Guest post by David Middleton
William D. Nordhaus is an economics professor at Yale University. He recently published this essay in the New York Review of Books…
Why the Global Warming Skeptics Are Wrong
March 22, 2012
William D. Nordhaus
The threat of climate change is an increasingly important environmental issue for the globe. Because the economic questions involved have received relatively little attention, I have been writing a nontechnical book for people who would like to see how market-based approaches could be used to formulate policy on climate change. When I showed an early draft to colleagues, their response was that I had left out the arguments of skeptics about climate change, and I accordingly addressed this at length.
But one of the difficulties I found in examining the views of climate skeptics is that they are scattered widely in blogs, talks, and pamphlets. Then, I saw an opinion piece in The Wall Street Journal of January 27, 2012, by a group of sixteen scientists, entitled “No Need to Panic About Global Warming.” This is useful because it contains many of the standard criticisms in a succinct statement. The basic message of the article is that the globe is not warming, that dissident voices are being suppressed, and that delaying policies to slow climate change for fifty years will have no serious economic or environment consequences.
My response is primarily designed to correct their misleading description of my own research; but it also is directed more broadly at their attempt to discredit scientists and scientific research on climate change.1 I have identified six key issues that are raised in the article, and I provide commentary about their substance and accuracy. They are:
• Is the planet in fact warming?
• Are human influences an important contributor to warming?
• Is carbon dioxide a pollutant?
• Are we seeing a regime of fear for skeptical climate scientists?
• Are the views of mainstream climate scientists driven primarily by the desire for financial gain?
• Is it true that more carbon dioxide and additional warming will be beneficial?
[…]
Source: New York Review of Books
Professor Nordhaus then proceeds to address his six strawmen answer his own questions.
Is the planet in fact warming?
First off, the “planet” hasn’t warmed. The atmosphere has warmed and cooled throughout the planet’s history. And, apparently, the ability to conjugate verbs is not a prerequisite for Ivy League economics professors. Professor Nordhaus’ answer is that the lower atmosphere (AKA planet) is warming because it did warm from 1978 to 1998…
It is easy to get lost in the tiniest details here. Most people will benefit from stepping back and looking at the record of actual temperature measurements. The figure below shows data from 1880 to 2011 on global mean temperature averaged from three different sources.2 We do not need any complicated statistical analysis to see that temperatures are rising, and furthermore that they are higher in the last decade than they were in earlier decades.3
One of the reasons that drawing conclusions on temperature trends is tricky is that the historical temperature series is highly volatile, as can be seen in the figure. The presence of short-term volatility requires looking at long-term trends.
Yes! By all means, let’s have a look at some long-term trends. Let’s take the long-term trend back to a time when mankind wasn’t burning much fossil fuel…
From Ljungqvist, 2010…
The amplitude of the reconstructed temperature variability on centennial time-scales exceeds 0.6°C. This reconstruction is the first to show a distinct Roman Warm Period c. AD 1-300, reaching up to the 1961-1990 mean temperature level, followed by the Dark Age Cold Period c. AD 300-800. The Medieval Warm Period is seen c. AD 800–1300 and the Little Ice Age is clearly visible c. AD 1300-1900, followed by a rapid temperature increase in the twentieth century. The highest average temperatures in the reconstruction are encountered in the mid to late tenth century and the lowest in the late seventeenth century. Decadal mean temperatures seem to have reached or exceeded the 1961-1990 mean temperature level during substantial parts of the Roman Warm Period and the Medieval Warm Period. The temperature of the last two decades, however, is possibly higher than during any previous time in the past two millennia, although this is only seen in the instrumental temperature data and not in the multi-proxy reconstruction itself.
[…]
The proxy reconstruction itself does not show such an unprecedented warming but we must consider that only a few records used in the reconstruction extend into the 1990s. Nevertheless, a very cautious interpretation of the level of warmth since AD 1990 compared to that of the peak warming during the Roman Warm Period and the Medieval Warm Period is strongly suggested.
[…]
The amplitude of the temperature variability on multi-decadal to centennial time-scales reconstructed here should presumably be considered to be the minimum of the true variability on those time-scales.
[…]
Ljungqvist is recommending caution in comparing the modern instrumental reconstruction to the older proxy reconstructions because the proxy data are of much lower resolution. The proxy data are showing the “minimum of the true variability on those time-scales.” The instrumental data are depicting something closer to actual variability.
Even then, the instrumental record doesn’t exceed the margin of error for the proxy data during the peak of the Medieval Warm Period…
Since someone is bound to chime in with, “But Ljungqvist isn’t a real climate scientist!”… Let’s compare Mann et al., 2008 (EIV) and Ljungqvist, 2010…
Apart from the 20th century hockey stick, they are very similar. Here’s a blow up of the above from 1950 with HadCRUT3 (NH)…
The entire blade of the hockey stick is post-1995.
Now, on to the verb conjugation. The lower atmosphere is not currently warming, irrespective of what it did from 1978-1998, or what it has done since the 1850’s, or what it has done since 1600 AD…
There has been no global warming for more than a decade. To paraphrase Paul Revere, “None if by land”…
“None if by sea”…
All of the anomalous warming occurred between 1995 and 1998. This, amazingly, is what the satellite data indicate…
Are human influences an important contributor to warming?
Maybe. Urban heat islands are “human influences.” Most other land-use changes are “human influences.” Anthropogenic greenhouse gas emissions are “human influences.” Are they important? It all depends on the model.
This model says, “Not very important”…
Although, the authors seem to have concluded that “human influences” related to global cooling were masking the “human influences” related to global warming.
Models are great heuristic tools; but they cannot and should never be used as substitutes for observation and correlation. I can build a valid computer model that tells me that an overpressured Cibicides opima sandstone at depth of 15,000′ should exhibit a Class 3 AVO response. If I drill a Class 3 AVO anomaly in that neighborhood, I will drill a dry hole. A little bit of observation and correlation would quickly tell me that productive overpressured Cibicides opima sandstones at depth of 15,000′ don’t exhibit Class 3 AVO anomalies.
