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  1. I’m going golfing in Pennsylvania in December and will be going in January also. So before you educated readers tell me there is a difference in weather and climate and before you go back eating your chinese and toasting to the betterment of the human condition, let me say the land masses are heating up and will be the demise of most land dwelling creatures including people. The human condition is that people are reactive, as the state of the world shows today. In a very short while, perhaps 300 years, land masses will be in the 110 degree range, and there is nary one thing we can do about it. Go back and observe, analyze, and make predictions, but do it as a Don Quixote, because we are not getting out of this one.

    Comment by PaulM — 9 Dec 2007 @ 10:39 AM

  2. Economic activity is rooted in the now global capitalist push for both the desire for energy and desire for profit, deadly bedfellows for the planet, and mankind lacks the collective proactive skills to do anything different than buy and burn fossil fuels until we all die. Are temperature trends affected by economic activity? decidedly, yes. The question should be Is economic activity causing temperature trends, and we all know the answer to that.

    Comment by PaulM — 9 Dec 2007 @ 10:57 AM

  3. Well, if by “econmic activity” they mean consumption of fossil fuels and forests, economic activity has a conspicuous effect. And the economic slowdown expected by many would be a relief. Moreover, or so it seems to me, if they divorce the economy from consumption of fossil fuels and forests, they risk irrelevance on economic or ecological grounds.

    Comment by Lance Olsen — 9 Dec 2007 @ 11:10 AM

  4. The probability that RC will comment on a paper being actively discussed elsewhere is approaching unity.

    Comment by Steven mosher — 9 Dec 2007 @ 11:32 AM

  5. re Svalbard:

    Economy:
    Economic activity centres on coal mining, supplemented by fishing and trapping. In the final decades of the 20th century, tourism, research, higher education, and some high-tech enterprises like satellite relay-stations grew significantly. A 200 nautical mile (370 km) Fisheries Protection Zone around Svalbard was established in 1977 pursuant to the Act of 17 December 1976 relating to the Economic Zone of Norway. Despite recent discussions, Russia and Norway dispute their maritime limits in the Barents Sea and Russia’s fishing rights beyond Svalbard’s territorial limits within the Svalbard Treaty zone.

    The Svalbard Undersea Cable System which started operation in January 2004 provides dual 1440 km fiber optic lines from Svalbard to Harstad via Andøy, needed for communicating with polar orbiting satellite stations on Svalbard, some owned by the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA), both United States government agencies.

    The Norwegian state-owned coal company employs nearly 60% of the Norwegian population on the island, runs many of the local services, and provides most of the local infrastructure. Coal production has increased significantly over the past 10 years, rising from less than 500,000 tons in 1994 to over 2,500,000 tons in 2004.[6]

    Exploration for oil and natural gas is underway.

    Coal mining in Svalbard:
    The Ny Ålesund mine was closed down in 1963 after an explosion in 1962 when 21 lives were lost, and has since been converted to a scientific post.

    As of 2006, there are three operational coal mines in Svalbard. There are large mines in Sveagruva (production 2 million tonnes per year,[13] and Barentsburg, while the small mine in Longyearbyen is used mainly to supply the town’s own power plant.

    Demographics:
    Svalbard has a population of approximately 2,400 people as of 2005. Approximately 70% of the people are Norwegian; the remaining 30% are Russian, Ukrainian and Polish.[citation needed] The official language of Svalbard is Norwegian. Russian is used in the Russian settlements, but formerly, Russenorsk was the lingua franca of the entire Barents Sea region. The annual population growth is -0.02%

    Comment by Patrick M. — 9 Dec 2007 @ 12:07 PM

  6. Economic activity obviously has no direct effect on climate. Some things related to economic activity, such as urbanization, energy use, and pollution, do have effects on climate, both local and global, but economic activity in and of itself has no effect and it’s just silly to state that it does.

    Economic activity means money changing hands (if we’re talking about GDP), and a few electrons, piles of paper, or sacks of gold changing hands are not going to change the climate.

    At best, it’s sloppy use of language. At worst, it makes the results meaningless by not distinguishing between agriculture and coal plants (high climate effect/GDP) and a financial district (minimal climate effect/GDP).

    PS: It appears that this paper is wrong on plenty of other counts, as mentioned in the main article.

    Comment by Robert Edele — 9 Dec 2007 @ 12:32 PM

  7. Re 4. Indeed. This site has been losing its innovative edge (and some of its contributors), and has deteriorated into a column commenting other people’s work. This is not what the headline promises: Climate science by climate scientists. Furthermore, the choice of topics gives the impression that the so-called climate contrarians are the only people finding out anything interesting (true or not) about climate and its change.

    Comment by Dodo — 9 Dec 2007 @ 12:35 PM

  8. You said: “I think it is difficult to argue that factors such as the urban heat island effect plays an important role here”

    Consider the fact that many of the weather stations are located within the ever expanding “Heat Islands” mentioned. It would seem logical that the temperatures taken over time would reflect a corresponding rise with the growth of the urban heat islands.

    Respectfully,

    Joe Alderman

    Comment by Joe Alderman — 9 Dec 2007 @ 12:37 PM

  9. What’s with the RealClimate bashing in 4 and 6? This post exemplifies what’s best about RC: it’s educational and directly on-topic. This caviling borders on trolling.

    Comment by Jim Galasyn — 9 Dec 2007 @ 1:53 PM

  10. Re: #4 (Steven Mosher), #6 (Dodo)

    Don’t blame RC for sidetracking the discussion from real climate science to bogus pseudo-science. Place the blame squarely where it belongs: on McKitrick, Michaels, and Loehle.

    The non-stop stream of sloppy research in order to discredit genuine climate science makes it necessary for RC to set the record straight. Keep up the good work!

    Comment by tamino — 9 Dec 2007 @ 1:55 PM

  11. Rasmus : They find that the greatest differences between measured and adjusted trends at Svalbard and other places in the Arctic and Antarctic (See marked sites in Figure below). This is not convincing. Thus, the results themselves provide examples of spurious values obtained by their analysis. Even if they were identified as ‘outliers’ (Svalbard was apparently not one), the fact that their analysis produced highest corrections for economic activity at these places suggest that their analysis is not very reliable.

    I’m still reading M&M2007, but it seems they study two kinds of “artifact”: one due to local anthropic effect on measured data, other due to inhomogeneities. Could the Arctic and peri-Arctic biases be mainly related to observationnal difficulties (inhomogeneity) rather than economic activity as you suggest here ? There are probably few meteo. stations north to 60°N, so a lot of interpolation.

    For example, I empirically observed that on Nasa Giss (Gistemp), when you smooth at 1200 km, 2007 is bit warmer than 1998, but when you smooth at 250 km (no data when no covergage), that’s the contrary. The main differences between the two estimates arise from Africa and… peri-Arctic, precisely (70-90°N).
    http://data.giss.nasa.gov/gistemp/

    [Response: Good question. If you want to look at trends over a longer period, inhomogeneouity is definately a problem, but is has not been a problem since 1979. THe very strong recent warming is also supported by bore holes on Spitzbergen. -rasmus]

    Comment by Charles Muller — 9 Dec 2007 @ 2:03 PM

  12. I think it’s also worth pointing out that their analysis assumes a priori that any correlation with economic activity must perforce be related to a contamination of the surface temperatures by urban heat effects. This is certainly not the the only possibility, and the fact that they have apparently discovered urban heating in the satellite trends as well should have alerted them to this fact.

    For instance, tropospheric ozone and black carbon emissions have local forcing components that are closely related to local emissions. Large scale land use similarly. The test of whether these factors produce correlations like those reported by M&M is available in the IPCC AR4 model archive. The fact that in 3 years since they first started this analysis, they didn’t once take a model simulation over the same period and do the same calculation is telling. This is of course in addition to the rather poor statistical significance alluded to by Rasmus. Checking their conclusions with random 25 year sequences from a model control run would have been a good test of the robustness to climate variability. Again something they didn’t apparently think of.

    Comment by gavin — 9 Dec 2007 @ 2:17 PM

  13. Another point : this paper of Hinkel et al. showed that UHI effect can be huge in peri-Arctc areas too : at Barrow (Alaska), 71,3°N, during the winter period, the urban area is 2.2 K warmer than the rural area.

    Hinkel K.M. et al. (2003), The urban heat island in winter at Barrow, Alaska, International Journal of Climatology, 23, 1889-1905.

    Comment by Charles Muller — 9 Dec 2007 @ 2:17 PM

  14. re: #11

    The paper under discussion is outside my areas of expertise, but I get the impression that the author primarily focused on data from the physical world. Getting a handle on the quality of that data seems to be an issue.

    For any given piece of research there are basically an uncountable number of things that were not done; some of more importance, some of less. Let’s make a list of what apparently has not been thought of with respect to, say, the NASA/GISS ModelE computer code. Many would say that because of what apparently has not been thought of, the ‘data’ from the code has no quality and is useless.

    [Response: Your argument can be applied to anything and therefore nothing has quality or usefulness. Including your argument. Which is then self-contradicting. Think of it this way instead. All analysis is incomplete in some way. Thus conclusions should always be preliminary. As more analysis is done, the preliminary conclusion becomes stronger or falls. Writing an op-ed declaring that M&M proves that the surface record (and satellite record!) are contaminated by UHI effects is rather putting the cart before the horse, don't you think? Especially, since most of the ideas for further analysis were already put to them in Rasmus's original comment in the journal, and are pretty obvious in any case. If you have some obvious things to test with ModelE or new analysis you want to do, go ahead. That's why the code is public. - gavin]

    Comment by Dan Hughes — 9 Dec 2007 @ 3:34 PM

  15. It is important that RC stay current with those such as McKitrick who believe that there are aspects to the science which are overlooked. RC represents the mainstream and as such is under continual attack. I often come here looking for specific refutations of contrarian views, especially when (as often) those views undermine orthodoxy.

    RC should present current work and latest understandings as well, of course, but it is simply necessary to, sometimes, comment on other work, especially when that work gains a bit of traction.

    We don’t see RC wasting much time disputing obvious denier rhetoric, but when a paper represents a seeming legitimate effort to do science, I (and I’m sure others) want to know what RC thinks.

    Comment by Walt Bennett — 9 Dec 2007 @ 3:35 PM

  16. I am unable to pull up the original papers (subscription required, etc.)

    Is the “Michaels” in the M&M2007 paper Patrick J. Michaels at the University of Virginia?

    Thanks!

    (And, FWIW, I also thought the analysis by Rasmus was interesting and useful — Thanks!)

    [Response: Yes. FYI there is a preprint on McKitricks' site. - gavin]

    Comment by Gary L. Herstein — 9 Dec 2007 @ 3:48 PM

  17. At the center of this discussion is the explicit role of the GHGs in the observed warming. The terrestrial data likely remain contaminated to some degree by factors related to land use change, including vegetation change, urban heat island, changes in wetland distribution, etc. I have no doubt that due diligence has been exercised to remove the effects of the urban heat island from the terrestrial record (this has been discussed at length elsewhere on RC and other forums), but it is reasonable to conclude that artifacts related to economic activity likely remain. In light of this probability, which data should we use to validate the forcing effect of the GHGs? What are the implications of using only the ocean record?

    I am an academic ecologist, and I speak and write regularly about land use change and climate change. While I have a better understanding than most on issues related to climate sensitivity, I would benefit from a direct, clear discussion of the relative importance of the forcing agents as they relate to the temperature record. Has the IPCC AR4 derived an incorrect estimate of climate forcings and feedbacks related to the GHGs? While it is unlikely that we can obtain complete certainty on this issue, it is important for mainstream climate scientists to continue to debate this issue in a manner that can be interpreted by rest of the academic community.

    There is an ongoing tug of war between the global climatologists and those academics that seem to hail more from the meteorology groups. This debate is often contaminated by pejorative, and could benefit from more light and less heat. Within the academy there is a small, but influential and vocal group of GHG skeptics, including Pielke, Sr., M&M, Christy and others who variously argue that we are placing too much emphasis on mitigating the GHGs, to the detriment of the economy and human well being. While it is apparent that a low carbon economy could be a thriving economy, climate scientists must be as clear as possible about the explicit role of the GHGs. Pielke, Sr. has repeatedly claimed that the IPCC estimate of the forcing effect of the GHGs is in error. I urge the scientists at RC and elsewhere to develop a detailed analysis of this and deal with this issue as best they can. Please don’t refer me to an earlier post – instead let us see the most recent thinking on this issue explicitly addressing the most recent claims.

    This issue is especially crucial to the construction of sound policy. I have recently returned from DC where I spoke with policy makers about the energy bill and cap-and-trade. My personal view is that a risk assessment approach is far preferable to a cost/benefit approach, and thus we should aggressively mitigate GHG emissions. Unfortunately, this is not sufficiently compelling to policy makers given that there are some credible scientists who argue that our money is better spent on other measures. It is arguable that we should also develop a portfolio of mitigation options related to compensating for changes in land use.

    I look forward to seeing more discussion of this issue at RC and in the peer-reviewed literature. I agree with 8 and 9. It is essential for RC to do its best to clarify and set the record straight. Although I am skeptical of its conclusions, M&M2007 is being published in a top tier journal, and thus needs to be addressed as serious science.

    Sincerely,

    Stephen

    Comment by Stephen Mulkey — 9 Dec 2007 @ 3:54 PM

  18. rasmus wrote in the essay:

    I find it a bit ironic when people use satellite data measurements to argue that GHG is unimportant. They rely on the fact that these measurements are derived using the very same type of physical laws as those predicting an enhanced greenhouse effect due to increased GHG levels (neglecting feedback processes).

    What makes this especially ironic is the fact that we measure the levels of greenhouse gases at various altitudes by means of the increased opacity of the atmosphere to various wavelengths (i.e., “channels” in satellite lingo). This is the mechanism by means of which greenhouse gases have an enhanced greenhouse effect as their concentrations increase over time.

    Comment by Timothy Chase — 9 Dec 2007 @ 4:10 PM

  19. The probability that RC will comment on a paper being actively discussed elsewhere is approaching unity…

    and…

    the choice of topics gives the impression that the so-called climate contrarians are the only people finding out anything interesting (true or not) about climate and its change.

    Complaints of this sort are right out of the creationist/IDist playbook. When scientists and mathematicians attack claims and arguments made by [ID]creationists, the response is … “look, our work is so important ‘darwinists’ have to attack it to support the ‘darwinist conspiracy’. So obviously, we’re right!”.

    I suspect it’s common among science denialists of all flavors.

    Comment by dhogaza — 9 Dec 2007 @ 4:20 PM

  20. Paul, your golfing experience notwithstanding, the east coast of the U.S. has actually experienced cooling. This site explains that in the FAQ section on the Michael Crichton book “State of Fear.”

    As for this article, I think the author missed the point. The HADcrut dataset and analysis presumes a randomness in the data for the purposes of assessing error. Even if the dataset is smooth and continuous, if there is a non-random component (i.e. a correlation), the correlation will need to be modeled in the error bars. IF that didn’t happen, this new paper is pretty significant. I suspect the reviewers at JGR-Atmos have representation in IPCC and must believe this new paper is significant.

    Comment by TimB — 9 Dec 2007 @ 5:31 PM

  21. This view of Longyearbyen give a slightly different perspective than the Google Earth view you provided.

    http://static.panoramio.com/photos/original/2129791.jpg

    Economic impact on temperature? Depends on where the thermometer is.

    [Response: Thanks for the nice picture. The thermometer is located near the airport (with about two landings/departures a day), to the far left of the picture. Other measurements from nearby sites, such as Ny Ålesund, Sveagruva, Hopen & Bjørnøya, show similar warming as Longyear byen. There is no economic activity near these sites, except for at Sveagruva. -rasmus]

    Comment by John Norris — 9 Dec 2007 @ 5:38 PM

  22. Every action within an economic system has associated with it an ensemble of ghg emissions. Those emissions can be traced and accounted for in the carbon accounts of the economic unit, and specific patterns and relationships can be identified amongst the myriad of self-organising economic units and subsystems. Thus, provided one accepts the relationship between ghg and temperature, it would be fine to assume that temperature trends are affected by economic activity. Economic activity is in effect an order parameter. Interestingly, the inverse problem can be examined. Does temperature trend affect economic activity? It certainly does.

    Comment by Michael — 9 Dec 2007 @ 5:51 PM

  23. Robert Edele #5:

    The utilization of natural resources is the very basis of economic activity, therefore it IS economic activity with a direct and measurable impact on many facets of the environment, climate included,.

    Money does not change hands just so the “exchangers” can have fun!

    Every time I start my internal combustion engine I am taking part in econimic activity. Why? Because I have to work to buy gasoline, and in a cascade of “economic activity” a fossil fuel company has to employ and pay people to make the fuel available.

    When I start my automobile, just because money is not changing hands at that instant, does preclude that activity from being economic.

    We all know what is meant by the term, is it then not a bit, in your word, “silly” to argue that economic activity has no direct effect on climate?

    Steve Horstmeyer

    Comment by Steve Horstmeyer — 9 Dec 2007 @ 5:59 PM

  24. Statistics is such a difficult and counter-intuitive subject that we and the public need the best possible assistance in countering the claims of liars. Statistics makes life too easy for liars otherwise. Since very smart and honest professors have been known to make mistakes in statistics, checking by other professors is needed. Thank you, rasmus, for making us aware of a few of the pitfalls the unwary may fall into, and the level of care required to write a good paper on the subject of climate.

    Comment by Edward Greisch — 9 Dec 2007 @ 6:18 PM

  25. Here is a planned ‘economic activity’ which ought to have a positive impact, not only on climate, but also on the well-being of the peoples of the Sahel:

    http://biopact.com/2007/12/eu-and-africa-to-build-green-wall.html

    Comment by David B. Benson — 9 Dec 2007 @ 7:25 PM

  26. John Norris (#19) wrote:

    This view of Longyearbyen give a slightly different perspective than the Google Earth view you provided.

    http://static.panoramio.com/photos/original/2129791.jpg

    Economic impact on temperature? Depends on where the thermometer is

    You can get windspeed here:
    http://www.unis.no/research/geology/Geo_research/Ole/TemperatureGruvefjell.htm

    Several meters per second looks pretty standard.

    This has links to the information on the various climate monitoring equipment in the area:
    http://www.unis.no/research/geology/Geo_research/Ole/ClickableLongyearbyenSurroundings.htm

    … including the location of the thermometer.

    Comment by Timothy Chase — 9 Dec 2007 @ 8:36 PM

  27. Economic impact on temperature? Depends on where the thermometer is.

    And satellites are SUCH hotbeds of economic activity …

    And your panorama makes it clear that Longyearbyen is a small place.

    Was that photo created by the surface stations photo documentation project, by any chance?

    (end sarcasm)

    Comment by dhogaza — 9 Dec 2007 @ 9:02 PM

  28. Could someone please tell me how this paper got through peer-review at JGR-Atmosphere? I am stunned and disheartened that something this horribly flawed is coming out of an AGU publication.

    Comment by egb — 9 Dec 2007 @ 9:22 PM

  29. If urban heat islands are to be discounted when looking for trends – surely they must be included when looking at the big picture.

    If one looks at those classic images of The Earth at Night one can see the twinkling evidence of mankind’s presence most places. And those lights are mostly identifying the location and extent of UHIs.

    Is not the heat from UHIs entitled to sit at the same table as heat from bare earth when we ask about the present global temerpature? When does the data from the UHI’s get considered – when their sweltering streets, shimmering towers and streaming chimneys cover more than 50% of the earth, or somewhat sooner?

    Comment by Nigel Williams — 9 Dec 2007 @ 10:30 PM

  30. Re 25

    The UHI effect IS accounted for, and its (rather negligible) effect is mentioned in the IPCC 2007 and other documents. It is not whether UHI is discounted or not; the question is what effect that has on the the Global mean temp, and regardless of what McKitrick says, it is not a practical amount. It is also not influencing increased ocean heat content, melting ice caps and glaciers, satellites showing tropospheric warming or strato cooling, etc

    Comment by Chris — 9 Dec 2007 @ 11:01 PM

  31. Nigel Williams (#25) wrote:

    Is not the heat from UHIs entitled to sit at the same table as heat from bare earth when we ask about the present global temerpature? When does the data from the UHI’s get considered – when their sweltering streets, shimmering towers and streaming chimneys cover more than 50% of the earth, or somewhat sooner?

    Love the poetry, but the answer is still no.

    Not when you are trying to determine global or latitudinal trends in temperature. Need to keep things weighted according to area – and cities are pretty tiny in comparison to the countryside.

    *

    Fortunately we don’t seem to have to worry all that much regarding urban heat islands — most of the time. As is well-known, there are various corrections made to eliminate any urban heat island effect, and they appear to have been quite successful:

    Assessment of Urban Versus Rural In Situ Surface Temperatures in the Contiguous United States: No Difference Found
    Thomas C. Peterson
    Journal of Climate, VOL. 16, NO. 18, 15 September 2003
    http://www.ncdc.noaa.gov/oa/wmo/ccl/rural-urban.pdf

    *

    Likewise, according to Peterson and Vose (1997) analysis cited by IPCC 2001, the long-term (1880 to 1998) rural (0.70 C/century) and full set of station temperature trends (0.65 C/century) showed that rural stations were trending slightly higher. More recently, a 1998 analysis for the long-term trends (1951-1989) rural (0.80 C/century) and full set of station temperature trends (0.92 C/century) showed urban stations trending slightly higher.

    However, in both cases, the difference between urban and rural trends were not statistically significant. As such, it would appear that the Urban Heat Island effect is either negligible or corrected for when climatologists derive their trends for temperature.

    Please see:

    2.2.2.1 Land-surface air temperature
    http://www.grida.no/climate/ipcc_tar/wg1/052.htm#2221

    *

    What I would be interested in is whether GISS corrects for the Urban Heat Island effect in Barrow. I would presume they do. That is standard operating procedure, I believe. And we have known that it would be a problem if left uncorrected since 1983. For the winter, not summer, since for the latter it is weak to non-existent.

    Please see:

    Conversely, summer demand for lighting and interior temperature maintenance is minimal compared with mid-latitude or tropical settings, where air conditioning is required. The presence and strength of the UHI in Arctic regions, therefore, has a strong seasonal component with maximum development and intensity in winter, and only weak or nonexistent expression in summer (Benson et al., 1983).

