Monthly Archives: February 2008

Interesting Paper On Trends In Atmospheric Moist Enthalpy

Souleymane Fall of Purdue University has alerted us to a very interesting new paper on trends in the combined effect on heat of water vapor and sensible temperature (i.e., moist enthalpy; see Pielke et al. 2004). The paper is P. Ribera, D. Gallego, L. Gimeno, J.F. Perez-Campos, R. García-Herrera, E. Hernández, L. de la Torre, R. Nieto and N. Calvo 2004: The Use of Equivalent Temperature to Analyze Climate Variability. Studia Geophysica et Geodaetica. 459-468.

The abstract reads

“Equivalent temperature based in the NCEP/NCAR reanalysis database has been used as a simultaneous measure of temperature and humidity. Its variations during the 1958−1998 added to the effect of the inclusion of satellite data during the late seventies have been analyzed. An increase of the globally averaged equivalent temperature has been detected, the trend has been considerably greater during the first half of the study period and significant differences can be found between continental and oceanic areas. The relation of the trend with four of the main modes of climate variability has been assessed. The North Atlantic Oscillation and the Artic Oscillations are closely related to the equivalent temperature over the North Atlantic basin, extending toward Northern Asia in the second case. El Niño/Southern Oscillation and the Antarctic Oscillation seem to have a more global effect.”

An important statement from the Conclusions reads,

“The small global trend for the two separate periods 1958−78 and 1979−98 suggests that the trend for the entire study period could be due to the late 70’s shift in the data. Nevertheless, not all the ET trends are attributable to this shift, which is neither spatially nor temporally uniform. Significant trends of different sign and strength can be found over continental or oceanic areas depending on the considered period.”

The journal’s name is Studia Geophysica et Geodaetica.

“Studia Geophysica et Geodaetica is an international journal covering all aspects of geophysics, meteorology and climatology, and of geodesy. Published by the Geophysical Institute of the Academy of Sciences of the Czech Republic, it has a long tradition, being published quarterly since 1956. Studia publishes theoretical and methodological contributions, which are of interest for academia as well as industry. The journal offers fast publication of contributions in regular as well as topical issues.”

This paper shows why it is so important to evaluate total heat energy (sensible and latent heat) in the assessment of multi-decadal climate trends of warming and cooling.

Comments Off

Filed under Climate Change Metrics

New Research Paper “Assessment Of Three Dynamical Climate Downscaling Methods”

Lo, J., Z. Yang, and R. A. Pielke Sr. (2008): Assessment of dynamical climate downscaling methods using the Weather Research and Forecasting (WRF) Model. J. Geophys. Res.,  J. Geophys. Res., doi:10.1029/2007JD009216, in press.

The abstract reads

The common methodology in dynamical regional climate downscaling employs a continuous integration of a limited-area model with a single initialization of the atmospheric fields and frequent updates of lateral boundary conditions based on general circulation model outputs or reanalysis datasets. This study suggests alternative methods that can be more skillful than the traditional one in obtaining high-resolution climate information. We use the Weather Research and Forecasting (WRF) model with a grid spacing at 36 km over the conterminous U.S. to dynamically downscale the 1-degree NCEP Global Final Analysis (FNL). We perform three types of experiments for the entire year of 2000: 1) continuous integrations with a single initialization as usually done, 2) consecutive integrations with frequent re-initializations, and 3) as 1) but with a 3-D nudging being applied. The simulations are evaluated in a high temporal scale (6-hourly) by comparison with the 32-km NCEP North American Regional Reanalysis (NARR). Compared to NARR, the downscaling simulation using the 3-D nudging shows the highest skill, and the continuous run produces the lowest skill. While the re-initialization runs give an intermediate skill, a run with a more frequent (e.g. weekly) re-initialization outperforms that with the less frequent re-initialization (e.g. monthly). Dynamical downscaling outperforms bi-linear interpolation, especially for meteorological fields near the surface over the mountainous regions. The 3-D nudging generates realistic regional  scale patterns that are not resolved by simply updating the lateral boundary conditions as done traditionally, therefore significantly improving the accuracy of generating regional climate information.”

This paper has very important implications in terms of providing regional and local climate prediction information to policymakers and others. It further confirms our conclusions in the paper

Castro, C.L., R.A. Pielke Sr., and G. Leoncini, 2005: Dynamical downscaling: Assessment of value retained and added using the Regional Atmospheric Modeling System (RAMS). J. Geophys. Res. – Atmospheres, 110, No. D5, D05108, doi:10.1029/2004JD004721.

