June 8, 2009
Mike MacCracken attended my George C. Marshall Institute seminar titled ”Considering the Human Influence on Climate” on May 14 2009. First I want to thank the Institute again for graciously inviting me to present a lecture, and for encouraging the open participation by climate scientists and others of all viewpoints.
I also want to thank Mike for attending and for the time he took to complete his weblog. While he and I disagree on a number of substantive issues, he is willing to engage in constructive discussions, unlike quite a few others who are involved in the IPCC and CCSP process.
Mike has posted a summary of my talk titled “Michael MacCracken’s review of Roger Pielke, Sr.’s May 14 climate talk to the Marshall Institute”. While, he correctly summarized much of the talk, his summary does need clarification and correction in places. Below, I will comment on these issues in which we disagree.
1. Mike’s comment:“Pielke noted that the term “climate change” was not the right term to be using because climate was always changing. True, but by how much and how rapidly really matters. The recent pace of change is very unusual, given the present set of surface conditions (i.e., we do not have continental ice sheets melting around the Northern Hemisphere).”
The climate system has had much larger natural excursions in the recent past. We provide examples in
Rial, J., R.A. Pielke Sr., M. Beniston, M. Claussen, J. Canadell, P. Cox, H. Held, N. de Noblet-Ducoudre, R. Prinn, J. Reynolds, and J.D. Salas, 2004: Nonlinearities, feedbacks and critical thresholds within the Earth’s climate system. Climatic Change, 65, 11-38
and
Pielke Sr., R.A., 2008: Global climate models - Many contributing influences. Citizen’s Guide to Colorado Climate Change, Colorado Climate Foundation for Water Education, pp. 28-29.
We also need to make sure we do not use the term “climate change” when we are referring to “global warming or cooling”. Climate variability and change cover a much wider set of influences on society and the environment (e.g. see).
2. Mike’s comment: “He then made the point that CO2 is not like a traditional pollutant in that CO2 is and has always been a part of the climate system. He later said that it should not therefore be regulated like a traditional pollutant—suggesting that it would seem that with EPA treating it as a pollutant needing to be regulated, in the future EPA could regulate water vapor and land cover. On these points Pielke is being quite sloppy—methane, non-methane hydrocarbons, carbon monoxide, nitrogen oxides, and ozone are all present naturally and are being regulated as pollutants.”
Mike is the one who is not accurate here. Human caused emissions of “methane, non-methane hydrocarbons, carbon monoxide, nitrogen oxides, and ozone“ can result in atmospheric concentrations, that humans are exposed to, that have direct health effects, while CO2 at current, or even doubled or tripled atmospheric concentrations, does not.
3. Mike’s comment: “The focus solely on CO2 is mainly in the media and so in the public discussion—mainly to keep the matter focused and not to make things overwhelmingly complex. In addition, for the long-term (over centuries to millennia), CO2 is the major factor contributing to climate change (as indicated by the recent paper in Proceedings of the National Aacdemy of Sciences by Susan Solomon).”
The claim that CO2 is dominant over centuries to millennia is oversimplistic. Landscape and aerosol emissions (e.g. dust, fires) also have long term changes. Mike agrees the climate system involves these forcings, so he should be more vocal about letting the policymakers know this.
Moreover, with respect to policy actions, we are focusing on the coming decades, where all of the climate forcings that we identified in the 2005 NRC report are occurring; see
National Research Council, 2005: Radiative forcing of climate change: Expanding the concept and addressing uncertainties. Committee on Radiative Forcing Effects on Climate Change, Climate Research Committee, Board on Atmospheric Sciences and Climate, Division on Earth and Life Studies, The National Academies Press, Washington, D.C., 208 pp.
Policymakers need to be correctly informed of the diversity of human climate forcings that are altering local, regional and global climate. The IPCC and CCSP reports did not provide an accurate report to policymakers on this fundamental climate science issue.
Mike writes “The focus solely on CO2 is mainly in the media and so in the public discussion—mainly to keep the matter focused and not to make things overwhelmingly complex”. This narrow focus, also results in erroneous information being communicated to the public and policymakers!
4. Mike’s comment: “As specific illustrations of his assertion, Pielke showed the trends in satellite-derived observations of tropospheric and stratospheric temperatures (interestingly, and sensibly, using the RSS data set), indicating that while the former showed warming over the last four decades and the latter showed cooling over this period, the results for the last 10 years did not show the expected trends.”
I presented the RSS data since their figures were easier to extract from their webpage than the corresponding analysis of the UAH group. Both analyses show a lack of lower tropospheric warming in recent years. However, from your comment, it appears you have concluded the RSS analyses are superior. This issue was addressed, however, in an independent assessment and reported in the peer reviewed literature;
Randall R. M., B. M. Herman (2008), Using limited time period trends as a means to determine attribution of discrepancies in microwave sounding unit–derived tropospheric temperature time series, J. Geophys. Res., 113, D05105, doi:10.1029/2007JD008864.
I reported on this paper on my weblog (see), where I concluded that
“While both UAH and RSS are outstanding research groups, with respect to the assessment of multi-decadal tropospheric temperature trends, the independent comparison reported in Randall and Herman indicates that the trend values of the UAH group are more accurate.”
5. Mike’s comment: “For sea ice, Pielke suggested that Arctic sea ice had recovered its average area this past winter and Antarctic sea ice cover had recently been increasing, drawing the conclusion that sea ice feedback is not monotonic.”
I did not report that the Arctic sea ice has recovered to its long terms average (see my slide 8). Arctic sea ice has been below average for several years, and we published on this issue even before the more recent greater decline; see
Pielke Sr., R.A., G.E. Liston, and A. Robock, 2000: Insolation-weighted assessment of Northern Hemisphere snow-cover and sea-ice variability.J. Geophys. Res. Lett., 27, 3061-3064.
Pielke Sr., R.A., G.E. Liston, W.L. Chapman, and D.A. Robinson, 2004:Actual and insolation-weighted Northern Hemisphere snow cover and sea ice — 1974-2002. Climate Dynamics, 22, 591-595 DOI10.1007/s00382-004-0401-5.