Is carbon dioxide a pollutant?
I thought about answering with a treatise on plant stomata, but this was “easier”…
JPL-Developed Clean Energy Technology Moves Forward
A team of scientists at NASA’s Jet Propulsion Laboratory originally developed this 300-watt engineering prototype of a Direct Methanol Fuel Cell system for defense applications. Image credit: NASA/JPL-Caltech
May 26, 2011
A team of scientists at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., in partnership with the University of Southern California in Los Angeles, developed a Direct Methanol Fuel Cell technology for future Department of Defense and commercial applications. Recently, USC and the California Institute of Technology in Pasadena, which manages JPL for NASA, awarded a license to SFC Energy, Inc., the U.S. affiliate of SFC Energy AG. The non-exclusive license for the technology will facilitate the expansion of the company’s methanol fuel cell products into the U.S. market.
This novel fuel cell technology uses liquid methanol as a fuel to produce electrical energy, and does not require any fuel processing. Pure water and carbon dioxide are the only byproducts of the fuel cell, and no pollutants are emitted.
[…]
If NASA and the JPL say carbon dioxide is not a pollutant, that’s good enough for me. The plant stomata treatise will follow along shortly.
Are we seeing a regime of fear for skeptical climate scientists?
“Fear” is probably not the right word. However, this kind of attitude from government officials is somewhat disconcerting…
“When you are in that kind of position, as the CEO of one the primary players who have been putting out misinformation even via organisations that affect what gets into school textbooks, then I think that’s a crime.”
It’s of particular concern when the self-appointed inquisitor takes pride in influencing “the nature of the measurements obtained, so that the key information can be obtained” (AKA “Torturing the data until it confesses”…
It’s also a bit disconcerting when the people who make our laws are threatening skeptics with tobacco-style inquisitions. The recent Fakegate shows that the Warmists are quite willing to engage in fraud in order to bring about such an inquisition. Concerned: yes. Afraid: no.
Are the views of mainstream climate scientists driven primarily by the desire for financial gain?
No, all “mainstream climate scientists” are unpaid volunteers. (/Sarcasm).
Is it true that more carbon dioxide and additional warming will be beneficial?
Yes, Professor Nordhaus, more carbon dioxide and additional warming will be beneficial…
The Little Ice Age was quite possibly the coldest part of the Holocene since the 8.2 KYA Cooling Event…
The climate has oscillated between warming and cooling throughout the Holocene with a period of ~1,000 years, with an underlying secular cooling trend. This millennial-scale cycle is clearly present in the Greenland ice cores…
The millennial-scale cycle is also painfully obvious in non-hockey stick climate reconstructions…
The polynomial trend line simulates a Gaussian filter. It is not intended to be predictive of the magnitude of future climate changes. Its purpose is to highlight the cyclical nature of the climate reconstruction.
If “more carbon dioxide and additional warming” prevent the next “Little Ice Age” from being as cold as the last “Little Ice Age,” it will be very beneficial. If it slows our inevitable transition into the next Quaternary glacial stage by a few hundred years, it will be very beneficial. Although, elevated CO2 levels didn’t make much difference in the Eemian. If CO2 was such a potent forcing mechanism, this shouldn’t be possible…
Sangamonian CO2 levels didn’t start falling (and possibly kept rising) until the cooling into the most recent glaciation had progressed 20,000 years.
The models can’t account for any of the observed cyclicity using only solar forcing. So they assume that CO2 forcing must be about 3-6 times greater than the instrumental data suggest. Funny thing: recent papers have concluded that solar forcing has been underestimated by a factor of six and CO2 forcing is much lower than the so-called consensus estimate.
As promised: A plant stomata treatise!
The so-called consensus will continue overestimating CO2 forcing until they accept the fact that ice core temperature estimates are at least an order of magnitude of higher resolution than ice core CO2 estimates. The ever-growing volume of peer-reviewed research on the relationship between plant stomata and CO2 will eventually force a paradigm shift.
Wagner et al., 1999. Century-Scale Shifts in Early Holocene Atmospheric CO2 Concentration. Science 18 June 1999: Vol. 284 no. 5422 pp. 1971-1973…
In contrast to conventional ice core estimates of 270 to 280 parts per million by volume (ppmv), the stomatal frequency signal suggests that early Holocene carbon dioxide concentrations were well above 300 ppmv.
[…]
Most of the Holocene ice core records from Antarctica do not have adequate temporal resolution.
[…]
Our results falsify the concept of relatively stabilized Holocene CO2 concentrations of 270 to 280 ppmv until the industrial revolution. SI-based CO2 reconstructions may even suggest that, during the early Holocene, atmospheric CO2 concentrations that were .300 ppmv could have been the rule rather than the exception.
The ice cores cannot resolve CO2 shifts that occur over periods of time shorter than twice the bubble enclosure period. This is basic signal theory. The assertion of a stable pre-industrial 270-280 ppmv is flat-out wrong.
McElwain et al., 2001. Stomatal evidence for a decline in atmospheric CO2 concentration during the Younger Dryas stadial: a comparison with Antarctic ice core records. J. Quaternary Sci., Vol. 17 pp. 21–29. ISSN 0267-8179…
It is possible that a number of the short-term fluctuations recorded using the stomatal methods cannot be detected in ice cores, such as Dome Concordia, with low ice accumulation rates. According to Neftel et al. (1988), CO2 fluctuation with a duration of less than twice the bubble enclosure time (equivalent to approximately 134 calendar yr in the case of Byrd ice and up to 550 calendar yr in Dome Concordia) cannot be detected in the ice or reconstructed by deconvolution.
Not even the highest resolution ice cores, like Law Dome, have adequate resolution to correctly image the MLO instrumental record.