Since the results deteriorate when the driving large scale atmospheric information is applied only at the lateral boundaries, this means that the regional model is a slave to the parent global scale information. If the global model has errors, it is not possible for the regional model to correct for these errors.  Using  regional and local scale predictions based on dynamic downscaling from multi-decadal global climate model projections to make policy decisions decades into the future, therefore, is  erroneous and misleading.  Those who disagree with this conclusion need to provide quantitative tests that should be used to assess whether dynamic downscaling can predict regional weather patterns in the coming years (such as drought events) that provides skillful and useful information to policymakers. Certainly the forecasts for the winter 2007/2008 in the western USA have been a major bust.

Comments Off

Filed under Climate Models

TRMM (Tropical Rainfall Measuring Mission) Data Set Potential in Climate Controversy By Joanne Simpson, private citizen

I am pleased to be able to post a weblog by Dr. Joanne Simpson who is among the most preeminent scientists of the last 100 years.  Her comments were first distributed on a limited mail group, and are reproduced here with her permission.

 Dr. Joanne Simpson

“Since I am no longer affiliated with any organization nor receive any funding, I can speak quite frankly. For more than a decade now “global warming” and its impacts has become the primary interface between our science and society. A large group of earth scientists, voiced in an IPCC[1] statement, have reached what they claim is a consensus of nearly all atmospheric scientists that man-released greenhouse gases are causing increasing harm to our planet. They predict that most icepacks including those in the Polar Regions, also sea ice, will continue melting with disastrous ecological consequences including coastal flooding. There is no doubt that atmospheric greenhouse gases are rising rapidly and little doubt that some warming and bad ecological events are occurring. However, the main basis of the claim that man’s release of greenhouse gases is the cause of the warming is based almost entirely upon climate models. We all know the frailty of models concerning the air-surface system. We only need to watch the weather forecasts. However, a vocal minority of scientists so mistrusts the models and the complex fragmentary data, that some claim that global warming is a hoax. They have made public statements accusing other scientists of deliberate fraud in aid of their research funding. Both sides are now hurling personal epithets at each other, a very bad development in Earth sciences. The claim that hurricanes are being modified by the impacts of rising greenhouse gases is the most inflammatory frontline of this battle and the aspect that journalists enjoy the most. The situation is so bad that the front page of the Wall Street Journal printed an article in which one distinguished scientist said another distinguished scientist has a fossilized brain. He, in turn, refers to his critics as “the Gang of Five”.

Few of these people seem to have any skeptical self-criticism left, although virtually all of the claims are derived from either flawed data sets or imperfect models or both. The term “global warming” itself is very vague. Where and what scales of response are measurable? One distinguished scientist has shown that many aspects of climate change are regional, some of the most harmful caused by changes in human land use. No one seems to have properly factored in population growth and land use, particularly in tropical and coastal areas.

What should we as a nation do? Decisions have to be made on incomplete information. In this case, we must act on the recommendations of Gore and the IPCC because if we do not reduce emissions of greenhouse gases and the climate models are right, the planet as we know it will in this century become unsustainable. But as a scientist I remain skeptical. I decided to keep quiet in this controversy until I had a positive contribution to make. That point is to be celebrated in the TRMM 10 year anniversary in a Conference in February, 2008. With a 10-year record the TRMM, users of the data can begin to look for and test for trends. With the TRMM sampling limitations, other data sets, from geosynchronous and other sources are being used now in the group led by Bob Adler. Their products can detect trends in global tropical rain on several scales, including regional.

These patterns can be compared over the past ten years with the patterns predicted ten years ago by the climate models. An example is the Walker circulation, normally with descent of air over the eastern Pacific Ocean and ascent of air over the western Pacific. When this cell weakens, perhaps breaking over the middle Pacific, we have an El Niño. The modelers say that higher greenhouse warming produces recognizable changes in the Walker circulation. What better data is there to test such model results than the tropical rain products from TRMM? While the TRMM data set provides no panacea on the volatile hurricane front, useful information for the several ocean basins relating the rainfall to claimed and observed storm structure can be made if dedicated work is committed. I would be most interested to find out how the distribution of hot towers relates to storm intensity and rain production. Examining the data already posted on the TRMM Website shows that such projects are tractable. The major lack for TRMM data use in testing climate theories is latitude limitation. Global warming impacts appear much more severe in polar latitudes than in tropical regions. The best news is that the Global Precipitation Mission (GPM) is on schedule for a 2013 launch. In conclusion I can just pray that GPM scientists and engineers are as smart and as lucky as we TRMM participants have been.”

