The word “skeptic” has been used to either implicitly and explicitly criticize those who disagree with the IPCC perspective on the role of humans in global climate change. As presented at the website Wikipedia, the definition of a “climate skeptic” is given as
“Climate scientists agree that the global average surface temperature has risen over the last few decades. Within this general agreement, a small number of scientists disagree with the conclusions drawn by the mainstream scientific community that most of this warming is attributable to human activities. The consensus position of the climate science community has been summarized in the 2001 Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) as follows:
1. The global average surface temperature has risen 0.6 ± 0.2 °C since the late 19th century, and 0.17 °C per decade in the last 30 years.
2. There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities”, in particular emissions of the greenhouse gases carbon dioxide and methane.
3. If greenhouse gas emissions continue the warming will also continue, with temperatures increasing by 1.4 °C to 5.8 °C between 1990 and 2100. Accompanying this temperature increase will be a sea level rise of 9 cm to 88 cm, and increases in some types of extreme weather. On balance the impacts of global warming will be significantly negative, especially for larger values of warming.”
There is another link on Wikipedia titled “Category:Global warming skeptics”.
However, the issue really is which segment of the climate science community (and other communities) is actually more skeptical?
The Wikipedia definition of a “skepticism” includes
“1. an attitude of doubt or a disposition to incredulity either in general or toward a particular object
2. the doctrine that true knowledge or knowledge in a particular area is uncertain”
By this definition, the actual climate skeptics are the authors of the 2007 WG1 IPCC report! They have decided to ignore or minimize the findings of other climate assessments, such as in the report
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.
Listed below are the climate science findings that the IPCC WG1 authors are skeptical about since they do not appropriately assess these issues in their report. As written in the 2005 NRC report
“EXPANDING THE RADIATIVE FORCING CONCEPT
Despite all these advantages, the traditional global mean TOA radiative forcing concept has some important limitations, which have come increasingly to light over the past decade. The concept is inadequate for some forcing agents, such as absorbing aerosols and land-use changes, that may have regional climate impacts much greater than would be predicted from TOA radiative forcing. Also, it diagnoses only one measure of climate change—global mean surface temperature response—while offering little information on regional climate change or precipitation. These limitations can be addressed by expanding the radiative forcing concept and through the introduction of additional forcing metrics. In particular, the concept needs to be extended to account for (1) the vertical structure of radiative forcing, (2) regional variability in radiative forcing, and (3) nonradiative forcing….”
1. Account for the Vertical Structure of Radiative Forcing
“The relationship between TOA radiative forcing and surface temperature is affected by the vertical distribution of radiative forcing within the atmosphere. This effect is dramatic for absorbing aerosols such as black carbon, which may have little TOA forcing but greatly reduce solar radiation reaching the surface. It can also be important for land-use driven changes in the evapotranspiration flux at the surface, which change the energy deposited in the atmosphere without necessarily affecting the surface radiative flux. These effects can be addressed by considering surface as well as TOA radiative forcing as a metric of energy imbalance. The net radiative forcing of the atmosphere can be deduced from the difference between TOA and surface radiative forcing and may be able to provide information on expected changes in precipitation and vertical mixing. Adoption of surface radiative forcing as a new metric will require research to test the ability of climate models to reproduce the observed vertical distribution of forcing (e.g., from aircraft campaigns) and to investigate the response of climate to the vertical structure of the radiative forcing.
PRIORITY RECOMMENDATIONS:
Test and improve the ability of climate models to reproduce the observed vertical structure of forcing for a variety of locations and forcing conditions.
Undertake research to characterize the dependence of climate response on the vertical structure of radiative forcing.
Report global mean radiative forcing at both the surface and the top of the atmosphere in climate change assessments.
2. Determine the Importance of Regional Variation in Radiative Forcing
Regional variations in radiative forcing may have important regional and global climatic implications that are not resolved by the concept of global mean radiative forcing. Tropospheric aerosols and landscape changes have particularly heterogeneous forcings. To date, there have been only limited studies of regional radiative forcing and response. Indeed, it is not clear how best to diagnose a regional forcing and response in the observational record; regional forcings can lead to global climate responses, while global forcings can be associated with regional climate responses. Regional diabatic heating can also cause atmospheric teleconnections that influence regional climate thousands of kilometers away from the point of forcing. Improving societally relevant projections of regional climate impacts will require a better understanding of the magnitudes of regional forcings and the associated climate responses.
PRIORITY RECOMMENDATIONS:
Use climate records to investigate relationships between regional radiative forcing (e.g., land-use or aerosol changes) and climate response in the same region, other regions, and globally.
Quantify and compare climate responses from regional radiative forcings in different climate models and on different timescales (e.g., seasonal, interannual), and report results in climate change assessments.
3. Determine the Importance of Nonradiative Forcings
Several types of forcings—most notably aerosols, land-use and land-cover change, and modifications to biogeochemistry—impact the climate system in nonradiative ways, in particular by modifying the hydrological cycle and vegetation dynamics. Aerosols exert a forcing on the hydrological cycle by modifying cloud condensation nuclei, ice nuclei, precipitation efficiency, and the ratio between solar direct and diffuse radiation received. Other nonradiative forcings modify the biological components of the climate system by changing the fluxes of trace gases and heat between vegetation, soils, and the atmosphere and by modifying the amount and types of vegetation. No metrics for quantifying such nonradiative forcings have been accepted. Nonradiative forcings have eventual radiative impacts, so one option would be to quantify these radiative impacts. However, this approach may not convey appropriately the impacts of nonradiative forcings on societally relevant climate variables such as precipitation or ecosystem function. Any new metrics must also be able to characterize the regional structure in nonradiative forcing and climate response.