Kouwenberg et al., 2005. Atmospheric CO2 fluctuations during the last millennium reconstructed by stomatal frequency analysis o fTsuga heterophylla needles . Geology; January 2005; v. 33; no. 1; p. 33–36…
The discrepancies between the ice-core and stomatal reconstructions may partially be explained by varying age distributions of the air in the bubbles because of the enclosure time in the firn-ice transition zone. This effect creates a site-specific smoothing of the signal (decades for Dome Summit South [DSS], Law Dome, even more for ice cores at low accumulation sites), as well as a difference in age between the air and surrounding ice, hampering the construction of well-constrained time scales (Trudinger et al., 2003).
Stomatal reconstructions are reproducible over at least the Northern Hemisphere, throughout the Holocene and consistently demonstrate that the pre-industrial natural carbon flux was far more variable than indicated by the ice cores.
Wagner et al., 2004. Reproducibility of Holocene atmospheric CO2 records based on stomatal frequency. Quaternary Science Reviews. 23 (2004) 1947–1954…
The majority of the stomatal frequency-based estimates of CO 2 for the Holocene do not support the widely accepted concept of comparably stable CO2 concentrations throughout the past 11,500 years. To address the critique that these stomatal frequency variations result from local environmental change or methodological insufficiencies, multiple stomatal frequency records were compared for three climatic key periods during the Holocene, namely the Preboreal oscillation, the 8.2 kyr cooling event and the Little Ice Age. The highly comparable fluctuations in the paleo-atmospheric CO2 records, which were obtained from different continents and plant species (deciduous angiosperms as well as conifers) using varying calibration approaches, provide strong evidence for the integrity of leaf-based CO2 quantification.
The Antarctic ice cores lack adequate resolution because the firn densification process acts like a low-pass filter.
Van Hoof et al., 2005. Atmospheric CO2 during the 13th century AD: reconciliation of data from ice core measurements and stomatal frequency analysis. Tellus 57B (2005), 4…
AtmosphericCO2 reconstructions are currently available from direct measurements of air enclosures in Antarctic ice and, alternatively, from stomatal frequency analysis performed on fossil leaves. A period where both methods consistently provide evidence for natural CO2 changes is during the 13th century AD. The results of the two independent methods differ significantly in the amplitude of the estimated CO2 changes (10 ppmv ice versus 34 ppmv stomatal frequency). Here, we compare the stomatal frequency and ice core results by using a firn diffusion model in order to assess the potential influence of smoothing during enclosure on the temporal resolution as well as the amplitude of the CO2 changes. The seemingly large discrepancies between the amplitudes estimated by the contrasting methods diminish when the raw stomatal data are smoothed in an analogous way to the natural smoothing which occurs in the firn.
The derivation of equilibrium climate sensitivity (ECS) to atmospheric CO2 is largely based on Antarctic ice cores. The problem is that the temperature estimates are based on oxygen isotope ratios in the ice itself; while the CO2 estimates are based on gas bubbles trapped in the ice.
The temperature data are of very high resolution. The oxygen isotope ratios are functions of the temperature at the time of snow deposition. The CO2 data are of very low and variable resolution because it takes decades to centuries for the gas bubbles to form. The CO2 values from the ice cores represent average values over many decades to centuries. The temperature values have annual to decadal resolution.
The highest resolution Antarctic ice core is the DE08 core from Law Dome.
The IPCC and so-called scientific consensus assume that it can resolve annual changes in CO2. But it can’t. Each CO2 value represents a roughly 30-yr average and not an annual value.
If you smooth the Mauna Loa instrumental record (red curve) and plant stomata-derived pre-instrumental CO2 (green curve) with a 30-yr filter, they tie into the Law Dome DE08 ice core (light blue curve) quite nicely…
The deeper DSS core (dark blue curve)has a much lower temporal resolution due to its much lower accumulation rate and compaction effects. It is totally useless in resolving century scale shifts, much less decadal shifts.
The IPCC and so-called scientific consensus correctly assume that resolution is dictated by the bubble enclosure period. However, they are incorrect in limiting the bubble enclosure period to the sealing zone. In the case of the core DE08 they assume that they are looking at a signal with a 1 cycle/1 yr frequency, sampled once every 8-10 years. The actual signal has a 1 cycle/30-40 yr frequency, sampled once every 8-10 years.
30-40 ppmv shifts in CO2 over periods less than ~60 years cannot be accurately resolved in the DE08 core. That’s dictated by basic signal theory. Wagner et al., 1999 drew a very hostile response from the so-called scientific consensus. All Dr. Wagner-Cremer did to them, was to falsify one little hypothesis…
In contrast to conventional ice core estimates of 270 to 280 parts per million by volume (ppmv), the stomatal frequency signal suggests that early Holocene carbon dioxide concentrations were well above 300 ppmv.
[…]
Our results falsify the concept of relatively stabilized Holocene CO2 concentrations of 270 to 280 ppmv until the industrial revolution. SI-based CO2 reconstructions may even suggest that, during the early Holocene, atmospheric CO2concentrations that were >300 ppmv could have been the rule rather than the exception (23).
I merged the data from six peer-reviewed papers on stomata-derived CO2 to build this Holocene reconstruction…
The plant stomata pretty well prove that Holocene CO2 levels have frequently been in the 300-350 ppmv range and occasionally above 400 ppmv over the last 10,000 years.
The incorrect estimation of a 3°C ECS to CO2 is almost entirely driven the assumption that preindustrial CO2 levels were in the 270-280 ppmv range, as indicated by the Antarctic ice cores.
The plant stomata data clearly show that preindustrial atmospheric CO2 levels were much higher and far more variable than indicated by Antarctic ice cores. Which means that the rise in atmospheric CO2 since the 1800’s is not particularly anomalous and at least half of it is due to oceanic and biosphere responses to the warm-up from the Little Ice Age.
As the Earth’s climate continues to not cooperate with their models, the so-called consensus will eventually recognize and acknowledge their fundamental error. Hopefully we won’t have allowed decarbonization zealotry to bankrupt us beforehand.
