Chris Mooney has some comments on the Peiser/Oreskes dispute about the scientific literature on climate change.
I asked Benny Peiser for his list of 34 abstracts that “reject or doubt the view that human activities are the main drivers of the ‘the observed warming over the last 50 years’.” (mentioned in his letter to Science).
Peiser wrote back:
I have attached those ISI abstracts which question that there is a complete “consensus” as defined by Oreskes. Please note that the most important difference to the Oreskes study is not that there are, contrary to her claim, a few abstracts that question or even reject the “consensus”. More importantly, her claim that 75% of abstracts support the ‘consensus’—explicitely or implicitely—is not borne out by my analysis. In fact, from my analysis I would argue that the vast majority of papers published on global warming, both pro and contra – are not included in the ISI data set that feature the key words “global climate change”. I guess that’s why I could only find 13 abstracts that explicitely endorsed the consensus (you might want to ask Oreskes if she can provide more than these few). Obviously, most of the really important papers, in particular empirical studies, are to be found in the 11,000 or so ISI listed papers that weren’t analysed. I make this point clear in my letter to Science, and even stress that I do not wish to question that the majority of papers support the theory of anthropogenic global warming. Even so, it is simply untrue to claim that no sceptical papers have been published in the peer-reviewed literature. There are far too many issues still wide open to debate, not least the whole literature on solar forcing, satellite measurements, and the crucial issue of interpreting paleo-environmental proxy data.
I noticed the debate on your website. No matter how you wish to interpret the sceptical abstracts, there can be no doubt that most of them question that all uncertainties about anthropogenic forcing of recent global warming have been removed.
Oreskes asserted that none of the papers rejected the consensus position (anthropogenic climate change). Peiser asserts that these 34 reject or doubt the consensus position. Note that Peiser added “or doubt” to the category so it is logically possible for both of them to be correct. So, judge for yourselves by looking at the abstracts. I want to see what my readers think so leave a comment giving your count for how many “reject” and how many “reject or doubt” the consensus. (Yes, there are only 33 abstracts.)
Update 2: Peiser has posted the missing abstract in comments. Chris Mooney isn’t impressed either.
1. Review and Impacts of Climate-change Uncertainties
Fernau ME, Makofske WJ, South DW
Futures 25 (8): 850-863 Oct 1993
Abstract: This article examines the status of the scientific uncertainties in predicting and verifying global climate change that hinder aggressive policy making. More and better measurements and statistical techniques are needed to detect and confirm the existence of greenhouse-gas-induced climate change, which currently cannot be distinguished from natural climate variability in the historical record. Uncertainties about the amount and rate of change of greenhouse gas emissions also make prediction of the magnitude and timing of climate change difficult. Because of inadequacies in the knowledge and depiction of physical processes and limited computer technology, predictions from existing computer models vary widely, particularly on a regional basis, and are not accurate enough yet for use in policy decisions. The extent of all these uncertainties is such that moving beyond no-regrets measures such as conservation will take political courage and may be delayed until scientific uncertainties are reduced.
2. Cloud Condensation Nuclei
Journal of Applied Meteorology 32 (4): 596-607 Apr 1993
Abstract: The state of knowledge of the particles upon which liquid droplets condense to form atmospheric water clouds is presented. The realization of cloud condensation nuclei (CCN) as a distinct aerosol subset originated with the cloud microphysical measurements and theoretical insights of Patrick Squires 40 years ago. He helped originate and continue the development of CCN counters and made significant CCN measurements for more than 25 years. Recognition of the importance of CCN has expanded from warm-rain efficiency to aerosol scavenging, cloud radiative properties, and other topics. In spite of a promising beginning and much encouragement over the years, CCN knowledge has increased minimally. Significant uncertainties about global climate change cannot be reduced without expansion of the knowledge base of CCN.
3. High-Latitude Oceanic Variability Associated with the 18.6-year Nodal Tide
Journal of Geophysical Research-Oceans 98 (C3): 4639-4644 Mar 15 1993
Abstract: Ocean temperatures in the upper 250 m in the northern North Pacific (60-degrees-N, 149-degrees-W) increased bt more than 1-degrees-C from 1972 to 1098 but are now decreasing. Subsurface temperature anomalies are well correlated (approximately 0.58) with the air temperature anomalies at Sitka, Alaska; hence the coastal air temperatures can be used as a proxy data set to extend the ocean temperature time series back to 1828. Up to 30% of the low-frequency variance can be accounted for with the 18.6-year nodal signal. Additionally. spectral analysis of these air temperature variations indicates a significant low-frequency peak in the range of the 18.6-year signal. Similar low-frequency signals have been reported for Hudson Bay air temperatures since 1700, for sea surface temperatures in the North Atlantic from 1876 to 1939, and for sea level in the high-latitude southern hemisphere. The water column temperature variations presented here are the first evidence that the upper ocean is responding to this very long period tidal forcing. An enhanced high-latitude response to the 18.6-year forcing is predicted by equilibrium tide theory, and it should be most evident at latitudes poleward of about 50-degrees. These low-frequency ocean-atmosphere variations must – be considered in high-latitude assessments of global climate change, since they are of the same magnitude as many of the predicted global changes.
4. A Critical Analysis of Climate Change Policy Research
Rothman DS, Chapman D
Contemporary Policy Issues 11 (1): 88-98 Jan 1993
Abstract: After more than a decade of scientific warning, the policy community has begun to take up the challenge of global climate change. This paper considers recent efforts to analyze policymaking in this area. Shortcomings in present policy research include: (i) inconsistencies in data and methods, (ii) myopic vision of available options, (iii) overly anthropocentric cost/benefit assessments, (iv) inadequate treatment of uncertainly and irreversibility, (v) lack of recognition of developing and developed countries’ differential motives, (vi) unsatisfactory presentation and interpretation of results, and (vii) limited peer review.