PRIORITY RECOMMENDATIONS:
Improve understanding and parameterizations of aerosol-cloud thermodynamic interactions and land-atmosphere interactions in climate models in order to quantify the impacts of these nonradiative forcings on both regional and global scales.
Develop improved land-use and land-cover classifications at high resolution for the past and present, as well as scenarios for the future.
4. Provide Improved Guidance to the Policy Community
The radiative forcing concept is used extensively to inform climate policy discussions, in particular to compare the relative impacts of forcing agents. For example, integrated assessment models use radiative forcing as input to simple climate models, which are linked with socioeconomic models that predict economic damages from climate impacts and costs of various response strategies. The simplified climate models generally focus on global mean surface temperature, ignoring regional temperature changes and other societally relevant aspects of climate, such as rainfall or sea level. Incorporating these complexities is evidently needed in policy analysis. It is important to communicate the expanded forcing concepts as described in this report to the policy community and to develop the tools that will make their application useful in a policy context.
PRIORITY RECOMMENDATION:
Encourage policy analysts and integrated assessment modelers to move beyond simple climate models based entirely on global mean TOA radiative forcing and incorporate new global and regional radiative and nonradiative forcing metrics as they become available.”
The conclusion that the IPCC WG1 authors consciously chose to minimize and even ignore most of these recommendations certainly permits them to be labeled as climate skeptics.
Dr. Pielke,
I remembered that earlier this month you posted this: http://climatesci.colorado.edu/2007/05/04/a-new-paper-on-the-differences-between-recent-proxy-temperature-and-in-situ-near-surface-air-temperatures/
but I can’t quite remember if you posted anything specifically regarding the temperature reconstruction of the last 2,000 years.
RealClimate just posted http://www.realclimate.org/index.php/archives/2007/05/the-weirdest-millennium/ and I wonder if you might consider commenting on your website about this if you haven’t done so already.
Comment by Bruce Hall — May 31, 2007 @ 7:29 am
I prefer the label “climate heretic”. It implies not anti-science but anti-religious/political cult. A non-believer in Gaia worship and sacrifices.
Comment by Reid — May 31, 2007 @ 2:21 pm
Bruce - Thank you for the link to the RealClimate website.
They continue to ignore the issue that the upswing in their hockeystick looking figure is based on pasting together the proxy data with the instrument record at the end of their record. As as has been disussed in a variety of papers now; e.g. see the papers listed 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, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res. in press.
there is a warm bias in this data.
This is an example of how ignoring peer reviewed papers that conflict with a particular view in climate science has compromised the scientific process. RealClimate is perpetuating this cherrypicking.
Comment by Roger Pielke Sr. — May 31, 2007 @ 2:27 pm
Our own National Acacamy of Sciences are also a group of skeptics..Here’s the Nation Acadamey possition on climate change records
http://dels.nas.edu/basc/reportDetail.php?link_id=3475
Comment by roconnell — May 31, 2007 @ 3:18 pm
I am a proud heretic in bold affront to the Church of Gaia.
I even have ruffly sleeves and a big old floppy hat with a giant feather it …
I’m rather good with telescopes …
Comment by Steve Sadlov — May 31, 2007 @ 3:34 pm
Fellow Citizens,
Considering the fact the we use meteorological station data to make up the temperature reconstructions of the planet earth (ie GISS, CRU etc…) I thought it would only be fair to do a little comparison between what these stations measure and what they don’t.
There are differing numbers of stations used in differing temperature reconstructions but using the 4000 stations that are currently used in the GISS data set which is referred to frequently in media stories/movies, let’s be frank about it and say that these meteorological stations only sample the micro-climate surrounding the sensor. Let us assume an area around the sensor of, on average about 25 square meters…5m X 5m….too small? Ok how about 100 square but that is quite generous since the sensor bulb itself really only measures the tiny area/volume immediately around the sensor…ie quite small.
So then, with 100m2 of area around a sensor being the representative area sample in the micro climate, multiplied by 4000 sensors we can agree that roughly 400,000 meters squared or 400 kilometers squared of earths surface is actually represented in the meteorological station data used in reconstruction of temperature; compare this to the actual area of earth’s surface 510,065,600km2, shows you the folly of using this data set to measure a global mean temperature. The area being covered by station data is but .00008% of the earths total surface.
Comment by tom s — May 31, 2007 @ 3:45 pm
Bruce,
That wouldn’t be the post where mike (Michael Mann?) responded to what seemed a legitimate question about the so-called divergence problem with:
[Response: p.s. just a point of clarification: Do the above represent your views, or the views of Shell Oil in Houston Texas (the IP address from which your comment was submitted)? -mike]
and then retracted it having thought better of it?
There would seem to be an unhealthly interest in snooping IP addresses that would seem to be, at best, impolite.
Comment by Simon Templar — May 31, 2007 @ 4:34 pm
Simon,
I’m not certain as to which post you refer. The first reference was one of Dr. Pielke’s recent posts. The second was to a May 29 post at RealClimate by Stefan Rahmstorf.
If you want to know who I represent, click on the hyperlink associated with my name.
Regarding proxy data, I have a “show me” attitude when someone says that they can have a consistent dataset with estimates gleaned from tree ring growth or other various indicators and digital recording devices.
