRUARY 23 1989


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