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1934 and all that

Filed under: — gavin @ 10 August 2007

Another week, another ado over nothing.

Last Saturday, Steve McIntyre wrote an email to NASA GISS pointing out that for some North American stations in the GISTEMP analysis, there was an odd jump in going from 1999 to 2000. On Monday, the people who work on the temperature analysis (not me), looked into it and found that this coincided with the switch between two sources of US temperature data. There had been a faulty assumption that these two sources matched, but that turned out not to be the case. There were in fact a number of small offsets (of both sign) between the same stations in the two different data sets. The obvious fix was to make an adjustment based on a period of overlap so that these offsets disappear.

This was duly done by Tuesday, an email thanking McIntyre was sent and the data analysis (which had been due in any case for the processing of the July numbers) was updated accordingly along with an acknowledgment to McIntyre and update of the methodology.

The net effect of the change was to reduce mean US anomalies by about 0.15 ºC for the years 2000-2006. There were some very minor knock on effects in earlier years due to the GISTEMP adjustments for rural vs. urban trends. In the global or hemispheric mean, the differences were imperceptible (since the US is only a small fraction of the global area).

There were however some very minor re-arrangements in the various rankings (see data [As it existed in Sep 2007]). Specifically, where 1998 (1.24 ºC anomaly compared to 1951-1980) had previously just beaten out 1934 (1.23 ºC) for the top US year, it now just misses: 1934 1.25ºC vs. 1998 1.23ºC. None of these differences are statistically significant. Indeed in the 2001 paper describing the GISTEMP methodology (which was prior to this particularly error being introduced), it says:

The U.S. annual (January-December) mean temperature is slightly warmer in 1934 than in 1998 in the GISS analysis (Plate 6). This contrasts with the USHCN data, which has 1998 as the warmest year in the century. In both cases the difference between 1934 and 1998 mean temperatures is a few hundredths of a degree. The main reason that 1998 is relatively cooler in the GISS analysis is its larger adjustment for urban warming. In comparing temperatures of years separated by 60 or 70 years the uncertainties in various adjustments (urban warming, station history adjustments, etc.) lead to an uncertainty of at least 0.1°C. Thus it is not possible to declare a record U.S. temperature with confidence until a result is obtained that exceeds the temperature of 1934 by more than 0.1°C.

More importantly for climate purposes, the longer term US averages have not changed rank. 2002-2006 (at 0.66 ºC) is still warmer than 1930-1934 (0.63 ºC – the largest value in the early part of the century) (though both are below 1998-2002 at 0.79 ºC). (The previous version – up to 2005 – can be seen here).

In the global mean, 2005 remains the warmest (as in the NCDC analysis). CRU has 1998 as the warmest year but there are differences in methodology, particularly concerning the Arctic (extrapolated in GISTEMP, not included in CRU) which is a big part of recent global warmth. No recent IPCC statements or conclusions are affected in the slightest.

Sum total of this change? A couple of hundredths of degrees in the US rankings and no change in anything that could be considered climatically important (specifically long term trends).

However, there is clearly a latent and deeply felt wish in some sectors for the whole problem of global warming to be reduced to a statistical quirk or a mistake. This led to some truly death-defying leaping to conclusions when this issue hit the blogosphere. One of the worst examples (but there are others) was the ‘Opinionator’ at the New York Times (oh dear). He managed to confuse the global means with the continental US numbers, he made up a story about McIntyre having ‘always puzzled about some gaps’ (what?) , declared the the error had ‘played havoc’ with the numbers, and quoted another blogger saying that the ‘astounding’ numbers had been ‘silently released’. None of these statements are true. Among other incorrect stories going around are that the mistake was due to a Y2K bug or that this had something to do with photographing weather stations. Again, simply false.

But hey, maybe the Arctic will get the memo.


620 Responses to “1934 and all that”

  1. 501

    [[Isn’t this a misunderstanding? What Gavin describes are just measures for removing a warm bias from the microclimate, not adding a cooling artefact. A thermometer is supposed to be in the shade anyway, so trees and south side-north side issues will not cause artificial cooling in well-mixed air.]]

    If the surroundings of a station are getting lighter in color with time it will induce a spurious cooling trend.

  2. 502
    guthrie says:

    #496- Steve reynolds- building dams is expensive, and not always a good idea in an earthquake zone.
    Plus, you need nice narrow valleys with good rock to anchor the foundations in, or else you need tens of millions of tons of rocks and earth and concrete to make a large gravity dam. This would still fail to solve issues with evaporation.
    Suffice to say, if dams were a really good idea for this problem, i would expect construction companies to be queueing up for work, and dam building programs to be making their way onto the agenda. That they appear not to be, suggests that dams will not solve this problem. If we have some engineers from India reading this, perhaps they will be able to comment.

    Otherwise, you could provide some evidence that dams can be built in the correct places, and that people are thinking of doing so.

  3. 503
  4. 504
    Chuck Booth says:

    Re: 496 and 502 Dams as a solution to a water shortfall

    Dam-building is not to be taken lightly – they can have undesirable effects on people and their cities (displaced) and the environment ( severely disturbed). The Three Gorges Dam is a great example of that:

    http://www.american.edu/ted/threedam.htm

    “However, social costs of resettlement and environmental damage
    are enormous. Environmental sustainability of the project in
    relation to massive resettlement and ecological damage is to be
    focused in this paper. Chinese officials estimate that the
    reservoir will partially or completely inundate 2 cities, 11
    counties, 140 towns, 326 townships, and 1351 villages. About 23800
    hectares, more than 1.1 million people will have to be resettled,
    accounting for about one third of the project’s cost. Many critics
    believe resettlement would fail and create reservoir refugees. The
    forced migration would raise social unrest. Many of the residents
    to be resettled are peasants. They would be forced to move from
    fertile farmland to much less desirable areas.
    However, social costs of resettlement and environmental damage
    are enormous. Environmental sustainability of the project in
    relation to massive resettlement and ecological damage is to be
    focused in this paper. Chinese officials estimate that the
    reservoir will partially or completely inundate 2 cities, 11
    counties, 140 towns, 326 townships, and 1351 villages. About 23800
    hectares, more than 1.1 million people will have to be resettled,
    accounting for about one third of the project’s cost. Many critics
    believe resettlement would fail and create reservoir refugees. The
    forced migration would raise social unrest. Many of the residents
    to be resettled are peasants. They would be forced to move from
    fertile farmland to much less desirable areas….
    The project will also cause devastating environmental damage,
    increasing the risk of earthquakes and landslides. It will also
    threaten the riverþs wildlife. In addition to massive fish
    species, it will also affect endangered species, including the
    Yangtze dolphin, the Chinese Sturgeon, the Chinese Tiger, the
    Chinese Alligator, the Siberian Crane, and the Giant Panda.
    Moreover, silt trapped behind the dam will not only deprive
    downstream regions, but also will impede power generation from the
    back-up. Construction of the dam would require extensive logging
    in the area. Finally, the dam and the reservoir will destroy some
    of Chinaþs finest scenery and an important source of tourism
    revenue.”