    Hinkel K.M. et al. (2003), The urban heat island in winter at Barrow, Alaska, International Journal of Climatology, 23, 1889-1905.

    Comment by Timothy Chase — 9 Dec 2007 @ 11:19 PM

  32. Am I the only one who noticed that reducing the land warming trend by 50% would make it lower than the ocean warming trend??

    land =http://www.cru.uea.ac.uk/cru/data/temperature/crutem3vgl.txt
    ocean =http://www.cru.uea.ac.uk/cru/data/temperature/hadsst2gl.txt

    given that land responds faster to solar warming “seasons” it would make some sense that land should also warm faster

    also there are some cool spots that surprised me like the east coast of the U.S.A and Australia

    personally I think their trying to make a case for urban heat continents..

    [Response: You get the prize for being the first to mention it. Well spotted! -rasmus]

    Comment by jacob l — 10 Dec 2007 @ 12:30 AM

  33. Firstly, I’ve only had a 15 minute look at this paper, but the quality of the analysis concerns me.

    In the abstract M&M say, “…we test the null hypothesis that the spatial pattern of temperature trends in a widely-used gridded climate data set is independent of socioeconomic determinants of surface processes and data inhomogeneities. The hypothesis is strongly rejected (P= 7.1×10−14 )…”

    Rasmus is completely correct. They have not considered correlation between data points. If they’d doubled the number of grid points the p value would be infinitesimal.

    I noticed they left out outliers – such as Arctic and Antartic “hot-spots” when fitting the model. Outliers can be a result of measurement errors or even chance results, but high lattitude “hot-spots” are clearly neither of these. They are regions of stronger than average warming trend. These outliers are most likely a sign of model failure.

    I’m still coming to terms with their model, but the inclusion of many non-significant parameter estimates in Table 1 is a worry.

    I suspect another big problem with the model is omitted variable bias. The rate of southern hemisphere (and tropical) warming is slower than northern hemisphere warming and that includes landmasses. But economic activity is strongly associated with the extra-tropical nothern hemisphere. As far as I can tell there is no variable in the model to account for this hemisphere effect. This effect will then be incorporated into other variables associated with hemisphere – i.e. GDP, coal production etc – resulting in a biased estimate of these effects, the so called “omitted variable bias”.

    Comment by Bruce Tabor — 10 Dec 2007 @ 12:53 AM

  34. From the abstract of the paper

    Using the regression model to filter the
    extraneous, nonclimatic effects reduces the
    estimated 1980-2002 global average
    temperature
    trend over land by about half.

    So I’m confused – is there a global average temperature or isn’t there? ;-)

    Comment by John Cross — 10 Dec 2007 @ 1:43 AM

  35. PaulM posts:

    [[Economic activity is rooted in the now global capitalist push for both the desire for energy and desire for profit]]

    And yet the Soviet Union and Peoples’ Republic of China were/are the most egregious polluters in the world. Funny how that works.

    Comment by Barton Paul Levenson — 10 Dec 2007 @ 6:40 AM

  36. All due apologies for going OT.
    On CNN this morning (around 6:30AM 10 Dec), their science reporter Miles O’Brien did a story on Al Gore at the Nobel Prize ceremony. This is a SCIENCE reporter! Instead of illuminating us on the SCIENCE (and Gore’s efforts to publicize the science) behind the Prize, Miles lead off with Chris Horner (of “Politically Incorrect Guide to GW”) denouncing Gore. I won’t repeat Horner’s trash talk, only that it was vicious ad hominem.

    Why they gave this luddite corporate hack a platform in the middle of this story is puzzling, to say the least!

    The piece may show up on CNN.com. This style of reporting is despicable and must be protested.

    Comment by jimvj — 10 Dec 2007 @ 9:51 AM

  37. Maybe OT, but does anyone have any idea of what kind of money it would cost in the way of funding to research and produce a paper like this? McKitrick has been recieving what looks to be rather substantial funding from the Social Sciences and Humanities Research Council to do this work (into the $100,000s).

    Comment by bigcitylib — 10 Dec 2007 @ 10:08 AM

  38. What I’m trying to understand might be in the post but I haven’t been able to dig it out. Sorry.

    I take it that a simple summary of the paper’s contention is that climatic terrestrial temperature measurements have been and are overstated because of increases in economic activity. My question: do they contend that economic activity per se is the culprit, or that heat islands are the culprit — stemming from economic activity which tends to move things from rural to urban areas. It’s not obvious how economic activity per se can add any heat without extreme stretching of the meaning of “economic activity”, other than maybe its increase in GHG output, which would form a ludicrous circular logic. In other words does their argument boil down to simply the heat island effect? Or would they claim something else?

    I’m posting this before reading the comments which might have the answer….

    Comment by Rod B — 10 Dec 2007 @ 10:51 AM

  39. Re #30 (Barton Paul Levenson)

    “PaulM posts:

    [[Economic activity is rooted in the now global capitalist push for both the desire for energy and desire for profit]]

    And yet the Soviet Union and Peoples’ Republic of China were/are the most egregious polluters in the world.”

    Not really, at least so far as GHGs are concerned: neither approached/approaches the per capita emissions of the USA, Canada, Australia, or even western Europe – though not for want of trying. With regard to the PRC, a considerable proportion of current emissions result from manufacture for export to the rich world; and more fundamentally, it is arguable that China is now an integral part of the capitalist world-system (although the USSR was not). It is the very success of capitalism in increasing economic activity that now threatens to bring about its own collapse.

    Comment by Nick Gotts — 10 Dec 2007 @ 11:19 AM

  40. Hello Rasmus. Thank you for your comments on my new paper. Here are some responses.

    Spatial autocorrelation is an issue, in principle, with any cross-sectional study. I agree with you. You should have mentioned, though, that we applied a GLS estimator with White’s HCCME terms and clustering structure built in. Adding in local spatial AC coefficients would, for many of the regions, be redundant on top of the exiting off-diagonal elements. My conjecture is it would not affect things. However, that’s no more than a conjecture. Perhaps a reader who is interested, and better than me at programming, will figure out the math to put spatial AC controls in the GLS estimator while also controlling for heteroskedasticity and clustering.

    I accept your concerns about whether we used the most updated data possible. It was a large data base to put together. It’s available at my web site. If someone wants to swap in columns with newer series (making sure the definitions are consistent) then the code can easily be re-run.

    I don’t agree with your concerns about over-fitting. Over-fitting becomes a detectable problem when you have a high r2 and very low t-stats. We don’t have that, and the variance inflation factors indicate that our covariates are contributing unique explanatory power.

    Your paragraph beginning “I have not examined the economic data…” seems to rule out using socioeconomic covariates under any circumstances. Yes, they change abruptly at national borders. Yes, an ideal data set would have them change continuously, but discrete changes doesn’t mean a variable can’t be used in a regression model. You’ve set up a criterion where it’s Heads-disqualified, Tails-disallowed. Can you state what circumstances you would permit socioeconomic covariates for this type of test?

    You raise concerns about spurious results, but we have a few tests for this, including the endogeneity discussion in Sct 4.4. Can you be more specific? Your point was rather vague.

    The oceans are obviously not at issue here. Perhaps there is an issue whether data collected from ship intakes will prove to be comparable to data collected by the argo network, but that’s for others to examine.

    It is not true that our discussion of the effect of urbanization and land-use change rested only on our 2004 paper. In the on-line preprint (http://www.uoguelph.ca/~rmckitri/research/jgr07/jgr07.html)
    pages 4-11 discuss anthropogenic surface processes and inhomogeneities, and there are many references therein.

    Yes, we used the UAH data. I will eat my toque if that choice matters greatly, but, again, the data base is on-line and others can easily check.

    Is 24 years too short to extract a trend? Well, 30 years would be better. If we had 30 years and the same results emerged, would your position change? I doubt it. So maybe the point is at most a secondary one.

    Re the use of MSU data. Nothing in my paper disputes the idea that GHG are infrared-absorbing, or that oxygen emits microwaves. I’m not in a position to say anything about these things either way. But your qualifier is key: “…neglecting feedback processes…” Feedback processes are pretty much what is at issue.

    Your conclusion says that there may very well be some contamination of the data. I suppose this admission represents progress. But considering the importance of the data at issue, is this an adequate response on your part? I have made the case that there is substantial contamination of the data. You don’t accept my results, which is your prerogative, but if you want to argue that there is only a small contamination problem, taking into account both surface processes and inhomogeneities (i.e. not just UHI effects), you should make the case with clear empirical methods.

    Oh, and bcl, this kind of research doesn’t cost much at all. I used a bit of time of one of my research assistants for part of the data assembly. Otherwise the data are free and I used software I already own. And there are page charges for JGR. I am funded by SSHRCC for a range of research projects.

    [Response: Thanks for your response, Ross. I think that your model is over-fit because I think that you have not eliminated the dependence and include too many inputs without any clear/understood connection. A regression analysis will always find a combination of weights giving the 'best' fit. You find greatest 'biases' in locations far away from places such as the Arctic and Antarctic. I don't find that convincing. -rasmus]

    Comment by Ross McKitrick — 10 Dec 2007 @ 11:39 AM

  41. Re 34 McKitrick

    “the oceans are not an issue here”

    If the oceans are warming, and we know that heat is going in and not going out or just being redistributed, then we know an external agent is acting on the climate system and this is unequivocal across the globe from ice sheet/glacier responses to SST/atmosphere/surface temperatures, snow cover decline, etc. I am not sure why this wouldn’t be an issue in a study going over UHI impact of global land temperatures, since one would imagine this external agent is also acting on land. One couldn’t say that the CO2+feedbacks are just acting on oceans and polar and rural regions, but not in urban areas, and that UHI makes up for this in the instrumental record.

    As for the UAH data, it was not right, so shouldn’t have been used but I have no reasonable insight into how that would have effected your study. — C

    Comment by Chris Colose — 10 Dec 2007 @ 12:36 PM

  42. John Cross (#29) wrote:

    From the abstract of the paper:

    Using the regression model to filter the
    extraneous, nonclimatic effects reduces the
    estimated 1980-02 global average
    temperature trend over land by about half.

    So I’m confused – is there a global average temperature or isn’t there?

    The following might help:

    Inter-annually, the 18-year Pathfinder data in this study showed global average temperature increases of 0.43 Celsius (C) (0.77 Fahrenheit (F)) per decade.

    By comparison, ground station data (2 meter surface air temperatures) showed a rise of 0.34°C (0.61°F) per decade, and a National Center for Environmental Prediction reanalysis of land surface skin temperature showed a similar increasing trend in global and land surface temperature, in this case 0.28°C (0.5°F) per decade. Skin temperatures from TOVS also prove an increasing trend in global land surface temperatures. Regional trends show more temperature variations.

    April 21, 2004
    Earth Observatory: NASA News Archive
    Satellites Act as Thermometers in Space, Show Earth has a Fever
    http://earthobservatory.nasa.gov/Newsroom/NasaNews/2004/2004042116878.html

    According to the Pathfinder data, it would appear we have slightly underestimated the trend in the global temperature (by 0.09 C) — using ground-based measurements from 1981-1998. NCEP reanalysis of the data had shaved another 0.06 C, so it underestimated the trend by 0.15 C, according to the Pathfinder data. Not sure how statistically significant that is though.

    Comment by Timothy Chase — 10 Dec 2007 @ 1:16 PM

  43. > It is not true that our discussion of the effect
    > of urbanization and land-use change rested only
    > on our 2004 paper. In the on-line preprint …

    Can we assume the journal’s peer reviewers approved the online preprint version? I am not sure why they differ.

    Comment by Hank Roberts — 10 Dec 2007 @ 1:36 PM

  44. The real question here is whether measured global warming has been exaggerated by changing human activity in the vicinity of the measuring stations.

    There is no question that the measurements themselves are affected by local human activity. We attempt to adjust for this “contamination” (to use McKitrick’s term) algorithmically.

    Are these adjustments correct? For purely algorithmic reasons, I have long been skeptical.

    The way to test this is to do precisely the sort of study that McKitrick has done. The correlation that McKitrick has shown between socioeconomic activity and the temperature anomaly is truly startling. I’m surprised that so many here are willing to dismiss it so quickly.

    I agree with Rasmus that spatial correlations would tend to reduce the confidence with which McKitrick makes his conclusions (and I simply don’t have the background to understand McKitrick’s response), but even if the conclusions are overstated, the correlation is real, and difficult to question.

    Isn’t it incumbent on purveyors of global temperature data to prove that their data is NOT “contaminated”?

    Doesn’t McKitrick’s analysis STRONGLY suggest that this is not the case?

    Comment by Jason — 10 Dec 2007 @ 2:00 PM

  45. RE Longyearbyen

    Does anyone know of a site with graphs of cloud cover and temperature anomalies for Longyearbyen? I’m particularly looking for records that cover the period from about 1935 to present. Anomalous high temps at west-facing near-ocean locations are my interest, and this looks like a prime candidate. All the papers I’ve googled have been behind a pay-to-view wall.

    I would expect it to exhibit a rising temperature spike starting in 1939.

    TIA.

    JF

    Comment by Julian Flood — 10 Dec 2007 @ 2:18 PM

  46. re #34/Rasmus: I think overfitting due to dependence and too many inputs without clearly understood connection might be a problem also in other areas like multiproxy temperature reconstructions (many uncalibrated proxies regressed on, say, instrumental temperature PCs). Maybe you could help Ross by explaining how the problem has been avoided, e.g., in the landmark paper by Mann et al. (1998)?

    [Response: Step-wise regression is often preferred, but I'd recommend a proper cross-validation. -rasmus]

    [Response: Cross-validation (and objective selection rules) are the key here, as indeed emphasized by Mann et al (1998), and driven home fairly convincingly by the followup papers by Wahl and Ammann we've referenced above. You should read these (and obviously, re-read Mann et al 1998) to understand the issues better. -mike]

    Comment by Jean S — 10 Dec 2007 @ 3:08 PM

  47. Thanks Timothy 26.

    Need to keep things weighted according to area – and cities are pretty tiny in comparison to the countryside.

    I would have thought you needed to keep ‘things’ weighted in terms of energy content per unit area not just area alone? Thus won’t the energy of the UHIs figure rather more strongly in the overall picture?

    Otherwise it just seems to me that we are looking for trends among a sample we are ever-reducing as old stations are knobbled by the UHI effect. Isn’t this obscuring how ‘inconvenient’ the truth really is about warming globally?

    Yet would not the UHIs put more (in fact most) anthropo-energy into circulation, capture more insolation and (because of effects like inversions holding higher concentrations of GHGs) retain more energy locally at lower altitudes?

    That there is still an upward trend to be found in the remaining non-UHI stations is useful info, but what do we see if we use all stations on say a 10km square grid (or 10″ grid or whatever) with stations within a square averaged and look at the past and present energy content (Joules) of the total atmosphere globally over time?

    Isn’t that total energy content including UHIs the figure that matters because that energy is the meat in the sandwich between the energy additions to the system and the energy loss to space which in turn defines the global temperature?

    Comment by Nigel Williams — 10 Dec 2007 @ 3:46 PM

  48. Re: #11 Response by Gavin
    [........If you have some obvious things to test with ModelE or new analysis you want to do, go ahead. That’s why the code is public. - gavin]
    Is this a valid challenge? Many (Most ?) of us don’t have the expertise or the capacity( by a long shot) either in our gray matter or on our hard drives to run alternative tests on Model E or any equivalent. Also Nasa/ Giss works as a team and on company time. Do you really expect a poster working alone in his spare time to take you up on the above statement. I don’t much like the way the war in Iraq has been handled, but if somebody were to say “We’ll put you in charge – go ahead and solve the debacle”, I’m sure I couldn’t do any better.
    You shouldn’t have to have the knowledge of say a four star general or an expert climate modeler in order to make good faith criticisms. Also this works both ways. Because you’re unhappy with the M&M paper, you shouldn’t have to develop your own paper on the same topic, using their method of analysis or another method of analysis with their own or your own data.

    [Response: I agree. Good faith criticisms should be welcome. But McKitrick's op-ed and declarative statements seem to have done before any of those criticisms were dealt with. (PS. you could run ModelE on your home linux box if you want, and we have a port for windows in the works- you don't need to do that to make good faith criticisms, but if you wanted to see how it worked you could in fact see for yourself). - gavin]

    Comment by Lawrence Brown — 10 Dec 2007 @ 5:23 PM

  49. RE Nigel Williams (#40)

    In principle, global average temperature over a given period would be defined as the integral over the surface area, then integrated over the time period under consideration, then divided by the product of the surface area times the time.

    As stations measure temperature over a limited number of points, one will need to interpolate temperatures between stations over a given area, but in no small part this will involve removing the effects of Urban Heat Islands. Technically such an average will be refered to as being weighted by area and will make reference only to temperatures, not heat content.

    Satellite measurements should be more accurate, both in arriving at global average temperatures and in identifying trends over a given period as they are able to take readings from a far larger number of points. As such when Pathfinder satellite gives a larger trend in global temperature of 0.43 C/decade but groundbased measurements give 0.34 C/decade, I suspect that the higher satellite-based trend is more accurate.

    But yes, urban temperatures are important for their own sake — but they are relatively insignificant when compared to the effects of greenhouse gases, and without corrections for UHI would give a distorted picture of the rise in global average temperature. However, given the results of Pathfinder, it would appear that we have overcompensated for the effects of UHI.

    Comment by Timothy Chase — 10 Dec 2007 @ 5:24 PM

  50. #41 Timothy, what is Pathfinder Satellite ? (The link leads to another discussion without a precise reference). If you look at UAH data for lower troposphere trends on land and NH (used by M&M 2007), you get 0,24 K/dec (0,33 K/dec CRU, 0,34 K/dec NCDC, 0,29 K/dec Giss, cf AR4 tab. 3.2 p. 243). Anyway, even if the trends were the same, I guess it’s not the M&M2007 purpose to look at global correlation, rather to assess local (grid by grid) correlations between Ts, Ttropo, economic activity.

    Other point (more general) : UHI is detectable even for small towns (see Torok 2001), not just big cities, and anthropic effects on surface energy budget is not limited to urbanization.

    Torok S.J. et al. (2001), Urban heat island features of southeast Australian towns, Aust. Met. Mag., 50 1-13.

    Comment by Charles Muller — 10 Dec 2007 @ 6:04 PM

  51. Over-fitting: Re. Rasmus, Ross McKitrick @34, Jean @39,
    Although I have reservations and criticisms of the model generally, I think the concerns about over-fitting are over-done. Over-fitting usually results in models which follow data noise well but have large errors on parameter estimates and poor predictive precision. It will not however have much influence on the global test of the null hypotheis, which is stated in the abstract as:

    “…the null hypothesis that the spatial pattern of temperature trends in a widely-used gridded climate data set is independent of socioeconomic determinants of surface processes and data inhomogeneities.”

    This hypothesis is rejected with a p=7.1*10^-14.

    My bigger concerns are with the model itself. Two of which Rasmus has stated:
    1) Failure to appropriately incorporate spatial correlation of temperature measurements. This will result in exaggerated p-values.
    2) Poor model fit for land areas at extreme latitudes. This is evidence of outright model failure – the model does not fit the data as it is inappropriate.
    And an additional issue:
    3 Omitted variable bias.
    http://en.wikipedia.org/wiki/Omitted_variable_bias
    This is a bias that appears in parameter estimates – such as the effect of economic activity on local temperature measurement in Ross’s model – that is due to the omission of a variable that is better able to explain the relationship between location and temperature. Such a variable might be hemispheric effects, or oceanic effects that extend beyond coastlines.

    Essentially omitted variable bias is a type of poor model specification that results in biased estimates of model parameters even when the model fits the data.

    Comment by Bruce Tabor — 10 Dec 2007 @ 7:07 PM

  52. Re. Gavin @11 and my earlier comment about omitted variable bias.

    Gavin’s concerns about tropospheric ozone and black carbon emissions having local forcing components is another example of omitted variable bias. A fitted model that excludes these will attribute these forcing effects to other variables in the model which have large values at the same locations, such as GDP.

    Comment by Bruce Tabor — 10 Dec 2007 @ 7:15 PM

  53. Anyone care to hazard an estimate of the percentage of human induced CO2 of the 100 ppmv that finds its way into the +.7 observed trend in the mean global anomaly?

    [Response: That's not a well-posed question. See here for a discussion. - gavin]

    Comment by Ralph Smythe — 10 Dec 2007 @ 7:39 PM

  54. Charles Muller wrote
    > what is Pathfinder Satellite? (the link leads to
    > another discussion without a precise reference …

    the discussion includes this reference:
    http://earthobservatory.nasa.gov/Newsroom/NasaNews/2004/2004042116878.html

    and at the bottom of that page

    > For more information and images … visit:
    http://www.gsfc.nasa.gov/topstory/2004/0315skintemp.html

    Comment by Hank Roberts — 10 Dec 2007 @ 8:01 PM

  55. Charles Muller (#43) wrote:

    #42 Timothy, what is Pathfinder Satellite ? (The link leads to another discussion without a precise reference).

    The link was to my earlier comment that included a relevant quote and the link to my source:

    April 21, 2004
    Earth Observatory: NASA News Archive
    Satellites Act as Thermometers in Space, Show Earth has a Fever
    http://earthobservatory.nasa.gov/Newsroom/NasaNews/2004/2004042116878.html

    I simply didn’t want to duplicate the quote.

    Charles Muller (#43) wrote:

    If you look at UAH data for lower troposphere trends on land and NH (used by M&M 2007), you get 0,24 K/dec (0,33 K/dec CRU, 0,34 K/dec NCDC, 0,29 K/dec Giss, cf AR4 tab. 3.2 p. 243). Anyway, even if the trends were the same, I guess it’s not the M&M2007 purpose to look at global correlation, rather to assess local (grid by grid) correlations between Ts, Ttropo, economic activity.

    Pathfinder was using skin temperature — which is actually closer to the surface than land-based.

    They state:

    Furthermore, satellite skin temperatures have global coverage at high resolutions, and are not limited by political boundaries. The study uses Advanced Very High Resolution Radiometer Land Pathfinder data, jointly created by NASA and the National Oceanic and Atmospheric Administration (NOAA) through NASA’s Earth Observing System Program Office. It also uses recently available NASA Moderate Resolution Imaging Spectroradiometer skin temperature measurements, as well as NOAA TIROS Operational Vertical Sounder (TOVS) data for validation purposes. All these data are archived at NASA’s Distributed Active Archive Center.