6. Mike’s comment: “…..he suggested, measuring the temperature at 2 meters above the surface tends to yield a warm bias—for reasons that seemed to me a bit obscure during his lecture.”
The paper below provides a discussion of the reason for this bias. We have another paper, almost through the review process, which shows this is a global scale issue for all land areas.
Lin, X., R.A. Pielke Sr., K.G. Hubbard, K.C. Crawford, M. A. Shafer, and T. Matsui, 2007: An examination of 1997-2007 surface layer temperature trends at two heights in Oklahoma. Geophys. Res. Letts., 34, L24705, doi:10.1029/2007GL031652.
7. Mike’s comment: …”many other variables suggest that the surface temperature is rising. For example, snow cover is retreating; ranges of species are shifting, etc.”
Observational data conflicts with Mike’s assertion. Although not specifically on the range of species, with respect to phenology (see) the new White et al 2009 article reported on in that weblog writes
“We found no evidence for time trends in spring arrival from ground- or model-based data; using an ensemble estimate from two methods that were more closely related to ground observations than other methods, SOS trends could be detected for only 12% of North America and were divided between trends towards both earlier and later spring.”
For northern hemisphere snow cover, see from the Rutgers Snow Lab, where since about 1988 there has been no clear long term trend in this metric of snow cover.
8. Mike’s comment: ” …it seems to me that while land cover change can indeed affect local weather, even by significant amounts, and might well need to be locally regulated, the increase in the CO2 concentration is very dramatically altering the underlying baseline climate for everyone in the world—and so it has drawn the attention of international regulators.”
Mike has ignored, or is unaware, of the rich literature that documents that human caused landscape results in alterations of regional and global climate including; for example, the Asian monsoon (e.g. see); the summer weather over the eastern USA (e.g. see); and planetary circulation patterns (e.g. see). A NASA press release on our Florida research effectively summarizes this issue (see).
9. Mike’s comment: “I also agree with Pielke that the spatial variations in aerosols and their forcing should be considered, but I am more interested in scales larger than in the more localized areas that Pielke seemed to focus on.”
Mike and I agree on this issue. I am also concerned about scales larger than localized areas. However, Mike is inconsistent in his conclusion. If spatial variations in aerosol heating are important in terms of their role in altering regional scale circulation features, land use/land cover change, and other aspects of landscape dynamics, should be of a comparable importance.
10. Mike’s comment: “Near as I could discern, he believes the main problem is that IPCC and other assessments are not, even after review, sufficiently accounting for his views on the effects of land cover change on the regional weather and climate.”
My concerns with the assessment process are much more significant than just that my per reviewed viewpoint on the important climate issues was excluded. The problem with the assessment process is that indepedent evaluations of them are not being completed. I have documented the resulting narrowness of the IPCC and CCSP assessments in detail, and invite Mike to respond to the specific concerns that I report. This documentation can be read at
Pielke Sr., Roger A., 2005: Public Comment on CCSP Report “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences“. 88 pp including appendices.
Protecting The IPCC Turf - There Are No Independent Climate Assessments Of The IPCC WG1 Report Funded And Sanctioned By The NSF, NASA Or The NRC.
The appendices in Pielke Sr., Roger A., 2008: A Broader View of the Role of Humans in the Climate System is Required In the Assessment of Costs and Benefits of Effective Climate Policy.Written Testimony for the Subcommittee on Energy and Air Quality of the Committee on Energy and Commerce Hearing “Climate Change: Costs of Inaction” – Honorable Rick Boucher, Chairman. June 26, 2008, Washington, DC., 52 pp.
11. Mike’s comment: “On the question of having the author teams be neutral, I don’t think a coherent vision emerged. For this to be implemented, these neutral authors would, at the start, have to not be doing research in the area, for it would not be helpful to change the process if all that we ended up with was a new set of authors citing their own work.”
The assumption that the authors would be “neutral” or “not to be doing research in the area” is not correct. There are many well-qualified climate scientists working on climate research, who do not have the significant vested interest in the outcome of a climate assessment.
As an example of the current conflict of interest, Tom Karl was Chair of the committee evaluating the quality of his own surface temperature trend data in the CCSP Report “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences“. I was strong-armed on that committee to accept Tom Karl’s conclusion on the robustness of his data and analyses. This failure in the assessment process led us subsequently to complete our own multi-authored peer reviewed assessment which we reported on, for example, in
Pielke Sr., R.A. J. Nielsen-Gammon, C. Davey, J. Angel, O. Bliss, N. Doesken, M. Cai., S. Fall, D. Niyogi, K. Gallo, R. Hale, K.G. Hubbard, X. Lin, H. Li, and S. Raman, 2007: Documentation of uncertainties and biases associated with surface temperature measurement sites for climate change assessment. Bull. Amer. Meteor. Soc., 88:6, 913-928.
Pielke Sr., R.A., C. Davey, D. Niyogi, S. Fall, J. Steinweg-Woods, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res., 112, D24S08, doi:10.1029/2006JD008229.
12. Mike’s comment: “In seeking win-win strategies, Pielke also urged that the climate effects of all factors, including natural variability, be accounted for in addition to the climate change effects of greenhouse gases. Well, the National Assessment urged that as well. Indeed, regional assessment leaders were urged to consider three types of scenarios for the 21st century: (a) a repeat of the 20th century climate, but with altered societal conditions; (b) the changes in climate projected by a set of climate models (unfortunately, appropriate and complete model results were then available from only two modeling groups, although less complete results could also be used in some analyses); and (c) based on longer-term paleoclimatic data (derived, for example, from tree-ring reconstructions and other means), evaluate where sensitive thresholds might be and their likelihood and consequences. It is true that the first (and so far only) time through the National Assessment process most of the emphasis was on the use of the model-based scenarios, but the intent was there (although unfortunately not the resources and the time)—the effort really needed to be continued and improved rather than halted as the Bush-43 Administration ended up doing”.
I am glad that Mike and I agree on the scenario approach above. However, the choice of ONLY the model-based scenarios resulted in a seriuosly incomplete miscommunication to policymakers of the actual possible threats we face in the future. I urge Mike to encourage funding in the current Administation for such an inclusive vulnerability assessment.