5. Global Climate-Change and Tropical Cyclones
Lighthill J, Holland G, Gray W, Landsea C, Craig G, Evans J, Kurihara Y, Guard C
Bulletin of the American Meteorological Society 75 (11): 2147-2157 Nov 1994
Abstract: This paper offers an overview of the authors’ studies during a specialized international symposium (Mexico, 22 November-1 December 1993) where they aimed at making an objective assessment of whether climate changes, consequent on an expected doubling of atmospheric CO2 in the next six or seven decades, are likely to increase significantly the frequency or intensity of tropical cyclones (TC). Out of three methodologies available for addressing the question they employ two, discarding the third for reasons set out in the appendix. In the first methodology, the authors enumerate reasons why, in tropical oceans, the increase in sea surface temperature (SST) suggested by climate change models might be expected to affect either (i) TC frequency, because a well-established set of six conditions for TC formation include a condition that SST should exceed 26 degrees C, or (ii) TC intensity, because this is indicated by thermodynamic analysis to depend critically on the temperature at which energy transfer to air near the sea surface takes place. But careful study of both suggestions indicates that the expected effects of increased SST would be largely self-limiting (i) because the other five conditions strictly control how far the band of latitudes for TC formation can be further widened, and (ii) because intense winds at the sea surface may receive their energy input at a temperature significantly depressed by evaporation of spray, and possibly through sea surface cooling. In the second methodology, the authors study available historical records that have very large year-to-year variability in TC statistics. They find practically no consistent statistical relationships with temperature anomalies; also, a thorough analysis of how the El Nino-Southern Oscillation cycle influences the frequency acid distribution of TCs shows any direct effects of local SST changes to be negligible. The authors conclude that, even though the possibility of some minor indirect effects of global warming on TC frequency and intensity cannot be excluded, they must effectively be ”swamped” by large natural variability.
6. Establishing Research Objectives to Address Issues of Climate-Change
Socio-Economic Planning Sciences 28 (1): 1-8 Mar 1994
Abstract: The implications of global climate change are enormous. However, there are major questions concerning whether climate change is occurring. If it is, subsequent questions should consider when and how the changes will affect society. There are numerous possible expensive research projects that could address each of the many facets of these questions. Wise decision making about global climate change research is thus seen as important. This paper describes a systematic process to identify and structure the objectives of research on global climate change. The result is a hierarchy of 81 important research objectives. This hierarchy was constructed based on interviews with a diverse set of individuals knowledgeable about climate change, and on discussions at an international workshop on global climate research objectives. The participants in both exercises included scientists, policy analysts, and executives of utility companies and national agencies from Europe, Asia, and North America. The main uses of these objectives should be to promote constructive communication about research programs designed to examine climate change issues, to stimulate the creation of potentially significant research tasks, and to provide a basis for evaluating and comparing research tasks.
7. Atmospheric Greenhouse-Effect in the Context of Global Climate-Change
Kondratyev KY, Varotsos C
Nuovo Cimento Della Societa Italiana di Fisica C-Geophysics and Space Physics 18 (2): 123-151 Mar-Apr 1995
Abstract: Great interest in the problem of the atmospheric greenhouse effect (not only in scientific publications, but also in mass media), on the one hand, and the undoubtfully overemphasised contribution of the greenhouse effect to the global climate change, on the other hand, motivate a necessity to analyse the role which the greenhouse effect plays as a factor of climate change. Significant progress in the analysis of existing observational data as well as succesful development of numerical climate modelling which have been achieved during the recent few years create a basis for a new survey of the atmospheric greenhouse effect in the context of global climate change. Such a survey is the principal purpose of this paper. After discussing a notion of the greenhouse effect, the detailed analysis of the present-day and paleoclimatic observational data has been conducted with subsequent consideration of numerical modelling results. A special attention has been paid to assessments of the greenhouse warming vs. aerosol cooling. Then possibilities of the early detection of a greenhouse climate signal have been analysed and a few comments on the global climate observing system have been made with the general conclusion that more observations and further numerical modelling efforts are necessary to more reliably assess the contributions of various mechanisms to the observed global climate changes. It is only in the context of a coupled totality of significant climate forming factors and processes that the contribution of the greenhouse effect may be estimated.
8. Integrated Risk Analysis of Global Climate-Change
Shlyakhter A, Valverde LJ, Wilson R
Chemosphere 30 (8): 1585-1618 Apr 1995
Abstract: This paper discusses several factors that should be considered in integrated risk analyses of global climate change. We begin by describing how the problem of global climate change can be subdivided into largely independent parts that can he linked together in an analytically tractable fashion. Uncertainty ploys a central role in integrated risk analyses of global climate change. Accordingly, we consider various aspects of uncertainty as they relate to the climate change problem. We also consider the impacts of these uncertainties on various risk management issues, such as sequential decision strategies, value of information, and problems of interregional and intergenerational equity.
9. Managing the Risk of Global Climate Catastrophe – An Uncertainty Analysis
Risk Analysis 15 (1): 69-78 Feb 1995
Abstract: Despite much scientific progress over many decades, the nature of global climate change remains highly uncertain, and the possibility of global climate catastrophe is one of the main concerns in public debates about global climate change. In this paper, we present a model which incorporates the risk of climate catastrophe in an analysis of greenhouse gas abatement strategy. In this model, the timing and severity of climate catastrophe are treated probabilistically. The impacts of key uncertainties on optimal policy are analyzed, and the expected values of additional information that reduces the uncertainty associated with the world economy, carbon cycle, climate change, and climate damage are estimated.