Comments Off

Filed under Guest Weblogs

Influence Of Water Vapor Trends On Multi-Decadal Surface Temperature Trends – Part IV From Our JGR Paper

This weblog continues the discussion of the issues that we raised in our 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.

Weblogs on the first three sections of our JGR paper have already appeared (see, see see, and see),  along with an excellent follow up on the first section by Lucia Liljegren (see February 18, 2008 Guest weblog).

The current weblog discusses the role of surface air water vapor trends in terms of how surface air temperatures trends, used to diagnose global warming and cooling, can be misinterpreted. As we write in our paper

“Near-surface air temperature trends are also significantly influenced by trends in surface air absolute humidity over the same time period since even with the same amount of heat within the near-surface air, the heat would be distributed differently between sensible and latent heat of the air. This issue has not been investigated in the assessment of multidecadal surface air temperature trends…….Ignoring concurrent trends in surface air absolute humidity therefore introduces a bias in the analysis of surface air temperature trends.”

The equation that combines the effect of temperature and humidity on the heat content of surface air can be described as follows from Pielke et al. 2004:

slide-25-2.png

(Thanks to Dan Hughes for pointing out the error in the previous version of the above figure!) 

An example of how T and TE often vary on the hottest summer afternoons in Colorado is illustrated in the figure below [Figure 11 in Pielke et al. 2005]

r-313-figure-11.png

What is informative about the above figure is that the time of day with the largest amount of heat (in Joules per kilogram of air) measured at the surface is in the morning, not the afternoon! In this case, which is typical of many location where drier air is mixed downward from higher in the atmosphere during the afternoon, if the goal is to use surface temperature data to diagnose global warming, then using the maximum temperature during the day without including the amount of water vapor in the air will, in this case, result in a bias.

The neglect of including water vapor in the assessment of global warming is a serious oversight. There are the following consequences of neglecting this contribution to the heat content of surface air in the warm season at mid- and high-latitudes and all year in the tropics. For example, neglecting the effect of the change in surface albedo [which is a large effect also],

  1. When land is converted such as due to deforestation, during the growing season the maximum near-surface air temperature is likely to be higher yet the near-surface is water vapor content is lower since transpiration is reduced, compared to what it was previously.  As a result, the near-surface air heat content in Joules per kilogram is lower.
  2. When arid and semi-arid land is coverted to irrigation, during the growing season, them maximum temperature is likely to be lower yet the water vapor content will be higher than it was before the landscape conversion due to the added transpiration. The near-surface heat content is  higher.

 The effect of the albedo change would further reduce the near-surface  heat content in #1, since, except for dark soils, deforested surfaces generally have a higher albedo, and this a larger reflection of solar insolation.  With #2, the opposite typically occurs, as irrigated landscapes have lower albedos than the natural arid and semi-arid landscapes; thus thus the solar insolation absorbed at the surface (and this the near-surface heat content) is even higher.

What this means is that assessing the  global warming by using temperature alone will introduce a significant bias in the diagnosis. Since, for instance, the land conversion by deforestation in the tropics is much larger in areal extent than the conversion to irrigation in the tropics, the result is a yet another warm bias in the diagnosis of global warming if the near surface air temperature is used by itself. Even the extent of vertical mixing of drier air and warmer air downward during sunny afternoons (and thus the value of the daily maximum temperature) will result in a bias if this vertical mixing changes over time.

Clearly, this is yet another issue with respect to the diagnosis of global warming using a global temperature trend, which the IPCC has ignored.

Comments Off

Filed under Climate Change Metrics

Follow Up By Fergus Brown To “Is There Agreement Amongst Climate Scientists on the IPCC AR4 WG1?”

Fergus Brown has weblogged on the article that was presented on Climate Science on February 22, 2008 entitled Is There Agreement Amongst Climate Scientists on the IPCC AR4 WG1?. His weblog invites constructive comments, and Climate Science encourages its readers to respond there. It will be very valuable to build on this very important contribution that was led by Fergus.

Comments Off

Filed under Climate Science Reporting

Volunteers Across the Nation To Track Climate Clues In Spring Flowers

There was a press release by the USGS in the Department of the Interior
on Febryary 14, 2008 by Jake Weltzin, David Hosansky, Catherine Puckett andRachael Drummond title

Volunteers across the Nation to Track Climate Clues in Spring Flowers

Climate Science has discussed the value of monitoring the phenology of vegetation as an important cllimate metric (see and see). The full press release is reproduced below. Interested readers of Climate Science are encouraged to join in this important effort!