13. Mike’s comment: “I would also note that I do not think that scientists should be asked what they “believe,” but instead what their analysis and interpretation of the evidence indicates.”
I agree with Mike on this. However, he is in error in reporting what is written on my powerpoint slide on this issue. I wrote “The climate science community should be polled with respect to which of the following three hypotheses have been rejected” (see slide 53).
14. Mike’s comment: “in that for four IPCC assessments there has been unanimous acceptance of the IPCC chapters by the nations of the world without any nation taking exception..”
Mike is mixing up a political acceptance of the chapters with the scientific rigor of the assessments. We have completed a preliminary poll of the climate science community (see) and found more diversity of perspectives than claimed by Mike’s statement of the “unanimous acceptance of the IPCC chapters”.
15. Mike’s comment: “Overall, my sense was that this was a more thoughtful discussion of the issues than Prof. Pielke has presented in the past—and one that one could engage with. So, that’s progress. ”
I agree with Mike on this, and welcome his contributution to a constructive debate. I also want to thank again the George C. Marshall Institute for their graciousness in providing a venue so that these discussions can take place. We need more such opportunities, if the public and policymakers are going to be provided the true diversity of viewpoints by climate scientists on the role of humans within the climate system.
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February 2, 2009
In response to a request for a further discussion of the term “unmasking”, as discussed in the weblog Can The Climate System “Mask” Heat?, I provide more information below.
The use of the term “unmasking”, as used by Professor Ramanathan and Feng, is not an appropriate synonym to describe the removal of a radiative forcing (or other forcings). The accurate terminology is the removal of an ”offset”. This is more than semantics, since the term “unmasking” used in the Ramanathan and Feng, 2008 paper appears to have a broader meaning, as discussed below.
The term “unmasking”, as used by Ramanathan and Feng, implies an accumulation of heat that has occurred while the forcing was “masked”, but which will appear when the offset is removed. In reality the heat will only start to accumulate once the offset is removed. Over the last four years, for example, there has been little if any heat accumulation in the climate system. Thus there is no GHG stored heat to be released from these four years, as implied in the statement by Ramanthan that there is “GHGs-forcing stored in the oceans”.
His text that
“About 90% or more of the rest of the committed warming of 1.6°C will unfold during the 21st century, determined by the rate of the unmasking of the aerosol cooling effect by air pollution abatement laws and by the rate of release of the GHGs-forcing stored in the oceans.”
should be written as
”The positive radiative forcing of well-mixed GHG gases during the 21st century will not be offset by an aerosol cooling effect, if these aerosols are eliminated by air pollution abatement laws. The actual change in the heat content of the climate system in Joules will depend on the integrated effect of all of the remaining human and natural radiative forcings and feedbacks, which would still include the well-mixed GHGs as one of the first-order forcings. The climate system will be warmer without these aerosols, but until we better understand the net effect of the remaining forcings, we do not know how the heat in Joules will change in the 21st century.”
Thus, while I agree wth Ramanathan and Feng that the elimination of the aerosol cooling effect would remove an offset to the radiative warming from the well-mixed greenhouse gases, the term “unmasking” has a broader possible interpretation. The term “unmasking” implies that an accumulation of the positive heating (i.e. an accumulation of Joules) is occuring while the offset is present. The terminology “removal of an offset” is clearer.
The Ramanthan and Feng article also continue to use the over-simplified model of the radiative forcing based on a global average surface temperature trend, which as we have shown in
Pielke Sr., R.A., C. Davey, D. Niyogi, S. Fall, J. Steinweg-Woods, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res., 112, D24S08, doi:10.1029/2006JD008229.
and
Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer. Meteor. Soc., 84, 331-335.
is an inadequate metric of global warming and cooling.
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Marcel Crok asked an interesting and important question
Can The Climate System “Mask” Heat?
This question is important because the use of this concept appears in the peer reviewed literature; e.g. see
Ramanathan, V. and Y. Feng, 2008: On avoiding dangerous anthropogenic interference with the climate system: Formidable challenges ahead, PNAS, 105, 14245-14250, Sept 23, 2008.
where they write
“About 90% or more of the rest of the committed warming of 1.6°C will unfold during the 21st century, determined by the rate of the unmasking of the aerosol cooling effect by air pollution abatement laws and by the rate of release of the GHGs-forcing stored in the oceans.”
Climate Science discussed their paper in the weblog
Misconception And Oversimplification Of the Concept Of Global Warming By V. Ramanthan and Y. Feng.
The concept of masking, however, indicates that the heating from the greenhouse gases continues under cover (it is concealed), and accumulates over time only to be exposed (i.e. unmasked) when a covering effect (aerosols in the case of the Ramanathan and Feng paper) is “unmasked”. The release of “GHGs-forcing in the oceans” is, presumably, the unmasking of the heat that is supposed to be continually stored there. Recent ocean data, however, documents that there has been no storage of heat since 2004; see the figure in
Pielke Sr., R.A., 2008: A broader view of the role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55.
The use of the term “masking” with respect to radiative forcing, is an incorrect description of the science. Heating from the greenhouse gases, if balanced by cooling from aerosols, results in no heat accumulation within the climate system. If the aerosols were not permitted to enter the atmosphere, yet the well-mixed greenhouse gases continued to accumulate, global warming would result, but there would be no concealed accumulated heat to suddenly enter the climate system, once the aerosols are eliminated. There is no “masking” of heat.
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January 20, 2009
Real Climate has a weblog titled “FAQ on climate models: Part II”.
Climate Science has a response to several of the questions that are posed there as well as questions for Gavin Schmidt [who wrote the Real Climate Q&A]. Climate Science has already posted on Part I of the Real Climate FAQs; see
Real Climate Misunderstanding Of Climate Models,
which Gavin has either not seen, or cared to respond to. In either case, he continues to incorrectly communicate important aspects of modeling on Real Climate.
Q & A by Gavin Schmidt
What are parameterisations?