10. The evolution of an energy contrarian
Annual Review of Energy and the Environment 21: 31-67 1996
Abstract: An analysis of the forces that have shaped energy and energy-related environmental policies is presented through the eyes of an active participant in their evolution over the past 53 years. The problem of self-interest in taking energy and environmental policy positions is addressed candidly. The ”energy crisis” is cited as an example. Its credibility depended on excessive demand projections, coupled with erroneous assessments of US and global hydrocarbon resources and of prospects for making these resources economically recoverable through technology advances. Many energy crisis proponents benefited from the misguided government response and from the large investments in uneconomic synthetic fuel technologies. Today, proponents of catastrophic anthropogenic climate change, again claiming scientific consensus, threaten to create even greater energy market distortions at large social and economic costs. The author traces his conversion to energy contrarian to the general failure of consensus and to his own misjudgments in these critical policy areas.
11. The suitability of montane ecotones as indicators of global climatic change
Kupfer JA, Cairns DM
Progress in Physical Geography 20 (3): 253-272 Sep 1996
Abstract: Because of the difficulties involved with separating natural fluctuations in climatic variables from possible directional changes related to human activities (e.g., heightened atmospheric CO2 concentrations related to fossil fuel consumption), some researchers have focused on developing alternative indicators to detect hypothesized climate changes. It has, for example, been suggested that the locations of ecotones, transitions between adjacent ecosystems or biomes, should be monitored. It is assumed that changes in climate, especially increases in atmospheric temperature, will result in shifts in the location (altitude or latitude) of ecotones as plants respond to the newly imposed climatic conditions. In this article, we address the use of two montane ecotones, the alpine tree-line ecotone and the deciduous/Boreal forest ecotone, in monitoring global climatic change. In so doing, we 1) outline the factors that create and maintain each ecotone’s position at a given location; 2) assess the projected response of the ecotones to various aspects of global warming; and 3) discuss the usefulness of both ecotones as indicators of global climate change. While it is likely that extended periods of directional climate change would bring about an altitudinal shift in the ranges of montane species and the associated ecotones, we question whether the response at either ecotone will be at a timescale useful for detecting climate change (a few decades) owing to disequilibrium related to upslope edaphic limitations and competitive interactions with established canopy and subcanopy individuals. Further, limitations related to the prediction of the complex and interacting effects of projected changes in temperature, precipitation and site water balance on photosynthetic processes of plant species raise uncertainties about the expected responses of both ecotones.
12. Representing uncertainty in global climate change science and policy: Boundary-ordering devices and authority
Shackley S, Wynne B
Science Technology & Human Values 21 (3): 275-302 Sum 1996
Abstract: This article argues that, in public and policy, contexts, the ways in which many scientists talk about uncertainty in simulations of future climate change not only facilitates communications and cooperation between scientific and policy communities but also affects the perceived authority of science. Uncertainty tends to challenge the authority of climate science, especially if ii is used for policy making, but the relationship between authority and uncertainty is not simply an inverse one. In policy contexts, many scientists are compelled to talk about uncertainty but do not wish to imply that uncertainty is a serious challenge to the authority of scientific knowledge or to its substantial use in policy making. ”Boundary-ordering devices,” the contextual discursive attempts to reconcile uncertainty and authority in science, depend critically for their success on their ”dual” interpretation: at a general level across a boundary and differently on either side of it The authors empirically identify a range of such boundary-ordering devices in the climate field.
13. SSK’s identity parade: Signing-up, off-and-on
Social Studies of Science 26 (2): 357-391 May 1996
Abstract: This paper examines the debate over the relationship between SSK and politics by exploring the implications of ‘the reflexive turn’ during the 1980s. However, it does this by looking outward, at the ways in which a reflexive SSK can potentially help enlighten the culture of political issues, rather than inwards, at the methods and forms of SSK itself. The key element of this strategy is to sustain an analytical vocabulary which problematizes the human subject, whether as author of SSK work, or of public policies and public policy knowledges. I take it for granted that this cannot be fully achieved, but it remains a key principle. Reconsidering the ‘Capturing’ debate, the paper notes several unfortunate features held in common land uncritically reinforced) by both ‘sides’ to that agenda. These include the reification of ‘sides’ and (more generally) of social actors (and thus of the issues at stake); and the reproduction of an implicit model of society as constituted exhaustively by active choices and decisions – thus neglecting the cultural dimensions of social (including cognitive) life. Using examples drawn from environmental opposition to nuclear power; and the construction of scientific and policy knowledge about global climate change, I argue that problematizing the identities and interests of actors within our own sociological knowledge forum, as is achieved through ‘the reflexive turn: and extending this to the construction and deployment of knowledge in public issues, allows a much richer, more contingent and more multivalent understanding of what is at stake in any ‘given’ issue to come into view. This may appear to undermine the basis of policy bodies’ authority – except that their authority is, I suggest, already failing precisely because they cannot recognize the contingencies in the knowledges on which they rely. Refusing to enter public controversies with scientific or technical content as either partisans or disengaged neutrals, and eschewing false debates about epistemic probity, SSK scholars can nevertheless offer intellectual resources with which to encourage institutional reflexivity, and to rebuild a democratic culture of public policy.