NEWS RELEASE

“Starting this week, citizen-scientist volunteers will be able to help track climate change by observing and recording the timing of flowers and foliage.Project BudBurst, operated by the University Corporation for Atmospheric Research (UCAR) and a team of partners including the U.S. Geological Survey’s USA National Phenology Network, allows U.S. students, gardeners, and other citizens to enter their observations into an online database that, over time, will give researchers a more detailed picture of global climate change.The project, which will be launched on Feb. 15, will operate year-round so that early- and late-blooming species in different parts of the country can be monitored throughout their life cycles. Project BudBurst (http://www.budburst.org) builds on a pilot program carried out last spring, when a thousand participants recorded the timing of the leafing and flowering of hundreds of plant species in 26 states.The Chicago Botanic Garden, University of Montana, and the USA National Phenology Network (USA-NPN) are collaborators on Project BudBurst, which was funded in part with a grant from the U.S. Bureau of Land Management and the National Fish and Wildlife Foundation. The project is also supported by the National Science Foundation and Windows to the Universe ( http://www.windows.ucar.edu/), a UCAR-based Web site that will host the project online as part of its citizen science efforts.“Climate change may be affecting our backyards and communities in ways that we don’t even notice,” says project coordinator Sandra Henderson of UCAR’s Office of Education and Outreach. Project BudBurst is designed to help both adults and children understand the changing relationship among climate, seasons, and plants, while giving the participants the tools to communicate their observations to others. Based on the success of last year’s pilot program, this project is capturing the public?s imagination in a way we never expected.?Project Budburst is one of the citizen-science partnerships of the newly created USA-NPN  (www.usanpn.org), which is managed by the U.S. Geological Survey, and includes partners such as the National Science Foundation, the University of Arizona, the U.S. Fish and Wildlife Service and many other agencies. The goal of the USA-NPN is to engage governmental agencies, environmental networks and field stations, educational institutions, and mass participation by citizen scientists in collecting phenological information on plants and animals.Phenology is the study of periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate, said Dr. Jake Weltzin, executive director of the USA-NPN.
 

Examples of phenological events include the timing of leafing and flowering, agricultural crop stages, insect emergence, and animal migration.”By observing these cycles through time, researchers can better understand and predict global climate change, and monitor drought conditions, wildfire risk, invasive species, and the spread of infectious diseases,” said Weltzin. “In the long-term — and with enough data — such information can help us better understand, mitigate and adapt to ongoing and future climate change.” The USA-NPN will begin enlisting the help of working professional scientists and training citizen volunteers for more intensive plant-phenology monitoring later this spring. In addition, Weltzin said USA-NPN is closely collaborating with other already-existing networks “such as Project Budburst” to maximize the data collected. How Project Budburst Works

As described on the Project BudBurst webpage, each participant selects one or more plants to observe. Participants begin checking their plants at least a week before the average date of budburst — the point when the buds have opened and leaves are visible. After budburst, participants continue to observe the tree or flower for later events, such as the first leaf, first flower and, eventually, seed dispersal. When participants submit their records online, they can view maps of these phenological events across the United States.

Along with the partners noted above, Project BudBurst collaborators include the Plant Conservation Alliance and the universities of Arizona; California, Santa Barbara; Wisconsin-Milwaukee; and Wisconsin-Madison.”

As emphasized on Climate Science (and also concluded in the 2005 National Research Council Report Radiative Forcing of Climate Change: Expanding the Concept and Addressing Uncertanties, vegetation processes are as much a component of the climate system as the weather variables of temperature and precipitation. 

Comments Off

Filed under Climate Change Metrics

Is There Agreement Amongst Climate Scientists on the IPCC AR4 WG1?

One of the readers of Climate Science (Fergus Brown), in response to the questions that have been raised by the weblog (and elsewhere)  wanted to poll the climate community to ascertain their views on the IPCC WG1 report.  The article that we completed on this subject, under his leadership, is given in its entirety later in this weblog.  However, a brief history as to why we are publishing as a weblog and not in another venue is discussed below.

After the survey was completed last summer and the article written, it was submitted to the AGU publication EOS as a “Forum piece. The EOS description of a Forum is that it

 “contains thought-provoking contributions expected to stimulate further discussion, within the newspaper or as part of Eos Online Discussions. Appropriate Forum topics include current or proposed science policy, discussion related to current research in our fields especially scientific controversies, the relationship of our science to society, or practices that affect our fields, science in general, or AGU as an organization. Commentary solely on the science reported in research journals is not appropriate.”