  5. 505
    Matt says:

    #478 James: This is at best a half truth, because GM has invested large amounts of money to a) persuade large segments of the buying public that it wants a particular sort of car; and b) establishing a design & manufacturing infrastructure to build the sort of car that they’ve persuaded their market to want.

    From an engineering perspective understanding, strong, lightweight structures is key to all automobiles and you can bet the auto companies spend a fortune trying to make all cars (even monster SUVs) much lighter. That same technology—in fact all the non-engine technology—is directly applicable to hybrids and pure electric cars. The major pieces needed for both, batteries, brushless motors and controllers, will be purchased from suppliers.

    So the cost to switch from 1% hybrid/99% ICE to 99% hybrid and electric to 1% ICE will be relatively small IF the public is willing to live with the tradeoffs.

    [edit]

    At some point in the very near future an electric car will offer more for less money, and at that point you can bet every car maker in the world will switch. But until those economics actually make sense, they won’t. You can chalk that up to black helicopters or simple market demands.

    [I see this same pattern at all levels, from individuals who seemingly can’t alter self-destructive behaviors on up to entire societies. Indeed, I expect this is at the root of a lot of denialism: the denialists have established a set of habits, and reject any information that suggests a need to change them.]

    Or perhaps those behaviors aren’t as destructive as you claim them to be???

    [Response: Please keep the rhetorical excesses to a minimum. There are plenty of places for that elsewhere on the web. – gavin]

  6. 506
    SecularAnimist says:

    Steve Reynolds wrote: “There is a similarity in ignoring real science in both the extreme alarmist and denialist arguments.”

    That is incorrect. There is no similarity whatsoever. Denial of the reality of anthropogenic global warming, or denial of the likely horrific consequences thereof, is entirely based on ignoring “real science”. Many of your comments here are a good example.

    On the other hand, “Alarm” is an entirely appropriate response to the “real science” of global warming. Numerous “real” scientists conducting “real” scientific research on global warming, whose results are published in “real” peer-reviewed journals, have been quoted in interviews as characterizing their own research as “alarming”.

  7. 507
    Matt says:

    #487 Catman306: This kind of spinning makes me gag

    Which aspect of the article bugged you the most? I’ll note that the “science is settled” argument evokes the same response in me.

    [Response: I’m curious. Where have you seen this claim made here? I think it more likely that you are falling for a classic false dichotomy: the false idea there are simply two classes of scientific knowledge, ‘settled’ versus ‘unsettled’. No scientist thinks this way, and no statements here or in the IPCC reports can be read this way. The only people using this phrase appear to be politicians trying to spin any uncertainty into total ignorance. I would advise against arguing with caricatures. – gavin]

  8. 508
    SecularAnimist says:

    Steve Reynolds wrote that mitigating anthropogenic global warming will lead to “… extending the time required for the people of developing nations to rise out of poverty, and the likely reduction of resources supplied from developed nations to help provide clean water and reduce disease.”

    Where is the evidence that mitigating global warming will have either of these outcomes? I have never seen any such evidence, only this talking point repeated over and over.

    On the other hand, several other commenters have already posted links to real science that strongly indicates that unmitigated anthropogenic warming will exacerbate the poverty of developing nations, decimate existing fresh water supplies and increase disease. And several international agencies, including those working to advance the Millennium Development Goals of reducing poverty worldwide, have opined that unmitigated global warming threatens to undermine this agenda and negate any advances in reducing poverty and promoting well-being in the developing world.

  9. 509
    wildlifer says:

    Too late for the Yangtze dolphin. It’s “officially” extinct.

    http://www.guardian.co.uk/environment/2007/aug/08/endangeredspecies.conservation

  10. 510
    steven mosher says:

    Gavin has a good sense of things when he writes:

    “the false idea there are simply two classes of scientific knowledge, ’settled’ versus ‘unsettled’. No scientist thinks this way, and no statements here or in the IPCC reports can be read this way. The only people using this phrase appear to be politicians trying to spin any uncertainty into total ignorance. I would advise against arguing with caricatures. – gavin”

    Agreed spinning any uncertainity into ignorance is rhetoric. As is spinning any hunch into QED, rhetoric
    as well. A while back, I beleive there was a well deserved pummeling of Beck here. The issue of
    Gore’s Accuracy came up. Precisely, claims made in AIT. Given the current reordering of the hottest
    year batting order, do you care to comment on Gore’ accuracy? For the record.

    [edit]

    [Response: Gore’s statement was the that nine of the ten warmest years globally occurred since 1995. This is true in both GISS indices and I think is also true in the NOAA data and CRU data. So that’s pretty accurate. – gavin]

  11. 511
    Ron Taylor says:

    Re 491 – Timothy, you keep referring the the loss of glaciers on the Tibetan plateau causing a reduction in flow of six major rivers in China. Actually, the situation is more serious than you indicate. The six rivers are vital sources of fresh water, not just for China, but also for India, Bangladesh, Pakistan, and much of Southeast Asia. The rivers are the Yangtze and Yellow in China, the Indus in Pakistan, the Ganges and Brahmaputra in India and Bangladesh, and the Mekong in Southeast Asia. The scope of the potential problem would appear to be much greater than you are indicating.