14. Measuring global mean sea level variations using TOPEX/POSEIDON altimeter data
Journal of Geophysical Research-Oceans 100 (C12): 25135-25151 Dec 15 1995
Abstract: The variations of global mean sea level are an important indicator of global climate change, and their measurement can provide important information for determining the socioeconomic impact of sea level change on coastal land use. The analysis of historical tide gauge records generally indicates that sea level has risen at a rate of about 2 mm/yr during the last 100 years; however, this estimate is somewhat uncertain due to the effects of regional crustal motion, lack of uniform temporal coverage, and the limited spatial sampling of tide gauges. The prospect of measuring variations in global mean sea level has been assessed using approximately 2.5 years of satellite altimeter data from the TOPEX/POSEIDON (T/P) mission, where synoptic mapping of the geocentric height of the ocean surface is routinely achieved with a point-to-point accuracy of better than 5 cm. The global mean sea level variations measured by T/P every 10 days have an rms of 6 mm (4 mm after detrending), some of which is shown to be correlated with sea surface temperature variations. The rate of change of global mean sea level derived from 2.5 years of data is +5.8 mm/yr with a scatter of 0.7 mm/yr. Currently, it is impossible to accurately estimate the error in the measured rate of sea level rise, since little is known about the long-term behavior of the measurement errors at the millimeter level. In addition, there is evidence from the sea surface temperature record that the measured rate of sea level rise is associated with a relatively short-term (interannual) variation unrelated to the long-term signal expected from global warming. Nevertheless, these results suggest that T/P is achieving the necessary repeatability to measure global sea level variations caused by climate change, and a longer time series will significantly improve the sea level rise estimate by averaging measurement error and real sea level variations. A longer time series will also reduce the errors in estimates of the altimeter calibration, providing an important constraint on any long-term instrument drift. Future research will focus on establishing a realistic error budget for these measurements of global mean sea level, so that they can be put in the proper context with other observations of global climate change.
15. Solar forcing of global climate change since the mid-17th century
Climatic Change 37 (2): 391-405 OCT 1997
Abstract: Spacecraft measurements of the sun’s total irradiance since 1980 have revealed a long-term variation that is roughly in phase with the 11-year solar cycle. Its origin is uncertain, but may be related to the overall level of solar magnetic activity as well as to the concurrent activity on the visible disk. A low-pass Gaussian filtered time series of the annual sunspot number has been developed as a suitable proxy for solar magnetic activity that contains a long-term component related to the average level of activity as well as a short-term component related to the current phase of the I I-year cycle. This time series is also assumed to be a proxy for solar total irradiance, and the irradiance is reconstructed for the period since 1617 based on the estimate from climatic evidence that global temperatures during the Maunder Minimum of solar activity, which coincided with one of the coldest periods of the Little Ice Age, were about 1 degrees C colder than modem temperatures. This irradiance variation is used as the variable radiative forcing function in a one-dimensional ocean-climate model, leading to a reconstruction of global temperatures over the same period, and to a suggestion that solar forcing and anthropogenic greenhouse-gas forcing made roughly equal contributions to the rise in global temperature that took place between 1900 and 1955. The importance of solar variability as a factor in climate change over the last few decades may have been underestimated in recent studies.
16. Problems associated with homogeneity testing in climate variation studies: A case study of temperature in the northern Great Plains, USA
Keiser DT, Griffiths JF
International Journal of Climatology 17 (5): 497-510 Apr 1997
Abstract: Global climate change is a controversial issue facing researchers and climatologists today. In order to obtain the most reliable results when studying climate change, the data being analysed must be as homogeneous as possible. A homogeneous time series is one in which trends and variations are caused only by effects of weather and macroclimate.
The concept of homogeneity has been addressed by some researchers, but only by testing ‘average’ time series such as the means and the annuals. This paper utilizes a homogeneity test developed by Alexandersson and applies it to mean monthly maximum, minimum, and mean temperature data from 22 stations in the northern Great Plains, USA. One of these, Valentine, is a first-order station and is used as the reference station. When Valentine was adjusted for a possible inhomogeneity due to its move, it was found that Valentine’s adjustments had a distinct seasonal pattern.
After testing the other stations against Valentine, it was found that the position of a significant discontinuity in a station’s monthly mean or annual series was not always the same in a corresponding monthly maximum and minimum series. In addition, a seasonal pattern similar to that of Valentine was found for each station’s adjustment values. (C) 1997 the Royal Meteorological Society.
17. Tree-limits and montane forests in the Swedish Scandes: Sensitive biomonitors of climate change and variability
Ambio 27 (4): 312-321 Jun 1998
Abstract: The elevational tree-limit constitutes an ideal and sensitive proxy indicator of climate change and variability, i.e. an essential part of monitoring systems focusing on global climate change. That contention is purported by multi-scale records and reconstructions of changes in altitudinal tree-limits and northern boreal forests. Climatically forced trends in their position, structure and composition have occurred at all temporal scales throughout the Holocene. A progressive elevational descent of Pinus sylvestris tree-limit since the earliest Holocene, concurs with the deterministic theory of millennial climate forcing by changes in the Earth’s orbital parameters. The successively less seasonal climate with cooler, more humid summers and winters with increasing snow cover has preconditioned the emergence of a subalpine birch forest belt during the past ca. 7000 yrs BP as well as the growing gee-ecological prominence of Picea abies. Superimposed on this longterm trend, climatic anomalies of shorter duration have been inferred from the tree-limit chronology. Some exceptionally warm and stable centuries, with high tree-limits and dense montane forests occurred during the Medieval period. Thereafter, the Little Ice Age prevailed until the late 19th century. Northern and high-elevation ecosystems were profoundly stressed, disturbed and destabilized by cold, windy and highly variable climate conditions. An episode of warmer climate during the first half of the present century imposed some recovery of structures decayed by the Little Ice Age. However, tree-limits and high-elevation forests were far from restored to their medieval levels. During the past 4-5 decades, a more martime and slightly cooler climate has been instrumentally recorded. High-elevation arboreal vegetation has responded retrogressively by defoliation, retarded growth, ceasing regeneration and locally some tree-limit retraction. Neoglacial processes have been resumed, e.g. dieback of subalpine/alpine dwarf shrub heaths, followed by deflation of humus and surface mineral soils. These processes are readily monitored in a unique regional network, with baseline data since the early 20th century.