    Inter-annually, the 18-year Pathfinder data in this study showed global average temperature increases of 0.43 Celsius (C) (0.77 Fahrenheit (F)) per decade.

    Anyway, it wouldn’t surprise me if lower trop and ground-based were actually closer to one-another. In fact, I seem to remember they are almost the same — at least for the continental US — but I will have to check. However, I do remember there is somewhat greater variability with lower trop — the hot years tend to be higher.

    Charles Muller (#43) wrote:

    Other point (more general) : UHI is detectable even for small towns (see Torok 2001), not just big cities, and anthropic effects on surface energy budget is not limited to urbanization.

    Torok S.J. et al. (2001), Urban heat island features of southeast Australian towns, Aust. Met. Mag., 50 1-13.

    Certainly it is detectable. But it is also in very large part accounted and corrected for.

    In 26, I had stated:

    Fortunately we don’t seem to have to worry all that much regarding urban heat islands — most of the time. As is well-known, there are various corrections made to eliminate any urban heat island effect, and they appear to have been quite successful:

    Assessment of Urban Versus Rural In Situ Surface Temperatures in the Contiguous United States: No Difference Found
    Thomas C. Peterson
    Journal of Climate, VOL. 16, NO. 18, 15 September 2003
    http://www.ncdc.noaa.gov/oa/wmo/ccl/rural-urban.pdf

    … and I gave additional sources, as well as pointed out that we knew about Barrow in 1983. Somehow I suspect the UHI at Barrow has been corrected for. In any case, there are a fair number of corrections made depending upon location, altitude, etc. There is the law of large numbers which cancels out much of the local variation. Then there is also the Park Cool Island effect. All of this is covered in a fair amount of detail in the paper by Peterson. I believe it has become a classic.

    In any case, pointing out literature which shows and details an Urban Heat Island effect isn’t sufficient for criticizing the estimated trends in temperature. One needs to show that the features of UHI have not been accounted for, that they are not cancelled out by various corrections made to the data in combination with the law of large numbers, etc.. But oddly enough, climatologists at NASA GISS seem to keep up with the literature and know what needs to be accounted for, typically. I suppose this might be because it is their job.

    Comment by Timothy Chase — 10 Dec 2007 @ 8:08 PM

  56. Re # 37 Hank Roberts: “Can we assume the journal’s peer reviewers approved the online preprint version? I am not sure why they differ.”

    I don’t know about J of Geophysical Research, but here is Science magazine’s policy on online rapid publication (Science Express):

    “Each week, Science selects several papers for rapid online publication in advance of the scheduled print publication date. These papers are published essentially as supplied by the authors, with minimal copyediting by Science; a fully copyedited version appears later In print.”
    http://www.sciencemag.org/about/authors/prep/gen_info.dtl#express

    Comment by Chuck Booth — 10 Dec 2007 @ 8:10 PM

  57. Bruce Tabor (#44) wrote:

    Over-fitting: Re. Rasmus, Ross McKitrick @34, Jean @39,
    Although I have reservations and criticisms of the model generally, I think the concerns about over-fitting are over-done. Over-fitting usually results in models which follow data noise well but have large errors on parameter estimates and poor predictive precision. It will not however have much influence on the global test of the null hypotheis, which is stated in the abstract as:

    “…the null hypothesis that the spatial pattern of temperature trends in a widely-used gridded climate data set is independent of socioeconomic determinants of surface processes and data inhomogeneities.”

    I would think that if you wanted to check for the accuracy of global temperature trends calculated by means of ground-based observations using satellites, you would calculate the the global average trend using satellite measurements, e.g., Pathfinder, then compare. The same would hold for latitudinal averages.

    Bringing in additional factors such as economic activity, etc. simply overcomplicates the math and introduces more opportunities for losing or distorting a signal that can be obtained in a fairly straightforward fashion. But I suppose this is what is meant by “over-fitting.”

    Comment by Timothy Chase — 10 Dec 2007 @ 8:41 PM

  58. Re 34 McKitrick

    “the oceans are not an issue here”

    Being less polite than Chris, oceans provide a simple bull(you know what) test of the hypothesis. It fails.

    It seems obvious to me also that MSU data, in so far as it is affected by surface temperature has to average over very large areas.

    Comment by Eli Rabett — 10 Dec 2007 @ 9:22 PM

  59. Would it be not easier to disprove the effects of UHI’s by simply using Antarctica, Arctic data as well as every remote location on Earth? There is no argument in these stations about economics, unless they have been massively paved for no reason. As a pure form of temperature trends there are none so potent. Being in a very remote location, I already know that there is a strong warming, Most people need not be knowledgeable about the real finer climate details which get marred in mud on purpose, the more compelling arguments are simple and straightforward.

    Like November 2007 NASA GISS Latitude analysis, North of 60 North was the strongest warming

    http://data.giss.nasa.gov/cgi-bin/gistemp/do_nmap.py?year_last=2007&month_last=11&sat=4&sst=0&type=anoms&mean_gen=11&year1=2007&year2=2007&base1=1951&base2=1980&radius=1200&pol=reg

    How many big cities contributed to that result? BTW With Nov 07 in , 2007 is the warmest year in history for the Northern Hemisphere, a lot of this warming was well away from mega cities.

    Comment by wayne davidson — 10 Dec 2007 @ 10:20 PM

  60. In the past few weeks, RC has offered criticism of Scafetta, Loehle and McKitrick. As the comments poured in, I found my eyes rolling at the cheerleading of the RC groupies. The most valuble responses came from the authors themselves, defending their work and responding the the criticism.

    So my thought is this, when doing such a post, wouldn’t it be most valuble to invite the author to respond, and close the comments to all others at least for a little while. I would love to see a little back and forth between author and critic. Then the comments could be opened to the RC admiration society for some typical back slapping and piling on.

    Comment by Lucky — 10 Dec 2007 @ 10:28 PM

  61. Re 50

    Perhaps you can make useful contributions in showing where the RC team went wrong, instead of the typical “RC groupy” attacks. The 3 works were bad science, and in my opinion show a breakdown of peer review. To say the least, they were not defensible; to say the worst, I think people out there are concerned only with forwarding certain notions and will do what it takes to get the madvanced (like up the solar contribution, up the UHI contamination, up the MWP) I would almost like to see an article on the peer review process and what is going on now.

    RealClimate is doing a great job here. Other blogs are dedicated exclusively to bashing other peoples work and generally by people who do not sit on the mainstream of that work. Scientific-sounding but content-free material going around the internet is probably not a good thing, and I thank RC for going over the material.

    Comment by Chris — 10 Dec 2007 @ 11:17 PM

  62. Lucky (#50) wrote:

    In the past few weeks, RC has offered criticism of Scafetta, Loehle and McKitrick. As the comments poured in, I found my eyes rolling at the cheerleading of the RC groupies. The most valuble responses came from the authors themselves, defending their work and responding the the criticism.

    So my thought is this, when doing such a post, wouldn’t it be most valuble to invite the author to respond, and close the comments to all others at least for a little while. I would love to see a little back and forth between author and critic. Then the comments could be opened to the RC admiration society for some typical back slapping and piling on.

    As someone who you would probably regard as one of the groupies, while I may not like the way you put things all that much, you have brought up an interesting idea. A discussion between the authors and the contributors could form the backbone of later discussion, giving it more structure and making it less likely to veer off into unrelated topics once the “groupies” and “anti-groupies” come in.

    On-topic there is a better chance for a process of discovery. Offtopic things can easily turn into bullsessions. It would provide a better opportunity to learn — and I think the caliber of discussion that would be possible may be something that the contributors would enjoy.

    But obviously this will be up to the contributors and the authors. Perhaps letting the authors know that their papers will be discussed either way will mean they will be more likely to attend.

    Comment by Timothy Chase — 10 Dec 2007 @ 11:26 PM

  63. re rasmus response to #18

    1. Got any nice pictures of the thermometer clear of the tarmac?
    2. re
    “Other measurements from nearby sites, such as Ny Ålesund, Sveagruva, Hopen & Bjørnøya, show similar warming as Longyear byen.”
    - Is this measurement data available online?
    3.re
    “There is no economic activity near these sites, except for at Sveagruva.”
    - Got any nice pictures?

    [Response: The measurements are being done very carefully. High-quality stuff. -rasmus]

    Comment by John Norris — 10 Dec 2007 @ 11:28 PM

  64. # 50 Lucky

    What if the author in question doesn’t respond?

    Comment by Chuck Booth — 10 Dec 2007 @ 11:30 PM

  65. “Cheerleading?” “Groupies?” “Admiration society?” “Backslapping?” “Piling on?” I think Real Climate is being confused with another site with “climate” in the title.

    Comment by cce — 11 Dec 2007 @ 12:02 AM

  66. he most valuble responses came from the authors themselves, defending their work and responding the the criticism.

    You assume a couple of things that have not been proven to be accurate.

    1. Those commenting aren’t competent to do so. There are several physicists and at least one professional statistician here who are clearly competent to comment, and whose comments aren’t simply “cheerleading”.

    2. You assume the authors of these denialist pieces are honest, and therefore are open to honest discourse. [edit]

    There was a great thread over in Tamino’s blog … [edit]

    [Response: No more on this please. -gavin]

    Comment by dhogaza — 11 Dec 2007 @ 12:38 AM

  67. cce (#54) wrote:

    “Cheerleading?” “Groupies?” “Admiration society?” “Backslapping?” “Piling on?” I think Real Climate is being confused with another site with “climate” in the title.

    I agree it was put in a rather derogatory fashion, and likewise it isn’t very descriptive of what goes on here. But the author may have had a good idea nevertheless — despite himself. Different objectives require different methods and different approaches. I believe being more systematic and more methodical — perhaps even going section by section — might serve ours. One slight modification might be in order, though: limited, non-leading questions from ordinary participants. Just a thought.

    Anyway, it certainly isn’t my decision.

    Comment by Timothy Chase — 11 Dec 2007 @ 1:52 AM

  68. Re 51
    I didn’t say they went wrong, I just think it would be best for the authors to be the first ones to address the criticism.

    Re 52
    Backbone and structure would be great. BTW groupie isn’t necessarily a bad thing, way back when I was playing Rugby, I loved the groupies.

    Re 53
    If they don’t respond, open it up.

    Re 55
    I didn’t assume anything. Yes, my eyes often roll when reading CA. They have groupies and cheerleaders as well. You resent the groupie characterization, but you freely to throw out denialist and liar. We are all entitled to our own opinion.

    I know the RC scientists can handle a one on one, I am sure the authors in question can handle it, and I think that a brief closed discusion would be very enlightening. Then open comment.

    Comment by lucky — 11 Dec 2007 @ 2:18 AM

  69. I have found a very informative site with hundreds of articles on every phase of climate change in — sciencedaily.com, a great adjunct to real climate and reports stretching back for many years. Your contributers ought to check this one out.

    Comment by Lawrence Coleman — 11 Dec 2007 @ 3:46 AM

  70. More Svalbard:

    #18, from Rasmus:

    The thermometer is located near the airport (with about two landings/departures a day), to the far left of the picture.

    …umm, far right

    #22:

    This has links to the information on the various climate monitoring equipment in the area … including the location of the thermometer.

    No, it’s way out of shot, to the right.

    The Svalbard Luft record is plotted here as monthly anomalies, alongside another older, but rather distant, record. Read the y-axis scale…

    Comment by GlenFergus — 11 Dec 2007 @ 5:18 AM

  71. As it is the correlation between the surface and the lower troposphere (TLT) records are ~90%, but even though the areas compared (5o x 5o) are quite large, I’ll bet that a more sophisticated analysis, for example, using some sort of weighted averaging for neighboring boxes would be better.

    One’s first thought on the surface ground correlation would be that it should be high, because of a near radiative equilibrium between the ground and the lower troposphere (they are exchanging energy rapidly by radiation), which leads to the further thought that this equilibrium would be perturbed by clouds, and that unless the effects of cloud cover is controlled for the whole thing is spinach.

    Comment by Eli Rabett — 11 Dec 2007 @ 9:20 AM

  72. GlenFergus (#57) wrote:

    No, it’s way out of shot, to the right.

    The Svalbard Luft record is plotted here as monthly anomalies, alongside another older, but rather distant, record. Read the y-axis scale…

    I guess you are right. I had hit one, and silly me, I thought that was the only one. But in an extreme climate you would undoubtedly have more than a few. And the airport would be a great place for recording temperatures, far removed from the rest of town.

    Thanks!

    Comment by Timothy Chase — 11 Dec 2007 @ 9:21 AM

  73. Having now perused the article and digested its contents and methodology, I had the following very general thoughts:
    1)The very complexity of the model seems to make it almost inevitable that spurious correlations will develop in the data. Science is replete with admonitions to avoid unnecessarily complicated models-from Occam’s “I will not multiply causes…” to von Neumann’s “Give me 4 parameters and I will fit an elephant; five and I will make him wiggle his trunk.” It is crucial to ensure that the added complexity actually adds information and doesn’t just become an exercise in “curve-fitting”. Climate models do a very good job of constraining their forcings and parameters independently of trends they are trying to model. I don’t see much “theory” guiding this model and the types of correlations it is seeking.
    2)An example of the type of spurious correlation that concerns me is this: We know that the industrialized countries are disproportionately in the north of the Northern Hemisphere. This is precisely where we expect to see the most economic activity and where climate models also predict the most warming (due to geographic features–e.g. greater land mass, polar amplification…). Could it be that the article merely rediscovers this well known fact?
    3)It is a mistake to lump all “economic activity” together. Deforestation and Reforestation are both economic activities, but presumably have opposite effects. Economic growth fueled by manufacturing would presumably have a different signature than economic growth fueled by e-commerce…
    4)To suggest that warming is half of current estimates is actually quite surprising. As pointed out above, this would put it below estimates for the Oceans–physically unreasonable. Also, we know we are starting to see signs of significant feedbacks–saturation of the Ocean’s ability to take up CO2, outgassing from melting permafrost, and these are occurring in areas that are far from economic development.
    5)As emphasized repeatedly, GHG forcing is pretty well constrained. If we’ve seen only half the predicted warming, where’s the rest of it. Is physics wrong? Is it being masked by some other factor? If so, will it kick in with a vengeance at some future date? Since I don’t think physics is wrong, I would point out that even if M&M2007 were correct, the implications might be much more alarming than reassuring.

    Finally a response to “Lucky”: Like it or not, Lucky, this is how science gets done. You throw your ideas to the wolves of the community. Some of them wind up as “wolf muscle”. Some wind up as wolf crap. The measure is found in the subsequent influence they have. M&M2007 is unlikely to be cited in very much future work, primarily because it is not that useful. There are flaws in the methodology and validation that call the results into question. More importantly, though, it makes the claim that data are contaminated but does little to indicate the nature or origin of those contaminations or what to do about them. Had their goal been to shed light on the issue they purport to treat, I suspect a less ambitious project might have had more influence. Instead, I think their goal is to say the problem doesn’t exist. However, as pointed out above, even ef their contention were right (and this is doubtful), its implications could be grim rather than reassuring.

    Comment by Ray Ladbury — 11 Dec 2007 @ 9:45 AM

  74. Re # 37 Hank: “Can we assume the journal’s peer reviewers approved the online preprint version? I am not sure why they differ.”

    I tried responding to this yesterday, but the post got lost in the ether (AGW denialists and skeptics take note: Even RC groupies sometimes don’t get their comments posted):

    I don’t know about the Journal of Geophysical Research, but here is an excerpt from Science magazine’s policy on rapid online publication (Science Express):

    “Each week, Science selects several papers for rapid online publication in advance of the scheduled print publication date. These papers are published essentially as supplied by the authors, with minimal copyediting by Science; a fully copyedited version appears later In print. …”

    If the JGR policy is similar, this could explain the discrepancy you noted.

    Comment by Chuck Booth — 11 Dec 2007 @ 10:01 AM

  75. Ray, you read the full article, can you answer the question I asked way back at #37?

    > It is not true that our discussion of the effect
    > of urbanization and land-use change rested only
    > on our 2004 paper. In the on-line preprint …

    Can we assume the journal’s peer reviewers approved the online preprint version?

    Comment by Hank Roberts — 11 Dec 2007 @ 11:31 AM

  76. In reply to #37, Yes, that is the approved version.

    #50: I suspect the readers would appreciate such an exchange as well. It is essentially what happens when a comment is submitted to a journal, which remains the most appropriate way to address technical challenges.

    For those who are convinced that the paper and its results are just wrong, wrong, wrong, you have to put your arguments into the form of a testable hypothesis. My paper takes the hypothesis that local temperature trends are independent of local economic activity and shows that it fails a test. Various speculations have been offered above to the effect that surface data are not contaminated but these test scores could nonetheless be obtained under restricted conditions. Maybe you’re right, but you’re going to need an encompassing statistical model to show it.

    Ray (#63) – we control for latitude, not to mention the tropospheric trend at each latitude. Unnecessary complexity of a model does not usually lead to spurious gains in significance, it more typically leads to collinearity and loss of significance. That’s not a problem here, and we do test for spurious correlations. On your 3rd point, we don’t lump all economic activity together, we include a variety of indicators to pick up both cross-sectional and rate-of-change effects. You seem to be objecting that the model is both overspecified and underspecified.

    Bruce (#44) – If the problem is omitted variable bias it should be easy to prove. Raising the mere possibility of it doesn’t make for much of a counterargument, since any regression model could suffer from it, and you can’t prove its absence. The IPCC suggested (Chapter 3 page 244) that the correlations are due to naturally-caused coincidence:

    McKitrick and Michaels (2004) and De Laat and Maurellis (2006) attempted to demonstrate that geographical patterns of warming trends over land are strongly correlated with geographical patterns of industrial and socioeconomic development, implying that urbanisation and related land surface changes have caused much of the observed warming. However, the locations of greatest socioeconomic development are also those that have been most warmed by atmospheric circulation changes (Sections 3.2.2.7 and 3.6.4), which exhibit large-scale coherence. Hence, the correlation of warming with industrial and socioeconomic development ceases to be statistically significant. In addition, observed warming has been, and transient greenhouse-induced warming is expected to be, greater over land than over the oceans (Chapter 10), owing to the smaller thermal capacity of the land.

    So you could add controls for AO, NAO, PDO etc to my statistical model and — if the IPCC is right — the socioeconomic effects will vanish. Or maybe Eli is right (#61) and it’s all due to cloud cover.

    But then again, maybe not. And considering what rides on this data set not being contaminated, I hope the practitioners in the RC audience will agree that the issue deserves some serious attention rather than just casual dismissal.

    [Response: The seriousness of our attention goes in inverse proportion to how the authors spin their results. In this forum, you are all about the investigation and understanding, yet in the National Post op-ed you instead claim that the surface temperature rise is "an exaggeration" (no ifs, no buts, no caveats about the existence of other possibilities) and that the IPCC "concedes ... that ... its main data set is contaminated". This is completely untrue. I would suggest that your hyping of this result is a big disincentive to other researchers taking your hypothesis seriously. - gavin]

    Comment by Ross McKitrick — 11 Dec 2007 @ 11:55 AM

  77. Hank, I’m afraid we won’t know until they actually publish. The “date received” and “date published” might provide a quick indication, as a long lag may indicate that the article went through significant revision. However, I’d be surprised if there were major substantive differences. The suggestion that the new references support the contention of the 2004 paper struck me as a little bit stretched.

    Comment by Ray Ladbury — 11 Dec 2007 @ 12:16 PM

  78. #65 in addition to Gavin’s comments. What about the far North? Are +10 C monthly anomalies an exaggeration or an error? And the over all not so small Polar temperature trends a mistake? The push to claim GT temperature trends as a UHi mistake completely falls apart with data from remote stations.
    Why not look at remote stations data alone? The case will be closed if it was so.

    Comment by wayne davidson — 11 Dec 2007 @ 12:51 PM

  79. I don’t (amateur reader here) see how this approach avoids just equating fuel use and economic activity.
    This chart for example — if you didn’t have the label, what would you think it described?
    http://web.whittier.edu/academic/math/jmiller/United%20States%20National%20Debt_files/usdebt1.gif

    Comment by Hank Roberts — 11 Dec 2007 @ 1:27 PM

  80. I myself wouldn’t be at all surprised if there is a correlation between local economic activity and local temperature trends. My question is, “How would you determine the direction of causation?” Does economic activity affect apparent trends in temperature, or do actual trends in temperature affect economic activity?

    We are dealing with climates that are barely habitable in the latitudes under consideration. Furthermore, if all we were concerned with was a static economic activity, this would not result in a higher apparent trend in temperature. To have a higher apparent trend in temperature as the result of some Urban Heat Island effect, one has to have economic growth. But since we are dealing with arctic regions, any small increase in temperature will make possible considerably more economic growth, e.g., growing broccoli and strawberries in Greenland.

    Consider the following…

    Theory: in subarctic regions, the rate of increase in economic activity will show a strong positive correlation with the rate of increase in temperatures as higher temperatures decrease costs and make available more resources, e.g. days in the growth season. Null hypothesis: no such correlation exists. Test: check for correlation. Result: a strong correlation exists.

    Question for Ross McKitrick: how does one distinguish between the theory that actual higher temperatures result in increased economic activity vs. increased economic activity resulting in spuriously high temperature readings?

    Comment by Timothy Chase — 11 Dec 2007 @ 1:52 PM

  81. I hadn’t read McKitricks Op-Ed before I made my comment #41 and see now that it contains some loaded, or non-objective,words and phrases, such as the word manipulations in the first paragraph, referring to the temperature graph at the end of the op-ed. Later on he refers to the “biases of their lead authors” of the IPCC. Hardly an objective or good faith criticism.

    I know that both sides refer to the word contamination when referring to unadjusted data, which I think is too strong and gives a wrong impression. Contaminated connotes impurity or infectation. When economists make statements like ‘the price of gas in 1995, adjusted for inflation to 2007 $’ no one infers that the 1995 data is infected. When correcting fathometer soundings,many years ago, for the purpose of making coastal charts, by taking nansen bottle casts to compensate for temperature and salinity adjustments for the speed of sound in water, we didn’t consider the raw data as infected. Astronomers correct for lens and atmospheric effects all the time.

    Almost all raw data require known corrections and adjustments. Adjustments for UHI are no exception.