Our article certainly fits this description.  However, after 4 months without a decision, our contribution was summarily rejected by Fred Spilhous without review. He said our article did not fit EOS policy. We disagreed, of course, based on the explicit EOS policy given above, but our follow request for an appeal was ignored.

We then submitted to Nature Precedings where their policy states

“Nature Precedings is a place for researchers to share pre-publication research, unpublished manuscripts, presentations, posters, white papers, technical papers, supplementary findings, and other scientific documents. Submissions are screened by our professional curation team for relevance and quality, but are not subjected to peer review. We welcome high-quality contributions from biology, medicine (except clinical trials), chemistry and the earth sciences.”

Our article was quickly rejected without explanation.

From this experience, it is clear that the AGU EOS and Nature Precedings Editors are using their positions to suppress evidence that there is more diversity of views on climate, and the human role in altering climate, than is represented in the narrowly focused 2007 IPCC report.  

Our article follows below. We invite colleagues who are expert in polling techniques to build on the polling questions that we pose in our contribution, and to provide the community and policymakers with the actual range of perspectives on climate science.

Our paper is

Brown, F., J. Annan, and R.A. Pielke Sr., 2008: Is there agreement amongst climate scientists on the IPCC AR4 WG1?

Fergus W.M. Brown, CPE, UCLAN, Preston, UK
Roger A. Pielke Sr. CIRES, University of Colorado, Boulder, CO
James D. Annan, FRCGC/JAMSTEC, Yokohama, Japan

An online poll of scientists’ opinions shows that, while there is strong agreement on the important role of anthropogenically-caused radiative forcing of CO2in climate change and with the largest group supporting the IPCC report, there is not a universal agreement among climate scientists about climate science as represented in the IPCC’s WG1. The claim that the human input of CO2  is not an important climate forcing is found to be false in our survey. However, there remains substantial disagreement about the magnitude of its impacts. The IPCC WG1 perspective is the mean response, though there are interesting differences between mean responses in the USA and in the EU. There are, also, a significant number of climate scientists who disagree with the IPCC WG1 perspective.

The issue of whether scientists agree about the causes of climate change has persisted in discussions of climate science in general and in the development of policy to respond to the threats implied by climate variability and change. We have undertaken a poll of scientists’ opinions in which authors of climate papers in the journals: Geophysical Research Letters (2007), Atmospheric Chemistry and Physics (2007), Climate of the Past (2007), the Journal of Atmospheric Science (2007) and the Journal of Climate (2007), and authors of presentations (oral and poster) in the 2007 AGU and 2007 EGU General Assemblies, as provided in online schedules for these events, were invited to express their opinion. While this polling does not follow the randomized selection of individuals to poll as used to completely sample a population (see, for example: The American Association for Public Opinion Research, guidelines for research) it is a valid approach to assess whether a significant set of climate scientists agree or disagree with the perspective of the role of humans within the climate system as reported by the 2007 Intergovernmental Panel on Climate Change’s (IPCC) Fourth Assessment Report (AR4), as represented by the content of the Working Group 1 (WG1) report.

However, as there is no currently available information on the complete community of ‘climate scientists’, the poll cannot be tested for statistical significance. In the absence of such information, the methodology adopted was the only practicable means of attempting such a poll. It should be recognised, however, that the methodology is not strictly statistically formal and the results should be viewed accordingly.

The initial results of the poll are presented below, with an invitation to climate scientists to participate online if they have not already responded. This follow-up response will permit a further examination of the findings of the poll.

In our poll, there were 140 responses out of the 1807 who were contacted by the first author. The authors participated along with poll specialist David Jepson (Bsc Hons) in writing the polling questions (see Table 1 for the questions), but had no knowledge of who participated in the polling. It is interesting to note, however, that among the respondents were a substantial number of senior scientists and leading figures in climate science, whose support and interest in the poll were much appreciated. It is important to recognize that we are not presenting the results as representing anything other than the views of those who responded as we have no way to assess the relationship of the responders with the total relevant population.

The results are quite informative. No scientists were willing to admit to the statement that global warming is a fabrication and that human activity is not having any significant effect on climate [0%]. In total, 18% responded that the IPCC AR4 WG1 Report probably overstates the role of CO2, or exaggerates the risks implied by focusing on CO2-dominated Anthropogenic Global Warming (AGW), to a greater or lesser degree. A further 17% expressed the opinion that the Report probably underestimates or seriously underestimates the consequences of anthropogenic CO2 -induced AGW and that the associated risks are more severe than is implied in the report. The remaining 65% expressed some degree of concurrence with the report’s science basis, of which the largest group [47% of all respondents] selected option 5. The exact response rates are given in Figure 1.

 figure-1.PNG

The questions used in the opinion poll are listed below in Table 1. The methodology is described in the online supplement.