Until the paradigm shifts, all estimates of the pre-industrial relationship between atmospheric CO2 and temperature derived from Antarctic ice cores will be wrong… Because the ice core temperature and CO2 time series are of vastly different resolutions. And until the “so-called consensus” gets the signal processing right, Professor Nordhaus will continue to get it wrong.
References
Alley, R.B. 2000. The Younger Dryas cold interval as viewed from central Greenland. Quaternary Science Reviews 19:213-226.
Davis, J. C. and G. C. Bohling. The search for patterns in ice-core temperature curves. 2001. Geological Perspectives of Global Climate Change, AAPG Studies in Geology No. 47, Gerhard, L.C., W.E. Harrison,and B.M. Hanson.
Finsinger, W. and F. Wagner-Cremer. Stomatal-based inference models for reconstruction of atmospheric CO2 concentration: a method assessment using a calibration and validation approach. The Holocene 19,5 (2009) pp. 757–764
Fischer, H. A Short Primer on Ice Core Science. Climate and Environmental Physics, Physics Institute, University of Bern.
Garcıa-Amorena, I., F. Wagner-Cremer, F. Gomez Manzaneque, T. B. van Hoof, S. Garcıa Alvarez, and H. Visscher. 2008. CO2 radiative forcing during the Holocene Thermal Maximum revealed by stomatal frequency of Iberian oak leaves. Biogeosciences Discussions 5, 3945–3964, 2008.
Jessen, C. A., Rundgren, M., Bjorck, S. and Hammarlund, D. 2005. Abrupt climatic changes and an unstable transition into a late Holocene Thermal Decline: a multiproxy lacustrine record from southern Sweden. J. Quaternary Sci., Vol. 20 pp. 349–362. ISSN 0267-8179.
Kaufmann, R. K., H. Kauppi, M. L. Mann, and J. H. Stock (2011), Reconciling anthropogenic climate change with observed temperature 1998-2008, Proceedings of the National Academy of Sciences, PNAS 2011 : 1102467108v1-4.
Kouwenberg, LLR. 2004. Application of conifer needles in the reconstruction of Holocene CO2 levels. PhD Thesis. Laboratory of Palaeobotany and Palynology, University of Utrecht.
Kouwenberg, LLR, Wagner F, Kurschner WM, Visscher H (2005) Atmospheric CO2 fluctuations during the last millennium reconstructed by stomatal frequency analysis of Tsuga heterophylla needles. Geology 33:33–36
Ljungqvist, F.C.2009. Temperature proxy records covering the last two millennia: a tabular and visual overview. Geografiska Annaler: Physical Geography, Vol. 91A, pp. 11-29.
Ljungqvist, F.C. 2010. A new reconstruction of temperature variability in the extra-tropical Northern Hemisphere during the last two millennia. Geografiska Annaler: Physical Geography, Vol. 92 A(3), pp. 339-351, September 2010. DOI: 10.1111/j.1468-0459.2010.00399.x
Mann, M.E., Z. Zhang, M.K. Hughes, R.S. Bradley, S.K. Miller, S. Rutherford, and F. Ni. 2008. Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia. Proceedings of the National Academy of Sciences, Vol. 105, No. 36, September 9, 2008. doi:10.1073/pnas.0805721105
McElwain et al., 2001. Stomatal evidence for a decline in atmospheric CO2 concentration during the Younger Dryas stadial: a comparison with Antarctic ice core records. J. Quaternary Sci., Vol. 17 pp. 21–29. ISSN 0267-8179
Rundgren et al., 2005. Last interglacial atmospheric CO2 changes from stomatal index data and their relation to climate variations. Global and Planetary Change 49 (2005) 47–62.
Van Hoof et al., 2005. Atmospheric CO2 during the 13th century AD: reconciliation of data from ice core measurements and stomatal frequency analysis. Tellus 57B (2005), 4
Wagner F, et al., 1999. Century-scale shifts in Early Holocene CO2 concentration. Science 284:1971–1973.
Wagner F, Aaby B, Visscher H, 2002. Rapid atmospheric CO2 changes associated with the 8200-years-B.P. cooling event. Proc Natl Acad Sci USA 99:12011–12014.
Wagner F, Kouwenberg LLR, van Hoof TB, Visscher H, 2004. Reproducibility of Holocene atmospheric CO2 records based on stomatal frequency. Quat Sci Rev 23:1947–1954
@P. Solar,
The moving averages on the climate reconstructions are Excel trend lines. I should have calculated centered running averages. It’s just easier and quicker to use the basic Excel tools. I do most of this “work” on my lunch hours. Same thing with the polynomial trendline; plus, I don’t have the foggiest idea how to do Fourier transforms in Excel… Dif. Eq. was, “a long time ago in a galaxy far, far away…” (ca. 1979, across town from Yale). Figuring out how do Fourier in Excel is on my to do list.
I wouldn’t say that plant stomata are better than ice cores. They simply have better resolution because of their higher frequency content. They also have a lower signal-to-noise ratio. Once I figure out a way to do Fourier analysis in Excel, I plan to see if I can use the stomata data to build an operator for a signature deconvolution of the ice core signal. For the best explanation of this, see Van Hoof et al., 2005.
Sceptics make the point that warming has now stopped. A few commentators here have exercised great ingenuity to challenge that point on the basis of carefully selected datasets, carefully selected start and end points and even discarding data which doesn’t exactly fit and so must be wrong. As a reward for their efforts they do eventually succeed in fabricating a trend line showing minimal warming this century. As someone once said, “If you torture the data long enough then it will confess”.
Putting all this juggling aside, anyone who can read a graph can se that the warming trend at the end of the 20th. century has effectively stopped and assertions that warming is continuing at an accelerating pace are clearly wrong.
None of the climate models predicted this plateau in global temperatures. In consequence, as Henrik Svensmark says, their future projections are not reliable. The frightening aspect is that if by chance the Kyoto protocol or some other ‘last chance to save the world scenario’ had been successful, so that we bankrupted ourselves back to the stone age, then the prophets of doom would have claimed a great success. They would have said – Look, the warming has stopped now, we were right all along. But in reality CO2 emissions have increased by over 25% this century and the warming stopped anyway. So what happened to the runaway greenhouse effect and the ‘tipping points’ ?