    Comment by Lawrence Brown — 11 Dec 2007 @ 5:10 PM

  82. #65 Ross/Gavin

    Partisanship is a truism in the discipline of climate science. There seems no getting away from it even from the most authoritative voices. Gavin is correct that Ross’s National Post op ed clearly represents strong views which of course makes for interesting reading, whether it is right, wrong, exaggerated or incomplete. Let the reader beware. Gavin, you are guilty of the same partisanship editorializing. Your defense of Al Gore’s movie is case and point.

    There are facets in the M&M2007 paper that are worthy of further analysis and research regardless of partisan views. What has not been mentioned yet but warrants a passing acknowledgment, is the fact that Ross has made his data available for others to scrutinize and reproduce. If his analysis is wrong, what better way to prove it?

    Comment by Ian McLeod — 11 Dec 2007 @ 7:37 PM

  83. Since data quality is pretty important to science — especially experimental science, why not just scrap all these thermometers in cities and even suburbs for that matter and evenly disperse them across the Earth’s uninhabited land mass. Measurements could be sent by solar powered satellite uplink bursts so that they never need to be visited or their observations corrupted by any kind of vehicle traffic.

    I suppose the answer to “why not” is $$$. Still when your main data source has to be “adjusted” for UHI effect, me thinks any final result can be obtained depending on who is doing the adjusting…

    Perhaps urban/suburban ground based temperature measurement should just be thrown out until better data is available.

    Comment by David Goebel — 12 Dec 2007 @ 1:00 AM

  84. The ANALYSIS – which is what it is – is more likely wrong, and almost, but not quite, completely wrong, and the arguments made in this post ESTABLISH that. It’s not “his data,” either. It’s data that’s out in the public domain, and other, better studies have been done. This approach is not fraud, nor is it pseudoscience, but it’s a very low bar. Particularly pernicious is that this paper is not very different from the authors’ first, unsupported paper.

    If Gavin’s defense of most of the presentation in AIT is partisan, then given that it squares with the picture of a sampling of scientists around the world, it must be a big party he’s in, and its agenda must be actual science, vs. the politicized and economic interests model of reality presented in Ian McLeod’s post.

    Moreover, this represents Orwell’s “duckspeak,” unfortunately – the reflexive posting of “the data is available” where it doesn’t apply and the reflexive demand that people must replicate the analysis in order to criticize it, even though the paper itself shows signs of serious flaws.

    Comment by Marion Delgado — 12 Dec 2007 @ 6:09 AM

  85. Ian McLeod, It is not partisanship to insist on good science. M&M2007 really does little to elucidate the problem it purports to consider. It does not shed light on the nature of the contamination and the very complexity of the model makes it nearly inevitable that it would find some correlation–spurious or not. As to Gore, he is a layman who actually got most of the science right. That is to be commended. He is also alone among politicians on the global stage in his unrelenting efforts to get people to pay attention to this threat. I find the howls over Gore’s Oscar and Nobel from the political right amusing, as all a rightwing politican would have had to do to deprive him of it would be share the stage with him in calling attention to threat. And despite the fact that many on the right have acknowledged the threat, none had the courage or foresight to do so.

    Comment by Ray Ladbury — 12 Dec 2007 @ 8:15 AM

  86. Ross, #63, thanks for your response. I was wondering if you could respond to my other point–the fact that if your estimates of surface warming are correct and we are starting to see positive feedbacks already, this would be cause for serious concern rather than complacency.
    Also, your discussion of trying to include multiple indices for economic growth sort of illustrates my point. How do you know you are using the right indices? Without a real theoretical framework to guide you as to the types of contamination you are looking for, adding multiple indices may unnecessarily complicate the model while still not capturing important differences in regional growth patterns.
    Finally, there is the question of what you expect to be done with your research. Even if we were to take at face value your conclusions, they give little indication how to reliably estimate and correct for the biases you say you see. Moreover, I don’t think it is advisable to adopt the “Don’t Worry, Be Happy” approach you seem to have taken in you Post editorial, given the unmistakable indications of significant change we are seeing independent of any global temperature estimate. The real concern here is when do we reach the point where natural ghg feedbacks overtake our own contribution, since at that point mitigation becomes pointless. It is not alarmist to be alarmed by significant perturbations to a physical system with known but ill characterized positive feedbacks.

    Comment by Ray Ladbury — 12 Dec 2007 @ 9:20 AM

  87. Re David Goebel @ 71: “Perhaps urban/suburban ground based temperature measurement should just be thrown out until better data is available.”

    As if that would make the warming in the Arctic and the acceleration of sea ice and glacial melting in Greenland go away (discussed in raypierre’s most most recent report from the AGU meeting).

    Gavin has repeatedly addressed this very proposal in past topic comments, btw. The existing urban stations are kept precisely because they have a long, unbroken temperature record and any deviations due to UHI can be corrected for. Newly created stations would have exactly zero temperature record, which, I suppose, is pretty much what those who advocate this course desire. No record, no increase, at least not for some time off into the future.

    Comment by Jim Eager — 12 Dec 2007 @ 12:21 PM

  88. Gavin, you seem to be making a lot about Ross’s language in an OP ed. An Op ed is like a movie. Nobody expects it to live up to the standards of peer review.
    An Op ed is like the posts that Hansen makes on his personal site. [edit - quote's wrong please check your source]
    Do you want your science judged by those remarks? Obviously not. Anymore than Hansen wants his science judged by his personal remarks, and any more than Ross deserves to have his science judged by his Op-ed.

    [Response: Which planet are you living on? Hansen gets judged on his personal remarks all the time. McKitrick's brand of 'science by op-ed' undermines every supposedly scientific statement he makes. You don't get a pass on making stuff up just because it's not a journal article. - gavin]

    Comment by steven mosher — 12 Dec 2007 @ 1:37 PM

  89. Gavin, you are guilty of the same partisanship editorializing. Your defense of Al Gore’s movie is case and point.

    How is saying “The science in Al Gore’s movie is largely consistent with the consensus view of climate scientists” an example of “partisanship editorializing”?

    Statements like this make my head spin.

    Comment by dhogaza — 12 Dec 2007 @ 3:56 PM

  90. David Goebel (#71) wrote:

    Since data quality is pretty important to science — especially experimental science, why not just scrap all these thermometers in cities and even suburbs for that matter and evenly disperse them across the Earth’s uninhabited land mass. Measurements could be sent by solar powered satellite uplink bursts so that they never need to be visited or their observations corrupted by any kind of vehicle traffic.

    I suppose the answer to “why not” is $$$. Still when your main data source has to be “adjusted” for UHI effect, me thinks any final result can be obtained depending on who is doing the adjusting…

    Perhaps urban/suburban ground based temperature measurement should just be thrown out until better data is available.

    You write, “Since data quality is pretty important to science — especially experimental science, why not just scrap all these thermometers in cities and even suburbs for that matter and evenly disperse them across the Earth’s uninhabited land mass.”

    As Jim Eager pointed out in 73, without the urban and subrural, one wouldn’t have any real trends to speak of — beyond what is provided by means of satellite measurements. Thus even if one were to create an entirely new network, the trends produced by such a network would be lacking in statistical significance for some time. However, it is also worth pointing out that a great many corrections are made which reduce and according to more prominent analyses, efectively eliminate the Urban Heat Island effect.

    There are also reasons for thinking that it is not particularly significant, e.g., Park Cool Islands. But more significantly, we do have means for determining the trend in temperatures which are largely independent of ground-based networks. In the lower troposphere, we have UAH and RSS trends, both of which are based off of Microwave Sounder data. Likewise we have Pathfinder — but this measures skin-temperatures, making it closer to the surface than so-called ground-based measurements, and while I know that the Pathfinder trend for 1980-2002 was 0.43 C/decade, I do not know how this should be compared to ground-based measurements.

    Independently of the models, it would be natural to assume that the trend in the lower troposphere would be roughly the same as surface measurements. However, models would project a lower troposphere trend which is 1.3 times higher that that of the surface. Given ground-based measurements with a trend of 0.187 C/decade for January 1982 to December 2004 and model projections that the trend in lower troposphere temperatures should be 1.3 times the trend in surface measurements, one would expect a tend in the lower troposphere of 0.2431 C/decade. This compares quite favorably with the RSS trend of 0.239 C/decade, differing by 1.7%, which I would assume is well within the range of expected statistical error.

    However, it does not compare quite so well with UAH with its trend of 0.163 C/decade for the same period — assuming that models are correct. In fact, it suggests that ground-based measurements are inflated by roughly 49%, or else that models are wrong and that surface measurements are roughly 15% above lower troposphere measurements, or that somehow both the models and surface temperatures are wrong.

    It is worth noting that UAH has had a troubled history. For example, in 2005, it was discovered that John Christy’s algorithm used for processing the Microwave Sounder data was incorrectly adjusting for the difference between night and day. Nevertheless, in some way that still is unclear to me, Ross’ study employs UAH. But I do not know whether their analysis includes the correction for the difference between night and day.

    David Goebel (#71) wrote:

    I suppose the answer to “why not” is $$$. Still when your main data source has to be “adjusted” for UHI effect, me thinks any final result can be obtained depending on who is doing the adjusting…

    Multiple organizations act as a double-check, for example, there are the people at NASA GISS and those at Hadley MET, as well as a great deal of literature devoted to the analysis of data. If there are discrepencies, one looks for the source of these discrepancies.

    In contrast I have noticed that Patrick Michaels, Ross McKitrick, John Christy and Stephen McIntyre all belong to the Exxon-funded George C. Marshall Institute, so you might find it preferable to leave out motives and instead begin with the assumption that work is being done in good faith.

    Comment by Timothy Chase — 12 Dec 2007 @ 4:40 PM

  91. Ross,

    One point that concerns me is whether — when considering trends in economic development — you are considering them at the local or national levels.

    It would seem that any cause of a spurious trend in the readings of a given ground-based station would be the result of local economic development, not national. Particularly if the cause of the spurious trend were the Urban Heat Island effect. So when considering economic development, it would seem appropriate to compare economic development at the local level rather than the national level.

    Furthermore, it would seem that an increasing Urban Heat Island effect would be required to produce a spurious trend in temperatures rather than a one-time distortion. This too would be a function of local economic development, not economic development at the national level.

    Then I saw the socioeconomic variables which you claim are correlated with trends in apparent local temperature:

    g = GDP/ million square kilometers
    e = education
    p = percent population growth
    m = percent growth in real average income
    y = percent growth in real national gross domestic product
    c = percent growth in coal consumption

    pg 47

    Quantifying the influence of anthropogenic surface processes and inhomogeneities on gridded global climate data
    Ross R. McKitrick & Patrick J. Michaels
    http://www. uoguelph.ca/~rmckitri/research/jgr07/M&M.JGRDec07.pdf

    Furthermore, you state:

    Our data set has a low resolution for strictly local measures of economic density within countries. Since we detect significant effects on temperature trends even with low spatial resolution we conjecture that if future studies are able to examine the issues at the subnational level, even more significant and detailed results will emerge.

    pg. 38

    These would appear to be at the national level. As such I find it difficult to see how this would tend to explain trends in temperature by way of an Urban Heat Island effect — which is necessarily limited in nature.

    Likewise, given the fact that the former Soviet Union has an economy largely in disarray, whereas Europe, Canada and the United States are doing comparatively well over the period from 1979 to 1999 with the former Soviet Union experiencing weaker warming would produce a substantial amount of the correlation which you see. And as such, if one were able to explain why the trend in temperature over Siberia is weaker than the trend throughout much of the rest of the subarctic, this would be in essence an alternative explanation of the very same “correlations” uncovered by your analysis.

    Furthermore, given the wide variety of economic measures and a limited number of countries in the upper northern latitudes, it would seem fairly easy to select a combination of economic measures for which there would exist spurious correlations. Particularly if no causal explanation of the relationship between these economic measures and the trend in temperatures is given or required.

    So at this point I have to ask:

    Do you have any sort of causal explanation of the correlation relationship between the economic measures you’ve selected and the trends in temperature?

    Comment by Timothy Chase — 12 Dec 2007 @ 7:09 PM

  92. #70, equivalency is the lowest form of argumentation. McKitrick’s paper arrives at some pretty heady conclusions that if valid would more or less upend the state of the mainstream science, (something I gather would not upset him). Despite this, and despite the truism that the making of groundbreaking discoveries is more often an indication of mistake than virtuosity, he doesn’t see fit to investigate the former possibility through the normal channels. Quite the contrary, he promptly shouts his results from a mountaintop to the public at large (and the PR machine eager for these types of results), as the man says, without ifs, buts, or caveats about the existence of other possibilities.

    Meanwhile, Gavin- who has, at least informally, consulted Al Gore as to the state of the science if I have my facts right- defends AIC’s treatment of the then mainstream science. Just fyi, even disregarding the difference in context and character of these instances, and even allowing that each equivalently reveals an opinion about the veracity of the mainstream science, they are hardly equivalent. ‘Partisanship’ and ‘bias’ are not a binary tests of validity. To illustrate a biased journalist, which is to say any and all journalists, can write an article that reflects a genuine effort to cover the story and wherever that takes him or her, (plenty such instances exist), or a work of hackery bent on distortion, (and, certainly, everything in between). It goes without saying, any two such articles are not equivalent despite the existence of an opinion that shapes the story to a greater or lesser extent in both cases. Anyone attempting to short circuit a judgment about the relative validity of work produced by ‘partisan’ or ‘biased’ authors by inane citation of the corresponding existence of a point of view is doing everyone involved a disservice, not to mention playing their part in the stunting of human discourse.

    Speaking of which, I find it interesting that in the comments here McKitrick has not seen fit to explain why we might expect to see UHI effects in the satellite record, what accounts for, given his titanic findings, large high latitude temperature anomalies, or the disconnect that his manuscript implies in the terrestrial and oceanic temperature records, to name a few. Of course, were interested in those questions, they probably would’ve occurred to him before he published his paper, not least before that paper became the foundation of a message meant to influence public opinion.

    Comment by Majorajam — 12 Dec 2007 @ 7:36 PM

  93. Steven Mosher, A scientist must be especially circumspect in his statements to a lay audience about scientific matters. Looking at the Post editorial, it is hard to reach any other conclusion but that the results are being vastly oversold–and to a gullible audience. This is improper to say the least. James Hansen’s occasional allegedly intemperate remarks concern politics and policy, not science. I presume you would not deny him a right to his political opinions just because he is a scientist.

    Comment by Ray Ladbury — 12 Dec 2007 @ 9:00 PM

  94. Thank you to those who provided very thoughtful insights to my concerns about UHI, albeit laymen’s concerns. The level in the discourse here is far superior to what’s in the media or what our “leaders” say.

    Today in Bali, UN sec gen said, “”We are at a crossroad, one path leads to a comprehensive climate change agreement, the other to oblivion.” Oblivion?!? Honestly, does he not understand the meaning of the word? If the Sun was to super nova, OK, that’s oblivion. 10C over two centuries could/would lead to mass animal/plant extinctions which spells very very bad news for human civilization and a severe downsizing, but it’s not oblivion.

    Also today, the announcer (not a guest) on BBC World Service commented that all the smoke coming out of our car exhausts was leading to global warming. Sigh. “Smoke” has a specific meaning involving particulate matter and has nothing to do with GHG. In fact the irony is that the smoke component belched out is likely exerting a negative forcing effect (global dimming), and therefore impeding global warming.

    Which brings me to my final concern. Who on this site would bet money that we’ve discovered all the significant (> 10%) climate forcing phenomena? Global dimming was not understood until recently. How about the possibility that a very significant (> 50%) climate forcing phenomena is still unknown? Hmmm

    I applaud Hansen for having the balls to make a model based prediction (that can be sustained or falsified within his lifetime) that if CO2 levels are not reduced in the next ten years, we will be beyond the tipping point leading to run away warming.

    [Response: Science embodies the best and most convincing knowledge that man has up to date, I guess. We can only discuss issues that we know, and what we know tends to be confirmed through scientific methods and tests based on empirical evidence. -rasmus]

    Comment by David Goebel — 13 Dec 2007 @ 6:13 AM

  95. 79. David, the word oblivion is correct. For example, use the Google satellite map to look at Dungeness. It is just one example of the types of infrastructure at risk in the coming decades through Hansen-type scenarios. There are others which I have discussed with Secretaries of State here in the UK, and the urgency of the matter is appreciated at least at that level. Having spent about 15 years working on the oblivion-avoidance strategies, I do hope that today’s leaders have the courage, in whatever endeavour they are associated and wherever in the world they have influence, to transition to the highest-impact mitigation efforts that are required.

    Comment by mg — 13 Dec 2007 @ 6:56 AM

  96. Majorajam in #78:

    … Gavin- who has, at least informally, consulted Al Gore as to the state of the science if I have my facts right- defends AIC’s treatment of the then mainstream science.

    Did I miss something, or did you mean the converse?

    Comment by Dr Slop — 13 Dec 2007 @ 7:18 AM

  97. David Goebel asked: “Who on this site would bet money that we’ve discovered all the significant (> 10%) climate forcing phenomena?”

    My decision to wager would depend on the bet and the odds. I believe it is reasonable that the most significant forcings are at least identified, albeit not necessarily 100% determined. However, I believe you are asking the wrong question. A more interesting question is would I expect estimates of GHG forcing to change significantly (>2x, say) regardless of future discoveries. There, I think you would attract a lot of smart money. We do not have to understand everything about a system to make significant statements about it. We may know some things very well even as others remain uncertain. If you look at the models you will find that the conclusion of GHG driven warming for the current epoch is extremely robust.

    Comment by Ray Ladbury — 13 Dec 2007 @ 3:01 PM

  98. How about “all the significant (over a decade to a century) climate forcing phenomena”? Leaving out changes in position in the plane of the galaxy, asteroid impacts, basalt outbursts, and all the biological feedbacks, say.

    Comment by Hank Roberts — 13 Dec 2007 @ 3:51 PM

  99. In relation to the 2004 paper, Tim Lambert quotes a four-step analysis by a Robert Grumbine regarding the earlier attempt at correlating per capita income and observed temperature changes. Steps 1 and 2 are well worth looking at, but I would just like to focus on steps (3) and (4):

    3. Ignored that we do expect, and have reason to expect that the warming will be higher in higher latitudes
    4. Ignored that the wealthy countries are at higher latitudes

    More McKitrick
    Thu 29 Apr 2004
    http://timlambert.org/2004/04/mckitrick2/

    This paper would seem to be more of the same, although in some ways the paper seems rather opaque about it.

    We have more of the adjusting of apparent temperatures by income and standard of living increases, the “raster” figure 4 which shows how many tenths of a degree per decade they would remove from the apparent trends to arrive at their adjusted trends instead of before and after pictures. Apparently with the United States having had a cooler warming trend than Western Europe due to the North Atlantic Oscillation having been been locked in a positive phase, it is less in need of adjusting than Western Europe — which I suppose is why dividing the Gross Domestic Product by land area becomes so important.

    Not sure exactly how one justifies cooling the trend of the Tibetan Plateau by so much since we are speaking of people who are fairly isolated from the outside — but I will take his word for it. Besides, he may simply be regarding it as part of the Republic of China. The political boundaries matter quite a bit in these sorts of calculations, no doubt.

    Then there is the question of the UAH-data. UAH is generally avoided given its history of problems. One of the biggest problems was taken care of in the move from version 5.1 to 5.2 which corrected for night and day. But we wouldn’t know that UAH was even being used if it were for two things:

    1. In the paper under the references, we have the link to John Christy’s website:

    Global Hydrology and Climate Center (GHCC) (2005) Web site
    http:// wwwghcc.msfc.nasa.gov/temperature/. Global temperature anomalies. Accessed June
    2005. Data are now archived at http://www.nsstc.uah.edu/data/msu/t2lt/

    2. Ross admitted as much with one sentence buried in the middle of 34:

    Yes, we used the UAH data. I will eat my toque if that choice matters greatly, but, again, the data base is on-line and others can easily check.

    In 2004, it turned out that McKitrick, Michaels and all were making use of a version 5.0 of UAH which did not include the corrections for night and day (see: timlambert) even though the first version to include those corrections had been superceded by a later version. This time around there is virtually no mention of UAH at all — let alone what version it is or the specifics of how it is used — which leaves us quite in dark.

    Yes, we can examine the code and whatnot, but the balloon has already gone up, the flyers have gone out, and chances are the discussion will be pretty much over here and elsewhere by the time these sorts of details comes to light.

    Comment by Timothy Chase — 13 Dec 2007 @ 5:10 PM

  100. The total world primary energy production in 2003 was 4.4 × 10^20 Joules, which was sufficient to melt 1.3 × 10^3 Gigatons of ice, where 1 Gt = 10^9 metric tons. This figure is about twice the estimated amount of ice actually melted.

    Comment by AEBanner — 14 Dec 2007 @ 9:57 AM

  101. AEBanner, assuming your “ice actually melted” refers to arctic ice in 2007 (correct me if I am wrong). I have 2 questions about the significant relevance of your observation.

    - Why didn’t the (arctic) ice melt as dramatically in 2003, since world energy consumption has not increased by 20% since then?

    - What percentage of anthropogenic energy production goes towards melting (arctic) ice, as opposed to the percentage that is radiated off (at one wavelength or another)?

    I have often wondered why anthropogenic heat production (beyond basic metabolism) is not considered in climate models. I have always assumed that it is insufficient to account for the observed climate changes, but I would like to see someone do the math.

    Comment by Dan Wentworth — 14 Dec 2007 @ 4:21 PM

  102. #75 dhogaza:

    “How is saying “The science in Al Gore’s movie is largely consistent with the consensus view of climate scientists” an example of “partisanship editorializing”?”

    Aside from a fragmented sentence, if ones political persuasion is more in tune with Al Gore and his brand of politics than the alternatives, then by default you have consciously or unconsciously made a choice and taken a partisan view, even if that view is the right one. This was the point I attempted to make. To defend Al Gore after legitimate criticisms were made of his movie, albeit some criticisms were more legitimate than others, in particular his exaggeration of sea level rise to name only one example that seems to stick in everyone’s head, where the defense boiled down to parsing words by nuance and subtly, rather than stating the difference between an effective message and a true one, is partisan, or worse, spin doctoring. If you disagree, then we agree to disagree.