18. Analysis of some direct and indirect methods for estimating root biomass and production of forests at an ecosystem level
Vogt KA, Vogt DJ, Bloomfield J
PLANT AND SOIL 200 (1): 71-89 MAR 1998
Abstract: The relationship of global climate change to plant growth and the role of forests as sites of carbon sequestration have encouraged the refinement of the estimates of root biomass and production. However, tremendous controversy exists in the literature as to which is the best method to determine fine root biomass and production. This lack of consensus makes it difficult for researchers to determine which methods are most appropriate for their system. The sequential root coring method was the most commonly used method to collect root biomass data in the past and is still commonly used. But within the last decade the use of minirhizotrons has become a favorite method of many researchers. In addition, due to the high labor-intensive requirements of many of the direct approaches to determine root biomass, there has been a shift to develop indirect methods that would allow fine root biomass and production to be predicted using data on easily monitored variables that are highly correlated to root dynamics. Discussions occur as to which method should be used but without gathering data from the same site using different methods, these discussions can be futile. This paper discusses and compares the results of the most commonly used direct and indirect methods of determining root biomass and production: sequential root coring, ingrowth cores, minirhizotrons, carbon fluxes approach, nitrogen budget approach and correlations with abiotic resources. No consistent relationships were apparent when comparing several sites where at least one of the indirect and direct methods were used on the same site. Until the different root methods can be compared to some independently derived root biomass value obtained from total carbon budgets for systems, one root method cannot be stated to be the best and the method of choice will be determined from researcher’s personal preference, experiences, equipment, and/or finances.
19. A look at global tropical cyclone activity during 1995: Contrasting high Atlantic activity with low activity in other basins
Lander MA, Guard CP
Monthly Weather Review 126 (5): 1163-1173 May 1998
Abstract: During 1995, there was a near-record number of named tropical cyclones in the North Atlantic basin. This unusual event fueled speculation that it marked a tangible signal of global:climate change, or that it marked a return to a period of higher tropical cyclone activity in the Atlantic, such as that which has been documented to have occurred during the decades of the 1940s through the 1960s. Less publicized, the tropical cyclone activity in other basins during 1995 was almost everywhere below normal. The concept of global and basin “prolific” years and “meager” years is introduced. During the past 30 years, the Atlantic has had two prolific years: 1969 and 1995. Although the annual number of tropical cyclones in each of the other basins is uncorrelated with the annual number of tropical cyclones in the Atlantic, the two Atlantic prolific years of 1969 and 1995 were meager years in some of the other major basins, and below normal years in all of them. In the time series of the annual number of tropical cyclones in all basins except the Atlantic, 1969 and 1995 rank lowest and third lowest, respectively. The known relationships of the annual number of tropical cyclones in the Atlantic with ENSO and with the quasi-biennial ossilation are insufficient to explain the unusual global distribution of tropical cyclones during 1995.
20. Uncertainty, complexity and concepts of good science in climate change modelling: Are GCMs the best tools?
Shackley S, Young P, Parkinson S, Wynne B
Climatic Change 38 (2): 159-205 Feb 1998
Abstract: In this paper we explore the dominant position of a particular style of scientific modelling in the provision of policy-relevant scientific knowledge on future climate change. We describe how the apical position of General Circulation Models (GCMs) appears to follow ‘logically’ both from conventional understandings of scientific representation and the use of knowledge, so acquired, in decision-making. We argue, however, that both of these particular understandings are contestable. In addition to questioning their current policy-usefulness, we draw upon existing analyses of GCMs which discuss model trade-offs, errors, and the effects of parameterisations, to raise questions about the validity of the conception of complexity in conventional accounts. An alternative approach to modelling, incorporating concepts of uncertainty, is discussed, and an illustrative example given for the case of the global carbon cycle.
In then addressing the question of how GCMs have come to occupy their dominant position, we argue that the development of global climate change science and global environmental ‘management’ frameworks occurs concurrently and in a mutually supportive fashion, so uniting GCMs and environmental policy developments in certain industrialised nations and international organisations. The more basic questions about what kinds of commitments to theories of knowledge underpin different models of ‘complexity’ as a normative principle of ‘good science’ are concealed in this mutual reinforcement. Additionally, a rather technocratic policy orientation to climate change may be supported by such science, even though it involves political choices which deserve to be more widely debated.
21. Tropical cyclones and global climate change: A post-IPCC assessment
Henderson-Sellers A, Zhang H, Berz G, Emanuel K, Gray W, Landsea C, Holland G, Lighthill J, Shieh SL, Webster P, McGuffie K
Bulletin of the American Meteorological Society 79 (1): 19-38 Jan 1998
Abstract: The very limited instrumental record makes extensive analyses of the natural variability of global tropical cyclone activities difficult in most of the tropical cyclone basins. However, in the two regions where reasonably reliable records exist (the North Atlantic and the western North Pacific), substantial multidecadal variability (particularly for intense Atlantic hurricanes) is found, but there is no clear evidence of long-term trends. Efforts have been initiated to use geological and geomorphological records and analysis of oxygen isotope ratios in rainfall recorded in cave stalactites to establish a paleoclimate of tropical cyclones, but these have not yet produced definitive results. Recent thermodynamical estimation of the maximum potential intensities (MPI) of tropical cyclones shows good agreement with observations.