From the initial response, we conclude that:

1. The largest group of respondents (45-50%) concur with the IPCC perspective as given in the 2007 Report.

2. A significant minority (15-20%), however, conclude that the IPCC understated the seriousness of the threat from human additions of CO2 .

3. A significant minority (15-20%), in contrast, conclude that the IPCC overstated the role of human additions of CO2  relative to other climate forcings.

4. Almost all respondents (at least 97%) conclude that the human addition of CO2  into the atmosphere is an important component of the climate system and has contributed to some extent in recent observed global average warming.

In addition, responses were broken down by country of response. By applying a numerical value to the responses it is possible to see interesting differences between opinions within the USA and outside, in particular in EU countries. The mean score was 5.0, (where 5.0 means agreement with the IPCC WG Report). In the USA, the mean response was 4.8, compared to 5.2 in all other countries, and 5.6 in EU countries. The scientists based in the USA who replied to the survey are slightly more in disagreement with the Report than scientists outside, and scientists based in the EU (with particularly strong signals [5.9] from a small sample coming from Germany), tend to be more ‘alarmed’ than in other countries. Another small response, from Mexico, showed anomalously large concern, scoring 6.3).

In conclusion, there is strong agreement on the important role of radiative forcing due to human additions of CO2  on AGW. However, the relative role of this forcing, in comparison to other human climate forcings, is still an open scientific question. Thus, those who claim that the radiative effect of human added CO2  is unimportant are not supported in our poll of climate scientists. However, a significant minority of 15-20% take the view that the IPCC does exaggerate the relative role of this forcing.

An important inference from these conclusions is that there continues to be an important debate about the correct attribution of forcings which should be clearly expressed as an area of uncertainty to policymakers in the relevant scientific summaries, and that there remains a strong case for continued investment and investigation into this area of climate research.

As a follow on to this preliminary polling, scientists engaged in disciplines related to climate in all its variety are invited to respond to the first author, in confidence, to aid in verification of the findings and development of the analysis as presented here, as well as to provide further insight into the degree of acceptance of the IPCC WG1 Report. The respondent should e-mail their numerical category in Table 1, the country that they are from, their scientific discipline and their highest academic degree and discipline, as well as their role, if any, in the preparation of the 2007 IPCC Report to fwmb@btinternet.com. It is hoped that a future article will be able to discern between differing attitudes by scientific discipline as well as by country, as well as have a larger sample of the professional community.

Table 1

These were the options and the questions as presented in the opinion poll:

Which one statement most nearly matches your personal opinion about the physical science basis of global warming, as exemplified by the IPCC WG1 report?

* [If your personal opinion falls between two adjacent statements, please mark both]

1. There is no warming; it is a fabrication based on inaccurate/inappropriate measurement. Human activity is not having any significant effect on Climate. The data on which such assumptions are made is so compromised as to be worthless. The physical science basis of AGW theory is founded on a false hypothesis.

2. Any recent warming is most likely natural. Human input of CO2  has very little to do with it. Solar, naturally varying water vapour and similar variables can explain most or all of the climate changes. Projections based on Global Climate Models are unreliable because these are based on too many assumptions and unreliable datasets.

3. There are changes in the atmosphere, including added CO2  from human activities, but significant climate effects are likely to be all within natural limits. The ‘scares’ are exaggerations with a political motive. The undue emphasis on CO2  diverts attention away from other, important research on climate variability and change.

4. There is warming and the human addition of CO2  causes some of it, but the science is too uncertain to be confident about current attributions of the precise role of CO2  with respect to other climate forcings. The IPCC WG1 overestimates the role of CO2  relative to other forcings, including a diverse variety of human climate forcings.

5. The scientific basis for human impacts on climate is well represented by the IPCC WG1 report. The lead scientists know what they are doing. We are warming the planet, with CO2  as the main culprit. At least some of the forecast consequences of this change are based on robust evidence.

6. The IPCC WG1 is compromised by political intervention; I agree with those scientists who say that the IPCC WG1 is underestimating the problem. Action to reduce human emissions of CO2  in order to mitigate against serious consequences is more urgent than the report suggests. This should be done irrespective of other climate and environmental considerations.

7. The IPCC WG1 seriously understates the human influence on climate. I agree with those scientists who say that major mitigation responses are needed immediately to prevent catastrophic serious warming and other impacts projected to result from human emissions of CO2. We are seriously damaging the Earth’s climate, and will continue to face devastating consequences for many years.