    #76 Timothy Chase:

    I suggest you be watchful of libeling individuals like Patrick Michaels, Ross McKitrick, John Christy and Stephen McIntyre with the unconscionable Exxon-funded George C. Marshall Institute link. You have made many fine suggestions, comments and several good insights. However, that comment is not one of them. You have now directly implicated RealClimate since it appears on their blog. Gavin and Rasmus know that Exxon does not fund these individuals and so do you. Retract and apologize.

    #78 Majorajam:

    As I said, climate science is a partisan endeavor, real or faux. Politicians make movies, the UN—a political organization—writes scientific policy summaries, scientists create blogs and write partisan books and then the media sensationalize the worst part of the doom and gloom message for all to witness. This is, as I understand it, to shock us from our siesta in order to re-educate us to the so-called new reality—so much for the wisdom of crowds.

    The euphemism “consensus science” is rife with worldview belief systems, which has more to do with faith than science. Science cannot progress in this manner. Not ever.

    I do not think Gavin consulted Al Gore about the state of climatic science. That was a goof on your part, no doubt, so I will let it go.

    As for bias, we all have them. This makes us human. To be completely open-minded means never governing ones actions on principle. We are by nature partisan and base our dialectics on our prejudice, right or wrong. Ross argues from his position and Gavin argues from his position. I hope that after arguing for some time a residue of progress can prevail, especially when each brings something to the table. The equivalency that you speak of comes from ones starting position on the ephemeral political spectrum. To suggest it does not exist, or that by arguing this point somehow short circuits discourse is intellectually dishonest.

    “Anyone attempting to short circuit a judgment about the relative validity of work produced by ‘partisan’ or ‘biased’ authors by inane citation of the corresponding existence of a point of view is doing everyone involved a disservice, not to mention playing their part in the stunting of human discourse.”

    Curiously, I partially agree with your statement, partially. So why do we do it? We do it because we are human. In the world of climate science, when facts are not on our side, it is easier to discredit the purveyor of partisan pomp rather than their multifaceted theoretical constructs. Have a look at the end of comment #76 as an example.

    Rather than arguing what is not in a paper, why did they not do this and why did they not do that, and so forth, which I think is the worst form of argumentation; why not disprove their conclusions by using their own source material, which is freely available and easily accessible on the internet. Then, you have validated your suspicions with experimental proof. Now with real evidence of false conclusions, you can stand on the mountaintops and shout, “This paper is deeply flawed!”, otherwise you are just whining.

    Comment by Ian McLeod — 14 Dec 2007 @ 7:58 PM

  103. Re 84

    Do you know how much of this heat was released in the Northern Hemisphere? Actually, the amount of energy released from electrical power generation is much larger if you include waste heat. Nuclear power plant have thermal efficiencies of 30-35% whereas conventional power plants using fossil fuels have thermal efficiencies of 35-40%. France gets about 80% of electrical power from nuclear power plants. I did rough calculation and found all energy released these plants results in regional climate forcing of about 0.25 watts per square meter.

    Comment by Harold Pierce Jr — 16 Dec 2007 @ 11:38 AM

  104. Ian,

    Climate science is no more a partisan endeavor than quantum mechanics. If you need it be for your own belief system, that is your problem. The UN does not write ‘scientific policy summaries’, whatever that is, although the climate scientists that make up the IPCC do summarize their efforts to comprehensively survey the existing peer reviewed literature, if that is what you mean. Such summaries are an exercise in pragmatism, not science, given that the survey is commissioned with the express purpose of informing policy.

    I fail to see how scientists creating blogs substantiates your religious belief that climate science is uniquely or especially partisan, so I should be little surprised it sits so neatly amongst your list of innuendo cum non sequitur. As for the media, in the field of climate science the media has given more credence to the views of the tiny fraction of climate scientists that deny the existence of anthropogenic global warming, (I say views because even in this tiny fraction there is next to no coherence in their scattershot criticism of the mainstream science), than they would in other fields. How often do we get to hear from scientists that don’t believe that HIV causes AIDS, or that the link between that virus and the disease is ‘controversial’?

    “Consensus science” is not a term I’m familiar with. If you mean to say “consensus amongst scientists” or “scientific consensus”, then I suggest you pick up a history book because that is indeed how science progresses (and that almost never means uniform consensus). It would be somewhat cumbersome to make all scientific discovery start from first principles, to make the understatement of the millennium. This is what is meant by ‘standing on the shoulders of giants’, in case you’ve come across that phrase before.

    I was referring to Gavin’s comment somewhere in the nether region of this blog where he indicated he had spoken to Al Gore- in particular, corrected him if I remember right- about the way he was conveying the science, (he also indicated that the former VP had taken his comments aboard). I suppose you can quibble with the term ‘informal consultation’ if you’re into semantics. In any case, no doubt you’ll want to take up that offhand assertion with me now.

    This next point of yours is curious. I think what I had expressly written is that citing the existence of an opinion in a given researcher about the veracity of the mainstream science, (I don’t know why you’ve chosen to introduce ‘position on the ephemeral political spectrum’ or perhaps I do, but in any case it is utterly irrelevant), i.e. ‘bias’, goes without saying. That because bias- for want of a word that isn’t totally misunderstood and abused, most notably by people of a certain position on the ephemeral political spectrum- is ubiquitous and to be expected, it is also immaterial. And that citing the immaterial, in this case an opinion about the science espoused in Al Gore’s movie, in order to supplant/short circuit the material- namely meaningful examination of the influence of bias on a second researcher’s scientific work- is fallacious, counterproductive and, yes, intellectually dishonest. As such, I would say that while what you’ve written resembles a rebuttal in tone, it isn’t in context.

    As to what has been argued on this blog thread about M&M 2007, I see nothing wrong with it. Is it your position that making the observation that M&M’s conclusions are nonsensical and hence a red flag- e.g. an urban heat island in the satellite record, biggest differences between measured and adjusted record at places like Svalbard, greater warming of land than oceans, etc.- is the worst form of argumentation? That figures. Were sanity checks a part of the denialist routine, there would be no denialist routine. And were M&M’s primary interest in the scientific value of their work, rather than implications for policy advocacy of their conclusions, you think it might occur to them to solicit scientific feedback before grabbing the first public-at-large microphone they could find, (just as it might have occurred to them to consider the scientific criticisms of their source literature, e.g. Benestad (2004), before rushing to publish). By their behavior, M&M have made it clear that science is not chief amongst their ends, if it is one at all, and hence this blog thread is precisely the appropriate response.

    Comment by Majorajam — 17 Dec 2007 @ 1:56 PM

  105. Ian McLeod, It is clear from your post that you have not been involved much with science. For one thing, you don’t seem to understand scientific consensus. It isn’t some sort of vote or popularity contest. It is an agreement about what the evidence will support, and it is almost always conservative–as in the case of projections of sea-level rise by the IPCC. Scientists do have opinions and biases. Scientific consensus forces them to put those aside as much as possible and look at what the evidence says.

    Comment by Ray Ladbury — 17 Dec 2007 @ 2:47 PM

  106. John Cross, you should have highlighted a bit more of your quote. “the estimated 1980-2002 global average
    temperature trend over land ” Sure there’s an estimated trend. What you’re more asking is if there’s such a thing as “a” global average temperature. Depends on how you think about it. There’s the anomaly trend of what the GHCN and ERSST are sampling, which I suppose I would say is acting as a proxy for energy levels in the climate system. (although in this case, the topic is just land of course). It seems intuitive that areas around a factory would do something to the surroundings differently than a forest would. The consensus is that human activity is the primary cause of the anomaly trending up, or man-made variability as the cause. That it is so frequently stated in terms of CO2 is that CO2′s one of the few things we can directly control. But there’s actually 2 things here. Land use changes. Burning fossil fuels. What does burning fossil fuels do? Creates air and ground particulates and creates greenhouse gases.

    So if the goal is to reduce the heating that our activities are creating, we have to understand all these things. Then we can consider:
    What can we do with land to remove as many heating influences as we can.
    What can we do related to burning fossil fuels to remove as many heating influences as we can.

    This leads to such questions as if cut fuel usage in half, what is the net effect, since we would be removing a whole bunch of things (versus sequestering carbon dioxide and/or methane etc). See figure SPM.2

    See http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf

    The range for human caused net forcing is given there as an additional .6 to 2.4 W-M2 although there are a couple things they don’t consider.

    We could say CO2 equivalent after taking various feedbacks and forcings. Something like that.

    Comment by Ralph Smythe — 17 Dec 2007 @ 6:35 PM

  107. I should say; that the anomaly trend is rising, and that it’s due to people is not really under dispute. How could buring fossil fuels and building cities/farms/roads not create more heat? That the system is mostly handling it, or not, that’s the question.

    The discussion (debate, whatever) is not on the science, really. It’s about policy implementation and risk management. Degrees of issues.

    The only questions now are:

    What can we do with land to remove as many heating influences as we can.

    What can we do related to burning fossil fuels to remove as many heating influences as we can.

    How can we best do the above in terms of time, money, and possible lost opportunities.

    Comment by Ralph Smythe — 17 Dec 2007 @ 7:03 PM

  108. Majorajam #107

    “Climate science is no more a partisan endeavor than quantum mechanics.” You say this with a straight face and without apology. You are right, this has do with how one sees the world or ones worldview, and yours and mine are different. We see the world differently. Enough said about that.

    You said, “The UN does not write ’scientific policy summaries’”. Yes is does. Scientists write the main body of the report, but a small group of carefully chosen scientists and bureaucrats writes the Summary for Policymakers. This is the summary prepared for the media and world governments. The media and world governments do not wade through a 900 plus page report and another 300 pages of appendices of physics and chemistry. It is difficult going even for fellow scientists. The media and governmental policy makers expect a condensed version so they can quickly report what information is important and get on with making governmental policy. I could say a great deal more about bias here, but it is off topic.

    You say, “… [I]n the field of climate science the media has given more credence to the views of the tiny fraction of climate scientists that deny the existence of anthropogenic global warming, (I say views because even in this tiny fraction there is next to no coherence in their scattershot criticism of the mainstream science), than they would in other fields.”

    Okay, I agree that there is no coherence or alleged conspiracy, and I agree that the criticism is scattershot, but, what you have given me here is a description how science progresses, and not a critique of the media. By the way, I hold up “falsifiability” as science’s gold standard al la Karl Popper (Ray Ladbury #105). I would not be surprised if your picture of science is a collective enterprise beholden to paradigms, al la Thomas Kuhn. Perhaps this is our problem. It is a technical point in epistemology—the theory of knowledge.

    This leads to the theory of scientific consensus we hear all the time, the science is settled, there is a wide consensus amongst scientists, and so forth. Science progresses in incremental steps as small improvements are made to refine uncertainty and by large leaps when scientists falsify conventional wisdom. Here is a very recent example of the latter. Researchers from the Max Planck institute for Nuclear Physics published a paper in the journal Nature for the January 2006 edition entitled Methane Emissions from Terrestrial Plants under Aerobic Conditions. This ostensibly impossible result, which seemingly defies the second law of thermodynamics—something difficult justifying to the review board while applying for grant money—is I think, a good example of conventional wisdom being falsified. There is a biochemical mechanism going on here humans’ have yet to explain. This new discovery not only turns conventional wisdom on its head, requiring all biochemical textbooks to be rewritten, but has a profound effect on our understanding and modeling of past, current, and future global warming and cooling.

    We are off topic so let us finish with an on topic argument. The M&M.JGR07 paper takes the 1972-2002 warming trend an applies the grid cell technique and regresses a multiplicity of climatic and economic variables. M&M.JGR07 shows a strong correlation with the warming trend when statistically examining economic and climatic variables. The authors also show that the results are not some fluke by spurious correlation. Here is what they did (see link for remarks and further info) http://www.uoguelph.ca/~rmckitri/research/jgr07/M&M.JGR07-background.pdf

    1. Tests for the influence of outliers and nonlinearity did not show any effects.
    2. Multicollinearity diagnostics show that we do have sufficient explanatory power in the data to identify the effects.
    3. A Hausman consistency test shows that we are not picking up biases effects due to reverse causality.
    4. In 500 repetitions, we found that if we hold back 30% of the data set and estimate the model on the remaining 70%, the model then successfully predicts what the withheld 30% looks like.
    5. The correlations with surface processes and inhomogeneities that are significant in the surface data disappear when compared to data from the lower troposphere.
    6. Differences in effects arise when the sample is divided into economically growing and stagnating regions. The growing regions exhibit much stronger contamination patterns.

    There is no such thing as perfect paper, particularly in the field of climate science. This is a fascinating paper despite its defects. It should be taken seriously and I think will be taken seriously by many scientists and economists. The link of UHI and economics is gathering momentum.

    It does not account for all the warming. The authors are careful to point this out, it accounts for some of it. Thus, we should account for it.

    [Response: Hmm... sorry to disappoint but I predict that this paper will neither gather momentum nor be taken seriously. It is much more likely that this result is statistical fluke than it is that the oceans are not warming, that the glaciers are not melting and that ecosystems are not moving upward and poleward. I'll even suggest a test - take the IPCC AR4 model runs and use their simulations of the surface and atmospheric temperatures. Since there is no possibility of extraneous contamination within the model system, following M&M's logic, one would expect that all of the economic correlations would be non-significant - implying indeed, that the alledgedly significant changes seen in this paper are indeed significant. However, should there be model runs which show similar levels of correlation with economic variables, that would indicate that the correlations are actually spurious and linked to some other third variable (such as the correlation of economic development and the mid-latitudes). Care to make a wager which one it will be? - gavin]

    Comment by Ian McLeod — 17 Dec 2007 @ 11:15 PM

  109. Gavin, Response #108

    Thank you for your response. You asked for a wager, so here it is. The statistical analysis presented in M&M.JGR07 is robust. Nevertheless, I grant that you may be correct in your supposition. It is possible that some other variable(s) will account for warming not indicated in their analysis. Conversely, the same thing could be said for climate sensitivity: 0.75 +/- 0.25 C/(W/m2) that represents approximately 3°C increase for doubling of CO2 based on models. I will wager that the climate sensitivity is smaller, by how much I do not know. I think the models have great value, but are incomplete describing reality.

    I will also wager that the UHI affect has not been fully accounted for by mainstream climatic scientists. If I’m wrong, then the current majority view wins the day and everyone can sigh a collective, phew. If I’m right, well then, “Lucy, you got some splaining to do.”

    A great deal of progress has shaped the landscape of climatology this past year and I for one suspect 2008 will be another seminal year in the field. I look forward to RealClimate’s continued success including your many excellent contributors.

    Lastly, will we be any closer to answering my wager by the end of next year, probably not?

    Comment by Ian McLeod — 18 Dec 2007 @ 1:34 AM

  110. Ian, Gavin offered a specific wager, that’s testable:
    – model runs show all of the economic correlations would be non-significant, or
    – model runs show similar levels of correlation with economic variables.

    That’s a test that a third party can make using the available data.

    And it makes sense, it would answer a valid question. Why not?

    Comment by Hank Roberts — 18 Dec 2007 @ 4:36 AM

  111. Re #109 [Ian McLeod] “Lastly, will we be any closer to answering my wager by the end of next year, probably not?”

    So Ian, when would you expect answers to your “wagers”, and what form could they possibly take?

    Comment by Nick Gotts — 18 Dec 2007 @ 5:12 AM

  112. I will also wager that the UHI affect has not been fully accounted for by mainstream climatic scientists.

    What is your hypothesis for how the UHI effect pollutes the satellite temperature record?

    What is your hypothesis for how the UHI effect accounts for polar amplification?

    For cooling of the stratosphere?

    For melting glaciers?

    For the well-documented northward move of ranges for a wide variety of plants and animals?

    For earlier spring and later fall migrations for a number of species of birds?

    Comment by dhogaza — 18 Dec 2007 @ 8:14 AM

  113. Blaming the UHI vs. GHG for global warming is an odd thing for skeptics of anthropogenic global warming to pick up on. How exactly is that a win? “Well, we’re painted into the upper left hand corner rather than the upper right hand corner”?

    Comment by Jeffrey Davis — 18 Dec 2007 @ 8:55 AM

  114. Ian McLeod, so we can add the Second Law of Thermo to the list of things you don’t understand. Not every discovery–or even every surprising discovery–represents a paradigm shift. WRT scientific consensus, consider 2 incidents involving the premiere physicists of their day:
    1)Newton’s advocacy of the corpuscular theory of light made it nearly impossible for scientists in Britain to pursue the wave theory of Huygens. This set optics in Britain decades behind the Continent.
    2)In contrast, Einstein’s opposition to indeterminacy in quantum mechanics presented no such obstacles. Scientists found–collectively–that the evidence could not support Einstein’s viewpoint, and physics continued to progress AROUND Einstein.
    The difference is that in Newton’s day, an international scientific community really did not exist, while in Einstein’s, science was inherently a collective enterprise that transcended not only international boundaries, but individual prestiege.
    I am neither a disciple of Kuhn nor Popper. Both have strong points and weak points, but my views on science have been informed by my experience as a scientist and my study of the history of science.
    WRT M&M2007, I suspect the correlations are spurious primarily because
    1)their model is very complicated, and complicated models are prone to spurious correlations
    2)there is no over-arching physics that guides the model.
    3)we have plenty of evidence that warming is occurring in regions where human activity is minimal.

    I look forward to the results of Gavin’s investigation.

    Comment by Ray Ladbury — 18 Dec 2007 @ 10:08 AM

  115. “– model runs show all of the economic correlations would be non-significant, or
    – model runs show similar levels of correlation with economic variables.”

    Yes, I bet you could do both of those.

    [Response: Indeed. And wouldn't that simply show that the reported correlations were spurious? - gavin]

    Comment by Ralph Smythe — 18 Dec 2007 @ 10:55 AM

  116. re 110. glad to see you get on board with auditing the results of papers.

    I welcome third party tests of results.

    I volunteer to be a third party.

    Send me the most current source code. The most current data sets. a windows executable.
    The IV&V report on the model. The unit test report on the model.

    When the model doesnt match the “statistical fluke” in of M&M study. They we will have to choose.
    Believe model A. Believe Model B.

    [Response: Surely it would be better to do it with model results already generated to avoid any implication that they were somehow fixed, and of course, you would want to do it with a range of models since you wouldn't want to rely on one particular one, and you'd want them to have used all the appropriate forcings for the exact same period, and lo! it is available: www-pcmdi.llnl.gov/ipcc/about_ipcc.php . Let us know how you get on. - gavin]

    Comment by Steven mosher — 18 Dec 2007 @ 12:29 PM

  117. Steven Mosher #116–There is good reason to choose the simpler model. Overly complex models tend to lead to spurious results, and a good indicator of this is when they produce a spectacular result without yielding any real insight as to why–the paper here being a case in point.

    Comment by Ray Ladbury — 18 Dec 2007 @ 3:05 PM

  118. Ian,

    If your quibble is with the summary for policy makers, I think that’s fair game (even as I wouldn’t at all agree with your characterization of it). But it sounds to me like you’re claiming somehow that bias accounts for the consensus view as represented in the IPCC chapters and the underlying literature. Frankly, I think you’ll find there is very little evidence to support that, and if there is any neither have you presented it nor I seen it. You have to ask yourself to imagine the perfect scientist, as objective as a human being can be, which is to say full of integrity and in strict observance of the policies and procedures that imbue his craft with meaning. Isn’t it the case that such an individual will have an opinion about, I don’t know, say, how fair a representation of the science was Al Gore’s movie? Isn’t it the case that this individual will have all sorts of opinions, just like you or I? Hell, isn’t it possible that he or she votes?!

    You seem to imply that quantum mechanics is a world apart from climate research, and yet Einstein’s rejection of it could probably fairly be characterized as an artifact of his own bias: namely that he was invested in the problems he was trying to solve, and this somewhat upended the stature of what he was able to accomplish and where he thought the field was going. “God does not play dice”. I think it’s pretty clear you don’t have to dismiss the import of all manner of biases that abound to believe that scientific consensus- as can rightly be claimed regarding the broad outlines of the theory of AGW- is meaningful and hence actionable. Relatedly, the fact that a new discovery can overturn previously ‘known’ scientific explanation is a dead end. If you accept that as being a deal breaker, then no amount of scientific evidence, no matter how vast and compelling, could ever justify any conclusion. Does that strike you as being rational? I mean, for all we know, Einstein could end up being right about quantum mechanics given some distant understanding that more resembles his erstwhile problems with it than current answers- does that mean we shouldn’t pay any attention to any of the information generated by that field of science? That it shouldn’t effect technological progress/our capabilities and understanding? Do you follow me?

    People that reject the current science should start confronting the fact that their problem is not the media, or the summary for policy makers, or Al Gore’s movie, and start appreciating the genuinely mammoth scientific case they should have to start building to bring the world around to their position. Either that or figure out a way to argue, for one, that individuals shouldn’t make decisions on physician determined diagnoses and treatments because they are uncertain, (and routinely far more so than our understanding of AGW). If they can’t do so, they should not feel aggrieved when society acts on what is essentially the same type of feedback. Partisanship has nothing to do with it.

    Bottom line, society can, should and routinely does make decisions based upon effectively agreed conclusions of a particular scientific or social scientific community, (and often times less than such). Members of that community that disagree should focus their efforts on persuading more scientists to the merits of their claims, not on the public at large (where in this case, they have been to date). History has UNAMBIGUOUSLY shown that the former works where there is a case to be made, while very recent history shows that the latter certainly will not.

    Comment by Majorajam — 18 Dec 2007 @ 3:17 PM

  119. Re #101 and #103

    Thank you for your comments. I did the calculations a couple of years ago and I’m afraid I’ve lost the reference to the practical figure for the amount of ice actually melted. However, the year for which this applied was around 2003. This was the latest for which energy data was available at the time from the Energy Information Administration of the US Department of Energy (1).

    The problem of the proportion of the anthropogenic energy which is lost to space before it can reach the polar regions and melt ice is one for which I should really appreciate some professional help. For now, though, I have assumed no losses in order to make some sort of estimate of the maximum value of the effect.

    Mr Pierce, thank you for your point about the thermal efficiencies of the power plants. This, of course, significantly enhances the ice melt.

    Again from the EIA data (2), and for 2000, the proportion of the world primary energy actually produced in the Northern hemisphere is 0.867, and so leaving 0.133 for the South.