As the greatest scientific scandal of all time continues to collapse faster than anyone thought possible, the ‘Daughter of Time’ has caught up with the lie.
David,
There are several problems with your article:
The actual signal has a 1 cycle/30-40 yr frequency, sampled once every 8-10 years.
30-40 ppmv shifts in CO2 over periods less than ~60 years cannot be accurately resolved in the DE08 core.
Here you are completely wrong. There is a lot of exchange in the zone above the sealing depth, even if that becomes less with increased firn density. At sealing depth, the ice age is about 40 years, but the average gas age is only 10 years older that in the atmosphere above (40 years of diffusion!). Below sealing depth, the average gas age is about 12 years older compared to the atmosphere with the bulk of the mixture between 7-20 years. A pulse of 20 ppmv during one year or a continuous increase/decrease of 2 ppmv over 20 years would be detected in the Law Dome ice core. See Fig. 11 in:
http://courses.washington.edu/proxies/GHG.pdf
Even a sinusoidal amplitude of 2 ppmv with a wavelength of 20 years can be detected in the DE08 ice core. There was no such variability in the past 110 years of direct measurements, ice cores and stomata data (neither in coralline sponges as d13C changes).
Not even the highest resolution ice cores, like Law Dome, have adequate resolution to correctly image the MLO instrumental record.
The lowest resolution Law Dome ice cores are below one decade, which gives an averaging over about 20 years, but with an accuracy of 1.2 ppmv (1 sigma). There is an overlap of about 20 years between the average gas age in the ice cores and the South Pole data:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_sp_co2.jpg
Thus no problem at all to image the South Pole (or MLO) instrumental record.
Stomatal reconstructions are reproducible over at least the Northern Hemisphere, throughout the Holocene and consistently demonstrate that the pre-industrial natural carbon flux was far more variable than indicated by the ice cores.
While stomata index data have some value as a high resolution proxy, one need to be cautious by interpretating the absolute values. By definition, plants grow on land, where huge hour by hour, day by day and year by year changes in CO2 level exist. While the local/regional bias in CO2 level is more or less accounted for by calibrating the SI data against… ice cores and direct data over the past century, there is no way to know how the local/regional bias changed over time. E.g. for The Netherlands, for one of the main places of SI data, the change in landscape/land use over the past millennium in the main wind directions (SW to NW) was enormous and even the main wind direction may have changed over the centuries (MWP and CWP vs. LIA).
The plant stomata data clearly show that preindustrial atmospheric CO2 levels were much higher and far more variable than indicated by Antarctic ice cores.
More variable, maybe, but unlikely. Much higher: impossible. While ice cores show an averaged figure over a longer time span, the averaging itself doesn’t change the average CO2 level. Thus if the SI data show an average higher (or lower) value than the ice cores over the same time span, the SI bias has changed and the SI data are too high (or too low).
The derivation of equilibrium climate sensitivity (ECS) to atmospheric CO2 is largely based on Antarctic ice cores. The problem is that the temperature estimates are based on oxygen isotope ratios in the ice itself; while the CO2 estimates are based on gas bubbles trapped in the ice.
The ECS can not be deduced from the CO2/temperature ratio, the opposite can: one can calculate the influence of temperature on CO2 levels. In pre-industrial times, the CO2 levels followed the temperature changes with ~800 years for a deglaciation, but with several thousands of years at a glaciation. At the end of the Eemian (the previous interglacial), as you showed, the CO2 levels remained high while temperature reached a new minimum. The subsequent ~40 ppmv drop didn’t show a discernable influence on temperature:
http://www.ferdinand-engelbeen.be/klimaat/eemian.html
that points to a very low impact of CO2 on temperature.
It doesn’t make much difference for the influence of temperature on CO2 levels if the CO2 levels are smoothed or not. The current seasonal ratio is ~5 ppmv/°C, the year by year variation around the trend is ~4 ppmv/°C and the MWP-LIA and glacial/interglacial ratio is ~8 ppmv/°C. Thus the frequency of the change has very little influence (maximum factor 2) on the CO2/temperature ratio.
Graphite says:
March 4, 2012 at 1:30 am
But I would like to have the “hockey stick” question cleared up.
It’s the Irish kind where the stick is used by the players to batter the hell out of each other.
Professor Nordhaus states,
Yes! By all means, let’s have a look at some long-term trends. Let’s take the long-term trend back to a time when mankind wasn’t burning much fossil fuel.
The temperature of the last two decades, however, is possibly higher than during any previous time in the past two millennia, although this is only seen in the instrumental temperature data and not in the multi-proxy reconstruction itself.
Exactly, If you are confident with the proxi data for the past you should be confident with it in the present, you cannot splice instrumental temperature data onto proxy data, it`s apples and pears, hence the divergence with proxy and instruments after 1960.
Norman Page says:
March 3, 2012 at 3:23 pm
For more on CO2 see the paper by Jaworowski and paricularly the fig in there from and references to Becks 2007
Sorry, but the objections of the late Jaworowski were rebutted by the work of Etheridge e.a. on the Law Dome ice cores, already published in 1996. Since then, Jaworowski didn’t change his mind. Not really good for a ice core specialist. See:
http://www.ferdinand-engelbeen.be/klimaat/jaworowski.html
And I had some 2 years of discussion with the late Ernst Beck about the historical data: many of them are measured over land, near huge sources and sinks and are completely unsuitable to know the average CO2 levels in the bulk atmosphere. Measurements taken over the oceans or coastal with wind from the seaside are around the ice core data. See further:
http://www.ferdinand-engelbeen.be/klimaat/beck_data.html
feet2thefire says:
March 3, 2012 at 7:28 pm
Far out. This aligns with Slocum 1955 (http://tiny.cc/soubs), which re-assessed the Callendar 1938 (http://tiny.cc/g63qo – paywalled) value of 290 ppm for the 19th century. Slocum arrived at a value of 335 – from the same data – simply by not cherry-picking the data.