I’d rather address a proposition that for several hundred years the Vikings farmed successfully in Greenland only to be driven out by severe cold which has not yielded to favorable growing conditions again… and conclude that temperatures had to be at least as warm as they are today. That type of empirical evidence is more persuasive [to me]than an obvious attempt to reconstruct specific [and consistently derived] temperatures over centuries.
I’d rather address the proposition that Hannibal crossed the Alps in areas that were/are impassible due to glaciers. http://adsabs.harvard.edu/abs/2004AGUFM.U43A0743J [cited in RealClimate by someone who is not me].
But, Simon, I most curious as to what your point really is.
Comment by Bruce Hall — May 31, 2007 @ 6:41 pm
The jokers over at the Wikipedia site you linked to [http://en.wikipedia.org/wiki/Scientists_opposing_the_mainstream_scientific_assessment_of_global_warming] want to know if you agree with all 3 criteria that William Connely has established there. I suggested you didn’t. Would you please clarify your position (again)?
Comment by Anon — May 31, 2007 @ 7:21 pm
And it appears that the head of NASA is a skeptic too!
http://abcnews.go.com/Technology/story?id=3229696&page=1
I thought James Hansen’s remarks were particularly humorous…
Frank K.
Comment by Frank K. — May 31, 2007 @ 8:44 pm
Anon - If your question is directed at Climate Science, the conclusions summarized http://climatesci.colorado.edu/main-conclusions/
provide my views.
Comment by Roger Pielke Sr. — May 31, 2007 @ 9:44 pm
Hello Bruce,
I wasn’t questioning your motivation, just pointing out a ‘curiosity’ I had observed while following the post on realclimate that you linked to (it was also noted over on climateaudit as well).
Specifically comment #47 of that post:
Thanks to #28 for posting the link to the complete charts. I presume that the grey bars on the Hadley reconstruction are some kind of error estimate made by varying the model inputs? What we are interested in in this thread, however, are the error bars on the temperature reconstructions from proxies. What is striking from the IPCC chart is that the “instrumental record” starts diverging seriously upwards from the “proxies” around 1950, and is in the “10%” overlap range by about 1980.
which produced the response (presumeably from MM):
[Response: p.s. just a point of clarification: Do the above represent your views, or the views of Shell Oil in Houston Texas (the IP address from which your comment was submitted)? -mike]
and was then retracted to become:
[Response: I've removed a comment which in retrospect was probably inappropriate. -mike]
I was then making the point that on realclimate there would seem to be an unhealthy focus on the IP addresses of the people who post on there.
Simon.
Comment by Simon Templar — June 1, 2007 @ 1:35 am
Dr. Pielke,
Re: Skeptics
It is disturbing that so many scientists use such a broad brush to deal with such a delicate subject. To be a full believer in IPCC reports one must believe all of the following:
1. The earth is warming and will continue to warm.
2. Near future warming will be very bad.
3. Man is the most significant cause of current and future warming.
4. Man’s activities have and will continue to increase CO2 in the atmosphere.
5. Most future warming will be caused by increased CO2 in the atmosphere.
6. Man can modify his behavior to reduce global CO2 production enough to reduce future global temperature without consequences more disastrous than the projected warming.
I am sure there are more, but my point is that there is some probability (less than one) that each of those propositions is correct. I believe many of us are skeptical of the certainty the IPCC applies to one or more of them. If failing to accept the IPCC assertions about confidence levels on every one of the propositions makes me a skeptic then I gladly accept the title.
Perhaps this is the heart of the problem. It is impossible to enlist global political cooperation if you acknowledge uncertainty. It is impossible to do good science if you don’t acknowledge uncertainty.
I sympathize with those who believe they are on a quest to save the world from itself and believe time is running out. But there is real uncertainty and I believe many of us are willing to take the risk of using time to reduce uncertainty through more research.
Thank you for your efforts to do so.
Comment by Allan J — June 1, 2007 @ 5:01 am
Bruce,
I think your sarcasm detector was temporarily disabled. Simon was referring to a thread over on realclimate where Michael Mann challenged a poster because his IP address appeared to be from Shell Oil in Houston.
He was not questioning your motivations (or at least I don’t think he was). I think you missed the fact that one of those paragraphs was a quote from Mann and not from Simon.
Comment by Aaron Wells — June 1, 2007 @ 7:28 am
Roger’s views statement
http://climatesci.colorado.edu/main-conclusions/
The conclusions statement is excellent. It is written by a scientist for scientists. A vernacular, non-science-speak translation for journalists and the general public would be useful.
A comment on Real Climate tracing commenters IP addresses. I don’t believe RC tracked a comment back to Shell offices in Houston. RC is advised by Fenton Communications, a political public relations firm. Fenton crafts talking points and teaches how to handle political debates. Fenton probably advised RC to use the “only oil company funded scientists disagree with the consensus” talking point when losing a debate.
Comment by Reid — June 1, 2007 @ 8:00 am
Simon & Aaron,
Thanks for the clarification. I tend to take the comments here as being more straightforward than many sites.
Comment by Bruce Hall — June 1, 2007 @ 10:05 am
Hi Guys,
Well there are many thing that influence climate. Just don’t think it is CO2, but CO2 may play a very small role in the warming. When you look at green house gases CO2 is only responsible for 2% to 3% with water vapor accounting for 95%.
These graphs illustrate what I mean. But there are many others things to consider such as the ocean current oscillations. I have linked to show CO2 at Mauna Loa compared to temp. and the solar output compared to temp.