Some physics in the real world, that is necessary for a climate model to work, is only known empirically. Or perhaps the theory only really applies at scales much smaller than the model grid size. This physics needs to be ‘parameterised’ i.e. a formulation is used that captures the phenomenology of the process and its sensitivity to change but without going into all of the very small scale details. These parameterisationsare approximations to the phenomena that we wish to model, but which work at the scales the models actually resolve. A simple example is the radiation code - instead of using a line-by-line code which would resolve the absorption at over 10,000 individual wavelengths, a GCM generally uses a broad-band approximation (with 30 to 50 bands) which gives very close to the same results as a full calculation. Another example is the formula for the evaporation from the ocean as a function of the large-scale humidity, temperature and wind-speed. This is really a highly turbulent phenomena, but there are good approximations that give the net evaporation as a function of the large scale (’bulk’) conditions. In some parameterisations, the functional form is reasonably well known, but the values of specific coefficients might not be. In these cases, the parameterisations are ‘tuned’ to reproduce the observed processes as much as possible.
R.A. Pielke Sr. Answer
The only basic physics in the models are the pressure gradient force, advection and the acceleration due to gravity. These are the only physics in which there are no tunable coefficients. Climate models are engineering codes and not fundamental physics. If Gavin concludes otherwise, he should provide examples of any parametrization that does not use tunable empirically derived coefficients. Also, he should provide examples of where the “functional form” is reasonably well known. This is true for a few types of processes, such as turbulence very near the surface, and for clear sky long- and short-wave radiative fluxes, but is not true for most other parametrizations.
The detailed form of the parameterizations of the atmospheric part of climate models is presented in
Pielke, R.A., Sr., 2002: Mesoscale meteorological modeling. 2nd Edition, Academic Press, San Diego, CA, 676 pp.
Request: Gavin should document the number of parameters used in each of the parameterizations used in the GISS model (or refer us to papers where this appears).
Q & A by Gavin Schmidt
How are the parameterisations evaluated?
In at least two ways. At the process scale, and at the emergent phenomena scale. For instance, taking one of the two examples mentioned above, the radiation code can be tested against field measurements at specific times and places where the composition of the atmosphere is known alongside a line-by-line code. It would need to capture the variations seen over time (the daily cycle, weather, cloudiness etc.). This is a test at the level of the actual process being parameterised and is a necessary component in all parameterisations. The more important tests occur when we examine how the parameterisation impacts larger-scale or emergent phenomena. Does changing the evaporation improve the patterns of precipitation? the match of the specific humidity field to observations? etc. This can be an exhaustive set of tests but again are mostly necessary. Note that most ‘tunings’ are done at the process level. Only those that can’t be constrained using direct observations of the phenomena are available for tuning to get better large scale climate features. As mentioned in the previous post, there are only a handful of such parameters that get used in practice.
R.A. Pielke Sr. Answer
The statement by Gavin that
“The more important tests occur when we examine how the parameterisation impacts larger-scale or emergent phenomena”
is not correct. Both the process and emergent scales must be accurately modeled. How can the emergent scale be represented skillfully unless the process scale is accurate?
Regarding the statement by Gavin that, with respect to emergent scales,
“As mentioned in the previous post, there are only a handful of such parameters that get used in practice”
this is quite an admission.
Request: Gavin should tell us what are the handful of such parameters used in the GISS model.
Q & A by Gavin Schmidt
What are the differences between climate models and weather models?
“Conceptually they are very similar, but in practice they are used very differently. Weather models use as much data as there is available to start off close to the current weather situation and then use their knowledge of physics to step forward in time. This has good skill for a few days and some skill for a little longer. Because they are run for short periods of time only, they tend to have much higher resolution and more detailed physics than climate models (but note that the Hadley Centre for instance, uses the same model for climate and weather purposes). Weather models develop in ways that improve the short term predictions, though the impact for long term statistics or the climatology needs to be assessed independently. Curiously, the best weather models often have a much worse climatology than the best climate models. There are many current attempts to improve the short-term predictability in climate models in line with the best weather models, though it is unclear what impact that will have on projections.”
R.A. Pielke Sr. Answer
Weather models are different from climate models for two main reasons. Weather models focus on the atmospheric part of the climate system and, very importantly, use observed values of temperature, humidity, and winds (and other weather variables, such as cloud information) within the atmosphere as initial conditions. Skill in weather prediction is lost when the memory of these initial conditions is lost.
Gavin’s claim that “Curiously, the best weather models often have a much worse climatology than the best climate models”, is an odd statement, since the weather models use real world observed data! This claim needs to be supported by referring us to peer reviewed studies.
Moreover, as written earlier in my response, weather and climate models are both engineering code in which, of the physical, biological and chemical processes within climate models, only the pressure gradient force, advection and gravity are fundamental physics. All other physical, chemical and biological processes are parameterized.
In order to insure that the dynamics of the atmospheric weather features are accurately predicted (which tests the representation of the pressure gradient force and advection, and of the parameterizations, within the models), the climate models should be run in the weather prediction mode. To my knowledge, the GISS model, and most of the IPCC models, have not completed such an engineering test.
Request: Gavin should tell us why not, or if GISS has completed such a test, provide us the relevant reports or research articles.
I will also post the url of this weblog on Real Climate. If Gavin is interested in a constructive scientific exchange, he will welcome this debate, and respond accordingly.
Update: Here is the comment I submitted to be posted on Real Climate
“Gavin - I have posted a weblog which questions several of your answers [http://climatesci.org/2009/01/20/comments-on-real-climates-post-faq-on-climate-models-part-ii/]. I would be glad to post as a guest weblog your responses on Climate Science. Roger”
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January 12, 2009
The Everglades Restoration Plan, while a very important and beneficial environmental project, intends to “restore the magnificent River of Grass [the Everglades]“. As they also write
“Marjory Stoneman Douglas wrote about the problems of the Everglades in 1947, describing a ecosystem that was beautiful yet already clearly suffering…..The Comprehensive Everglades Restoration Plan will capture freshwater destined for sea - the Everglades’ lifeblood - and direct it back to the ecosystem to revitalize it. It will improve water supplies for people and farms, too. The nation’s largest such project, it will cost $7.8 billion and take more than 20 years to develop.”
Having visited Everglades National Park many times, it is a worthy goal to seek this. However, unfortunately, as we and others have shown, the weather (and thus the hydrology and ecology) of the Everglades are affected by what occurs throughout central and southern Florida. The amount of freshwater today (from rain), unfortunately, is significantly less then it was prior to European disturbance.