    Greenland Ice Cap

    A study by W. Krabill et al (3) of the changes in the Greenland ice cap between two series of measurements, one from 1993 to 1994, and the other from 1998 to 1999, gave a conservative estimate of 51 Km^3 for the average annual amount of ice lost for that period, which is equivalent to a mass of 46.8 Gigatons per year. (Unfortunately, it is not clear how much was actually melted and how much was lost by ice going into the sea.)

    From the EIA (1), for 1997, the total world primary energy production was 4.017 × 10^20 Joules. Again assuming no losses as before, the Northern hemisphere energy was 3.48 × 10^20 Joules.
    Suppose that this is shared out amongst the ice covered areas in the North.
    Greenland ice cap 1.8 × 10^6 Km^2.
    Small glaciers 0.58 × 10^6 Km^2.
    Arctic sea ice 11.0 × 10^6 Km^2.

    Total ice area 13.38 × 10^6 Km^2.

    Then the Greenland ice cap share of Northern energy = ((1.8 ×3.48)/13.38) × 10^20 Joules
    = 4.68 × 10^19 Joules
    This amount of energy can melt a mass of ice of 140 Gt, for 1997 figures, which is about 3× the practical estimate provided by Krabill et al.

    References
    (1) http://www.eia.doe.gov/emeu/aer/txt/ptb1101.html
    (2) http://www.eia.doe.gov/emeu/aer/txt/ptb1102.html
    (3) Krabill, W., et al, Science 289(5478): 428-430

    Comment by AEBanner — 18 Dec 2007 @ 4:45 PM

  120. Hank Roberts #110

    Future modeling may well show that M&M.JGR07 results are spurious but it is unlikely. Dutch meteorologists, Jos de Laat and Ahilleas Maurellis, in a pair of papers published in 2004 and 2006 have shown quite independently from McKitrick and Michaels (M&M) that using different data and a different methodology came to the same conclusions. In their papers, de Laat and Maurellis showed that there is indeed a correlation between urbanization and warming and that their results were statistically significant. The IPCC has dismissed this by claiming it is Artic Oscillation. The problem of two independent and mutually exclusive research teams coming to the same conclusion is not going to go away. The IPCC cannot ignore their work come next assessment report.

    Nick Gotts #111

    You asked two good questions, which I purposely left vague because truthfully I do not know. I think that CO2 forcing is less than the models predict. However, I acknowledge that in the future a revolutionary paper may show the reverse. I’d say the results will be known with high certainty by 2015, perhaps sooner. The form they would take is less CO2 forcing and more UHI than is currently recognized by the IPCC. Please note that I say this only to answer your question directly.

    dhogaza #112

    UHI has nothing to do with polar amplification, cooling in the stratosphere, or melting of glaciers, and so forth. The IPCC have stated that it is the Artic Oscillation coupled with CO2 forcing, which is to blame for the warming in the Northern Hemisphere. That land mass has greater sensitivity to warming than the ocean because it has less thermal capacity.

    Jeffrey Davies #113

    You are right what I said does not make any sense. I misspoke.

    Ray Ladbury #114

    Newton was his present day IPCC, the voice of authoritative reason, just ask Leibniz. In Newton’s day, the late 1600s and early 1700s, scientists did not have a proper description of reality, as we understand it today. They knew nothing of quanta or the particle-wave duality inherent in the crazy world of quantum mechanics. It was Einstein in 1905 that defined the quanta and then later Niels Bohr et al in Copenhagen that defined the rudimentary constructs of quantum mechanics in the 1920s. Einstein’s stubbornness towards the so-called incomplete description of reality should not distract from his groundbreaking leap describing gravity in his special and general theory. Einstein was wrong, Niels Bohr was right, or until someone comes along and disproves both.

    I agree that science proceeds in fits and starts, but often boils down to intuition and some nebulous hunch by clever scientists, the learning and doing part of science. Science does not proceed by building a consensus, although it is an outcome once a theory is firmly established like F=ma or E=mc2, or can be shown to be true anywhere in the universe.

    Regarding the M&M.JGR07 paper and your comments:
    1. The model is very complicated but the high r2 and low t-stats suggest robustness.
    2. You said that if a climatic model does not contain physics, this is reason to be suspicious of the results. It is not sufficient or necessary in my opinion.
    3. As I mentioned above and as Rasmus rightly pointed out as well, the Artic and Antarctic bias is problematic. M&M should explain this.

    Majorajam #118

    We are going around in circles but I liked what you said about quantum mechanics and Einstein.

    Comment by Ian McLeod — 18 Dec 2007 @ 5:40 PM

  121. Gavin:

    “[Response: Surely it would be better to do it with model results already generated to avoid any implication that they were somehow fixed, "

    Well, I would have to validate that the model results were in fact the results of model. That would
    mean running the model. That is validition 101.

    "and of course, you would want to do it with a range of models since you wouldn’t want to rely on one particular one, "

    Actually, I might want to select one randomly. I might also want to consider truely independent models
    rather than several models from the same groups of scientists. Lot's of issues here.

    "and you’d want them to have used all the appropriate forcings for the exact same period, and lo! it is available: www-pcmdi.llnl.gov/ipcc/about_ipcc.php . Let us know how you get on. - gavin]”

    first one has to independently verify that the models in question actually put out the data you pointed to. This requires the data sets, the test data, and operating code. The
    nice thing about M&M is that I can actually go get the data, get the code, run it and see that there results match what they published. That’s 101. Now, sometimes people
    screw up there input datasets ( like from ushcn) and sometimes they screw up latitudea and longitudes.
    So step one is always, can you at least duplicate the published report. That’s a bare minimum check.
    What data did they use? did the program actually read that data in, what did it output. does the published
    output match the actual output. IV&V stuff. basic 101.

    [Response: Well if the idea is to waste your time, go ahead and re-derive the Navier Stokes equations, quantum mechanics and run a check over the HITRAN database. If you seriously believe that the data in the IPCC archive has somehow been hand written in order to match the observations and didn't actually come from the models they say it does, you are deluded. But the GISS GCM is online and so go ahead and run it. Those simulations took us about a year, so you should be done in a decade or so if you are working on your laptop. With respect to M&M07, they used STATA which is not open source, nor freely available. Thus I cannot check what exactly their 'regress' or 'test' routines do, or whether they do it correctly. I have no reason to doubt that they are correct, but that is a long way from knowing for certain - however, there are more interesting things to check - surely you're not dodging the question? (PS. you forgot to mention mixing up degrees and radians - probably a little more apropos here). - gavin]

    Comment by Steven mosher — 18 Dec 2007 @ 6:48 PM

  122. Ian Mcleod #120, Come on, did you really have a straight face as you were writing this? “Newton was his present day IPCC…” Please. Just where does the IPCC get such tremendous power that none would challenge it? And the thing is that it’s not just the IPCC. The American Physicsl Society, American Geophysical Union, National Academies… They’ve all endorsed the basic conclusions of the IPCC. In fact, there is not a single professional society of scientists or engineers that dissents from the basic fact of anthropogenic causation of climate change. Do you think that none of the scientists in fields outside of climate change has ever looked at the science to see whether it holds together? If so, then you don’t know many scientists.
    A model without physics behind it is reduced to the likes of an epidemiological study in medicine telling you that oat bran will make you live forever–oops, no it won’t.

    Comment by Ray Ladbury — 18 Dec 2007 @ 6:56 PM

  123. Steven Mosher #121, Your missive puts me in mind of a story I heard about a young man who found himself traveling by train across Wyoming with the Calvin Coolidge’s Secretary of the Interior. Desperate to find some way to start a discussion and impress the Secretary, the young man scanned the horizon for something, anything, to open the conversation. However, as they were traversing Wyoming, there was little remarkable to see. Finally, he spied a flock of sheep and thought he’d at least impress the secretary with his powers of observation. “Looks like those sheep have just been sheared,” he said in the direction of the Secretary.
    The Secretary looked out and pondered a moment, “Yeah…yeah,” he said finally. “This side, anyway…”
    Perhaps you would make more progress if you moved beyond wheel invention 101.

    Comment by Ray Ladbury — 18 Dec 2007 @ 9:12 PM

  124. http://scholar.google.com/scholar?q=Jos+de+Laat++Ahilleas+Maurellis

    Cite please?

    Comment by Hank Roberts — 18 Dec 2007 @ 10:43 PM

  125. Ray Ladbury #122

    You say, “Come on, did you really have a straight face as you were writing this?”
    I didn’t, my tongue was planted firmly in my cheek. Nice rhetoric Ray.

    Hank Roberts #124

    De Laat, A.T.J., and A.N. Maurellis (2004), Industrial CO2 emissions as a proxy for anthropogenic influence on lower tropospheric temperature trends, Geophys. Res. Lett.Vol. 31, L05204, doi:10.1029/2003GL019024.
    http://www.knmi.nl/~laatdej/2003GL019024.pdf

    De Laat, A.T.J., and A.N. Maurellis (2006), Evidence for influence of anthropogenic surface processes on lower tropospheric and surface temperature trends, International Journal of Climatology 26:897—913.
    http://www.knmi.nl/~laatdej/2006joc1292.pdf

    Complete McKitrick and Michaels paper. See references for more information.
    http://www.uoguelph.ca/~rmckitri/research/jgr07/M&M.JGRDec07.pdf

    Comment by Ian McLeod — 18 Dec 2007 @ 11:31 PM

  126. Ian, the point of my post–which you seem to have missed is that it is that the climate consensus is not a matter of politics distorting scientific opinion, but rather of science calling on politicians to act. Even if your contention of political bias by the IPCC were correct (and if there is a bias, it has been toward toning down the science), that would not explain why every scientific professional society that has independently investigated the claims has endorsed the IPCC conclusions. Now the reality of climate change runs counter to the interests of most of these societies. It means less funding will be spent on basic research in their fields and that more of their efforts will have to go into mitigation. Yet, because the scientific evidence is overwhelming and the threat is real, they have endorsed to reality of the threat. The only two sides in this debate are science and antiscience–and if you want to tell which is which, the science side is where all the scientists line up.

    Comment by Ray Ladbury — 19 Dec 2007 @ 8:28 AM

  127. Ian McLeod posts:

    [[Regarding the M&M.JGR07 paper and your comments:
    1. The model is very complicated but the high r2 and low t-stats suggest robustness.
    ]]

    You mean “high t-stats?” Studen’ts t statistics of low magnitude indicate that a variable is not significant.

    The spectacular p value of the M&M paper is itself suspicious. It looks like a spurious correlation. Did they test that their time series were stationary?

    [[2. You said that if a climatic model does not contain physics, this is reason to be suspicious of the results. It is not sufficient or necessary in my opinion.]]

    Your opinion is wrong. Otherwise it would valid to just feed the right answers into a model and then print them out.

    Comment by Barton Paul Levenson — 19 Dec 2007 @ 9:47 AM

  128. Ian,

    I think your comment to Ray said it best:

    “Science does not proceed by building a consensus, although it is an outcome once a theory is firmly established like F=ma or E=mc2, or can be shown to be true anywhere in the universe. ”

    Precisely. Consensus is not science but an outcome of science that sign posts scientific progress throughout history, (as well understood by Oreskes and scientific historians in general). And once certain scientific findings have been accepted, scientists largely do not revisit them, they pursue questions that the ‘settled science’ point up. Occasionally, those questions are not answerable, or their answers place the settled science in crisis. You are familiar with this narrative I presume.

    Bottom line, while science is not an exercise in consensus building, the existence of a broad consensus after the science is done is highly meaningful to policy makers. It means the information- in this case, the link between carbon emissions and future economic and environmental damages- is massively more reliable than it would be in the face of significant scientific controversy, and therefore it is far more prudent to act upon.

    Note that policy action does not require unanimous consensus, or the absence of uncertainty. To test that assertion, ask yourself whether you would be concerned to work in a building that had elevated levels of asbestos in the air or whether you pay attention to how much salt or cholesterol you eat, or whether you would give your children triple jab immunizations, or follow a doctor’s advice on treating any ailment or disease. Because if you would do any of the above, you would have effectively acted on uncertain science, in some cases, highly so, not to mention science almost never agreed on by all medical researchers, (and in some cases controversial in that regard). Actually, you will have taken a position on uncertain science no matter what you do- the issue is inevitable.

    Saying that, were it the case that persons or even scientists were attempting to stifle a scientific challenge of the consensus view by shouting “consensus, consensus!!!” or “the science is settled”, I would agree, that is not science. That is dangerous. However if they are attempting to challenge that mainstream scientific conclusion outside the realm of science- in Op-Eds and astroturf and advocacy organizations, etc., without first building any compelling scientific case, (as unambiguously describes the high public profile of self-proclaimed skeptics views), well, then, “consensus, consensus!!” is a meaningful retort, because in this instance it is the ‘skeptics’ that are attempting to drown out science; their actions that are dangerous.

    Michaels & McKitrick’s method in publishing this paper and not soliciting feedback and dialogue but instead diving headlong for the public mic, is, frankly, par for that course. And while that bad form isn’t sufficient to debunk their manuscript, and neither even are all the large waving red flags that have been highlighted here, (although Gavin’s test seems promising in this regard), it certainly increases suspicions that they don’t have anything scientific to add at all. And I hate to be the bearer of bad news, but confirmation of such would not be newsworthy enough to merit more than a blog post.

    Comment by Majorajam — 19 Dec 2007 @ 11:52 AM

  129. Re # 108 Ian McLeod: “This ostensibly impossible result, which seemingly defies the second law of thermodynamics… not only turns conventional wisdom on its head, requiring all biochemical textbooks to be rewritten, but has a profound effect on our understanding and modeling of past, current, and future global warming and cooling.”

    Or maybe not:
    Butenhoff CL, Khalil MA. 2007 Global methane emissions from terrestrial plants.
    “…We conclude that methane release from the terrestrial plant community as presently understood does not require major innovations to the global methane budget.”
    Environ Sci Technol. 2007 Jun 1;41(11):4032-7
    http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=17612186&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstractPlus

    And even if a novel pathway for methane synthesis is identified in terrestrial plants, I seriously doubt that “all biochemical textbooks” will need to be rewritten – in most introductory biochemistry textbooks, methanogenesis is covered only superficially (e.g., Nelson and Cox, 2000, Lehninger Principles of Biochemistry,3rd ed) or is not mentioned at all (e.g., Berg, Tymoczko, and Stryer, 2007, Biochemistry, 6th ed). I also doubt that the second law of thermodynamics is in danger of being overturned by a new metabolic pathway, should one be identified in this case.

    Comment by Chuck Booth — 19 Dec 2007 @ 1:53 PM

  130. Ray Ladbury #126

    Okay Ray, every scientific body on the planet agrees that the IPCC is the arbiter of truth. I get your point. I just disagree with it.

    [Response: I'll take your weighty and well-considered opinion into account along with that of just about every scientific body on the planet when I'm reading the IPCC report. Thanks for taking the time to make your opinion on this matter known. --raypierre]

    On a lighter side, are you aware of James Gleick’s book Isaac Newton? It is excellent. Every time Newton’s name comes up, I hearken back to this book.
    http://www.amazon.ca/exec/obidos/ASIN/1400032954

    Barton Paul Levenson #127

    The low t-stat test referred to the over fitting criticism. They also used it as a rejection of the null hypothesis indicating support for their linear model.

    The time series is bounded between 1972 and 2002.

    My comment about physics as a necessity referred to M&M’s model in particular and economic models generally. Obviously, if we are referring to global circulation models (GCMs) then one must utilize physics.

    PS: Interesting web page.

    Majoraram #128

    We finally agree that consensus is not science, phew. It took almost 2000 words. I call that progress. Then you go and cite Oreskes as a basis for consensus.
    Naomi Oreskes (December 3, 2004). “Beyond the Ivory Tower: The Scientific Consensus on Climate Change”. Science 306 (5702): 1686. doi:10.1126/science.1103618. (see also for an exchange of letters to Science
    Her bad social science paper should never have seen the light of day. It was flawed and unscientific. The editors at Science must have an agenda to put out and then defend their decision to publish such tripe. Although they have not said it publicly, I suspect they regret publishing the Oreskes paper. http://www.staff.livjm.ac.uk/spsbpeis/Oreskes-abstracts.htm

    [Response: You are putting words in peoples' mouth regarding the conclusions people can draw from the existence of consensus. I am beginning to worry that you are just trolling. --raypierre]

    Chuck Booth #129

    The Butenhoff and Khalil paper is money blocked, pity. Their conclusions outlined in the abstract are curious, but perhaps scientists are refining the work done initially by Kepler et al. The following is off-topic, but related to your comment. It is something I wrote last year and chopped down so it not onerous.

    Methane is important in the global warming debate because it can adsorb and emit infrared radiation approximately 23 times more efficiently than carbon dioxide (CO2) does (ref. 1). Scientists know that methane is produced naturally by three different methods. One, it is generated when conditions favour fermentation reactions in swamps, marshes, and rice paddies. Two, methane is produced “as a by-product of anaerobic microbial digestion” (ref.2) in the gut of termites, ruminant animals (especially cows), and some humans. Please, no fart jokes. And three, methane is produced in significant quantities by plants.

    [Response: The question of where methane comes from and what it will do in the future is an important an interesting one. However, I don't see what point you are trying to make, as we can measure the past concentrations of methane, and compute accurately its contribution to global warming vis a vis CO2. We can also say what difference it would make if we double CO2 but reduce the methane to zero (some difference, but it won't save you). On the upside, though, given uncertainties in the dynamics of methane sources, there is very considerable risk of unpleasant surprises if warming should cause methane production to increase. --raypierre]

    Keppler’s team (lead author of Nature article) calculated that plants pump between 60 and 240 million metric tons of methane per year into our atmosphere. This represents 10 to 40 percent of the current methane budget, which is roughly 600 million metric tons per year. What this means, of course, is that the IPCC have not accounted for hundreds of millions of tons of extra methane in the atmosphere due to planets; the IPCC’s budget is too small. This is big news.

    The following list is a breakdown of methane emissions in million metric tons per year as reported in Scientific American: wetlands (225), ruminants (115), energy production (110), landfills (40), biomass burning (40), waste treatment (25), termites (20), ocean (15), and hydrates (10) (ref. 4). Given that plants produce an additional 60 to 240 million metric tons of methane per year—not accounted for in the IPCC budget—this fact has an explicit outcome on the accuracy of the global circulation models.

    The discovery explained why concentrations of both methane and CO2 increased in the atmosphere during deglaciation periods. The explanation goes something like this. As ice and permafrost began melting, the retreating glaciers exposed more landmass for planet growth. Meanwhile, as the oceans warmed, dissolved CO2 became less soluble and outgassed to the atmosphere. More CO2 in the atmosphere created a natural fertilizer effect augmenting plant growth. Stimulated plant growth in turn produced more methane. With more methane and CO2 in the atmosphere, a small upshot in warming was produced. The important warming from the Sun, which started the entire process in the first place, increased the evaporation rate from the warming oceans and lakes, producing higher levels of water vapour in air. Higher levels of water vapour produced more clouds and precipitation and helped control Earth’s unique thermostat that exists today. What is vital to our new understanding here is the natural coupling between methane and CO2 in the atmosphere. Before 2006, this phenomenon was unknown.

    [Response: Possibly (but see below). What implications is this supposed to have for anthropogenic climate change? --raypierre]

    The paper clarified another mystery perplexing physicists because of suspected anomalous satellite observations. In 2005, Frankenburg et al measured huge plumes of methane emanating from evergreen forests all over the planet (ref. 6). Botanists and climatologists assessing this paper wrongly assumed that the methane was coming from dead vegetation biodegrading. No, it was coming from living plants.

    Ref.1 Keppler, F., Röckmann, T. February 2007. Methane, Plants and Climate Change. Scientific American, Vol. 296, No. 2, 52—57 (pg. 53)
    Ref. 2 Ibid, pg. 53
    Ref. 3 See 2 pg 56
    Ref. 4 See 2 pg 55
    Ref. 5 Ibid, pg. 54
    Ref. 6 Frankenburg, C., Meirink, J. F., van Weele, M., Platt, U. & Wagner, T. May 2005 Assessing methane emissions from global space-borne observations. Science Vol. 308, 1010—1014

    [Response: You should be more cautious about basing too many conclusions on one relatively new result on methane production by living plants. We know many bacterial means of producing methane from decomposing organic material, but there is only limited data on production of methane from live plants, which is subject to considerable methodological uncertainties. Even if these live-plant methane results hold up, you are jumping to conclusions when you say that the plumes of methane from forests come from living plants. There is a lot of bacterial activity in the soil, which could well be playing the major role. Science is more than just a matter of spinning convenient stories. It's about doing the hard work to test ideas. --raypierre]

    Comment by Ian McLeod — 19 Dec 2007 @ 10:03 PM

  131. Ian,

    You had me going. For a while there, I sincerely thought you were given to reason, but just now you’ve made it clear you are content to play semantic games. Bravo. To your second brief riposte, I would only say your segue onto Oreskes was a train wreck, (and not even the first of this blog thread- one marvels at what you could accomplish in a calendar year). Or do you think Science deeply regrets publishing Oreskes paper because of a critique that has been both exposed as a fraud, and, subsequent to that humiliation, publicly withdrawn?

    Peiser now admits he didn’t check the same articles that Naomi Oreskes used.

    “Which is why I no longer maintain this particular criticism. In addition, some of the abstracts that I included in the 34 “reject or doubt” category are very ambiguous and should not have been included.”

    — Email from Benny Peiser to Media Watch

    So how many of the 34 articles does Benny Peiser stand by?

    How many really “reject or doubt” the scientific consensus for man-made global warming?

    Well when we first contacted him two weeks ago he told us…

    “Only [a] few abstracts explicitly reject or doubt the AGW (anthropogenic global warming) consensus which is why I have publicly withdrawn this point of my critique.”

    — Email from Benny Peiser to Media Watch

    And when we pressed him to provide the names of the articles, he eventually conceded – there was only one.

    (Ad Hoc Committee on Global Climate Issues: Annual report, by Gerhard LC and Hanson BM, AAPG Bulletin 84 (4): 466-471 Apr 2000)

    Peiser says he withdrew his criticism in March this year.

    Here we are, a few years on, and you’re still proudly trumpeting poor old Benny Peiser’s public shame. My how you denialists enjoy hoisting yourselves up on your own petard. Next thing you’re going to tell us is that the scientists are suppressing the evidence of causation by benthic bacteria. Thanks for the morning chuckle old boy.