Here are the links and some data sets.
http://www.junkscience.com/Greenhouse/aerosol.gif
http://www.junkscience.com/MSU_Temps/CRUglobalan.png
http://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/solar_variability/lean2000_irradiance.txt
Comment by Jim Arndt — June 1, 2007 @ 11:22 am
RE: #10 - After 30 years of wasting time and money, and being derailed by a camp who subscribed to the belief that it was “immoral” to colonize space “while there is still so much suffering on Earth,” NASA is back on track with more narrowly focussed and more appropriate goals. The recent management changes, aimed at breathing new life into a sick organization, appear to be bearing fruit. The “just give me the facts” approach at the top will serve as an interesting contrast with some of the clowns who have been allowed to amass empires and cliques. One housecleaning, coming right up!
Comment by Steve Sadlov — June 1, 2007 @ 11:24 am
Doh! How could I be so insensitive to have omitted something important in #16. “After 30 years of wasting time and money…..” ought to have been written, instead “After 30 years of wasting time and money, not to mention, even more importantly, negligently extinguishing the lives of two teams of astronauts pursuing the pointless and overblown Space Shuttle program…..”
Comment by Steve Sadlov — June 1, 2007 @ 11:46 am
Allan, the problem with your statistics exercise is that almost none of your propositions are independent of each other so multiplying probabilities gets you a smaller but wrong answer. Perhaps we can boil it down
1. Man’s activities have increased CO2 in the atmosphere. (99.99+% from isotopic ratios etc.)
2. Given business as usual, man’s activities will continue to increase CO2 and other greenhouse gases in the atmosphere in the future (99.99% there is a LOT of coal out there)
3. Significant future warming will be due to increases of greenhouse gases inc. CO2 (IPCC >90+%, although our host differs from almost all his colleagues)
Your 1 and 3 are deductions from these, your 6 is a speculation. Let us hope. Your 2 is answered by WGII in the AR4.
Comment by Eli Rabett — June 1, 2007 @ 1:17 pm
Re #8: The cited poster abstract provides no support for that proposition, Bruce, nor, it turns out, does the subsequent paper. But please read it anyway, as you might learn something. Also, regarding your Greenland proposition, I don’t recall seeing any evidence for that.
Comment by Steve Bloom — June 1, 2007 @ 1:45 pm
Steve B.
Regarding you recall on evidence for #8’s Greenland proposition you need to do a little reading yourself!
See:
http://en.wikipedia.org/wiki/History_of_Greenland
and more specifically
http://en.wikipedia.org/wiki/Eastern_Settlement
Comment by Bob Thompson — June 1, 2007 @ 5:35 pm
Bob Thompson, where did the graph of T vs t come from? Do you have the link?
Comment by Eli Rabett — June 1, 2007 @ 11:08 pm
Roger, in #17 Jim Arndt states that 95% of the greenhouse effect is caused by water vapor, and only 2 or 3 percent is caused by carbon dioxide. Do you agree with this statement? If not, in the interest of scientific accuracy can you please provide what you think are the correct figures?
Comment by Blair Dowden — June 2, 2007 @ 7:07 am
Blair - Climate Science has weblogged on this subject; e.g. see
Relative Roles of CO2 and Water Vapor in Radiative Forcing
as well as discussed in our book
Cotton, W.R. and R.A. Pielke, 2007: Human impacts on weather and climate, Cambridge University Press, 330 pp.
The correct question, of course, should be not the total effect of each of these greenhouse gases, but their forcing from incremental increases, as we discuss in the above two sources of information.
The percentage contributions of the addition of each of the well-mixed greenhouse gases CO2 and H20 to a natural baseline very much depends on the latitude and time of year. In Siberia in the winter, for example, CO2 has a greater radiative forcing (due to the low atmopsheric concentrations of H20 in this cold air) than CO2 does in the humid tropics. The precise percentage for each gas will depend on these issues, but both are first order radiative forcings.
Climate Science agrees with the IPCC that human added CO2 is an important radiative forcing, and more generally an important climate forcing. However, we disagree that CO2 is THE dominate human climate forcing! The policymakers are being misled (or are using the primary focus to promote energy policy changes, as has been discussed on Climate Science).
Comment by Roger Pielke Sr. — June 2, 2007 @ 9:32 am
RE #20
Eli,
For at least 12 years I have been asking for some verification of the claim that the vast majority of scientists adhere to the (ever-growing) claims of the IPCC. To date, not one person making that claim has provided any substantial evidence, refering only to documents written by a small number of individuals and then claiming that all of their associates comply with that document (a claim that I know for a fact to be untrue).
Now you claim that Roger’s opinion is different than “almost all of his colleagues”! Really? Than perhaps you can tell me how many ‘colleagues’ Roger has and the number that disagree with him. Certainly a seeker-of-scientific-truth would not make such a bold claim absent any hard data!
Frankly, I do not know what every atmospheric scientist believes, but I can make the following speculations that are likely to be much more accurate than your oft repeated claim:
1. The vast majority of scientists who make a living studying anthroprogenic global warming believe that most of the global warming of recent decades is anthroprogenic.
2. Outside of this small subset of scientists, the precentage who believe the IPCC is very accurate is significantly smaller.
3. A majority of synoptic meteorologists, geologists, and solar physicists, comprising a much larger number of scientists than those who study CO2 induced climate change for a living, believe the claims of the IPCC are seriously flawed.
4. Considering only the opinions of AGW scientists when determining what ’scientists believe’ about climate change, is like standing outside Wrigley Field and asking what baseball team has the best fans; then proclaiming that the vast majority of people surveyed believe the Cubs have the best fans.