The plant stomata graph also shows a LOT of CE 1000-2000 values above 300 ppm, with 12 values above 350 ppm.
When will some skeptics learn to be real skeptics? Of course one must be skeptic to anything that is said by anyone. But one need to be consequent. If one rejects the temperature readings/trends made on parking lots and asphalted roofs, one must reject all historical CO2 readings taken in towns, forests and fields. That is what Callendar mainly did. If you don’t do that, one can find CO2 levels of over 400 ppmv in Germany and in the same year 1942, 250 ppmv in the USA. Both are biased, as taken over land near huge sources and/or sinks where one can find any level, depending of the time of the day…
There is a difference between cherry picking data and selecting data based on quality, instead of lumping all data together: the good, the bad and the ugly…
Reblogged this on and commented:
A pleasantly long post from WUWT, showing, among other things, the absurdity of the brief temperature record used in a recent New York Review of Books piece.
I agree with you, Rosco. The climate academics don’t seem to realize how eminently useful it is to increase the temperature of something by 10% (33c). To build a heater from something cheap and common like cold, rarefied air would be an amazing feat. I don’t need the full 33C, just give me a small part of that heat pump action for my living room. Venture capital would throw heaps of money on a start-up company that could do that–Gleik would be so rich he could buy Nissan Leaf’s for his cats.
A mathematician, a physicist, and an economist were interviewed interviewed by the NYT Review of Books as candidates to write an article on AGW.
In each case, the interview went along famously until the last
question was asked: “How much is one plus one?”
Each of them suspected a trap, and was hesitant to answer.
The mathematician thought for a moment, and said
“I’m not sure, but I think it converges”.
The physicist said
“I’m not sure, but I think it’s on the order of one”
The economist got up, went over and closed the door to the office,
came back, leaned over the desk, and said
“How much do you want it to be?”.
The economist got the job.
I am not a “skeptic”, I am a lover of the truth. I expect that people who hold themselves out to be “scientists” do so because they seek where facts, logic and data take them, not because they see “facts, logic and data” can be useful to take them where they desire to go.
Hardly a week goes by without some new revelation about how a “scientist” has corrupted science, perjured himself or suborned perjury of his peers.
I had long suspected this was the case. For me the tip-off was when I noticed that coincidentally all the proposed solutions took society to the same place: to a bigger government and to far less personal liberty.
I am happy to let good research speak for itself. If human activity is in fact giving us a harmful climate, then we must work towards modifying the factors that will cause harm. But we cannot rush to solution first, science later. As it is, we have over-committed our finite economic resources to wealth transfer payments. There is simply no money to waste on impractical and counterproductive schemes, that is unless facts, logic and data simply do not matter.
As an economist, I am completely embarrassed to see Nordhaus stepping out like this to pretend to be an expert in this climate science field. I also feel bad for any students being exposed to this. A lot of economists have been become prominent in the global warming policy and science debates and their lack of perspective is glaring.
@ur momisugly jim
Despite my own scepticism, I have a problem with your challemge to the unsceptical.
What evidence would you accept?
For the sake of discussion, assume for one moment that they are right. What evidence could they then bring forward that would satisfy you?
For instance, I’d have accepted it as strong evidence if real world temperatures had followed the model forecasts. I would not accept their proposed solution necessarily follows from that, but its an example of what I mean. The evidence they offer (that I’ve seen) does not prove their case. But if you’re merely looking at the evidence and demanding “show me the evidence, I don’t see any evidence” then you aren’t doing your argument any good, nor the reputation of your fellow sceptics.
Correction regarding the photo at the start of this piece:
The lagoon is not constantly growing as it exits to the sea within a mile or two from where the glacier calves into the lagoon.
Any surplus simply spills into the Atlantic.
I was there last summer. Seals can be observed swimming amongst the calved bergs.
Ferginand Engelbeen
Thanks for your links to your careful reviews of Beck and Jarowowski. You make very persuasive arguments. Regards Norman Page
Professor William D. Nordhaus claims it’s still getting warmer.
I just have to question the intelligence or objectivity of anybody who claims it’s still warming. Yes, this decade is warmer than last. No, it hasn’t become warmer this decade. The warming peaked last decade and there is a gradual downward trend.
Since we haven’t been warmer than the peak last century, it must be a deliberate misstatement to claim it’s still getting warmer. In other words, no the climate is not currently warming.
It’s a funny thing about the models — run the models with the estimated decreases in emissions if the Kyoto protocol was completely enacted. How do the results differ when the models are run with Kyoto and without Kyoto? No practical difference whatsoever.
Somebody should enlighten Professor Nordhaus.
Ferdinand Engelbeen says:
March 4, 2012 at 4:51 am
“If one rejects the temperature readings/trends made on parking lots and asphalted roofs, one must reject all historical CO2 readings taken in towns, forests and fields. That is what Callendar mainly did. If you don’t do that, one can find CO2 levels of over 400 ppmv in Germany and in the same year 1942, 250 ppmv in the USA. Both are biased, as taken over land near huge sources and/or sinks where one can find any level, depending of the time of the day…”
That raises the question- is there a “normal” amount of CO2 in the atmospshere, or does it variy all over the place like temperature? If CO2 content varies all over like temperature, then measuring CO2 at Mauna Loa and giving that as the average CO2 in the atmospherre makes about as much sense as taking daily temperatures at Mauna Loa and calling that the average world temperature. It seems to me that it would make more sense to take samples all over the world at different times and altitudes, and use some sort of averaging, as is attempted with temperatures.