Recently, I was asked to summarize what we have found in our studies of Florida. This information is given below.
Three dimensional modeling of south Florida began with the paper
Pielke, R.A., 1974: A three-dimensional numerical model of the sea breezes over south Florida. Mon. Wea. Rev., 102, 115-139. http://www.climatesci.org/publications/pdf/R-2.pdf
This study found that a spatial grid increment of 11 km was needed in order to accurately represent the sea breeze convergence patterns which form on many days over this region, and that focus thunderstorm activity over the peninsula. The curvature of the coastline, Lake Okeechobee, as well as wetlands exerts a major influence on these convergence zones. An example of this relationship is shown in Figure 1.
Figure 1: Vertical velocity prediction 9.5 hours after simulated sunrise and composite radar map for equivalent times for June 29, 1971.
This study built on the pioneering research on sea breezes of Estoque (1962 : The sea breeze as a function of prevailing synoptic situation. J. Atmos. Sci., 19, 244-250).
A number of research papers followed that further elucidated the role of the surface in south Florida in affecting the region’s weather. These include:
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Simpson, J., N.E. Westcott, R.J. Clerman, and R.A. Pielke, 1979:
On cumulus mergers. Arch. Meteor. Geophys. Bioklim., Ser. A., 29, 1-40.
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Pielke, R.A., R.L. Walko, L. Steyaert, P.L. Vidale, G.E. Liston, and W.A. Lyons, 1999:
The influence of anthropogenic landscape changes on weather in south Florida.Mon. Wea. Rev., 127, 1663-1673. {
NOTE: View related earlier pioneering work on the subject of Florida land-cover change and consequences by the late Arthur Marshall, Florida ecologist. http://www.climatesci.org/publications/pdf/marshall.pdf }
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Observationally related papers include
The specific paper
Marshall, C.H. Jr., R.A. Pielke Sr., L.T. Steyaert, and D.A. Willard, 2004: The impact of anthropogenic land-cover change on the Florida peninsula sea breezes and warm season sensible weather. Mon. Wea. Rev., 132, 28-52.
provides a demonstration of the major role that landscape change has had on south Florida. The change in landscape is illustrated in Figure 2 from http://www.climatesci.org/publications/pdf/R-272.pdf].
Figure 2. USGS land-cover data for (left) pre-1900 natural land cover and (right) 1993 land use.
This study had the following major conclusions:
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The region has become about 10-15% drier on average in July and August as a result of the conversion of the natural landscape. A major reason is the loss of wetlands which, in the past, provided significant water vapor input to sea breeze generated thunderstorms.
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The region has higher daytime temperatures and lower nighttime temperatures [of several degrees Celsius in places] as a result of the landscape change.
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There are local exceptions to #1 and #2 such as slightly cooler temperatures along the coast due to an invigorated sea breeze (since it is warmer inland during the day), as well as small regions of enhanced rainfall associated with the patterning of the landscape which produce local areas of increased low level wind convergence.
An important implication from this study is that attempts to mitigate changes to the south Florida hydrology and ecology as part of the Everglades Restoration Project cannot result in the return to the climate regime that existed prior to the large scale landscape disturbances of the 20th century. While the Everglades Restoration Plan should be pursued, there should be no illusion that the hydrology and ecology can be restored to what it was originally when first settled.
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December 10, 2008
Thanks to Vincent Gray of New Zealand for alerting us to a set of questions and answers on the NASA GISS website, with respect to the measurement of surface air temperatures (SAT) in regards to long term climate change.
The NASA questions and answers (in italics) are listed below along with the Climate Science response in bold font.
GISS Surface Temperature Analysis The Elusive Absolute Surface Air Temperature (SAT)
Q. What exactly do we mean by SAT ?
A. I doubt that there is a general agreement how to answer this question. Even at the same location, the temperature near the ground may be very different from the temperature 5 ft above the ground and different again from 10 ft or 50 ft above the ground. Particularly in the presence of vegetation (say in a rain forest), the temperature above the vegetation may be very different from the temperature below the top of the vegetation. A reasonable suggestion might be to use the average temperature of the first 50 ft of air either above ground or above the top of the vegetation. To measure SAT we have to agree on what it is and, as far as I know, no such standard has been suggested or generally adopted. Even if the 50 ft standard were adopted, I cannot imagine that a weather station would build a 50 ft stack of thermometers to be able to find the true SAT at its location.
Climate Science answer
This admission by GISS that there is not general agreement on an answer demonstrates why the surface air temperatures are such a poor metric to use to diagnose global warming or cooling. As shown, for example, in our papers
Pielke Sr., R.A., and T. Matsui, 2005: Should light wind and windy nights have the same temperature trends at individual levels even if the boundary layer averaged heat content change is the same? Geophys. Res. Letts., 32, No. 21, L21813, 10.1029/2005GL024407
Lin, X., R.A. Pielke Sr., K.G. Hubbard, K.C. Crawford, M. A. Shafer, and T. Matsui, 2007: An examination of 1997-2007 surface layer temperature trends at two heights in Oklahoma. Geophys. Res. Letts., 34, L24705, doi:10.1029/2007GL031652.
the height at which temperature measurements are made matters significantly both with respect to the absolute value of the temperature and its anomaly.
Q. What do we mean by daily mean SAT ?
A. Again, there is no universally accepted correct answer. Should we note the temperature every 6 hours and report the mean, should we do it every 2 hours, hourly, have a machine record it every second, or simply take the average of the highest and lowest temperature of the day ? On some days the various methods may lead to drastically different results.
The admission that there is no “universally accepted correct answer” demonstrates again how poor this temperature metric is as a measure of global warming and cooling.
Q. What SAT do the local media report ?
A. The media report the reading of 1 particular thermometer of a nearby weather station. This temperature may be very different from the true SAT even at that location and has certainly nothing to do with the true regional SAT. To measure the true regional SAT, we would have to use many 50 ft stacks of thermometers distributed evenly over the whole region, an obvious practical impossibility.
The admission by GISS that the one temperature “has certainly nothing to do with the true regional SAT” is remarkable! This spatially non-representative temperature and its anomaly cannot used to construct a quantitatively accurate global average.