Comment by Jim Clarke — June 2, 2007 @ 9:55 am
Eli,
I assume you are asking about the Reconstructed T graph at:
http://en.wikipedia.org/wiki/Little_Ice_Age
clicking on the graph will take you to the following where the details of the graph and its construction presented.
http://en.wikipedia.org/wiki/Image:2000_Year_Temperature_Comparison.png
Is you question on the graph in earnest or are you tring to make some other point?
/Bob T.
Comment by Bob Thompson — June 2, 2007 @ 1:59 pm
Jim, your 1 is true
2. “Very accurate” is a red herring. WGI characterizes its statements in levels of probability. I would venture that the vast majority of scientists in a particular area agree with the level of understanding/probability assigned to an issue in their area by the IPCC.
3. I strongly doubt.
4. Is a simple provocation.
Comment by Eli Rabett — June 2, 2007 @ 3:03 pm
Re #26: Some recent evidence would be the standing ovation for Al Gore from thousands of scientists at the AGU 2006 general meeting. You can google that, Jim. As well, denialist papers seen even thinner on the ground since the time of the Oreskes study. Evidence to the contrary? Oh, and I almost forgot my favorite: Even the AAPG has been embarassed into revising their absurd position on climate change.
Comment by Steve Bloom — June 2, 2007 @ 4:01 pm
Re #25: Erratum: You want “dominant” rather than “dominate.” The latter is a verb.
Comment by Steve Bloom — June 2, 2007 @ 4:07 pm
Re #22: Bob, the interesting thing about delusionists is how sloppy they are. My objection was to Bruce’s non-evidence-based claim that Greenland has “severe cold which has not yielded to favorable growing conditions again,” using this as evidence to “conclude that temperatures had to be at least as warm as they are today.” Your links provide evidence against this claim. In particular, the temp graph shows that the maximum temperature during the Viking occupation (the moment of their arrival, following which it got and remained colder) was about the same as in 1990. Greenland has warmed since then, which says what about current temps versus those the Vikings encountered? But the main problem I had with Bruce’s claim was in regard to the present state of Greenland agriculture, a subject upon which your links shed no light whatsoever. In any case, the big difference between temps now and during the early period of Viking settlement is that Greenland is about to get a lot warmer. While that’s probably good news for agriculturalists there, it has another implication that’s not so good. Melty, melty.
Comment by Steve Bloom — June 2, 2007 @ 4:38 pm
Steve B. “…Greenland is about to get a lot warmer.”
For the record, let us all know how much Greenland will be warming and over what time period? Your term “about” would seem to indicate “soon”, e.g., can you give us your prediction for 3-5 years…10 years?
I assume in making your prediction you are relying upon the output of one or more models. Specifically, which models?
Comment by Steve G. — June 2, 2007 @ 9:21 pm
Nope, I am talking about the graph at http://en.wikipedia.org/wiki/History_of_Greenland
and I am serious, there are things about that graph that I have serious questions about, even after trying to find the underlying data.
Comment by Eli Rabett — June 2, 2007 @ 9:35 pm
Roger, the more interesting question is at what altitude does the mixing ratio of CO2 exceed that of H2O vapor.
Comment by Eli Rabett — June 2, 2007 @ 9:37 pm
Re #31:Let me add that when the Vikings settled Greenland, agriculture was a matter of survival. In 20th century Greenland that is not the case, and the re-introduction of agriculture is also being resisted on the grounds of potential environmental damage. So the presence or absence of agriculture is not necessarily a good proxy for temperature.
Comment by Blair Dowden — June 3, 2007 @ 6:35 pm
Re #25: Roger, I believe the answer to the “wrong” question, ie. how much is water vapor responsible for the total greenhouse effect, is about two thirds, rather than 95%. I am not aware of any serious questioning of this finding of atmospheric science.
I agree the more interesting question is what is the marginal effect of adding more carbon dioxide to the atmosphere. Your reference is about measuring downwelling longwave radiation from increases in water vapor and carbon dioxide. That is not a good indicator of the total greenhouse effect, which is better measured by outgoing longwave radiation at the top of the troposphere. The 2001 IPCC report claimed the effect of doubling carbon dioxide is 3.7 watts per square meter, far larger than the figures you quote for downwelling radiation in the paper. Are you telling me that the IPCC got this basic piece of atmospheric science completely wrong?
I agree that there should not be a single minded focus on carbon dioxide. Carbon dioxide is a part of the greenhouse effect, which is a part of the cause of global climate change, which is part of what causes regional climate change, which is a part of the environmental problems we face, which is only one of many problems facing humanity. But it is a significant issue, and addressing it begins with a correct determination of its magnitude. That is why misinformation that carbon dioxide is responsible for only 2 or 3 percent of the greenhouse effect must be corrected.
Comment by Blair Dowden — June 3, 2007 @ 6:48 pm
Blair - You have succinctly and very effectively summarized the issue that Climate Science has sought to communicate; i.e.
“Carbon dioxide is a part of the greenhouse effect, which is a part of the cause of global climate change, which is part of what causes regional climate change, which is a part of the environmental problems we face, which is only one of many problems facing humanity. But it is a significant issue, and addressing it begins with a correct determination of its magnitude.”
Thanks!