  12. 512
    Alexandre says:

    On the reasoning that NOT to mitigate GW is good to developing nations, brought up especially by Steve Reynolds.

    Here in Brazil I hardly see an advantage of further warming. Our economy is largely dependent on agriculture, and climate change is already a motive of concern, as traditional farmland is having less rain than before. Permanent rivers have stopped flowing in a specially harsh dry season. We started having hurricanes. Dry spells are happening in the Amazon, suggesting some major change ahead. Coffe-bean plantation is slowly being pushed southwards, as its flowers don´t resist temperatures over 35ºC.

    I have seen people advocate less GW-mitigation on behalf of poor countries. Please don´t do it. It´s either naïve or plain mean.

  13. 513
    Michael says:

    Mr Chase, as far as I can tell the argument still stands “The cost of mitigation may not be less than the cost of doing nothing”. If Humanity were to vanish from the face of the earth tomorrow we would still see warming, partly because of the long term affects of the CO2 we have already added to the environment. Your cost estimates should not be warming vs no warming, but warming vs slightly more warming.

  14. 514
    Chuck Booth says:

    Re # 477 Steve Reynolds: “Most of your other concerns are speculation, with no consensus that they are likely to be severe (or even exist for some, such as malaria).”

    Researchers who study this seem to think it very definitely is a problem, a serious one:

    M. Pascual, J. A. Ahumada, L. F. Chaves, X. Rodó, and M. Bouma (2006) Malaria resurgence in the East African highlands: Temperature trends revisited.
    PNAS | April 11, 2006 | vol. 103 | no. 15 | 5829-5834
    http://www.pnas.org/cgi/content/full/103/15/5829 (Open Access)

    See also the Commentary on this article in the same issue:
    Malaria risk and temperature: Influences from global climate change and local land use practices
    Jonathan A. Patz*, and Sarah H. Olson. PNAS | April 11, 2006 | vol. 103 | no. 15 | 5635-5636
    http://www.pnas.org/cgi/content/full/103/15/5635 (Open Access)

    Perhaps Steve Reynolds knows something the researchers don’t?

  15. 515
    bjc says:

    Alexandre:
    The data suggests that Brazil is not warming, unless you live in one of the major Brazilian conurbations. On the other hand massive changes in land use will certainly impact regional climates and regional rainfall.

  16. 516
    Hank Roberts says:

    Has anyone asked the many other big climate modeling projects whether they were using the data with which this newly discovered problem was reported?

  17. 517
    Philippe Chantreau says:

    Alexandre, there is no sincerity in the “poor country” anti-mitigation argument. It is simply another rethorical talking point. It’s interesting to note that visible media figures have latched on to that argument while also arguing against increasing aid to poor countries. Furthermore, all the problems deemed more urgent than GW will be made worse by it. The ultimate farce is to argue that increased CO2 will improve yields without considering rain patterns (whose importance you’re aware of in Brazil), biological agents, or, as you mentioned, plain temperature. I’m sure that coffee would grow fine with high CO2 concentrations, so long as the temp remains below 35, conditions easily achieved in the lab.

  18. 518
    Alexandre says:

    bjc #513
    Could you please post that data you mention? That interests me even if I´m not a scientist. I live in a small town some 200Km north of Sao Paulo, and changes in the frequency of frosts and duration of Winter cold are noticeable comparing to, say, 20 years ago. Agricultural research institutes and the textile industry, for example, are already reacting to those changes.

    And the initial reasoning remains: policies of deliberate slow mitigation of GW are hardly in the interest of poor, tropical countries.

  19. 519
    Philippe Chantreau says:

    Re 516: I was under the following impression: GCMs use physics only and are adjusted for better understanding of physical phenomena or inclusion of new physical parameters; temps are used as an indicator of how well the model performs. Considering how small the change is (as very well shown by Tamino on Open Mind), I would not expect change to be warranted. Am I mistaken?

  20. 520
    Ike Solem says:

    You know, I wonder if the denialists on this thread such as Matt, Dodo or Steve Reynolds would care to comment on the following topic (which actually relate to the original topic of the post):

    NOAA’s decision to switch to a 1971-2000 baseline in 2000. Isn’t this a deliberate manipulation of data, which results in far lower temperature anomalies being reported by NOAA as ‘data’? Isn’t this a much larger (and deliberate) distortion of data than the original subject of this paper?

    No comments?

    [Response: I don’t think so. First off the baselines don’t have any affect on the trends and they are the key for climate change issues. Secondly, NOAA has more constituencies than just climate scientists. People need info on climatology for all sorts of purposes (insurance, engineering etc.) and it makes sense to provide up to date numbers. This is a bit of a red-herring…. – gavin]

  21. 521
    Jeffrey Davis says:

    Re: 511+512 (et al)

    Climate change is bad for agriculture. Farmers plant this year what grew best last year. They have to. There’s no other metric. If temperatures and rainfall flop around, yields suffer. Greater energy in the atmosphere will produce greater variability. Simply by definition. Even a zero sum game — no change in global means for temps and rainfall — would reduce yields due to an increased change in regional figures.

    Not for nothing is agriculture the image of stability. Undermine stability and Katy bar the door.

  22. 522
    Philippe Chantreau says:

    Ike, you’ve been sparring with denialists so much, you’re starting to think like them (yikes!). However, I have no doubt that anything comparable to what you mention but going the “other way” would set the denialist blogosphere ablaze…

  23. 523
    James says:

    Re #505: I think you missed my point completely. For instance, you say:

    [From an engineering perspective understanding, strong, lightweight structures is key to all automobiles and you can bet the auto companies spend a fortune trying to make all cars (even monster SUVs) much lighter.]

    Which I suppose is true as far as it goes (especially if you factor in the cost of lighter materials), but misses the obvious: the easiest way to make a car lighter is to make it smaller. That’s where the advertising/manufacturing cycle comes into play. So consider your following point:

    [At some point in the very near future an electric car will offer more for less money, and at that point you can bet every car maker in the world will switch.]

    That might well turn out to be correct, but I would bet that if it does you will still have US automakers turning out oversized electric SUVs that get 15 miles/Kwh, while the Japanese build smaller vehicles that get 35, and it’s perfectly possible to build something that gets 70.