    Comment by Majorajam — 20 Dec 2007 @ 11:35 AM

  132. Re # 130 Ian McLeod

    Thanks for the discourse on methane emissions and global warming. I don’t know where you came up with this: “Scientists know that methane is produced naturally by three different methods…” – as there really aren’t three methods: Aside from the report that some plants (I doubt the authors are claiming all plants, are they?) make methane, the only known biogenic source of methane is the group of Archaea (or Archaebacteria) known as the Methanogens – they make methane in anaerobic swamps, termite guts, and the foregut of cattle and other ruminants.

    I haven’t yet read the Kepler et al paper in Nature, but look forward to doing so, along with any letters to the editor in response to that article, as well as the Butenhoff and Khalil paper. In the mean time, I will remain skeptical that the plant cells actually generate the methane – there are too many cases of plant-microbe (and animal-microbe) symbioses to presume this is anything but another example of symbiosis (albeit a potentially novel one).

    However, I am still curious about your suggestion that methane production by plants “seemingly defies the second law of thermodynamics.” Surely Kepler et al didn’t state this? Could it be that you misread a statement such as this one from a Nature news item:
    “The newly revealed methane emissions have taken plant physiologists by surprise, because far more energy is required to create methane than, say, carbon dioxide in an oxygenated environment”?
    If you read this carefully you will realize it merely states that methane production is expensive, raising the question of why plants would waste energy producing methane that will be released to the atmosphere. One simple answer is that they do not – the plant itself is not producing the methane. But, I will withhold judgment on this until more work is done.

    Comment by Chuck Booth — 20 Dec 2007 @ 12:03 PM

  133. Re #130 Ian McLeod

    This news item in Scientific American (June 1, 2007) discusses the Kepler et al claim that tropical grasses produce methane and contradictory findings by Dueck and colleagues:
    http://www.sciam.com/article.cfm?id=are-plants-really-villains-in-climate-change

    I think Kepler et al have a lot of explaining to do before their findings will be taken seriously.

    Comment by Chuck Booth — 20 Dec 2007 @ 12:30 PM

  134. Look, Ian, First, if you look at the history of science, you will find that consensus is central to the scientific process. It is, however, not what is meant by consensus in the political sense, but rather an agreement about what inferences the data will support and at what level of confidence. For simplified cases, this can even be expressed mathematically–though not for cases where support comes from many different lines of argument/evidence. Second, the IPCC does not establish consensus–rather, it reflects it. The endorsements of professional scientific societies are a measure of how well they have done of expressing the consensus as supported by physicists, by chemists,… and in the case of the National Academies, by the most prestiegious official body of scientists in the country. What they are saying is the physics is solid, the chemistry is solid… So it is absolutely pointless to attack this consensus on the basis of the science as we currently know it–you won’t succeed. If you have some new science, fine. But nothing new has been proposed for nearly a decade now, and the consensus just gets stronger.
    So the question, Ian, is what we do about it–and that’s where the politics comes in. That is where your opinion is as valid as anyone else’s, but unless you learn about the science and express an educated opinion with a sound basis in the science, you views will likely be ignored. That is why the opposition by the political right is so counter to their interests. They are attacking the science–which they do not understand–and remaining mute on solutions that reflect their values and interests–which only they can represent.

    Comment by Ray Ladbury — 20 Dec 2007 @ 1:12 PM

  135. r: #130 Ian
    As others have noted, Peiser withdrew his claims.
    Maybe you want to try Monckton + Schulte’s (attempted, badly) refutation of Oreskes, but first, I suggest reading: Monckton+Schulte+SPPI vs Oreskes, which I wrote to capture the entire sequence of silliness in attacks on Oreskes. Are these people you really want to emulate?

    Comment by John Mashey — 20 Dec 2007 @ 1:43 PM

  136. Nature 447, 11 (3 May 2007)
    Missing gas saps plant theory
    Michael Hopkin

    “A team of plant scientists has cast doubt on one of the most startling research results the field has seen in recent years — the finding that green plants emit methane. Tom Dueck of Plant Research International in Wageningen, the Netherlands, and his colleagues say that they can find no evidence that plants produce the potent greenhouse gas…”

    http://www.nature.com/nature/journal/v447/n7140/full/447011a.html

    Comment by Arch Stanton — 20 Dec 2007 @ 4:34 PM

  137. I should have mentioned in 136 that the Tom Dueck et al paper was published in:

    New Phytol. doi:10.1111/j.1469-8137.2007.02103.x; 2007

    Oops.

    Comment by Arch Stanton — 20 Dec 2007 @ 4:58 PM

  138. Well, gavin since I have registered to get the data you suggested I get, we will see if they give me access.
    I gave you as a reference.

    Comment by Steven mosher — 21 Dec 2007 @ 5:45 PM

  139. Gavin and ray. More sheep.should I get the results from here:

    http://www.giss.nasa.gov/tools/modelE/modelE_AR4_issues.html

    Comment by Steven mosher — 21 Dec 2007 @ 7:22 PM

  140. What kind of computer do you have, Steven?

    Comment by Hank Roberts — 21 Dec 2007 @ 8:49 PM

  141. Chuck Booth #132, #133

    It looks like raypierre was right to suggest caution when holding up one study as a paradigm shift until it is independently corroborated. By the way, when I said, “… seemingly defies the second law of thermodynamics” I used the adverb “seemingly” quite on purpose. Meaning of course, superficially evident but not true. I did not say, “It defies the second law of thermodynamics”, which is saying something very different. Semantics, I know.

    I tried finding a free version of the Nature article, sorry, no luck thus far. I have presented below some information that I thought you might find interesting.

    Here is a copy of the Scientific American article that is more or less a summary of Keppler et al’s Nature paper.
    http://www.pages.pomona.edu/~cjt04747/Chem106PS/Scientific%20American%20Feb%202007.pdf

    This is a short summary of the Nature paper.
    http://www.sciencenews.org/articles/20060114/fob1.asp

    Here is an article that narrows the uncertainties.
    http://www.rsc.org/chemistryworld/News/2006/August/16080601.asp

    Here is an editorial that states plants are not to blame for global warming. I think raypierre would like this one.
    http://www.scidev.net/gateways/index.cfm?fuseaction=readitem&rgwid=2&item=News&itemid=2605&language=1

    Here is a major critique of the Keppler et al paper, which I think all RC pundits will like.
    http://ies.jrc.cec.eu.int/fileadmin/Documentation/Reports/Climate_Change/EUR_2006-2007/EUR_22240_EN.pdf

    Here is another overview. It discusses the consequences and shortcomings of some of the mitigation recommendations in the Kyoto Protocol and further outlines pitfalls of the Nature paper (click on the bottom of this page for pdf file).
    http://www.fao.org/forestry/site/33307/en/

    I read the linked paper from you and Arch Stanton #136. Tom Dueck’s team has not corroborated Keppler et al’s results. To the contrary, they used a different methodology to see whether the methane flux rate from plants (primarily grasses) produced the same concentrations discovered by Keppler’s team. As of June 1, 2007, the issue is still up for grabs as each research team is now claiming a lack of scientific rigor from one another. A scientific controversy has now ensued.

    If the Keppler et al claims hold up, I think those biochemical textbooks you mentioned will require an addendum during the next scheduled reprint. In addition, with the caveat, “if true”, the mitigation schemes outlined by the IPCC will require a rewrite as well, including a new methane budget. If on the other hand it is discovered that Keppler et al claims are false, then I retract what I said with a big fat Roseanna Roseannadanna, NEVER MIND.

    [edit - enough on Oreskes]

    Comment by Ian McLeod — 21 Dec 2007 @ 10:01 PM

  142. The Saturated Gassy Argument

    Initially, I was sceptical about the enhanced greenhouse gas effect due to carbon dioxide, but then I read Real Climate’s piece entitled “The Saturated Gassy Argument”, and it made me think there might be something in it after all.

    The SGA says that photons must escape into space in order to balance the Earth’s energy budget. They manage this escape mainly from high altitudes where the atmosphere is very thin and there is insufficient carbon dioxide to absorb all the photons in the relevant CO2 band. Therefore, so the SGA goes, additional CO2 enables more photons to be absorbed, so reducing the numbers escaping to space, and thereby increasing the temperature until energy balance is again attained.
    This is the enhanced GHG effect.

    However, after further thought, I am puzzled again, and I hope someone can resolve my difficulty.

    When a photon is absorbed by a CO2 molecule as above, its energy equivalent no longer contributes to the kinetic energy of the atmosphere. The absorbed energy has now become internal energy of the CO2 molecule by raising it into an excited rotational state. So the photon has been taken out of play, just as if it had escaped to space, and so the energy loss required for equilibrium has still been achieved.

    This process will occur for the other CO2 molecules. Therefore, if more CO2 is added to the atmosphere, extra energy loss from the atmosphere will occur. This is a cooling of the atmosphere, rather than the heating postulated by the SGA.

    Comment by AEBanner — 22 Dec 2007 @ 1:29 PM

  143. The absorbed energy has now become internal energy of the CO2 molecule by raising it into an excited rotational state.

    Eventually that extra rotational energy becomes “thermalized”. Note that according to the equipartition theorem of Statistical Physics, each degree of freedom contains an energy of 1/2 k T in thermal equilibrium. So, if you put extra energy in some dgrees of freedom, you get a nonequilibrium situation and eventually due to interactions this extra energy will be distributed equally over all the degrees of freedom of the system…

    Comment by Count Iblis — 30 Dec 2007 @ 7:47 PM

  144. AEBanner, The vibrationally excited mode of CO2 is quite long-lived. Therefore, there ar many collisions of the CO2 molecule with surrounding gasses before a radiative relaxation. This means that the probability of collisional relaxation is greater than radiative relaxation. Remember that the vibrational state is just kinetic energy of the atoms in the molecule–it can easily share that energy with other gas molecules in its vicinity. Thus the absorbed photon mostly goes into kinetic energy, raising the temperature of all the gas molecules, not just the CO2.

    Comment by Ray Ladbury — 30 Dec 2007 @ 8:34 PM

  145. Re #143 and #144

    Many thanks for your replies.

    AEB

    Comment by AEBanner — 31 Dec 2007 @ 9:07 AM

  146. Re #144, Ray Ladbury

    “Thus the absorbed photon mostly goes into kinetic energy, raising the temperature of all the gas molecules, not just the CO2.”

    Yes, but the kinetic energy of the atmosphere supplied the energy for the photon to be absorbed/created by the CO2 molecule in the first place, so cooling the atmosphere. So the process has simply gone full circle without any overall change of temperature.

    Comment by AEBanner — 31 Dec 2007 @ 12:01 PM

  147. Photon Absorption and Emission at High Altitudes

    I think that there is no doubt that global warming is occurring, witness the melting of the ice, and that it may well be due to anthropogenic activity. But, I believe it is not due to increased concentrations of carbon dioxide.

    I have recently been having a problem with understanding the “Saturated Gassy Argument”. Initially, I was convinced, but on further thought I came up with the following, which seems to show that there is no enhanced GHG effect which can be explained by the SGA. So I am presently a sceptic, but anxious to know the truth about what is happening in the atmosphere. If anyone can post helpful comments, I shall be grateful.

    Please consider the following.

    Let C = total number of CO2 molecules in the pre-industrial atmosphere at 280ppmv
    k = the increase factor in CO2 concentration relative to pre-industrial conc. of 280ppmv.
    s = proportion of emitted photons escaping to space
    win = total number of photons escaping to space through the “window” per unit time

    For CO2 increase factor k, let
    b = proportion of CO2 molecules excited by absorption of photons, and
    intermolecular collisions

    Then, number of CO2 molecules excited by absorption/collision = kbC

    All these molecules emit photons.

    Let the following expressions apply for unit time, where p is the appropriate constant of proportionality.

    Then in general, we have:
    Number of photons escaping to space = pskbC + win ………………….. (Eqn 1)

    Now consider the case of the pre-industrial atmosphere.
    We can put k = 1 and b = b1.
    Then, number of photons escaping to space = psb1.C + win ……………..(Eqn 2)

    Now in energy balance conditions, the number of photons escaping to space must be constant.
    Therefore, from Eqn (1) and Eqn (2), we have pskbC + win = psb1.C + win
    Hence, kb = b1

    But b1 is a constant.

    So as k increases, b must decrease for this relationship to be satisfied and energy balance to be maintained. That is, as the amount of carbon dioxide is increased, the proportion of the number of CO2 molecules participating in the process is reduced. This requirement can be accommodated either by a fall in temperature from the pre-industrial value at high altitudes, or alternatively by the emitting layer moving to higher, colder altitudes.

    What happens in the atmosphere?

    In general,
    Number of photons returning to the atmosphere = p(1 – s )kbC ……….… (Eqn 3)

    And for the case of the pre-industrial atmosphere, k = 1 and b = b1, as before.
    So, the number of photons returning to the pre-industrial atmosphere = p(1 – s )b1.C …..(Eqn 4)

    Therefore, the change in photons returning to the atmosphere = p(1 – s )kbC – p(1 – s )b1.C
    = p(1 – s )C(kb – b1)

    But, in energy equilibrium, kb = b1.

    Therefore, the change in the number of photons returning to the atmosphere = 0

    This means that there is no change in the temperature of the atmosphere due to increasing the amount of CO2 present.

    Comment by AEBanner — 31 Dec 2007 @ 12:25 PM

  148. AEBanner, You are neglecting the surface of the planet, where most of the IR photons originate. Since the temperature is warmer than the atmosphere, it will emit more IR. Moreover, as a solid, the radiation spectrum will look more like a blackbody to begin with.

    There are a number of problems with your argument. To begin with, photon number is not conserved. Second, we have a continual source of photons from the ground. These get absorbed, and most of the energy from the excited molecule gets transferred by collision to other molecules in the atmosphere. It is only where gas densities are sufficiently low and where the number of ghg molecules is sufficiently low that the excited molecule will decay radiatively and that photon has a chance of escaping to space. As you add more CO2, that level is pushed to higher altitudes and colder temperatures. Colder temperature means less radiation in that energy band, so less radiation escapes, and the planet warms.

    Please look at the argument again. Look at Ray Pierrehumbert’s book. You have not comprehended the physics.

    Comment by Ray Ladbury — 31 Dec 2007 @ 1:20 PM

  149. AEB, I am not a scientist and I too struggled with the problem you are having. I will try to explain it as I now believe I understand it:

    You are right; once the system regains equilibrium there is no change in the net gain or loss of energy into space. It is 0. Until that point however there is a net change in the energy gained or lost by our planet’s system.

    You are also right that GHGs also act to cool the atmosphere, however you are forgetting that that the atmosphere, besides being warmed by GHG absorbed photons is also warmed by convection from the surface and (likely even more important) latent heat of vaporization of water carried aloft. Heat that is recaptured by the upper troposphere when clouds condense. These 2 factors are constantly warming much of the troposphere.

    Increasing the “gassy” concentration increases the warming in the troposphere, as the photons “seeking escape” bounce around like pinballs more off the infreased GHGs. Subsequently more of them bump into relatively “cool” areas and are not quickly reemitted. Tjhe GHGs also tends to cool the stratosphere because convection rarely extends beyond the troposphere to bring the latent heat of water vapor up there (yet the CO2 does make it up there).

    Result: Troposphere tends to warm, stratosphere tends to cool. Once the level of the GHGs (and the temperature of the solid/liquid planet) stabilizes, this effect will stop and the planet will once again regain a 0 net energy balance, albeit at a slightly higher temperature.

    Comment by Arch Stanton — 31 Dec 2007 @ 2:02 PM

  150. This frequently asked question in past threads always gets stuck at the point where “pure mathematicians enter the discussion with rather surprising claims …” — which is to say, we’ve been repeating the history of this area of science.

    This may help:
    http://www.google.com/search?q=cache:kuMAjolHZfYJ:www.mzwtg.mwn.de/arbeitspapiere/Schirrmacher_2001_1.pdf+%2BBunsen+%2Bphotochemistry+%2Bgas+%2Bheat+%2Babsorb&hl=en&ct=clnk&cd=29&gl=us&lr=lang_en&client=firefox-a

    “… Looking at various proofs of a general physical law over a period of more than 50 years, a period in which theoretical physics in Germany developed into a new discipline, the problem of a history of proof is addressed and it is asked what different ways of reasoning can be found and whether these can be distinguished as styles of reasoning or thinking.

    The case chosen is Kirchhoff’s formulation of a general law that relates the emission of radiant bodies to their absorptive properties. It stands at an intersection of a number of developments and fields of physics in the 19th century. First, there is the development of spectroscopy and the beginning of astrophysics ….”

    “… physicists like Kirchhoff and later Helmholtz, succeeded to make the appropriate abstractions and arrived at general mathematical descriptions and at least claimed to be able to derive the laws from theoretical principles. This line we will follow further in this paper up to the point w[h]ere pure mathematicians enter the discussion with rather surprising claims as we saw in the beginning. The way to Kirchhoff’s law and the changing way of providing a theoretical foundation for it is hence a discussion that takes place in a process of a disciplinary formation and transformation that finally leads to the emergence of a theoretical physics for which Max Planck generally serves as the model scientist….”

    Comment by Hank Roberts — 31 Dec 2007 @ 2:10 PM

  151. Re #148, Ray Ladbury

    Mr Ladbury, thank you for your very prompt response to my #147.

    I have no problem with the natural GHG effect, but as I said, I am presently a sceptic about the Enhanced GHG effect. However, I am certainly willing to be convinced about it by sufficiently powerful reasoning. Ice cores, tree rings and the hockey stick, although interesting topics in themselves, cannot convince me. The effect of adding extra CO2 to the atmosphere is purely a problem of Physics, and so only a properly reasoned Physics approach can solve it. Whenever possible, I believe the best Physics approach must include a mathematical treatment. This is what I have tried to do, albeit very simply, in my #147 offering above.

    “You are neglecting the surface of the planet, where most of the IR photons originate. Since the temperature is warmer than the atmosphere, it will emit more IR. Moreover, as a solid, the radiation spectrum will look more like a blackbody to begin with.”

    I agree I did not mention the Earth’s surface, but this was for two reasons.
    (a) Real Climate’s Saturated Gassy Argument
    http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/#more-455
    and
    http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument-part-ii/#comment-37716
    accepts that all of the photons radiated from the surface, apart from those in the “window”, are 100% absorbed, either by CO2 and/or water vapour, and so no increase in CO2 can increase the surface temperature. This effect occurs at relatively low altitudes, and most of the absorbed energy is re-radiated back to Earth. This is, of course, the Natural Greenhouse Gas Effect.
    (b) This last point is illustrated by the work of Kiehl and Trenberth
    http://www.cgd.ucar.edu/cas/abstracts/files/kevin1997_1.html
    I based my piece on the idea in this reference, showing that a power of 165 Wm^-2 is radiated out to space by the atmosphere.

    In line with the SGA, I believe that this energy leaves from high altitudes in the atmosphere. I suggest that most of the photons are created in the atmosphere at fairly high altitudes by intermolecular collisions with CO2 molecules. Some of these photons will escape directly to space, but some will be absorbed by CO2 molecules.

    So far, I think I’m in agreement with the SGA, and with some of your comments. However, you stated “To begin with, photon number is not conserved”. But, the number of photons escaping to space must be conserved if energy balance is to be maintained.

    At high altitudes, some CO2 molecules can absorb photons of the correct wavelength, photons which derived their energy from the kinetic energy of the atmosphere. OK, so far.

    From here on, my ideas differ from the SGA.

    The excited molecules can then decay again to a lower energy level, either spontaneously or by collision, so emitting more photons. Some of these can go upwards and escape, but the remainder will return to the atmosphere, where they will transfer their internal energy to kinetic energy of the other gases. However, at high altitudes, more will escape than will return because of the infinite sink for photons, SPACE. This must be so, in order to maintain energy balance.

    If more CO2 is now added, there will be a tendency for extra photons to be absorbed/ emitted as above, so allowing even more photons to escape. This would tend to make too many photons escape, and this would lower the temperature at high altitude. The numbers leaving would then be reduced and so bring energy balance again. Alternatively, one can take the idea from SGA that more CO2 would raise the altitude to even higher, colder levels for photons eventually to escape. This is probably the more likely.

    Therefore, what we’re left with is the required number of photons escaping to space to maintain energy balance, and this occurs at still higher altitudes, presumably governed by the lapse rate.
    The temperature of the atmosphere remains unchanged.

    I suggest that what is happening is that only a small proportion of the total number of CO2 molecules in the atmosphere is involved in the high altitude processes, simply enough to provide energy balance. If more CO2 is added, then the proportion taking part is correspondingly reduced, so that the actual number taking part is kept constant.

    This can be seen mathematically in my post #147.

    This means that extra CO2 has no effect on the temperature of the atmosphere or the Earth’s surface. That is no Enhanced GHG effect.

    Comment by AEBanner — 31 Dec 2007 @ 4:15 PM

  152. Re #149, Arch Stanton

    Thank you for your post.

    “You are also right that GHGs also act to cool the atmosphere, however you are forgetting that that the atmosphere, besides being warmed by GHG absorbed photons is also warmed by convection from the surface and (likely even more important) latent heat of vaporization of water carried aloft. Heat that is recaptured by the upper troposphere when clouds condense. These 2 factors are constantly warming much of the troposphere.”

    No, I’m not forgetting about convection and latent heat. These factors are clearly shown in Kiehl and Trengerth’s piece
    http://www.cgd.ucar.edu/cas/abstracts/files/kevin1997_1.html
    I agree that energy is certainly carried up into the atmosphere by these means, indeed this MUST be so because it is necessary for the atmosphere to be able to supply 165 Wm^-2 to space.

    Comment by AEBanner — 31 Dec 2007 @ 4:29 PM

  153. Re #150 Hank Roberts

    A major reference.

    But which part of my # 147 or # 151 do you not agree with?