On the IPCC presentation of the radiative forcing of CO2, yes they are in error as has been discussed several times; e.g. see
Pielke, R.A. Sr., 2006: Regional and Global Climate Forcings. Presented at the Conference on the Earth’s Radiative Energy Budget Related to SORCE, San Juan Islands, Washington, September 20-22, 2006.
http://climatesci.colorado.edu/publications/presentations/PPT-69.pdf
as well as in Climate Science with respect to the 2007 IPCC Statement for Policymakers; e.g. see
http://climatesci.colorado.edu/2007/03/19/climate-feedbacks-must-be-a-negative-effect-on-the-global-average-radiative-imbalance-if-the-ipcc-conclusion-of-anthropogenic-radiative-forcings-are-correct/
Comment by Roger Pielke Sr. — June 3, 2007 @ 8:35 pm
There is a considerable doubt about the mental sanity of anybody giving a standing ovation to All Gory .
I would suggest that opinions of mentally insane people are at best subject to caution .
The matter of the alleged “scientific consensus” where nobody knows what is exactly being consented about has already been beaten to death anyway - post # 26 and especially the point 4 holds true .
The ever increasing amount of scientific blogs and publications showing the IPCC dogma as being false is demonstrating that science is becoming science slowly again .
Comment by Tom Vonk — June 4, 2007 @ 2:56 am
If I was in receipt of a climate research grant, I too would have been applauding Gore at AGU 2006, with $ signs in my eyes.
We do indeed live in a world under the ‘enhanced greenhouse effect,’ which actually has a very small effect:
http://www.sciencebits.com/IceCoreTruth
The non-CO2/temperature correlation and Sulphtes from the 1940’s to late 1960’s breifly examined here:
http://www.climateaudit.org/?p=1536
Nir Shaviv again:
Temperature variations of 4 degrees give rise to CO2 variations of about 80 ppm, or typically to a changed forcing of ln(80/240)/ln(2)*4 W/m2 ~ 2 W/m^2. If climate sensitivity is larger than 2 deg/(W/m^2), or 8 degrees for CO2 doubling, then Earth’s climate would have been totally unstable due to CO2 feedback. We would have ended up as either Venus or a cold Earth. Luckily, the sensitivity is more like a 1 to 1.5 deg increase for CO2 doubling. This implies that CO2 has at most a ~20% amplification effect.
There are two reasons why the temperature should rise from the 1970’s.
First, there is a decrease in the average cosmic ray flux. If you look at the average of each cycle (e.g., in the graphs that you have sent), you will see that there is an increase in the average cosmic ray until about the cycle of 1970, and then a decrease in the following two cycles. Note that the last cycle was not as strong, so the average CRF increased. This can explain why the temperature stopped warming from around 2000.
Second, one has to realize that the temperature response of Earth’s climate is a low pass filter due to the high heat capacity of the Oceans. This implies that:
- The temperature variations over the 11 year cycle are highly damped (but they are there at a level of 0.1 deg).
- There is a delay time in the system’s response. This means that the 11-year cycle will lag the solar forcing (and it does by 1-2 years). Over the centennial time scale, the sun’s activity significantly increased until the middle of the century, then it slightly decreased and somewhat increased from the 1970’s. If you pass this behavior through the climates “low pass filter”, you will find that because of Earth’s heat capacity, the temperature at 2000 should be higher than the temperature in 1950’s even if the decrease until the 1970’s is similar to the increase afterwards.
Comment by Paul Biggs — June 4, 2007 @ 4:02 am
Hi Guys,
I heard some question about regional climate change. I think this is where many people have been saying that there are big changes. This is absolutely true that human induced climate change is happening on a local scale. But this is not from CO2 but land use and deforestation. Take a close look at China and their droughts, its not from CO2 but deforestation and the lack of the land to retain and return water vapor to the local climate. Also a big contributer is the heat island effect of big cities. I think this is where a lot of people erroneously compare local climate change to global change.
Comment by Jim Arndt — June 4, 2007 @ 10:55 am
Re #37: Roger, the information you linked to does not discuss the direct radiative forcing due to doubling carbon dioxide. It talks about CO2 forcing relative to other forcings.
The direct forcing from carbon dioxide is fundamental to the climate change issue, and if the standard value of 3.7 watts per square meter for each doubling is wrong, then the science is in serious trouble.
If you think this value is wrong, please tell me what is the source of error, and what the correct value should be.
Comment by Blair Dowden — June 4, 2007 @ 11:00 am
Re #38: AFAICT that “ever increasing amount” is based on claims from wingnuts like Limbaugh and Drudge. While everybody has to keep up their morale somehow, is there any evidence for this claimed trend?
Re #39: Nir Shaviv is distinctly unqualified to discuss atmosphere physics. If you do a search over at RealClimate, you’ll see what happened when he tried to argue his case with people who do have such qualifications.
A fundamental problem with all of these insolation/cosmic ray arguments is that they cannot explain the Pleistocene glaciation cycles (to say nothing of other aspects of paleoclimate). Until then, they’re all non-starters.
I see from a quick glance at Nir’s new commentary that he’s not keeping up with current relevant research. Presumably he’s too busy doing that in his own field.
Comment by Steve Bloom — June 4, 2007 @ 12:42 pm
Blair - I do not know what else I can refer you to. The analysis that we report on in my book with Bill Cotton specifically contrasts H20 and CO2 radiative forcings for doubling and from zero CO2 atmospheric concentrations to the present, and it is clear that the value of 3.7 Watts per square meter for doubling is not correct.