Alan D McIntire says:
March 4, 2012 at 10:36 am
Ferdinand Engelbeen says:
March 4, 2012 at 4:51 am
“If one rejects the temperature readings/trends made on parking lots and asphalted roofs, one must reject all historical CO2 readings taken in towns, forests and fields. That is what Callendar mainly did. If you don’t do that, one can find CO2 levels of over 400 ppmv in Germany and in the same year 1942, 250 ppmv in the USA. Both are biased, as taken over land near huge sources and/or sinks where one can find any level, depending of the time of the day…”
That raises the question- is there a “normal” amount of CO2 in the atmospshere, or does it variy all over the place like temperature? If CO2 content varies all over like temperature, then measuring CO2 at Mauna Loa and giving that as the average CO2 in the atmospherre makes about as much sense as taking daily temperatures at Mauna Loa and calling that the average world temperature. It seems to me that it would make more sense to take samples all over the world at different times and altitudes, and use some sort of averaging, as is attempted with temperatures.
==================
The ‘well-mixed background’ of CO2 is a AGW con – from every angle.
Where was Keeling doing his work before Hawaii? Where there is practically no life producing carbon dioxide, except for some volcanic activity which some reckon interferes with the readings they have there. Not enough to present the ‘coal is bad’ with ‘science’ to back it up, make no mistake here, that was the agenda. And they managed to get funding to measure this ‘well-mixed background’ in – one of the world’s greatest CO2 producing areas! Come off it, if that doesn’t immediately strike you as absurd that any scientist would go to such an area and claim he could separate out this ‘well-mixed background’ levels from the top of the world’s largest volcano, with constant activity from other vocanoes, from thousands of quakes every year in warm seas over a massive hot spot creating volcanic island, and be believed.. And this poster child place is sold as being in a “pristine” spot for measure carbon dioxide.
Well, it took him less than two years to find a definite trend that man-made carbon dioxide background levels were rising – less than two years. Is that how scientists find annual trends? How on earth from that region could he say anything about ‘man-made CO2’ when there’s no real signature difference anyway? And have you looked at how they get their ‘background’ figures? They set their own limits, they simply decide what is going to be called volcanic and what background! There is no way, no way, that they can separate out anything ‘background’ from that place which is constantly releasing carbon dioxide into the atmosphere. It’s all volcanic smoke and mirrors.
I’m sorry, Ferdinand, I realise these data churning out the ever rising Keeling curve is seldom questioned, but that can only be from those who haven’t taken the history of this into consideration. They began with an agenda, and over the next few decades they got to run the other stations. There was a reason for choosing the lowest numbers they could, and that from discredited surveys.
However, that aside, where do expect to find carbon dioxide? This isn’t really like uhi, because where there’s life there is going to carbon dioxide. Plants produce it themselves when they’re not using it for photosynthesis, they breathe in oxgen and breathe out carbon dioxide as we do. The more lush the plant life, the more carbon dioxide there will be.
And, it cannot be separated out from its natural cycle – and here again shows that an agenda is at work to push the ‘well-mixed’. The strange fisics of the AGW energy budget has CO2 ‘accumulating in the atmosphere for hundreds and even thousands of years’ – how? For a start it’s heavier than air and will always sink to the ground unless work is done to move it, and, it is fully part of the great Water Cycle – it spontaneously joins with water vapour in the air and as that condenses out in the colder heights they come down together as rain, all pure clean rain is carbonic acid. There’s no ‘accumulating’ of some supermolecule defying gravity or saying no to water vapour..
And, my final point, the AIRS conclusion was that Carbon Dioxide was not well mixed – and it surprised them because they thought this meme was real physics. We haven’t got that data – they haven’t released any of the top or bottom of the troposphere. And what we do have from the mid has been air-brushed into oblivion, a couple of well-chosen pics to make it as least representative of the actual shock they got that it wasn’t well-mixed. And, in their conclusion they said they would have to look at ‘winds’ to try and explain what they found. Winds?? Maybe this was lost on most reading it, but they have consistently claimed that carbon dioxide acts like an ideal gas and that the atmosphere is empty space! They don’t have winds in the fisics of their carbon dioxide! It diffuses instantly into this ideal gas empty space atmosphere where all the molecules are zipping through at vast speeds bouncing off each other and so thoroughly mixing, without interactions! They don’t have the water cycle, because that isn’t ideal gas scenario ‘thoroughly mixing’, where it’s just empty space and molecules without volume or interactions apart from bouncing of each other in elastic collisions so ‘thoroughly spreading through the empty space atmosphere’ to create this fictional ‘background’.
I tried to download the raw AIRS of mid-troposphere a couple of years back, but my computer wasn’t up to it. But their conclusion stands even if we don’t have the raw data. They said carbon dioxide is not at all well-mixed, it is lumpy, and they said that it was insignificant against the water vapour effect.
Their whole energy budget is nonsense, but certainly their figures for carbon dioxide can’t be trusted, nor their fisics about it. Carbon dioxide by its nature is going to be predominantly localised.
Alan D McIntire says:
March 4, 2012 at 10:36 am
There is a huge advantage of CO2 measurements compared to temperature readings. CO2 is quite readily dispersed over the bulk of the atmosphere, what gives that one can find the same CO2 levels within +/- 10 ppmv all over the oceans and above 1000 m over land. That is over 95% of the atmosphere. The problematic readings are in the remaining 5%: near surface over land, because there are most huge and fast sources and sinks. One can find 550 ppmv at night during an inversion and 350 ppmv during the day when there is more wind and photosynthesis is at work. Take a look at the difference in measured CO2 levels during a few days at Giessen (where an important series of historical measurements were taken in the period 1939-1942) and at the South Pole, Barrow and Mauna Loa, where baseline stations are situated:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/giessen_background.jpg
All data are raw data without any cleaning or selection.