Supplement

Methods

A simple, single question opinion poll was carefully constructed to test scientific opinion. From the outset, this was designed to be conducted via email, so the format and wording were designed with this in mind. Under the supervision of Roger Pielke Sr., and with the assistance of James Annan and David Jepson, the wording and construction of the poll was constructed so as to address the specialist nature of the sample community and minimise the possibility of wording or construction bias.

1807 emails were sent to scientists, in 53 countries, with specialisations in fields of science directly related to a study of climate, selected from sources which were judged to be representative of the climate science community, in the context of the wider scientific community. To this end, and to provide the greatest opportunity for international coverage of the sample community, the following journals were selected: Geophysical Research Letters, Atmospheric Chemistry and Physics, Climate of the Past, the Journal of Atmospheric Science and the Journal of Climate. Author lists and article lists from 2007 only were initially used, as representing those scientists most likely to be currently active in their respective fields.

Additional emails were sent to members of the editorial boards of the Atmospheric Sciences section of the Journal of Geosciences of China, but an apparent server malfunction prevented any replies from this source. In an effort to make the international cross-section more representative, in particular the Asia-Pacific region, and to improve the proportion of statisticians involved in the field, emails were also sent to participants in the forthcoming 10th International Meeting on Statistical Climatology (Beijing, August 2007).

In the case of the journals, in each case the abstract and reference terms were checked individually to confirm that the authors were involved in work relating to climate science. In cases where the published article was not related to climate science, (for example, in the case of GRL, articles on planetary physics or geology), no email was sent. Each email was sent individually, to prevent duplication and reduce the possibility of sample error.

Email addresses were also collated from the session information of the 2007 AGU Joint Assembly and the 4th EGU General Assembly, 2007, from four sections: Atmospheric Sciences, Global Climate Change, Ocean Sciences (selectively) and Palaeoceanography and palaeoclimatology (for the EGU, this was Climates past, present and future). Once again, entries were cross-checked for relevance before a request was sent. Selecting potential respondents from the second and third authors of papers and posters in these assemblies allowed for a larger range of participation from less senior scientists and those active in roles such as research assistant and research fellow, thereby broadening the range of job roles and seniority in the sample.

140 replies were received from respondents in 23 countries. As agreed in the terms of response, these responses were classified only in terms of the country of origin, as defined by the institution cited by the scientist and the email address suffix. A process of cross-validation of suitability of respondent involved an anonymous online reference check for each respondent, where this was possible.

Sampling Issue

It is important to recognize that we are not presenting the results as representing anything other than the views of those who responded as we have no way to assess the relationship of the responders with the total relevant population. We view this article as the preliminary analysis of the active climate research community, a motivation for a more rigorous statistical polling, and a focused set of questions for the climate community to discuss.

On the coverage and responses, there are large discrepancies between the numbers of responses from various countries. The lack of response from China, along with the number of ‘message failure’ automated response, suggest that few, if any, of the scientists in that country received the email. This is interpreted as a function of a server error or malfunction. The relatively large responses from the United States and the United Kingdom are, at least in part, a function of the language in which the poll was constructed (although almost all climate change research is in English); no translations were made; all enquiries were in English. It should also be noted, though, that the Global community of scientists involved in climate related disciplines is heavily skewed, with a large proportion of the work taking place in US and EU academic and state institutions. Therefore, though the language bias is likely to have suppressed the level of response from countries where English is not the common language, the international range and proportion of responses is interpretable as broadly representative of the community as a whole. One consequence of the diverse and relatively low response rate from countries other than the USA and, to a lesser extent, the UK, however, is that no statistically meaningful international comparisons can be made at this time, though a comparison of scientific opinion from those who responded within the USA and in `other countries’ collectively is possible.

The ‘scientific’ opinion poll

The poll conducted amongst scientists was designed to replicate the range of ‘attitudes’ to what is commonly referred to as the ‘AGW hypothesis’. This took three parts: an opinion on the degree of recent and/or future climate impacts; an opinion on the reliability of the IPCC AR4 WG1 science; and an opinion on the relative role of CO2 as a climate forcing. Each of the seven options for the poll offered ‘matched’ statements which, collectively, can be interpreted as a generic ‘opinion’ on the scientific basis for the ‘AGW hypothesis’. In addition to the seven principle statements, respondents were also given the option to select an ‘interim’ stance, which represented a compromise between any two adjacent statements or ‘attitudes’. The poll was designed such that the lower numbered options represented varying degrees of disagreement, or uncertainty, below the thresholds outlined in the IPCC AR4 WG1. Statement 5 was the ‘pure agreement’ position, which represented a strong agreement with the scientific basis of the AR4 WG1 and little or no uncertainty. The higher numbered options represented opinions that conclude that the AR4 WG1 is too conservative in reporting on the changes humans are causing to the climate system through the radiative forcing of CO2.