Q. If the reported SATs are not the true SATs, why are they still useful ?
A. The reported temperature is truly meaningful only to a person who happens to visit the weather station at the precise moment when the reported temperature is measured, in other words, to nobody. However, in addition to the SAT the reports usually also mention whether the current temperature is unusually high or unusually low, how much it differs from the normal temperature, and that information (the anomaly) is meaningful for the whole region. Also, if we hear a temperature (say 70F), we instinctively translate it into hot or cold, but our translation key depends on the season and region, the same temperature may be ‘hot’ in winter and ‘cold’ in July, since by ‘hot’ we always mean ‘hotter than normal’, i.e. we all translate absolute temperatures automatically into anomalies whether we are aware of it or not.
The claim that “information (the [temperature] anomaly) is meaningful for the whole region” yet the “The reported temperature is truly meaningful only to a person who happens to visit the weather station at the precise moment when the reported temperature is measured, in other words, to nobody” is clearly contradictory. While the anomalies are expected to be closer to each other in magnitude and sign than the absolute temperature, they still must be linked back to the temperature data at the location where the “The reported temperature is truly meaningful ….. to nobody”.
Q. If SATs cannot be measured, how are SAT maps created ?
A. This can only be done with the help of computer models, the same models that are used to create the daily weather forecasts. We may start out the model with the few observed data that are available and fill in the rest with guesses (also called extrapolations) and then let the model run long enough so that the initial guesses no longer matter, but not too long in order to avoid that the inaccuracies of the model become relevant. This may be done starting from conditions from many years, so that the average (called a ‘climatology’) hopefully represents a typical map for the particular month or day of the year.
The creation of spatial temperature maps with models and to claim that eventually the “the initial guesses no longer matter” conflicts with almost everything we know of how the near-surface temperature data depends on surface conditions (see Chapter 13 in Pielke 2002). Unless the model accurately represents the surface conditions and has other data to validate the temperature predictions with, the models cannot create the real world distribution of temperatures.
Q. What do I do if I need absolute SATs, not anomalies ?
A. In 99.9% of the cases you’ll find that anomalies are exactly what you need, not absolute temperatures. In the remaining cases, you have to pick one of the available climatologies and add the anomalies (with respect to the proper base period) to it. For the global mean, the most trusted models produce a value of roughly 14 Celsius, i.e. 57.2 F, but it may easily be anywhere between 56 and 58 F and regionally, let alone locally, the situation is even worse.
The GISS authors make a fundamental error. You cannot diagnose accurate values of the anomalies unless the reason for the observed values of the absolute surface air temperature are understood. Quantitatively accurate spatial maps of temperature anomalies, therefore, cannot be generated.
The documentation of the fundamental problems with the use of SAT anomalies is reported, for example, in our multi-authored paper
Pielke Sr., R.A., C. Davey, D. Niyogi, S. Fall, J. Steinweg-Woods, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends.J. Geophys. Res., 112, D24S08, doi:10.1029/2006JD008229.
GISS, however, has chosen to ignore our study. There have also not been peer reviewed studies by anyone else which refutes the conclusions in our paper.
This means the use of GISS surface temperature anomalies [and those of other sources of SAT anomaly analysis (as summarized in CCSP, 2006) which are drawn from essentially the same raw temperature data] are providing erroneous and misleading quantitative diagnoses of global warming and cooling both within climate assessment reports and to policymakers.
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October 31, 2008
Mother Jones has just published an interview with me by Kiera Butler that was conducted several months ago: Q&A: Roger A. Pielke Sr. It is discussed very effectively by my son on Prometheus yesterday (see).
As written in the Prometheus weblog, it is a pretty good interview (although some editing would have made several of the issues clearer and the header to the interview oversimplifies my perspective). Nonetheless, presenting my different perspective, which is broader and more inclusive than reported in the IPCC and CCSP reports, is an example of open-minded and effective journalism.
For other summaries of my perspective on climate science, please read
Roger A. Pielke Sr.’s Perspective On The Role Of Humans In Climate Change
Roger A. Pielke Sr.’s Perspective On Adaptation and Mitigation
and
House Testimony of Roger A. Pielke Sr. “A Broader View of the Role of Humans in the Climate System is Required In the Assessment of Costs and Benefits of Effective Climate Policy”.
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October 16, 2008
There is a set of excellent publications and science reports by Forrest M. Mims III at
www.forrestmims.org and www.sunandsky.org. Mims has had a career as a science author, lecturer and syndicated columnist. He has written instructional books on electronics and published papers and photographs in some 70 magazines and journals, including Nature, Science and Popular Mechanics. He is a writer and editor for the Society for Amateur Scientists.
Among his substantial contributions, he soon will have a book published on the Mauna Loa Observatory (see), which will a very important new addition to our knowledge of this important climate monitoring site. This book will also provide much deserved recognition to Robert H. Simpson for the creation (i.e. the father) of the Mauna Loa Observatory.
Examples of his significant contributions include:
07 March 2008
Trees Can Cool Islands of Heat
http://www.sas.org/tcs/weeklyIssues_2008/2008-03-07/mimsci/index.html
16 April 2004
Announcing Citizen Science Challenge 1: Solar Warming of Asphalt Roads
http://www.sas.org/tcs/weeklyIssues/2004-04-16/news1/index.html
30 July 2004
Wanted: Citizen weather observers
http://www.sas.org/tcs/weeklyIssues/2004-07-30/news3/index.html
11 March 2005
Questions and Answers About Climate Change
http://www.sas.org/tcs/weeklyIssues_2005/2005-03-11/editorial/
08 April 2005
More Questions and Answers About Climate Change
http://www.sas.org/tcs/weeklyIssues_2005/2005-04-08/editorial/index.html
Pulse of the Planet
The radio programs are archived at http://www.pulseplanet.com/dailyprogram/
Mims Pulse of the Planet Blog:
http://pulseplanet.com/sci-diaries/sd_mims/
MY NASA DATA
http://mynasadata.larc.nasa.gov/science_projects.php
I’ve developed 14 science projects for this web site, including a new one soon to be posted on the urban heat island effect and how to measure it.