    The point is that there are two possible ways to reduce CO2 emissions. There’s the electric SUV approach, which uses as much or more energy than at present, but gets it from less CO2-intensive sources such as the electric grid. Then there’s the “drive a smaller car less”, which reduces the actual amount of energy used. A lot of marketing effort goes into creating & reinforcing public attitudes that favor the first, and denigrate the second.

  24. 524
    Ray Ladbury says:

    Steve Reynolds,
    While I wholeheartedly support the position that we need to be very careful not to make things worse by our mitigation efforts, I think your reasoning is flawed.
    First, there has been plenty of good research done on potential risks due to climate change. Here’s a webpage from EPA:
    http://www.epa.gov/climatechange/effects/health.html

    Now, certainly whether these effects will occur is uncertain, but the proper way to deal with this in risk mitigation is to scale effort by the potential cost of the adverse event multiplied by its probability. And indeed if there are a range of costs with different probabilities, you integrate over the probability vs. cost distribution. DOD has carried out similar studies, and there have been peer-reviewed studies of various aspects (e.g. crop yields, extinction, biodiversity, etc.).
    Given that all the infrastructure of civilization has evolved during the past 10000 years of relative climatic stability, it is not unreasonble to assume that significant changes will impact that infrastructure adversely.
    However, even if there are benefits, we will be most likely to capitalize on them if climate change occurs at a pace that can be managed by a market economy rather than a command economy.
    Another problem I see in your reasoning is that you assume that it is either climate change mitigation OR development. This is a false dichotomy. Development will occur–third world nations will not ask our permission. India and China certainly did not. Development and climate change are not alternative agendas–rather they are two sides of the same coin–sustainable development. Somehow we have to develop economies that can grow without trashing the environment.

  25. 525
    WVL says:

    If the error was only in data after 2000, why did the temperatures pre-2000 change? E.g., why did the relative rankings of 1934 & 1998 change?

  26. 526
    Michael says:

    Gavin, I find it troubling that you are showing resistance to weather station ‘investigations’. Do you have a good grasp on the quality of the US network data? Worldwide data? Shouldn’t you be leading the charge on these station audits (or at least involved or supportive) since you use this data in your models?

    [Response: Resistance is useless…. where have I heard that before? Seriously though, I haven’t expressed any resistance to their efforts. I have expressed a great deal of scepticism about whether they will achieve anything, but it’s a free country and people can go around photographing things if they want. And for the umpteenth time, the data is not ‘used in models’. -gavin]

  27. 527
    Timothy Chase says:

    Steve Reynolds (#496) wrote:

    Timothy Chase(not using numbers because they change)> Here is a brochure from the Hadley Centre… (#491)

    I looked at your referenced PR material, but did not see much supported by peer-reviewed studies supporting your dire predictions. They did have projections of increased food production due to higher CO2 concentrations, though.

    For all the glacier concerns: I still have not seen a good reason why building dams is not a complete solution. It is what we already do where glaciers do not exist.

    You are correct with regard to India and China. Greater precipitation implying greater biomass for rice and wheat, although this will be largely offset by decreased nutritional value.

    Dams – we can probably look into that in greater depth later.

    They will have increased harvests as the result of increased precipitation according to the Hadley projections. However, the point remains that according to the very same projections, 50% of the world will be experiencing drought at any given time. Additionally, the nutritional value of rice (according to FACE open air experiments) will be diminished to a by nearly the same degree as biomass increases by 2050. If nutritional value were to decline by an equal amount, there would be no net benefit.

    Please see:

    Rising carbon dioxide could make crops less nutritious
    Jia Hepeng
    4 March 2005
    http://www.scidev.net/News/index.cfm?fuseaction=readNews&itemid=1969&language=1
    (Sorry – no technical article found as of yet.)

    We also need to keep in mind the timing of the rainy season even where precipitation increases, and this will adversely affect many crops…

    El Nino events typically lead to delayed rainfall and decreased rice planting in Indonesia’s main rice-growing regions, thus prolonging the hungry season and increasing the risk of annual rice deficits. Here we use a risk assessment framework to examine the potential impact of El Nino events and natural variability on rice agriculture in 2050 under conditions of climate change, with a focus on two main rice-producing areas: Java and Bali. We select a 30-day delay in monsoon onset as a threshold beyond which significant impact on the country’s rice economy is likely to occur. To project the future probability of monsoon delay and changes in the annual cycle of rainfall, we use output from the Intergovernmental Panel on Climate Change AR4 suite of climate models, forced by increasing greenhouse gases, and scale it to the regional level by using empirical downscaling models. Our results reveal a marked increase in the probability of a 30-day delay in monsoon onset in 2050, as a result of changes in the mean climate, from 9-18% today (depending on the region) to 30-40% at the upper tail of the distribution. Predictions of the annual cycle of precipitation suggest an increase in precipitation later in the crop year (April-June) of ~10% but a substantial decrease (up to 75% at the tail) in precipitation later in the dry season (July-September). These results indicate a need for adaptation strategies in Indonesian rice agriculture, including increased investments in water storage, drought-tolerant crops, crop diversification, and early warning systems.
    (pg. 7752)

    Research Institute in the Philippines suggest that rice yields are closely linked to mean minimum temperatures during the dry season; for every 1 C increase in the minimum temperature, rice yields decrease by 10% (24). At a global scale, increased CO2 concentrations could partially offset expected yield declines caused by lower soil moisture and higher temperature, but recent models suggest a significantly smaller fertilization effect from CO2 than previously predicted (25). Global models that combine precipitation, temperature, and CO2 effects for the A2 scenario generally show reduced yields in the tropics and increased yields in temperate zones (26). (ibid, pg 7756)

    Assessing risks of climate variability and climate change for Indonesian rice agriculture
    Rosamond L. Naylor, et al
    PNAS | May 8, 2007 | vol. 104 | no. 19 | 7752-7757
    http://www.pnas.org/cgi/content/abstract/104/19/7752

    Now I will of course include increased precipitation and crop biomass in India and China whenever revisiting these topics in the future. However, I am curious whether you will do the same with respect to the diminished nutritional value of these crops, the increased global prevailence and severity of droughts, diminished agricultural output in Indonesia, etc, or, as is suggested by your response, do you intend to “accentuate the positive” with regard to climate change by omitting the costs?