The design of the poll thus allows for a graphic representation of responses which indicates the full range of opinions in a distribution curve. The poll design was skewed slightly to compensate for likely bias, by allowing more responses for doubt on the ‘conservative’ side than the opposite; therefore, it is to be expected that a normal distribution which reflected a broad consensus on the WG1 science would be centred around option 5, rather than the central option, thereby shifting the curve to the right of the graph.

A strength of the poll was that the three-part statements allowed for more respondents to find a statement which matched their personal understanding or opinion. A weakness is that the responses do not distinguish between the three elements of the statements, so no inference can be made about agreement with any one part of the statements. This is further discussed in the conclusions.

The seven ‘attitudes’ can be characterised broadly as:

  1. No warming, no scientific basis for AGW hypothesis;
  2. Some warming, probably natural, role of CO2 small, climate model projections unreliable;
  3. Some warming, probably within natural variability, impacts exaggerated;
  4. Warming; CO2 contributes; WG1 overestimates role of CO2, underestimates other forcings;
  5. WG1 an accurate assessment of human impacts, at least some robust consequences;
  6. WG1 too ‘conservative’, problems more urgent, need for mitigation urgent; 
  7. WG1 assessment seriously underestimates problem, immediate mitigation action needed.

Several responses by participants provided interesting additional information about the interpretation of the questions. One respondent suggested that he/she could have truthfully answered with any of four statement choices. Two respondents could find no statement which matched their personal opinion. Six respondents qualified their selection of option 5 with an additional statement that they also were inclined to agree with elements of option 7; these were recorded as selecting only option 5, as the additional information was discounted by the structure of the poll’s options. This latter response might imply, though, that the number of scientists who selected the ‘consensus’ option may have reduced the possible number of those who were unwilling to admit to an ‘alarmed’ position.

The authors would like to express their gratitude to all those busy individuals who took the effort to participate in this poll and were willing to place their trust in the first author, and to the useful suggestions and replies received in addition by respondents.

Text of cover letter sent by email to scientists by the first author between April-June 2007, with the poll questionnaire.

Dear Professor/Dr.,

Why am I contacting you?

I am contacting you to ask if you will participate in a simple opinion poll on the subject of Global Warming. The information provided is to be used for publication purposes in the form of anonymous data. I have extracted names from author and editor lists of six journals. These have been reduced to those active in the field of climate science or a closely related field. If you believe I have contacted you in error, please excuse my mistake and ignore this request.

Who am I?

I am an unaffiliated student of climate science and climate change issues. I contribute as a ‘poster’ to several climate science and related websites and weblogs, including RealClimate, Climate Science, Prometheus, and Climate Audit, for example. I also contribute to the individual weblogs of William Connolley, James Annan, Coby Beck, Michael Tobis, and Eli Rabett. I now also work my own weblog. Several of the above-named individuals have already agreed to participate in this research, which is being overseen by a professor active in the field.

What am I asking of you?

Your participation in an opinion poll, which involves only replying to this request with one answer from seven options. A prompt and intuitive response would be most valuable; this is most likely to reflect your ‘gut feeling’ on the subject. I am asking you to cooperate so I can produce a robust result from a sufficiently sizeable sample. If you choose to respond, your reply will be recorded on a password protected offline file and your email deleted from my files. In a separate offline file I will note the names of respondents without reference to the responses.

What is the purpose of this research?

The principal aim is to test the hypothesis that there is a divergence between public opinion and scientific opinion on the subject of Global Warming. Secondary aims include; establishing by proper method whether there is a scientific consensus on the subject, whether there is a public consensus, and whether any inferences can be made about the influence of the mass media on public opinion and, thereby, policy decisions. It is intended to publish the findings of this research.

What information will I share?

The only information to be published will consist of breakdowns of responses and products of these. No other data will be used except to identify the sources of the database/sample. No names other than those of myself and any co-authors will be revealed in any published form.

When the survey is complete, the names of all respondents will be deleted from files, to protect privacy; though this means the results cannot be precisely replicated, it should protect all participants from the need to justify their privately-held opinions.

With my sincere thanks for your time and in anticipation of your help in supporting this research, I am,

Yours sincerely,

Fergus Brown.

Comments Off

Filed under Climate Science Reporting