Climate Science readers will obtain new insight into a range of climate issues, including the urban heat island effect, by reading and listening to the information available on these links!
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October 14, 2008
Dr. Richard Keen of the Department of Atmospheric and Oceanic Sciences (ATOC) at the University of Colorado has a very interesting set of questions that he has posted with respect to global warming. It can be viewed at
http://icecap.us/images/uploads/Globalwarmingquiz.pdf
His class website, which illustrates his expertise in atmospheric science, is at http://atoc.colorado.edu/wxlab/atoc1050/Syl1050F08.htm.
His global warming quiz is quite informative.
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August 16, 2008
Andraes Sterl and I continued our constructive discussions of the weblog of August 15 regarding his published paper that was originally weblogged on July 17 2008, and our-mail exchange (edited for clarity) is presented below.
Comment By Andreas Sterl 14 Aug 2008
How can you validate a forecast? Only by waiting to the date for which the forecast is valid and to measure. Not very practical for 2100. In this sense every forecast/projection/scenario/speculation/call-it-how-you want for more than a few months in advance is non-scientific, as it cannot be validated. Should we therefore stop thinking about what the future might bring? No, we should not, but we should be aware of the limitations, and we should check the results for plausibility, obeying of physical (and other) laws, mechanisms behind, etc.
Reply by Roger A. Pielke Sr. 14 August 2008
The scientific method requires that real data be used to test models (and to seek to refute their forecasts). We can not do that with 2100 as you correctly recognize. Thus, why should policymakers believe the forecasts? What is the basis for claiming that they are skillful on the global and regional scales? Even Kevin Trenberth, one of the IPCC authors, has recognized this limitation [see http://climatesci.org/2007/06/18/comment-on-the-nature-weblog-by-kevin-trenberth-entitled-predictions-of-climate/]
We do not need the models to tell us that CO2 is increasing due to human activity since this is observed. That is where this part of the process should focus; on the unknown consequences of this added CO2, not by providing definitive (but unverifiable) forecasts to policymakers.
For the more general issue of dealing with the future environment, we have advocated a vulnerability bottom-up resource-based perspective (e.g. see my invited IGBP essay http://www.climatesci.org/publications/pdf/NR-139.pdf and also Chapter E in the book
Kabat, P., Claussen, M., Dirmeyer, P.A., J.H.C. Gash, L. Bravo de Guenni, M. Meybeck, R.A. Pielke Sr., C.J. Vorosmarty, R.W.A. Hutjes, and S. Lutkemeier, Editors, 2004: Vegetation, water, humans and the climate: A new perspective on an interactive system. Springer, Berlin, Global Change - The IGBP Series, 566 pp.
This vulnerability perspective fits quite well with Pavel’s “climate proofing” except the universe of what the future can hold needs to be broader than what is predicted by the multi-decadal global climate models.
We are risking the loss of credibility if the models continue to deviate from the observed trends (such as the absence of recent global warming; e.g. see Figure 7 in http://www.remss.com/msu/msu_data_description.html)}. I agree that humans are altering the climate system, but as you state below, “there are (a lot of) processes that are not included in the models”. The 2005 NRC report (basically ignored in the 2007 IPCC report) indicates that missing human climate forcings are quite important (http://www.nap.edu/openbook/0309095069/html/).
Thus, my conclusion is that papers which present predictions are not valid science contributions, unless they are validated by predictions. That the IPCC models are failing so far in this test is ably discussed in the weblog
http://rankexploits.com/musings/
Comment By Andreas Sterl 14 Aug 2008
Yes, there are (a lot of) processes that are not included in the models. Our current knowledge (belief?) is that those processes are of less importance than the increase of greenhouse gases (this is opposite to your view, I know). We have done our work under certain assumptions. If anybody thinks that these assumptions are insufficient, he (she) should repeat the work with his (her) assumption and report on the results. this will benefit the scientific community as it sheds light on the relative importance on assumptions.
Reply by Roger A. Pielke Sr. 14 August 2008
In my recent testimony [http://www.climatesci.org/publications/pdf/Testimony-written.pdf], we show that
“In Matsui and PielkeSr. (2006), it was foundfrom observations of the spatial distribution of aerosols in the atmosphere in the lower latitudes, that the aerosol effect on atmospheric circulations, as a result of their alteration in the heating of regions of the atmosphere, is 60 times greater than due to the heating effect of the human addition of well-mixed greenhouse gases.”
This analysis clearly shows that the other climate forcings are first order, and thus, by not being properly represented in the models, guarantees that the regional prediction forecasts decades into the future will not be skillful.
These other human climate forcings include land cover/land use (e.g see http://www.climatesci.org/publications/pdf/Feddema2005.pdf and http://www.climatesci.org/publications/pdf/R-311.pdf), and a diversity of aerosol effects such as nitrogen deposition, the thermodynamic effect of aerosols, etc) as I briefly discuss at http://www.climatesci.org/publications/pdf/Testimony-written.pdf.
Comment By Andreas Sterl 15 Aug 2008
It seems that we are not so far apart after all. I can agree with most of
your arguments - with two important exceptions:
1. The question whether increasing greenhouse gases are the first order driver of the climate, or whether other human-caused effects are. This is a purely scientific question - it can be answered by more research. For instance, in the case of the example you gave, aerosols, one could make make sensitivity runs altering several aspects of plausible (i.e., in accordance with present knowledge) aerosols physics and/or aerosol concentrations for several concentrations of CO_2. This would give the relative importance of the two processes.
Reply by Roger A. Pielke Sr. 15 August 2008
We, and others, have already done this. The first issue, of course, is what are the societally and environmentally important metrics to use to define what are “first order drivers of the climate”. The IPCC uses the global average radiative forcing, as represented by the globalaverage surface temperature trend. However, the 2005 NRC report concludes that this metric is incomplete. What we have concluded in our research is that the most important climate metrics involve those that alter circulation patterns, such as ENSO, the AO, etc. These are regional scale changes in circulations which have important consequences to the weather experienced throughout the globe. The globalaverage temperature trend is grossly inadequate as a metric for these changes in circulation.