  28. 528
    Hal P. Jones says:

    I understood you J.S. I was just making the point that I’ve seen both “sides” hit the rhetoric machine at times. I’m not commenting on who does it more, it probably depends on where you are and who else is there. Like this disagreement if output matching between two methods or not is the same thing as a code review, or if one approach is “better” than the other. Just trying to be neutral. In fact, I’d like to see both done. Even if I had the skills and the time to do both, one of them I couldn’t do. Gavin obviously believes one is worthless to do. McIntyre obviously believes one is very worthwhile to do. I don’t know. And I don’t really even care. Audit it. Don’t. Whatever.

    Lawrence Brown you mentioned original work. An audit of “the code” would be original work, wouldn’t it? The results and the output could even be useful to doing the adjustments in the future. Like I said, why not do both? He’s willing to do one of them.

    Some here are saying replicate the adjustments, then if there are problems, dig further. If McIntyre is willing to go through the code itself, which seems a much more difficult thing to do, if all is okay there’s nothing else to do. That argument would be, why worry about the intermediate step? Especially when his goal isn’t to verify the output, it’s to verify the code itself and understand exactly how it’s doing what it’s doing? Hasn’t anyone wanted to ever take apart a car to see how it’s put together (rather than how to build one)?

    Sheesh, let him spend the time even if it’s a waste of it. I don’t see why everyone cares so much one way or the other.

    I find it interesting, the idea that if a scientist works for or is funded by (Exxon-Mobile, Chevron-Texaco, Shell) then they are corrupted. Let’s see, what would happen if they couldn’t get any scientists. No exploration for more sources, no drilling, no refining, no quality control… I don’t know about you, but I like having gasoline available, and having it be less than a million dollars an ounce. Plus it’s quick to stop into the store for beer and cigarettes. Come on, they’re not “fighting” or “promoting” global warming, they’re spending their time finding, getting, processing and delivering gasoline. (and of course, governments make more money on their then any of them do either individually or as a total.) I will agree that if they’re doing anything, they’re doing PR. But as I started out, nobody has a lock on rhetoric, and nobody has a lock on PR, either.

    I don’t trust or distrust anyone based upon where they get their funding or not, who they work for or don’t, or anything else. I find this interesting on a level of the discussion and the ideas.

  29. 529
    Timothy Chase says:

    Ron Taylor (#511) wrote:

    Re 491 – Timothy, you keep referring the the loss of glaciers on the Tibetan plateau causing a reduction in flow of six major rivers in China. Actually, the situation is more serious than you indicate. The six rivers are vital sources of fresh water, not just for China, but also for India, Bangladesh, Pakistan, and much of Southeast Asia. The rivers are the Yangtze and Yellow in China, the Indus in Pakistan, the Ganges and Brahmaputra in India and Bangladesh, and the Mekong in Southeast Asia. The scope of the potential problem would appear to be much greater than you are indicating.

    I genuinely appreciate the correction. As you can see, I am still having problems just keeping up with the projected changes in precipitation.

    Thank you.

  30. 530
    trrll says:

    Prior to this incident, I think that I would have been with the “release the code and let them spend their time deciphering it if that’s what they want to do” faction. But we’ve just seen a huge media circus over a tiny correction that doesn’t affect anybody’s conclusions.

    It is pretty much a certainty that a program of any length is going to contain some bugs, most of them trivial, as well as some statistical and mathematical issues that somebody might quibble with.

    If people are prepared to point to a statistically insignificant correction as undermining all conclusions, they will go nuts over any kind of actual bug, whether or not it affects the output.

    Not to mention the inevitable ejaculations of “I’m a software engineer, and this is the worst code I’ve ever seen! How can anybody trust anything from these guys?”

    So I think you’re strategy is the right one. If you release the code, you’ll be spending your time in endless arguments about such things as whether rounding errors in the least significant digit can build up. Describe the algorithms in English, and if anybody thinks that you screwed them up badly enough to make a difference, let them recalculate the averages and show that they get meaningfully different numbers.

  31. 531
    Dodo says:

    Re 520. Thanks Ike, for bringing up the concept of climate, for a change. For practical reasons, it is defined as a collection of meteorological measurements, their averages and fluctuations over a period of 30 years. So if we look at the warming between 1976 and 1998 (no significant warming since), we don’t even have a time series long enough to call a climate.

    But as we have all seen, “global climate” has different rules than our classical climates, with which we defined Koeppen’s zones. So we can pick any period of weather data and read all kinds of climate messages from it. And everybody (I hope) gets to play the game: skeptics are happy to point out that global warming stopped at the end of 2001.

  32. 532
    Timothy Chase says:

    PS to 527, response to Steve Reynolds (#496)

    This might have some relevance regarding Hadley projections of greater harvests in India and China with CO2 fertilization and increased precipitation in those areas…

    The presumed benefits of CO2 enrichment have been overestimated as the result of the use of enclosure studies. Free-air concentration enrichment demonstrates enhanced yield of approximately half of what was projected by enclosure studies – which have as of yet (2006) to be incorporated into the models.

    Model projections suggest that although increased temperature and decreased soil moisture will act to reduce global crop yields by 2050, the direct fertilization effect of rising carbon dioxide concentration ([CO2]) will offset these losses. The CO2 fertilization factors used in models to project future yields were derived from enclosure studies conducted approximately 20 years ago. Free-air concentration enrichment (FACE) technology has now facilitated large-scale trials of the major grain crops at elevated [CO2] under fully open-air field conditions. In those trials, elevated [CO2] enhanced yield by ~50% less than in enclosure studies. This casts serious doubt on projections that rising [CO2] will fully offset losses due to climate change.
    (pg 1918)

    The FACE experiments clearly show that much lower CO2 fertilization factors should be used in model projections of future yields; however, the present experiments are limited in the range of growing conditions that they cover. Scientists have not investigated the interactive effects of simultaneous change in [CO2], [O3], temperature, and soil moisture. Technological advances suggest that large-scale open-air facilities to investigate these interactions over controlled gradients of variation are now possible. Although we have projected results to 2050, this may be too far in the future to spur commercial R&D, but it must not be seen as too distant to discourage R&D in the public sector, given the long lead times that may be needed to avoid global food shortage.
    (pg 1921)

    Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations
    Stephen P. Long
    30 JUNE 2006 VOL 312 SCIENCE 1918-1921

  33. 533
    Ike Solem says:

    RE Gavin’s response: Okay, that does make some sense… though I would think that anyone buying weather insurance would prefer to use the 1961-1990 baseline for calculation of insurance payouts, while anyone selling weather insurance would certainly prefer the 1971-2000 baseline. If the argument is that the decision to switch baselines was based on economic reasons – that I can agree with. What seems objectionable is NOAA’s use of this baseline in their (purely?) scientific report on The State of the Arctic. That little anomaly chart on the cover is based on the 1971-2000 baseline, isn’t it? What would it look like with the 1961-1990 baseline?

    RE NOAA and our upcoming hurricane season:
    I was just perusing NOAA’s website and they are still claiming that the main driving force behind this season’s predicted greater-than-normal hurricane activity is the Atlantic Mutidecadal Oscillation…

    http://www.noaanews.noaa.gov/stories2007/s2905.htm

    “The climate patterns responsible for the expected above-normal 2007 hurricane season continue to be the ongoing multi-decadal signal (the set of oceanic and atmospheric conditions that have spawned increased Atlantic hurricane activity since 1995), warmer-than-normal sea surface temperatures in key areas of the Atlantic Ocean and Caribbean Sea, and the El Nino/La Nina cycle”

    Regarding El Nino, here’s the recent update from Australia: http://www.bom.gov.au/climate/enso/
    “The past three or four weeks has seen a gradual strengthening of La Nina indicators: the near-equatorial Pacific has cooled both on and below the surface, the Trade Winds have been mostly stronger than normal and cloudiness has been lower than average over much of the tropical Pacific. However, it’s too early to tell if these signs are the beginnings of a sustained trend, especially when considered in the context of the fluctuating ENSO indicators that were apparent between May and mid-July. So the chance of a La Nina developing is still probably about 50:50, although it’s difficult to make this kind of assessment with high precision.”

    50:50? Hardly a definitive cause.

    There are indeed warmer-than-normal sea surface temperatures in the Atlantic basin, but NOAA appears unable to ascribe that to anything – are they still banned from using the phrase “global warming”?

    As far as the AMO, the notion that NOAA is promoting here is that since 1995 the ‘conveyer belt’ has speeded up, bringing warm water further north. Well, the measurements should reflect that theory…

    See John A. Church’s Perspective in Science, 17 Aug 2007 : Oceans: A Change in Circulation? It appears based on ship-borne measurements that northward heat transport has decreased by 20% in the North Atlantic. The main point is that there is such poor historical data that it’s hard to be clear about what’s been going on, and only now is it even possible to estimate the annual variability… but nowhere does there seem to be any real factual support for the AMO theory that NOAA has repeatedly put forward ( see http://www.magazine.noaa.gov/stories/mag184.htm and RC guest commentary 2006).

    RE #522
    Am I ‘thinking like a denialist’? I’m not quite sure what that would entail… overemphasizing certain minor issues while ignoring everything else? I’d be very happy to see evidence for decreased climate sensitivity and a slower pace of global warming – that would mean we have extra time to get off fossil fuels – but that just doesn’t seem to be the case – rather, the opposite seems to be true.

    Also, the political efforts to silence (some) NOAA scientists are pretty well-documented, aren’t they? NOAA is supposed to be a reliable source for journalists and the public… and they’re failing that mandate.

  34. 534
    Rafael Gomez-Sjoberg says:

    Regarding the oft-mentioned “CO2 fertilization”:

    The growth of plants in most of the world is limited by many factors different from the CO2 concentration in the atmosphere. The most important of such factors are water availability, soil fertility, amount of sunlight (for example, many rainforests are growth-limited by cloudy skies), and temperature.

    So in most places you can add as much CO2 as you want and the plants won’t grow one iota faster because their growth is limited by one or more of the other factors. Plants will only grow faster in a CO2 enriched atmosphere if they have all the water, soil nutrients, and sunlight that they want, plus the right temperatures. The only possible exception to this is water availibility, but this is just my own speculation. Plants loose a lot of water by evaporation when they open their stomata (pores in their leaves) to absorb CO2 (a small percentage of plant species, especially cacti, have particular mechanisms to drastically reduce this problem). So increased CO2 will allow them to open the stomata for a shorter amount of time and thus loose less water. This could allow for extra growth, but only if there are enough soil nutrients, light, and the temperature is right.

    See also my post #388 that talks about recent findings of stunted growth in tropical forests where the temperature has increased by jut one degree C. Many crops would also be stunted by higher temperatures, and by large shifts in precipitation.

    Here is an excerpt from a USDA publication that looked at the effect of temperature on plant photosynthesis:
    (http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=156279)

    “High temperatures often inhibit plant growth, with photosynthesis considered among the most sensitive plant functions to high temperature. Most temperate C3 plants exhibit a broad photosynthetic temperature optimum between 20° and 35°C with peak CO2 assimilation often occurring near 30’C. It is well understood that increasing leaf temperatures beyond this range reduces photosynthetic efficiency by stimulating photorespiration.”

    This web site has a nice, short introduction to photosynthesis:
    http://wc.pima.edu/~bfiero/tucsonecology/plants/plants_photosynthesis.htm

    Check also the Wikipedia entry on photosynthesis.

    So it is much more likely that a warming planet will see reduced crop yields, rather any potential benefit from “CO2 fertilization”. As the paper cited above says, the optimum temperature for most temperate plants is 20 to 35degC, so you can imagine what would happen to agriculture once temperatures in many places of the world climb into the mid/upper 40’s in the summer for longer periods of time. Also, if temperature stress increases the rate of photorespiration (see Wikipedia) the stressed vegetation becomes a net source of CO2. This is a pretty nasty positive feedback!!!