Although there are some uncertainties in these MPI approaches, such as their sensitivity to variations in parameters and failure to include some potentially important interactions such as ocean spray feedbacks, the response of upper-oceanic thermal structure, and eye and eyewall dynamics, they do appear to be an objective tool with which to predict present and future maxima of tropical cyclone intensity. Recent studies indicate the MPI of cyclones will remain the same or undergo a modest increase of up to 10%-20%. These predicted changes are small compared with the observed natural variations and fall within the uncertainty range in current studies. Furthermore, the known omissions (ocean spray, momentum restriction, and possibly also surface to 300-hPa lapse rate changes) could all operate to mitigate the predicted intensification.
A strong caveat must be placed on analysis of results from current GCM simulations of the “tropical-cyclone-like” vortices. Their realism, and hence prediction skill (and also that of “embedded” mesoscale models), is greatly limited by the coarse resolution of current GCMs and the failure to capture environmental factors that govern cyclone intensity. Little, therefore, can be said about the potential changes of the distribution of intensities as opposed to maximum achievable intensity. Current knowledge and available techniques are too rudimentary for quantitative indications of potential changes in tropical cyclone frequency.
The broad geographic regions of cyclogenesis and therefore also the regions affected by tropical cyclones are not expected to change significantly. It is emphasized that the popular belief that the region of cyclogenesis will expand with the 26 degrees C SST isotherm is a fallacy. The very modest available evidence points to an expectation of little or no change in global frequency. Regional and local frequencies could change substantially in either direction, because of the dependence of cyclone genesis and track on other phenomena (e.g., ENSO) that are not yet predictable. Greatly improved skills from coupled global ocean-atmosphere models are required before improved predictions are possible.
22. Global climate change and variability and its influence on Alpine climate – Concepts and observations
Wanner H, Rickli R, Salvisberg E, Schmutz C, Schuepp M
Theoretical and Applied Climatology 58 (3-4): 221-243 1997
Abstract: The paper discusses annual to decadal climate variability and change in the European Alps by utilizing the procedure of synoptic downscaling, i.e. it investigates the influence of global to continental scale synoptic structures and processes on the regional climate of the Alps. The European Alps lie to the southeast and under the right exit zone of the southwest-northeast oriented axis of the polar front jet over the North Atlantic ocean, in a transition zone between the Azores high and Icelandic low, between oceanic and continental and between Mediterranean and North Atlantic climates. Together with complex topographically induced phenomena like lee cyclogenesis, orographic precipitation, strong downslope winds and thermotopographical circulation systems, this transitional position makes climate studies in the Alps even more interesting. Only a minor correlation can be observed between global climate variability and Alpine climate. In contrast, the Alpine climate is strongly related to processes over the North Atlantic ocean and its sea ice system (e.g. it has a high correlation with the North Atlantic Oscillation and the dynamics and position of the Icelandic low), an area with a rather low climate prediction potential. Since the early 1970’s (or just after the “Great Salinity Anomaly” in the North Atlantic Ocean) the intensification of the wintertime westerly jet over the North Atlantic area led to a noticeable northwest-southeast mass transport in the exit area of the jet over Central Europe, leading to pressure and temperature rises and an increase in the amount of precipitation. There is a question over whether this phenomenon is a consequence of natural climate variability or the beginning of an anthropogenic climate change.
23. Solar irradiance during the last 1200 years based on cosmogenic nuclides
Bard E, Raisbeck G, Yiou F, Jouzel J
Tellus Series B-Chemical and Physical Meteorology 52 (3): 985-992 Jul 2000
Abstract: Based on a quantitative study of the common fluctuations of C-14 and Be-10 production rates, we have derived a time series of the solar magnetic variability over the last 1200 years. This record is converted into irradiance variations by linear scaling based on previous studies of sun-like stars and of the sun’s behavior over the last few centuries. The new solar irradiance record exhibits low values during the well-known solar minima centered at about 1900, 1810 (Dalton) and 1690 AD (Maunder). Further back in time, a rather long period between 1450 and 1750 AD is characterized by low irradiance values. A shorter period is centered at about 1200 AD, with irradiance slightly higher or similar to present day values. It is tempting to correlate these periods with the so-called “little ice age” and “medieval warm period”, respectively. An accurate quantification of the climatic impact of this new irradiance record requires the use of coupled atmosphere-ocean general circulation models (GCMs). Nevertheless, our record is already compatible with a global cooling of about 0.5 1 degrees C during the “little ice age”, and with a general cooling trend during the past millenium followed by global warming during the 20th century (Mann et al., 1999).
24. Regional climate change: Trend analysis of temperature and precipitation series at selected Canadian sites
Clark JS, Yiridoe EK, Burns ND, Astatkie T
Canadian Journal of Agricultural Economics-Revue Canadienne d Agroeconomie 48 (1): 27-38 Mar 2000
Abstract: Global climate change does not necessarily imply that temperature or precipitation is increasing at specific locations. The hypothesis of increasing temperature and precipitation trends associated with global climate change is tested using actual annual temperature and precipitation data for nine selected weather stations, spatially distributed across Canada. Vogelsang’s (1998) partial sum and Woodward et al’s (1997) bootstrap methods are used for testing for trend Both methods suggest no warming in the Canadian temperature series except for Toronto, Ontario, which had significant increase over time, along with Moncton, New Brunswick and Indian Head, Saskatchewan, which had marginal increases. There is no evidence of increasing trend in precipitation except for Moncton, New Brunswick, which had a significantly increasing trend, thus, public policies designed to address the regional effects of climate change need to be adapted for a particular ecological zone, based on knowledge of the climate trends for that region, rather than on general global climate change patterns.