Of course, as there are huge sources and sinks at work, not all measurements everywhere in the bulk of the atmosphere are the same at the same moment. The seasonal changes in the NH (with more land/vegetation) can go up to +/- 8 ppmv around the trend, but the opposite variability in the SH (more ocean) is only +/- 1 ppmv:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/month_2002_2004_4s.jpg
And there is a lag in the trend with altitude and for the SH compared to the NH, as the main source of extra CO2 is near ground in the NH and the ITCZ slows the exchange of air masses between the NH and the SH. But if you look at theslope of the yearly trends, these are near equal everywhere in the bulk atmosphere:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/co2_trends_1995_2004.jpg
Lots of graphs and data from CO2 (and other gases) in air measurements, as well as over the oceans as over land + airplane can be found at:
http://www.esrl.noaa.gov/gmd/ccgg/iadv/
Myrrh says:
March 4, 2012 at 12:27 pm
Please Myrrh, before you accuse somebody of having an agenda, read his autobiography at:
http://scrippsco2.ucsd.edu/publications/keeling_autobiography.pdf
Not enough to present the ‘coal is bad’ with ‘science’ to back it up, make no mistake here, that was the agenda.
C.D. Keeling was mainly interested in good CO2 measurements. Global “warming” was not even at order in the 1950’s and the global “cooling” scare of the 1970’s was yet to come.
Come off it, if that doesn’t immediately strike you as absurd that any scientist would go to such an area and claim he could separate out this ‘well-mixed background’ levels from the top of the world’s largest volcano
If you had read his biography, you would know that the first measurements were at the South Pole, not Mauna Loa. Mauna Loa is mostly taken as base, simply because it has the longest continuous series, the South Pole misses a few years. And as the CO2 levels at Mauna Loa are mostly real background it is quite simple to recognise interferences from the volcano vents (+4 ppmv and huge variability) or upwind depleted air from valley vegetation (-4 ppmv).
Moreover, as far as I know, there is no vegetation around the South Pole, neither volcanoes for at least 1,000 km, but that station gives near the same CO2 levels, except for less seasonal disturbances and a lag.
And, my final point, the AIRS conclusion was that Carbon Dioxide was not well mixed
Depends what you call “not” well mixed. If 20% of all CO2 in the atmosphere is exchanged with other reservoirs over the seasons, and AIRS detects monthly average differences of +/- 8 ppmv, that is 2% of the total amount of CO2 in the atmosphere, well I call that very well mixed. It takes time to mix an extra amount or a deficit into the bulk of the atmosphere. Days to weeks for the same height and latitude band, weeks to months for different latitudes and altitudes in the same hemisphere and months to years between the hemispheres.
For a start it’s heavier than air and will always sink to the ground unless work is done to move it, and, it is fully part of the great Water Cycle
Myrrh, have you ever put a few drops of a perfume at one end of a room (molecules which can be tens to hundreds of times heavier than air) and waited at the other end? CO2, once mixed in air by wind or turbulence will stay in the air nearly forever, if not catched by the oceans or vegetation. It is measured in near the same concentrations from near ground to 12 km height and beyond. Lookup Brownian motion… Only in stagnant air, like in firn, it increases somewhat at the bottom: 1% after 40 years…
CO2 is a little soluble in fresh water, thus rain contains a little CO2, but that was first released when water evaporated, that hardly influences the total amount in the atmosphere.
Daveo says:
March 4, 2012 at 1:56 am
Pick the right cherries; you can make a nice pie. Pick some other cherries; your pie will taste completely different.
I agree! Look at the pie that my cherries make.
Following is the longest period of time (above10 years) where each of the data sets is at least slightly negative (or flat for all practical purposes).
RSS: since December 1996 or 15 years, 2 months
HadCrut3: since March 1997 or 14 years, 11 months
GISS: since August 2001 or 10 years, 6 months
UAH: It never quite reaches a negative value but it might with the February or March numbers.
Combination of the above 4: December 2000 or 11 years, 1 month
Sea surface temperatures: February 1997 or 15 years, 0 months
See the graph below to show it all.
http://www.woodfortrees.org/plot/hadcrut3gl/from:1997.17/trend/plot/gistemp/from:2001.58/trend/plot/rss/from:1996.92/trend/plot/wti/from:2000.92/trend/plot/hadsst2gl/from:1997.08/trend
Ferdinand Engelbeen says:
March 4, 2012 at 4:51 am
I agree for the argument of not using different town and field sites compared with others around the world (absolute values). But, why not use anomaly changes for these sites at the same location up to now, as at least some of these should be reliable and be reasonable data to assist between ice core and instrumental data. (since the 1960’s) Basically this happens to all global temperature stations where only anomaly values are considered.
For example a town may had values early 20th century around 400ppm, but now could be around 490 ppm. Showing a 90 ppm rise over this period, so the absolute value may not be that important, but the change is. May give a more accurate veiw of how CO2 levels had increased before proper stations were first introduced (around 1960’s)
Speaking of cherry picking – EXCELLENT work doing exactly that :rollseyes
Since “those that say they know” claim we need 15 years minimum to determine a trend … try HADCRUT, RSS MSU, and HADSST2 for the last 15 years – from 1997 to present – one by land, one by air, and one by sea ….
http://goo.gl/rE5tZ
Matt G says:
March 4, 2012 at 1:36 pm
I agree for the argument of not using different town and field sites compared with others around the world (absolute values). But, why not use anomaly changes for these sites at the same location up to now, as at least some of these should be reliable and be reasonable data to assist between ice core and instrumental data.
The main problem is that there are very few long term series at the same place. And those which exist show such a huge variability, that it is difficult to draw any conclusion from the data. Modern continuous data over land show an average trend similar to the bulk atmospheric data, but that is of little help if you have a long historical series with three samples a day, where two of the samples were taken at the flanks of rising and dropping CO2 levels. Even a small time change of 15 minutes in sampling gives already a huge change in CO2 levels. See the modern day CO2 levels in one day at Linden/Giessen:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/giessen_2005-07-14.jpg
The historical samples were taken at 7 am, 2 pm and 9 pm.
High wind speeds are of help in modern day measurements, as that mixes the near ground levels with the bulk of the atmosphere. But unfortunately the interesting historical series have too few datapoints at high wind speed. See for some background information:
http://meteo.lcd.lu/papers/co2_patterns/co2_patterns.html