  35. 535
    Ike Solem says:

    RE#533

    I’m afraid I need to eat a little crow here… after looking over NOAA datasets it turns out that the CruTem2v dataset that the State of the Arctic report is based on is indeed using the 1961-1990 baseline – it’s only the ‘degree-day-normals’ for the continental US that use the 1971-2000 baseline. Mea culpa. The rest should be accurate.

  36. 536
    Philippe Chantreau says:

    Re Ike 533: I was just (jokingly) referring to the “conspiratory” NOAA idea (although you have a point as to what they’re permitted to say). Denialists love conspirations and spot green helicopters (running on biodiesel, I’m sure) as easily as they find gazillions in funding for “alarmist climatologists.”

  37. 537
    David B. Benson says:

    bjc & Brazilians — My understanding is that the ITCZ has been moving northwards. The last time this occurred, AFAIK, was about 40,000 years ago. At that time, almost the entire Amazon basin was savanna. A Dr. Jose Mendoza predicts that the Amazon basin will become a warm, dry savannah once again…

  38. 538
    Matt says:

    #523 James: The point is that there are two possible ways to reduce CO2 emissions. There’s the electric SUV approach, which uses as much or more energy than at present, but gets it from less CO2-intensive sources such as the electric grid. Then there’s the “drive a smaller car less”, which reduces the actual amount of energy used. A lot of marketing effort goes into creating & reinforcing public attitudes that favor the first, and denigrate the second.

    The “drive a smaller car” mandate is an example of you looking at your own life and deciding everyone should be just like you, isn’t it? And why single out the SUV? Why not go after anyone with a home air conditioner? Why not go after those that take airplane flights for non-essential purposes? Where would you draw the line?

  39. 539
    Matt says:

    Gavin in #507: Response: I’m curious. Where have you seen this claim made here? I think it more likely that you are falling for a classic false dichotomy: the false idea there are simply two classes of scientific knowledge, ’settled’ versus ‘unsettled’.

    I don’t hear the “SiS” (“science is settled”) claim from most on this board, but there are a few that really want to embrace the SiS and move on to talking about just how bad the countless disasters will be. And I think they believe those disasters are a certain thing.

    But the original poster was referring to the popular media, and I was merely noting that while the article he noted really made him ill, that I thought it reasonable and that the articles or statements from the popular media that the “SiS” rubbed me the wrong way.

    I heard an interview with Laurie David on NPR in which anyone that called with the slightest disagreement was bashed over the head with the “SiS–let’s move on” argument.

    I’m glad you asked, Gavin. It makes me feel a bit better about the debate as a whole.

  40. 540
    Rafael Gomez-Sjoberg says:

    To add to what David Benson says:

    The transition of the Amazon from rainforest to savannah will involve huge fires that will release enormous amounts of CO2 into the atmosphere. I shudder to think of that possibility.

    In 2005 the Amazon had the worst drought in 40 years (http://www.nature.com/news/2005/051010/full/051010-8.html), and this year seems to be heading in the same direction (http://news.mongabay.com/2007/0529-amazon.html). The forest might not be able to handle too many consecutive years of below-average rainfall.

    At the same time, Colombia (where I was born) has been experiencing unusually heavy rainfall since 2005 because of the same northward shift in the InterTropical Confluence Zone (ITCZ). This has already caused severe flooding, land-slides, crop losses, etc. All the rain that was supposed to fall on the Amazon is falling now on Colombia.

    The weather almost everywhere in the world is visibly shifting towards more extreme conditions, while the “skeptics” keep arguing about the color of the housing of some thermometers in Wyoming.

  41. 541
    Matt says:

    #521 Jeff Davis: Climate change is bad for agriculture. Farmers plant this year what grew best last year. They have to. There’s no other metric. If temperatures and rainfall flop around, yields suffer. Greater energy in the atmosphere will produce greater variability. Simply by definition. Even a zero sum game — no change in global means for temps and rainfall — would reduce yields due to an increased change in regional figures.

    Not for nothing is agriculture the image of stability. Undermine stability and Katy bar the door.

    If you have driven across the US, you will see all sorts of stuff being grown at a range of latitudes. Major corn production occurs in Minnesota and Missouri which have dramatically different climates.

    Heck, the most massive vegetables you have ever seen are grown in Alaska (http://www.gadling.com/2007/07/16/giant-mutant-like-vegetables-at-alaska-state-fair/) because of the longer days.

    We’ve adapted our crops for each location over hundreds of years of genetic engineering, and I suspect farmers continue to do this year over year in real time as the climate changes.

  42. 542
    Matt says:

    #479 DavidU: I can only repeat the basic fact that you again ignore. These models are _not_ constructed by fitting them to climate in the past. They are based on setting up the laws of physics together with our best knowledge of the state of earth at _one_ point in time and are then alloved to run.

    I’d be more inclined to believe you if I didn’t see so many constants scattered throughout the various models.

    I gave up counting the number of constants inside the first files I opened in modelE ghy_drv.f and ghy.f.

    In some (few) places, the constants have references. In other places, there is nothing to explain why a certain constant was selected.

    In some places, we see constants specified with excruciating detail–8 sigificant digits or more.

    In other places, we see one or two SDs.

    In GHY.f we see a plethora of comments that, frankly, are scary. “broot back to original values”, “changed..for 1.5m root depth”,”back to full heat capacity, to avoid cd oscillations”, “set im=36, jm=24″, “divide canopy heat capacities by 10.d0″

    And “use snow conductivity of 0.088 w/m/c instead of 0.3″

    Sure, there’s a lot of physics here. But, as I oringally asserted, it looks like there is a heck of lot of tweaking based on intuition. Is there a master doc that explains all this?

    Sorry, but a casual romp through the source tends to re-affirm by belief that there’s a lot of intuition in the model.

  43. 543
    James says:

    Re #538: [The “drive a smaller car” mandate is an example of you looking at your own life and deciding everyone should be just like you, isn’t it?]

    No, it’s an example of looking at available technology, and thinking about how CO2 emissions could most easily be reduced. I draw on my own life for illustration: a practical example is worth hours of theoretical argument. I manage to live quite happily without a large SUV; and indeed I’m wealthier and happier because I do so, therefore the advertising is false.