    AEB

    Comment by AEBanner — 31 Dec 2007 @ 4:38 PM

  154. > which part
    “… rather a history of justifications than a history of discoveries”

    Comment by Hank Roberts — 31 Dec 2007 @ 6:10 PM

  155. AEBanner, OK, let’s think about the radiation of the planet in the absence of greenhouse gasses. It will be a blackbody curve consistent with the temperature of the surface, correct? And in equilibrium, energy in (from insolation) equals energy out (via outgoing thermal IR). Now add greenhouse gasses and what happens? IR photons in the absorption band of the ghg get absorbed. Some of the molecules so excited than radiate another photon in the same band. However, because vibrational states tend to have a long half-life, many more excited molecules relax collisionally, transfering their energy (it is partly kinetic/partly potential after all). This heats the troposphere, but less energy reaches the stratosphere now, so it cools. Moreover, some excited ghg molecules still radiate, and some of the ghg molecules will be collisionally excited and radiate. Some of that radiation will be earthbound and some outbound. The outbound LWIR is still likely to encounter another ghg molecule and be absorbed. However, as we go higher in the atmosphere, it cools, the numbers of photons radiated away is lower, and finally when we’re high enough, the ghg molecules can radiate away the energy of their excited state–but at a much lower blackbody temperature. So when we look at the spectrum radiating from Earth, we expect to see a blackbody spectrum appropriate for Earth’s surface temperature–except in the absorption band of the ghgs, where we have a big hole. This is in fact what we do see.
    http://www.globalwarmingart.com/wiki/Image:Atmospheric_Transmission_png

    It is the energy that’s missing from the blackbody curve that is in fact responsible for warming by the greenhouse molecules. And why should that magically stop at 280 ppm for CO2. Add more CO2 and you get more CO2 that can absorb energy in the wings of the bands. You also get more CO2 at higher altitudes (it’s well mixed even into the stratosphere), so that pushes the altitude at which LWIR in the CO2 band can escape even higher (and colder).

    And if that doesn’t make sense to you, ask yourself: How likely is it that you would find a mistake when literally 10s of thousands of PhDs have looked this over and agree with the standard model for anthropogenic causation? I find when I disagree with all the smart people in the room that it is usually advisable for me to go back and check my thinking again. Happy New Year.

    Comment by Ray Ladbury — 31 Dec 2007 @ 7:16 PM

  156. Re #147 where AEBanner says

    “Therefore, the change in the number of photons returning to the atmosphere = 0

    This means that there is no change in the temperature of the atmosphere due to increasing the amount of CO2 present.”

    In general, your arguments are correct, but the conclusion is false because carbon dioxide does not warm the atmosphere in the way that you (following Ray Pierrehumbert and Spencer Weart) describe. Putting it simply, radiative balance to space is not achieved by the alteration the amount of outgoing long wave radiation. It is achieved by changes in the planetary albedo ie regulation of the incoming solar radiation. This was pointed out by G.C. Simpson 1n 1928.

    Moreover, the current understanding of the greenhouse gas mechanism is wrong. In the IPCC AR4 they say that it is analogous to the effect of glass in a greenhouse, but this was an error by Arrhenius. Wood showed that the glass in a greenhouse prevents convective cooling. It does not produce radiative warming.

    The warming of the air in a greenhouse is produced by the blackbody radiation from the ground being absorbed by trace gases in the air by a quantum mechanical effect, the details of which Tyndall, Arrhenius, and Wood had no knowledge.

    In a greenhouse and on Earth, the air close to the surface is warmed which prevents the surface losing heat by convection. The surface then warms and radiates more intently, which heats the adjacent air producing a positive feedback. Over oceans and vegetation the addional heat is lost by evaporation, but in deserts the thin laminar boundary layer heats up to such an extent mirages are formed.

    However, it is not in deserts but on ice sheets where CO2 concentrations affect climate. The concentration of CO2 sets the maximum temperature the surface of the ice can atain, since there is little water vapour at those temperatures. Thus CO2 concentration is a factor determining whether a surface remains ice covered in summer, and so whether the planet is in or out of an ice age.

    So, although changing the concentration of CO2 does not affect the longwave radiation to space or the backradiation to the surface, it does affect the albeodo of the planet which is a main climate determining factor.

    It is because this feedback, greenhouse gas on conduction, is not included in the models that they have underestimated the speed at which the Arctic sea ice and glaciers world wide have been retreating. It also explains why Spencer et al. have not found the warming in tropical troposphere predicted by the models. As you point out, the upper atmosphere will not warm with greater concentrations of CO2.

    Comment by Abbe\' Mac — 1 Jan 2008 @ 12:07 AM

  157. Re #156 Abbe\’ Mac

    Thank you for your comments. There is a lot there to think about.

    AEB

    Comment by AEBanner — 1 Jan 2008 @ 7:04 AM

  158. AEBanner, Now that I have a bit more time, I can point out some of the faults in your model.
    As I pointed out above, the assumption that the number of photons is constant is completely false. Photons are Bosons–they blip in and out of existence all the time.
    It is also false that fewer CO2 molecules will be excited. First, by thermodynamic arguments alone, the same proportion of molecules will be excited at the same temperature (e.g. collisionally). LWIR radiation will excite still more.
    You are also incorrect that all the excited molecules will emit photons. The vibrationally excited state of CO2 is quite longlived and undergoes many collisions prior to relaxing via photon emission. This means that at least near the surface (where densities are high), the main relaxation mode is collisional, imparting energy to all the gas molecules.
    Finally, your assumption of thermal equilibrium is incorrect. As long as the greenhouse gasses prevent the energy in their absorption bands from escaping, that energy goes into heating the system, and equilibrium is restored at a higher temperature.

    Abbe’ Mac, Where on Earth did you read this? Whoever wrote it was either joking or seriously deluded.

    Comment by Ray Ladbury — 1 Jan 2008 @ 8:19 AM

  159. Reply to #155 Ray Ladbury

    Firstly, I should like to refer you to Spencer Weart’s piece entitled “A Saturated Gassy Argument”.
    http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/#more-455

    This work implicitly seems to accept that carbon dioxide and water vapour can absorb 100% of the infrared radiation from the surface of the Earth. Most of this energy is radiated back to the surface. See Kiehl and Trenberth
    http://www.cgd.ucar.edu/cas/abstracts/files/kevin1997_1.html
    This is the natural GHG effect, and occurs at relatively low altitudes. For the purpose of easy discussion, let us consider the atmosphere to consist of three regions, lower and upper troposphere, and high altitude as in SGA.

    The infrared which is not radiated back to the surface heats the upper troposhere by increasing the kinetic energy of the molecules by inter-molecular collisions.

    Heat energy also leaves the surface as sensible heat, convection and latent heat, which rises into the upper troposphere where it too provides warming. Kiehl and Trenberth show that sufficient energy is provided to this region by these means for the necessary 165 Wm^-2 to escape to space in order to enable energy balance for the Earth’s system. ( Together with 30 Wm^-2 from the clouds and 40 Wm^-2 through the “window”. ) I suggest that the available energy is converted into the necessary photon form by inter-molecular collisions in the upper troposphere and at high altitudes.

    Some of the photons about to escape into space at high altitudes will be absorbed by CO2 molecules even at this height, as stated in the SGA, but it is at this point that my ideas diverge from the SGA.

    Quote from your #155
    “IR photons in the absorption band of the ghg get absorbed. Some of the molecules so excited then radiate another photon in the same band. However, because vibrational states tend to have a long half-life, many more excited molecules relax collisionally, transfering their energy (it is partly kinetic/partly potential after all). This heats the troposphere,…..”
    Unquote

    You are saying, are you not, that most of those excited CO2 molecules which relax by collision are giving up their vib/rotational energy for it to become increased kinetic energy of the troposphere (upper), and so to warm the troposphere. Right? But, I maintain that the troposphere is where the energy came from in the first place when kinetic energy became (collisionally) absorbed by the CO2 molecules!!
    So I’m afraid that that is a circular process and its argument gets you nowhere.

    The excited CO2 molecules will decay again to a lower rotational level, either spontaneously or by collision, so emitting photons. Some of these emitted photons will escape to space as required, and some will return to the atmosphere (as above), but the temperature will be adjusted by the overall feedback system so that energy balance will be maintained.

    It is important to understand that only a small proportion of the total atmospheric CO2 is involved in this process. The relevant actions are occurring at high altitudes “where the air is very thin”, after all, not throughout the whole atmosphere. This proportion is dependant on the high altitude temperature. The number of CO2 molecules involved will be set at this temperature to provide the required number of outgoing photons to get energy balance.

    If now, more CO2 is added, more photons will join in the process and escape to space, so tending to upset the balance. Correction is provided by the emitting region moving to still higher altitudes, ( in line with the SGA ), where the temperature is lower, and so the emission rate is reduced, as required.

    Note that the number of CO2 molecules involved must be constant, so that when more CO2 is added, the proportion involved is reduced accordingly. This is shown mathematically by the equation kb = b1 in my #147.

    You have also referred to the black body spectrum of the Earth, and the expected gap in the CO2 absorption band region. The ideas I have suggested have in no way affected the natural GHG process occurring relatively close to the surface, so the spectrum should not be significantly changed.

    Please refer again to my #147, and let me know which part you do not accept, and I shall do my best to explain.

    Quote from your #158
    “As I pointed out above, the assumption that the number of photons is constant is completely false. Photons are Bosons–they blip in and out of existence all the time.”
    Unquote

    I thought it could be taken for granted that I did not mean the self-same photons. I did not want to be pedantic. No, I simply meant that the energy equivalent had to be constant for energy balance. That is, the power radiated outwards, the OGLW energy, must be kept equal to the net incoming solar energy if equilibrium is to be maintained.

    Quote from your #158
    “First, by thermodynamic arguments alone, the same proportion of molecules will be excited at the same temperature (e.g. collisionally).”
    Unquote

    I absolutely agree with that. Where did I say otherwise?

    But, I suggest that final escape to space occurs at higher and colder altitudes because the proportion of CO2 molecules participating must be less, not greater, when more CO2 is added, in order for equilibrium. The total number of CO2 molecules participating has to stay constant.

    The problem with the SGA is that it stops too soon for the flaw to be seen. The crux of the SGA is where it refers to extra CO2 molecules absorbing photons at high altitudes. It neglects to say anything about the next, inevitable process, which is the following decay, with the “centralised energy packet” within the excited molecule distributing its energy into the various states available to it, in line with the Second Law of Thermodynamics. Must not forget that!

    Thank you for your interest and for taking the trouble to respond.

    Happy New Year to you, too.

    Comment by AEBanner — 1 Jan 2008 @ 12:47 PM

  160. PS to #159

    Does anyone have the audacity to say they agree with my #147 +++
    Can I take no replies as a “Yes”?
    AEB

    Comment by AEBanner — 1 Jan 2008 @ 12:50 PM

  161. AEBanner, Proportion of CO2 has nothing to do with it. What matters is the number of CO2 molecules an IR photon is likely to encounter on it’s way to the exosphere. Each CO2 molecule adds to the probability of absorption and thence to backradiation and heating of the atmosphere.
    The mistake you are making is that as you increase the ghg concentration, the atmosphere is no longer in thermal equilibrium. The IR that doesn’t escape is heating the atmosphere–and it does so until the temperature nudges up the blackbody curve and Energy IN=Energy Out once again. The IR photon does not care whether the CO2 molecule is in the troposphere or the stratosphere. To first order, the absorption cross section is the same. Yes, most of the energy transported to the mid troposphere got there via convection. That’s all the more reason why adding CO2 is effective in trapping the IR radiation emitted there (where you are above most of the water vapor). There is nothing magic about 280 ppm that says the greenhouse effect stops above this level. It doesn’t stop–that’s the whole point of the refutation discussed by Spencer and Ray Pierrehumbert.

    You state that the total # of CO2 molecules participating has to stay constant. How do you get that? That makes no sense unless you assume that once a photon is absorbed that energy is out of play–patently false. As long as there is energy escaping in that band, it can be absorbed by adding CO2 to the atmosphere above where it was emitted.

    I’m not sure what you mean by “cetralized energy packet”, but there’s no conflict with the 2nd law of Thermo. All that says is that if you dump energy into one mode, it will thermalize eventually.

    Comment by Ray Ladbury — 3 Jan 2008 @ 2:39 PM

  162. I am still hung up on the saturation argument and the debate between AEBanner and Ray Ladbury has provoked me to try again for enlightenment.

    1)The atmosphere is opaque to 13.5-17 micron IR emitted from the surface such that no photons of these wavelengths can pass to the upper atmosphere. Above the opaque layer, CO2 is present and able to absorb (and re-emit) photons of the appropriate wavelength. Where do they come from? They are clearly present at this level as can be determined from space (looking down). Presumably, they are produced from non radiative thermal energy convected from below reacting with CO2. Because of atmospheric opacity below, they can never get back to the surface but they can leave the atmosphere to space, albeit with increasing delay as CO2 concentration increases.

    2) Suppose, for the sake of argument, that there were no molecules of CO2 above the opaque layer. How would the non radiative energy then leave the system? Presumably, slowly by diffusion resulting in significant warming in the high troposphere. If one were then to add a small amount of CO2, energy would escape more quickly in emitted photonic form. If this reasoning is correct, CO2 would cool the upper troposphere. However, there may come a point when adding even more CO2 would start warming it again. This suggests that both AEBanner and Ray Ladbury are both correct and that the outcome (warming or cooling) would depend upon the current CO2 concentration.

    3)Suppose we have reached or are very close to a situation where the atmosphere at a given layer is opaque to all IR except that passing through the atmospheric window. Above that level, there is CO2 but almost no water vapour. Surface warming will lead to more water vapour but it won’t necessarily get any higher (vertically) in the atmosphere. Why, therefore, should there be a positive feedback? The second greenhouse blanket analogy won’t work in the case of water vapour.

    4) How does energy above an IR saturated layer contribute to surface warming. It can’t be due to net downward re-emission of photons because of underlying opacity. Is it explained by downward convection of non radiative energy and, if so, is this effect predominantly at the poles?

    5) Why try to explain warming on the basis of a second greenhouse blanket (high level CO2) when it is possibly more easily explained by a tighter wrapping of the first blanket (decreasing height from the ground as CO2 concentration rises)?

    6) I have read differing interpretations relating to absorption and re-emission of photons. Are the emitted ones always of the same wavelength as those absorbed or only sometimes. If an excited CO2 molecule could lose some energy in collisions, could it then also emit a photon of lower energy than that absorbed which would presumably have a longer wavelength? If so, this would seriously constrain the blocking effects of CO2 at high altitude where there is minimal water vapour.

    7) I have read that the brightness temperature measured from space for IR in the 15 micron band is 215K. If CO2 is blocking energy egress to space, this temperature should be falling. Is it?

    It will be obvious that I am no physicist so can anyone help?

    Comment by Douglas Wise — 4 Jan 2008 @ 9:35 AM

  163. Reply to #161, Ray Ladbury

    Thank you for your reply. I don’t think there is much difference between our two views of the overall Earth/atmosphere system, but there is a major difference in our thinking about one particular aspect. There have also been minor problems with understanding certain points of expression, which I shall come to later.

    The Saturated Gassy Argument (SGA) would seem to be the thinking not only of Real Climate’s majority readers/contributors, but also the IPCC. Correct? This explanation of the Enhanced Greenhouse Gas Effect accepts that no additional anthropogenic warming can arise from the GHGs fairly close to the Earth’s surface, but that it occurs at high altitudes “where the air is very thin”. OK, no problem!

    The basic SGA point is that a photon of the appropriate wavelength which is on its way out to space can be absorbed by a molecule of CO2, so reducing the output of energy to space which is required for energy balance to be maintained, and so increasing the temperature until balance is again achieved. Moreover, if this molecule relaxes again to a lower vib/rotational state by inter-molecular collision with another CO2 molecule or with one of oxygen or nitrogen, then its energy becomes kinetic energy of the atmosphere and thereby raises the temperature.

    OK, so far, but that is not the complete story!

    Now, let’s go back a bit, and think about that photon which was escaping to space, but was absorbed. I think we both probably agree that it originated in the troposphere. (This would be in line with Kiehl and Trenberth as mentioned in previous posts.) Therefore, its internal energy came from the kinetic energy of the troposphere, so making a cooling effect. When the photon is absorbed, its energy becomes the increased internal energy of the absorbing CO2 molecule. If then, the excited CO2 molecule relaxes by collision, as above, this amount of energy is put back into the troposphere, so making an equal heating effect, and restoring the original temperature.

    Alternatively, instead of relaxing by collision, suppose the excited CO2 molecule spontaneously decays to its lower state by simply emitting a photon which would be of the same energy (?).
    This new photon may be emitted upwards or downwards by the familiar argument. If it goes upwards, it can escape to space, simply replacing the original one. So energy balance is left undisturbed. If it goes downwards into the troposphere again, then it will be “thermalised” by collision, so restoring the energy removed from the troposphere to create the original photon. So there is no change in the temperature of the troposphere.

    This argument applies whatever the concentration of carbon dioxide. If more is added, the same processes operate as above, and there is still no overall change of temperature. So there is no enhanced greenhouse gas effect.

    Look at it another way. Carbon dioxide plays a part, as just described, in providing photons in the troposphere by the collision/excited molecule/photon emission process, and some of these photons escape to space to ensure energy balance. This balance will be achieved when a certain number of carbon dioxide molecules are participating in the process. (Of course, it does not have to be the self-same molecules all the time.)

    So only a certain proportion of the total number of CO2 molecules in the whole atmosphere are needed to do the job, to maintain energy balance.!!!!!

    If now, the amount of CO2 is doubled, then the required PROPORTION is halved, so the participating number is kept constant. This relationship applies in general; the participating proportion of CO2 molecules multiplied by the total number of molecules of CO2 must remain constant, and so no change in temperature occurs. This can be seen mathematically in my #147, in the equation kb = b1.

    A couple of small points in your last reply.

    I’m sorry, but I don’t know where you thought I had got hung up on 280 ppmv. I have explained my thoughts above on this matter without reference to any particular CO2 concentration. Again, sorry about the “centralised energy packet” phrase; I was just referring to the increased internal energy of the excited CO2 molecule.

    I shall be very interested in replies to help my understanding of this problem. To sum up, I have no problem with the natural greenhouse gas effect, but I do not accept the current explanation for the Enhanced effect. I believe there is global warming, caused by some other, as yet unknown, process.

    Comment by AEBanner — 4 Jan 2008 @ 4:29 PM

  164. Re #162

    The problem is that for every question you ask you are likely to get more than one reply. How do you tell which one is correct?

    When you ask 7 questions then you have a real problem sorting out the answers, that is if anyone can be bothered to answer 7 questions knowing that if they do, then they will be contradicted by other replies :-(

    Comment by Abbe Mac — 4 Jan 2008 @ 5:15 PM

  165. Douglas Wise (162) — Looks to be that you want to read a good book on Atmospheric Physics.

    Comment by David B. Benson — 4 Jan 2008 @ 6:32 PM

  166. AEBanner says: “This explanation of the Enhanced Greenhouse Gas Effect accepts that no additional anthropogenic warming can arise from the GHGs fairly close to the Earth’s surface, but that it occurs at high altitudes “where the air is very thin”.”

    Actually, this is not totally correct. Increasing CO2 means that there are more CO2 atoms to absorb in the wings of the spectrum, so more warming occurs even at low altitudes.

    AEBanner then says after an argument about energy balance: “This argument applies whatever the concentration of carbon dioxide. If more is added, the same processes operate as above, and there is still no overall change of temperature. So there is no enhanced greenhouse gas effect.”

    Your reasoning in this argument is incorrect on several fronts. First, the upper atmosphere is cooler than the surface and lower atmosphere. There fore a ground-state CO2 molecule struck by another molecule is less likely to have its vibrational state excited than is an excited CO2 molecule to relax via collision. Therefore there are fewer CO2 molecules in excited states to emit IR photons–thus less energy is lost at this level. Second, there is a continual flux of IR from the surface and lower levels. Third, you cannot assume that if the photon is emitted upwards that it WILL escape. It has a probability of escaping, and that probability decreases as we pile more CO2 molecules in its way, does it not?

    Finally, you keep clinging to equilibrium when the system is not in equilibrium. Yes, it starts out that way before we start heating the surface, but once IR photons start flowing from below, the cool gas in the upper atmosphere is NOT in equilibrium, but is being heated from below.

    Re: your comments on my comments–280 ppmv is concentration that causes the “natural” greenhouse effect prior to the industrial age. And again, why should the effect magically stop at 280 ppmv?

    Comment by Ray Ladbury — 4 Jan 2008 @ 6:49 PM

  167. Douglas Wise

    1)”Because of atmospheric opacity below, they can never get back to the surface”–not strictly true. Each absorption is followed by relaxation either radiatively or collisionally. Via many steps, photon can reach Earth. Also, if it doesn’t reach Earth, it heats the atmsophere. Thermal energy can travel down. Also, a warmer atmosphere radiates more photons (down and up), so there is radiation from the atmosphere making it to the ground.

    2)The energy cannot leave the system nonradiatively. If it diffuses up, it’s still in the system. Opaque is not really a description. Photons of the proper frequency originate not just at the surface, but wherever there is CO2–maybe even the molecule next door.

    3)Again, remember GHGs radiate as well as absorbing. They radiate less than the surface because they are cooler.

    4)Again, the problem is opacity–IR is emitted throughout the atmosphere and can be absorbed at any level. Heat the gas up–even just above the surface, it emits more IR, but at low levels it can also transport heat near the surface via convection.

    5)Not really a second blanket–think of it as increasing the number of muggers a commuter has to get past on his way home.

    6)The CO2 energy line is actually a range of energies–frequency vs intensity of emission looks like a bell curve, but with long wings to either side. Emission can occur anywhere within this band–collisions can distort the absorption or emission spectrum as well.

    7)The blocking of energy by CO2 is THE REASON why the temperature in that band looks lower. It’s because less energy can escape from below. In effect, adding more CO2 raises the level where significant IR photons in that band can escape, and since higher=colder, the temperature of emission does decrease.

    Don’t give up. I have a PhD in physics and 20 years experience (or you could look on it as I’ve had 20 years to forget what I learned), and this took work for me, too. Keep asking questions.

    Comment by Ray Ladbury — 4 Jan 2008 @ 7:09 PM

  168. Reply to #166 Ray Ladbury

    Again, thank you for taking the trouble to reply, but I am still unable to accept your reasoning. Things have become somewhat complicated, and I think it might make for better discussion if some simplification were attempted. [edited]

    [Response: We won't allow discussion threads to be hijacked with long, off-topic diatribes. You can continue this discussion off-site if you wish, but no more of this here. -mike]

    Comment by AEBanner — 5 Jan 2008 @ 2:12 PM

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