Comment by Roger Pielke Sr. — June 4, 2007 @ 12:42 pm
Hi Roger,
Isn’t it true that as CO2 concentrations increase that CO2 become less able to absorb and radiate heat back into the system. For example the temperature effect of atmospheric carbon dioxide is logarithmic. If we consider the warming effect of the pre-Industrial Revolution atmospheric carbon dioxide (about 280 parts per million by volume or ppmv) as 1, then the first half of that heating was delivered by about 20ppmv (0.002% of atmosphere) while the second half required an additional 260ppmv (0.026%). To double the pre-Industrial Revolution warming from CO2 alone would require about 90,000ppmv (9%) but we’d never see it - CO2 becomes toxic at around 6,000ppmv. What are your thoughts.
Comment by Jim Arndt — June 4, 2007 @ 1:51 pm
Blair, please see the discussion at http://climatesci.colorado.edu/2006/02/09/the-need-to-broaden-the-ipcc-perspective/
Comment by Douglas Hoyt — June 4, 2007 @ 2:57 pm
Jim, the ability of a single CO2 molecule to absorb and emit radiation remains the same. However, if we follow the path of multiple absorptions and emissions the net effect decreases. Ã… simple example (very oversimplified) would be if there were no CO2 in the atmosphere an IR photon emitted at the surface would go directly into space, cooling the surface. If the number of CO2 molecules were such that the photon was absorbed one time, eventually it would be re-emitted, but half would head out into space and half would be sent back to earth to heat the ground (CAUTION: in what actually happens, the CO2 molecule that emits is not the one that absorbs, complicated story). Now if on average the CO2 concentration was high enough that the re=emitted photon was absorbed again, and so on.
That captures the idea why CO2 forcing at 300 ppm is logarithmic with concentration.
Comment by Eli Rabett — June 4, 2007 @ 4:00 pm
Freeman Dyson is a believer in land use changes as the prime human forcing on climate. He also contends small land use changes effecting vegetation could easily lower atmospheric CO2 concentrations without worrying about emissions.
Freeman Dyson, another in a long list of non-consensus expert scientists. Steve Bloom won’t like this one bit. You Tube link to interview:
http://www.youtube.com/results?search_query=Sidewinder77+dyson
Comment by Reid — June 4, 2007 @ 5:10 pm
Re #47: I’m well aware of Dyson’s hand-waving. It’s an embarassing end to an otherwise distinguished career. But anyway, Reid, he’s not a climate scientist and so his opinion has no more value than that of any other amateur, e.g. Stephen Hawking (whom I therefore never quote except when needed to trump one irrelevant big name with an even bigger one). Regarding the long list, if it’s so long surely someone has gone to the trouble of compiling it so that it can be verified. Link?
Comment by Steve Bloom — June 5, 2007 @ 1:34 am
Eli, are you saying that the logarithmic is true only at 300 ppm?
In your too much oversimplified model it is not necessary to state that the IR photon would go directly into space. In fact, water does make most of the dirty work and the photon will stay in the air for a while.
Comment by Paolo M. — June 5, 2007 @ 5:06 am
Hi,
Just want to post this link because it is very interesting.
A critique of the 26 April 2007 testimony of James E. Hansen made to the Select Committee of Energy Independence and Global Warming of the United States House of Representatives entitled “Dangerous Human-Made Interference with Climate”
http://www.co2science.org/scripts/CO2ScienceB2C/education/reports/hansen/hansencritique.jsp
Comment by Jim Arndt — June 5, 2007 @ 11:07 am
RE: #40 - Consider also the impacts of excessive cultivation activities. There is such a thing as too much plowing and harrowing. Every time you turn over the soil you lose water and hinder its ability to retain it until a degree of recompaction sets in. Especially in Southern China, where there is year round growing, over cultivation is a serious issue. Same deal in India.
Comment by Steve Sadlov — June 5, 2007 @ 12:44 pm
Steve Bloom says “Regarding the long list, if it’s so long surely someone has gone to the trouble of compiling it so that it can be verified.”
I was going to search through the list of 2,500 IPCC climate scientists to pick out the heretics for you Steve. Unfortunately, the list of 2,500 IPCC scientists is classified. The IPCC claims it will eventually release a list of the scientists. Till then the notion that there is a consensus is an article of faith.
Comment by Reid — June 5, 2007 @ 1:14 pm
Re: ‘Dyson’s handwaving’. I’ve just viewed the link on youTube, and can confirm that Dyson spoke quietly with the tips of his fingers resting together in a steeple fashion. Hardly hand waving. Secondly Dyson spoke as one who believes CO2 is a serious problem, but has some criticisms with surface temperature trend measurements, and believes that stratospheric measurements provide a more useful metric. It is remarkable that even this small deviation from canon is being attacked by certain posters on this blog.
Comment by Vince Causey — June 5, 2007 @ 2:34 pm
Jim - Thank you for your comment.
Regarding #44, the radiative effect of CO2 is proportional to the logarithm of its atmosperic concentration, as you correct state. This does not, of course, account for the overlap with radiative effect of water vapor. Our analysis in the Cotton and Pielke book completed by Norm Woods is the quantitative evaluation of this effect. I recommend that you calculate the ratios from that analysis.