For example, for increased summer heat in the Netherlands, it is not a global average increase in temperature that would dominate, but alterations in the intensity and position of the middle and upper tropospheric large scale troughs and ridges. We showed this in our examination of the 2003 European heat wave; see
Chase, T.N., K. Wolter, R.A. Pielke Sr., and Ichtiaque Rasool, 2006: Was the 2003 European summer heat wave unusual in a global context? Geophys. Res. Lett., 33, L23709, doi:10.1029/2006GL027470 http://www.climatesci.org/publications/pdf/R-310.pdf
ConnolleyW.M. 2008: Comment on “Was the 2003 European summer heat wave unusual in a global context?” by Thomas N. Chase et al. Geophys. Res. Lett., 35, L02703, doi:10.1029/2007GL031171
http://www.climatesci.org/publications/pdf/R-310a-Connolley.pdf
Chase, T.N., K. Wolter, R.A. Pielke Sr., and Ichtiaque Rasool, 2008: Reply to comment by W.M. Connolleyon ..Was the 2003 European summer heat wave unusual in a global context?..Geophys. Res. Lett., 35, L02704, doi:10.1029/2007GL031574.
http://www.climatesci.org/publications/pdf/R-310a.pdf
The IPCC models have not demonstrated skill in predicting these regional, circulation change events in the last few decades. Thus, no confidence should be placed on their ability to predict these events decades into the future.
Moreover, even if the global average temperature did not increase, humans are still altering the circulation patterns through the diverse range of climate forcings that I overview in
Pielke Sr., Roger A., 2008: A Broader View of the Role of Humans in the Climate System is Required In the Assessment of Costs and Benefits of Effective Climate Policy. Written Testimony for the Subcommittee on Energy and Air Quality of the Committee on Energy and Commerce Hearing .Climate Change: Costs of Inaction. . Honorable Rick Boucher, Chairman. June 26, 2008, Washington, DC., 52 pp. [http://www.climatesci.org/publications/pdf/Testimony-written.pdf].
Comment By Andreas Sterl 15 Aug 2008
2. The second exception is more fundamental and either philosophic or semantic. It is “What is a forecast?”, or “How should the result of a climate model run be presented?” You argue that the (scientific?) process should focus on “the unknown consequences of this added CO2″. I completely agree with this statement, and this is what our paper is about: It explores the possible consequences of increasing greenhouse gas concentrations on extreme maximum temperatures. The result is that they
1. increase faster than average temperatures,
2. may reach dangerous levels in highly populated areas, and
3. the value for Phoenix (to repeat myself) is 49.1 deg C.
Which of these statements do you consider “unscientific”? And why?
Reply by Roger A. Pielke Sr. 15 August 2008
The presentation of model results without validation is not science. What the IPCC multi-decadal global climate models actually accomplish are process studies. This improves our understanding of whether particular climate forcings are important, but they should not be interpreted as predictions (projections) since, not only have they not shown forecast skill, but they do not include all of the known forcings and feedbacks.
I discussed this topic a few years ago in my Climatic Change article
Pielke Sr., R.A., 2002: Overlooked issues in the U.S. National Climate and IPCC assessments. Climatic Change, 52, 1-11. http://www.climatesci.org/publications/pdf/R-225.pdf
in which Mike MacCraken had an informative response
MacCracken, M., 2002: Do the uncertainty ranges in the IPCC and U.S. National Assessments account adequately for possibly overlooked climatic influences. Climatic Change, 52, 13-23. http://www.climatesci.org/publications/pdf/maccracken2002.pdf
In terms of your items #1 to # 3 [with respect to #1] This has not been confirmed with comparisons to data. This is a hypothesis [which, of course, is what a model is].
Dangerous levels of heat are already reached in many cities around the world with current and past climate. The first task should be to reduce the threat this poses to the urban population irrespective of how climate changes in the future. Our research and that of others, show that it is the urban alteration of the landscape (e.g. reduction in trees and other vegetation; waste heat from industry and residential areas; greater storage of heat in asphalt, concrete, etc) which is the much more important reason for excessive heat in urban areas. This excess heat is documented, for example, in
http://climatesci.org/2006/08/23/theres-a-change-in-rain-around-desert-cities/
The value of temperature that you present for Phoenix is at what location and height? Phoenix already reaches this temperature at 2m above the surface. This matters as the urban landscape has spatially varying values that determine the threat that is posed to people. An important issue is also that people have learned to live and thrive in that environment. They have minimized their vulnerability to the excessive heat in Phoenix.
Comment By Andreas Sterl 15 Aug 2008
Furthermore, you ask why policy makers should believe in unverifiable results. The answer is because they are based on sound principles. they should not believe the value of 49.1 for Phoenix, but they should believe that Phoenix may experience very hot (much hotter than today) temperatures, and that these temperatures will cause problems.
Reply by Roger A. Pielke Sr. 15 August 2008
The models are engineering code. Only the pressure gradient force, advection and gravity are from basic physics. All other representations of the physics are parameterizations, which are almost always one-dimensional column models. The boundary layer parameterizations and deep cumulus parameterizations, for example, are generally developed using empirical tuning values from a small set of field data using case study days.
I discuss these major limitations in the models in my book
Pielke, R.A., Sr., 2002: Mesoscale meteorological modeling. 2nd Edition, Academic Press, San Diego, CA, 676 pp.
and in my modeling classes where I have the students dissect the parameterizations (e.g. most recently in http://cires.colorado.edu/science/groups/pielke/classes/at7500/sp08.html).
The models are not fundamental physics.
Comment By Andreas Sterl 15 Aug 2008
Finally, you say “that papers which present predictions are not valid science contributions, unless they are validated by predictions”. I do not understand that. Do you mean that my number of 49.1 for Phoenix would become a valid scientific contribution if one (or more) other researchers, using a different model, came up with the same number? And what if he found 49.2?
Reply by Roger A. Pielke Sr. 15 August 2008
Model to model comparisons are not validation. The only validation is from observations. If the IPCC models were run to predict the seasonal weather for the next several years (as initial value problems), and they could show skill (statistically) in forecasting the seasonal temperature and precipitation anomalies, then they would have passed a necessary condition to seek to predict for longer time periods into the future. However, they have not yet even passed this test.
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