    [Why not go after anyone with a home air conditioner?]

    Because it didn’t come up? But since you raised the subject, I’ll just mention that thanks to decent insulation and some shade trees, I manage to live comfortably without one. That’s more money in that stays in my pocket instead of going to the power company :-)

    [Why not go after… Where would you draw the line?]

    I’m not sure what you mean by “go after”? I’m talking about changing people’s attitudes, and the choices they make as a result, so we might look at the selling of air travel, and possible less CO2-intensive alternatives. I don’t, in fact, understand why people willingly subject themselves to the various unpleasantnesses of commercial air travel, especially when their destination is rapidly becoming indistinguishable from their starting place. Why fly halfway around the world to see McDonalds’ signs in Chinese?

  44. 544
    Timothy Chase says:

    Himalayan Glaciers

    Ron Taylor (#511) wrote:

    Re 491 – Timothy, you keep referring the the loss of glaciers on the Tibetan plateau causing a reduction in flow of six major rivers in China. Actually, the situation is more serious than you indicate. The six rivers are vital sources of fresh water, not just for China, but also for India, Bangladesh, Pakistan, and much of Southeast Asia. The rivers are the Yangtze and Yellow in China, the Indus in Pakistan, the Ganges and Brahmaputra in India and Bangladesh, and the Mekong in Southeast Asia. The scope of the potential problem would appear to be much greater than you are indicating.

    I looked it up. Here is an article describing what you are talking about:

    Himalayan Glacier Retreat Blamed on Global Warming
    Tuesday, January 16, 2007
    http://geology.com/news/2007/01/himalayan-glacier-retreat-blamed-on.html

    .. and here is the technical paper the above article was based on:

    Glacial retreat in Himalaya using Indian Remote Sensing satellite data
    Anil V. Kulkarni, et al
    CURRENT SCIENCE, VOL. 92, NO. 1, 10 JANUARY 2007
    http://www.ias.ac.in/currsci/jan102007/69.pdf

    Thanks again.

  45. 545
    Chuck Booth says:

    Re # 528 Hal P.Jones: “I find it interesting, the idea that if a scientist works for or is funded by (Exxon-Mobile, Chevron-Texaco, Shell) then they are corrupted. ”

    Not necessarily corrupted,but certainly restricted in what they can publish and say publically. Not surprisingly, corporate scientists are paid to serve the companies goals. As a result, some of their scientific data are never published because they contain proprietary information. And some data are published, but scientists’ research papers are screened by company lawyers before they are submitted for publication. Clearly, the six Nobel Prizes awarded to scientists at Bell Labs
    (http://tinyurl.com/29u3uc) attest to the fact that some corporations sponser cutting-edge research. But, I strongly suspect that any Exxon-Mobile geologist who says publically that AGW is a serious threat to the planet will quickly be out of a job. We’ve already seen what happens to NASA scientists who offer their opinion about AGW.

  46. 546
    Bill Nadeau says:

    Re #538:

    Why worry about the production of CO2 at all? Just go carbon neutral. Plant a few trees, pay someone in India not to drive, piggy back onto someone else’s private jet, hide be hind “you’re just attacking the messenger”, etc.

    The fact is, the US could reduce it’s CO2 production by 5% overnight if those that believe it should be reduced actually reduce their production by measly 10%. Hybrid cars are economically feasible, but guess what, the believers think it’s industry that is the problem and not their own consumption. The “government will save us from ourselves” mentality.

  47. 547
    Chuck Booth says:

    A bit off topic, I suppose, but FYI: Media Matters for America (www.mediamatters.org) maintains a collection of its blog posts highlighting misrepresentation of global warming science in the media: Climate of Smear: Global Warming Misinformation (http://mediamatters.org/action_center/global_warming/.
    Guaranteed to elevate your blood pressure.

  48. 548

    [[skeptics are happy to point out that global warming stopped at the end of 2001]]

    Denialists say all kinds of stupid things, but that one kind of takes the cake. Here are the mean global annual temperature anomalies for 2001 to 2006 (NASA GISS):

    2001 57
    2002 68
    2003 67
    2004 60
    2005 76
    2006 65

    A cursory examination shows that every value later than 2001 is higher than the value for 2001.

  49. 549
    Harold Brooks says:

    Re: 533

    The baseline on the State of the Arctic report cover figure is 1961-1990. The curve is from CRUTEM2v (see Fig. 6 in the report), which uses 1961-1990 as a baseline. I don’t think the 0 line is particularly important in this case, since you can see the trend without it.

  50. 550
    Timothy Chase says:

    Matt (#541) wrote:

    Not for nothing is agriculture the image of stability. Undermine stability and Katy bar the door.

    If you have driven across the US, you will see all sorts of stuff being grown at a range of latitudes. Major corn production occurs in Minnesota and Missouri which have dramatically different climates.

    Well, it is projected that by 2020 we will no longer be able to grow wheat in the United States. That would seem significant.

    Heck, the most massive vegetables you have ever seen are grown in Alaska (http://www.gadling.com/2007/07/16/giant-mutant-like-vegetables-at-alaska-state-fair/) because of the longer days.

    Unfortantely global warming won’t lengthen the day down here. Additionally, you are talking about a cooler environmentment up there, perhaps the fifties during the summer. Plenty of moisture. Down here with the expansion of the hadley cell, a higher rate of evaporation and lower relative humidity in the continental interior, it will be rather dry for crops.

    We’ve adapted our crops for each location over hundreds of years of genetic engineering, and I suspect farmers continue to do this year over year in real time as the climate changes.

    I have some hope for genetic engineering. Retroelements were involved in the domestication of rice. If I remember correctly there is a family of MITEs. Fairly small even for retroelements. Still active. Likewise, we have been radiating seeds for some time – in order to develop new varieties. But that takes time – and we will need to have a better understanding of the genomes of the species we are modifying if we are going to try and speed that up. Even artificial selection takes time – and depends upon pre-existing genetic variation. Still, it won’t help us much in the lower 48 if there isn’t enough water.

    Oh, and you might want to remember that since domesticated plants are adapted to our needs, they are fairly pampered. Weeds will do better with climate change. So will various natural pests.


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