Comment by Roger A. Pielke Sr. — June 6, 2007 @ 3:24 am
Hi Guys,
Roger thank you for the comment. I just wanted to place a simple example to show that if you double CO2 it doesn’t cause double the warming and there are other factors such as solar output and the oceans oscillation (PDO & AMO). I have posted some links to show the effect of the PDO and AMO as well as solar output.
http://icecap.us/images/uploads/Ocean_Multidecadal_Cycles.pdf
http://www.junkscience.com/MSU_Temps/CRUglobalan.png
http://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/solar_variability/lean2000_irradiance.txt
Comment by Jim Arndt — June 6, 2007 @ 11:26 am
Re #33
Eli Rabbet,
Presumably you are referring to this graph?
http://en.wikipedia.org/wiki/Image:Grtemp.png
I’m no expert at divining identifications based on pseudonyms but I fail to see any indication that Bob Thompson is Masae. Perhaps you would get some insight by following up on the references indicated on the above page. Failing that, you may try posting your concerns here:
http://en.wikipedia.org/wiki/Talk:History_of_Greenland
Comment by Earle Williams — June 6, 2007 @ 5:21 pm
What are the main observations;Recommedations and shortcoming of IPCC Working group 1 reports and working group 111 reports.
Comment by Glory — June 7, 2007 @ 6:39 am
Ah, Mr. Bloom. Wing nuts. Hand waving. Delusionists are sloppy. etc Is there like some kind of handbook out there with the terms everyone’s supposed to use?
Ref #29 “Study”? Hah!!! Op-Ed, and a misleading one at that. Hardly any substance that says nothing and doesn’t even meet its own stated goals. But certainly seems to have met its real goals.
Here’s that Op-Ed boiled down into a sentence:
Scientists don’t disagree humans change the climate.
Wow. She needed an entire essay for that? Or my question: Yeah? And?
PS Read it and tell me who did the study.
Comment by Mike Nee — June 26, 2007 @ 7:20 pm
Ah, Mr. Bloom. Wing nuts. Hand waving. Delusionists are sloppy. etc Is there like some kind of handbook out there with the terms everyone’s supposed to use?
Ref #29 “Study”? Hah!!! Op-Ed, and a misleading one at that. Hardly any substance that says nothing and doesn’t even meet its own stated goals. But certainly seems to have met its real goals.
Here, just in case you were interested:
Op-ed (essay) paraphrasing with some comments:
If there’s a lack of disagreement, that shows climate science is not highly uncertain.Hunh?
Scientific consensus is shown by the reports of a intergovernmental entity known as the IPCC. Claims the snippet of WG II (Impact and Adaptation) technical summary 1.2 ‘What is potentially at stake?’ edited to remove certain terms not about CO2 as being evidence of an ‘unequivocal statement by the IPCC that there is consensus of scientific opinion that humans influence climate change’. How many ways can that be parsed, I wonder
And an NAS report agrees. The report asks if the IPCC is correct in its summary about professional scientific thinking and the report answers yes. circular reasoning
The AMS, AGU and Science magazine’s AAAS have issued statements there is compelling evidence humans influence climate change. more staring in the mirror
These reports and statements are gone over a lot, so they probably reflect the views of the members of these organizations. maybe, but not a given But the organizations might quash dissenters. undoubtedly they do, what’s your point So to test that idea, rather than do a survey of them and find out we go look at some abstracts only in the ISI database half-truth, it wasn’t the entire database search with “climate changeâ€? a lie, that wasn’t the search term and find 928.Which at best would be by the non-dissenters of course, meaningless or in other words, the experiment doesn’t test what it’s supposed to be testing for
75% either agreed or didn’t disagree that there was a lack of disagreement by the scientific community that humans influence climate change. 25% had no view on it, and none disagreed. And? What was that percent of ‘agree’ abstracts and why did you lump them in with those that ‘didn’t disagree’ What possible meaning can these stats prove vis a vis your claim?
None of the papers argued climate change was natural. Oh, really. Which ones are they? Who wrote them? Are they writing in IPCC reports also? Who do they work for?
We prove that published scientists agree with the statements of their groups by scanning a limited number of abstracts with certain words in them did that how exactly?. Some people incorrectly think that climate scientists don’t agree with each other. Which you haven’t proved and you didn’t ‘ask climate scientists’
now comes the pain The consensus might be wrong, we can’t blame anyone for not acting. okay… lets see how this gets followed up But we understand humans change the climate exceedingly vague so we should do something about it or we’ll look bad to our descendants.Hunh?
We don’t understand all the details, and we should keep researching the dynamics of climate. I agree What to do about climate change is not answered. I agree But scientists don’t disagree humans change the climate. So vague as to be meaningless; in fact, so obvious it doesn’t even need mentioning. But you didn’t prove it so whoop passive voice, why; that’s right, we know why Climate scientists keep telling us that and we should listen.They keep telling us? When? I’d like some names and the radio and TV stations I can listen to them on
Op-Ed boiled down into a sentence:
Scientists don’t disagree humans change the climate.
Wow. You needed an entire essay for that?
PS Who did the study?
Comment by Mike Nee — June 26, 2007 @ 7:23 pm
Re: #59 The Op-Ed (study) that was to demonstrate Scientific consensus on climate change has a bias (as every thing associated with the IPCC report). Great job!!!
Comment by Bob T. — June 27, 2007 @ 7:48 am
Thanks!
As to the PS, I have no idea who did the study. She doesn’t say SHE did it. (I’d bet she didn’t.) So that ‘climate change’ search term as a lie maybe isn’t true, it might be she just grabbed some report or had a student do it, she got the results she wanted, and had no idea if they were true or not.
Nice how we always have these transparent methods we can reproduce.
Then again, it might have been a lie, and the thing may have been to set up whomever might try and reproduce it….
Or as Larry R. said over at Motl’s:
Comment by Mike Nee — June 29, 2007 @ 3:13 pm