25. Public representations of scientific uncertainty about global climate change
Public Understanding of Science 9 (2): 85-103 Apr 2000
Abstract: This paper addresses the representation of scientific uncertainty about global warming and climate change in the U.S. popular press. An examination of popular press articles about global warming from 1986 to 1995 reveals that scientific uncertainty was a salient theme. The paper describes several forms of uncertainty construction and means through which it was managed. I argue that scientific uncertainty was used to help construct an exclusionary boundary between “the public” and climate change scientists. This rhetorical boundary delegitimated lay knowledge by suggesting that the public did nor hold appropriate reverence for scientific uncertainty and the need for more research.
26. Water vapor, CO2, and temperature profiles in and above a forest – Accuracy assessment of an unattended measurement system
Molder M, Lindroth A, Halldin S
Journal of Atmospheric and Oceanic Technology 17 (4): 417-425 Apr 2000
Abstract: The possibility of a global climate change has increased research interest in the least understood parts of the climate system. One of those parts is the boundary between the land surface of the earth and the lowest part of the planetary boundary layer. The structure of this layer and the exchange processes in it are still incompletely understood for a variety of situations and surfaces, especially in the boreal zone and during the dark parts of the day and the year. Progress in this area requires new data measured continuously and unattended with high accuracy and long-term reliability. A measurement system for profiles of temperature, humidity, and carbon dioxide was designed to meet the above goals. The system used thermocouples and a Li-Cor gas analyzer combined with an array of tubing to suck air from different heights. Turbulent fluctuations of water vapor and carbon dioxide concentrations were smoothed by continuous-flow mixing chambers without moving parts. Half-hourly mean differences in temperature, humidity, and CO2 were measured to better than 0.03 K, 0.015 g kg(-1) and 0.5 mu mol mol(-1), respectively. These accuracies were confirmed by comparisons with a thermometer-interchange (reversing) system and CO2 profiles theoretically deduced from eddy-correlation fluxes. Daytime temperature and humidity differences over the full height interval (24.5-87.5 m), as well as over the roughness sublayer part (24.5-58.5 m), commonly exceeded the estimated errors by five times. The CO2 differences could only be measured reasonably accurately over the entire height interval (24.5-87.5 m) and then only exceeded the error by a factor of 2-3. Temperature and humidity measurements were sufficiently accurate for studies of flux-profile relationships over a forest. The CO2 profiles were accurate only for rough flux estimates and may be especially useful for nighttime studies.
27. Ad Hoc Committee on Global Climate Issues: Annual report
Gerhard LC, Hanson BM
AAPG Bulletin 84 (4): 466-471 Apr 2000
Abstract: The AAPG Ad Hoc Committee on Global Climate Issues has studied the supposition of human-induced climate change since the committee’s inception in January 1998. This paper details the progress and findings of the committee through June 1999, At that time there had been essentially no geologic input into the global climate change debate. The following statements reflect the current state of climate knowledge from the geologic perspective as interpreted by the majority of the committee membership. The committee recognizes that new data could change its conclusions, The earth’s climate is constantly changing owing to natural variability in earth processes. Natural climate variability over recent geological time is greater than reasonable estimates of potential human-induced greenhouse gas changes. Because no tool is available to test the supposition of human-induced climate change and the range of natural variability is so great, there is no discernible human influence on global climate at this time.
28. Climate change and trend detection in selected rivers within the Asia-Pacific region
Cluis D, Laberge C
Water International 26 (3): 411-424 SEP 2001
Abstract: Global climate change is currently an issue of great concern. This phenomenon was studied using the runoff of large rivers, which can be considered a regional integrator of the local precipitation occurring in their basins. The long-term stationarity and the possibility of trends in streamflow records stored in the databank of the Global Runoff Data Center (GRDC) at the Federal Institute of Hydrology in Koblenz (Germany) were studied. Runoff records originating from. 78 rivers with long monthly runoff series that are geographically distributed throughout the whole Asia-Pacific region were selected for study. For each of the selected rivers, three time series were constructed and analyzed: the mean yearly, and the maximum and minimum monthly discharges. These series were submitted to a two-tier analysis. First, a segmentation procedure developed by Hubert was applied to assess their stationarity. Then the segmented series were submitted to a specialized trend detection software. The results show that about two-thirds of the series have remained stationary and that the monthly minimum runoff exhibited more changing levels (37/78) than the mean (26/78) and maximum (18/78) runoff. Most of the detected changes occurred during the 1960s and 1970s, a period of rapid demographic expansion and urbanization in Asia, when irrigation and other water uses were developed, especially in tropical areas. During the same period and within the area studied, a number of large dams and reservoirs were completed. Since these anthropic interventions could be at the origin of the changes in runoff, there is no regionally consistent evidence supporting global climate change.
29. Holocene paleoclimate data from the Arctic: testing models of global climate change
Bennike O, Bolshiyanov D, Dowdeswell J, Elverhoi A, Geirsdottir A, Hicks S, Hubberton H, Ingolfsson O, Miller G
Quaternary Science Reviews 20 (12): 1275-1287 Jun 2001
Abstract: To evaluate the spatial variability of Arctic climate change during the present interglacial, CAFE Project Members compiled well-dated terrestrial, marine, and ice-core paleoenvironmental records spanning the past 10-12 thousand years (ka). Six tundra biomes of increasing summer temperature requirements were defined based on regionally coherent pollen assemblages. Using a rule-based approach, pollen spectra were converted to tundra, forrst/tundra, or Forest biomes ranked by their average growing season requirements. Marine sea-surface reconstructions were based on proxy data following a similar rule-based approach. From these data-based reconstructions. departures in summer temperatures from modern normals were calculated in 1 ka time slices through the Holocene. To test predictive models, data-based summer temperature reconstructions were compared with general circulation model (GCM) simulations for 10 ka and 6 ka ago. Paleodata and model results both show that warming occurred earlier across Beringia and Asia relative to lands adjacent to the North Atlantic, and that Late Holocene cooling was most apparent in the North Atlantic region. However, the GCM over-predicts the magnitude of Mid-Holocene warming over northern Asia and underestimates the intensification of the North Atlantic drift in the early Holocene. Strong spatial variability in environmental response during the Holocene, despite symmetric (insolation) forcing, suggests that any future changes, whether caused by anthropogenic or natural factors, are unlikely to result in a uniform change across the Arctic, adding additional complexity to forecasts of global impacts. (C) 2001 Elsevier Science Ltd. All rights reserved.
30. Sub-saharan desertification and productivity are linked to hemispheric climate variability
Oba G, Post E, Stenseth NC
Global Change Biology 7 (3): 241-246 Mar 2001
Abstract: Vegetation productivity and desertification in sub-Saharan Africa may be influenced by global climate variability attributable to the North Atlantic Oscillation (NAO) and El Nino Southern Oscillation (ENSO). Combined and individual effects of the NAO and ENSO indices revealed that 75% of the interannual variation in the area of Sahara Desert was accounted for by the combined effects, with most variance attributable to the NAG. Effects were shown in the latitudinal variation on the 200 mm isocline, which was influenced mostly by the NAG. The combined indices explained much of the interannual variability in vegetation productivity in the Sahelian zone and southern Africa, implying that both the NAO and ENSO may be useful for monitoring effects of global climate change in sub-Saharan Africa.
31. Arctic sea ice thickness remained constant during the 1990s
Geophysical Research Letters 28 (6): 1039-1041 Mar 15 2001
Abstract: The ice cover of the Arctic Ocean is considered to be a sensitive indicator of global climate change. Recent research, using submarine-based observations, suggests that the Arctic ice cover was thinner in the 1990s compared to an earlier period (1958-1979), and that it continued to decrease in thickness in the 1990s. Here I analyze subsurface ice thickness (draft) of Arctic sea ice from six submarine cruises from 1991 to 1997. This extensive data set shows that there was no trend towards a thinning ice cover during the 1990s. Data from the North Pole shows a slight increase in mean ice thickness, whereas the Beaufort Sea shows a small decrease, none of which are significant. Transects between the two areas from 76 degrees N to 90 degrees N also show near constant ice thicknesses, with a general spatial decrease from the Pole towards the Beaufort Sea. Combining the present results with those of an earlier study, I conclude that the mean ice thickness has remained on a near-constant level around the North Pole from 1986 to 1997.
32. Expected threats of global climate change on mosquito and tick-borne arbovirus infections of human beings
Bulletin de l Academie Nationale de Medecine 186 (1): 89-101 2002
Abstract: Global warming [+ 0,5 – 0,6degrees C during the second half of the 20 th century] seems a reality although climatologists did not reach a common agreement on its actual origin, and this phenomenon may still increase along the 21 th century [+ 1,5 to 6degrees C]. Epidemiologists are anxious at the eventual effects of the resulting climate change on the evolution of arbovirus infections transmitted to human beings by hematophagous vectors such as mosquitoes and ticks. Analysis of the literature devoted to this problem did not lead to precise conclusions and the mathematical models used seems insufficient for they take into account mainly the climatic factors and not enough the human ones. Examples of dengue, european tick-borne encephalitis and other arbovirus infections are discussed. Peculiar attention is devoted to the eventual effects of climatic changes on the hibernation process in some small mammals and the dining of bird’s migrations, involved in enzootic cycles of arboviruses. It is likely, that arbovirus diseases may locally extend, both in latitude and altitude, leading to outbreaks, but regressions may also occur.
33. Recalcitrant problems in environmental instrumentation
Agronomy Journal 95 (6): 1404-1407 Nov-Dec 2003
Abstract: Frontiers in any science are generally defined by measurement limitations, and that is especially true in environmental biophysics. Among the more persistent issues are surface-atmosphere exchange, soil water and solute fluxes, plant water status, and plant/soil nutrient status. Measurement of surface-atmosphere exchange is particularly critical to global climate change research. Despite advances in instrumentation. accuracy of flux measurements, particularly eddy covariance. remains unacceptable, partly because the underlying assumptions of stationarity and surface homogeneity are so restrictive. Even when these assumptions are valid, the method appears to systematically underestimate for reasons that are not yet well understood. Similarly, soil water and solute fluxes cannot yet be measured accurately and routinely, hampering water quality research. Recent advances in tension lysimetry offer hope for improvement, but most field experiments still rely on modeling of water and solute now, supported by indirect measurements of ancillary variables, e.g., soil water content, soil water potential, and solute concentration, at discrete points in time and space. A third area of ongoing concern is that of plant water status. The major uncertainty here concerns which property should be measured. Nearly all of the effort over the past 30 yr has been directed at measuring water potential, but water potential measurements are equilibrium measurements, and plants operate in dynamic environments. Furthermore, many physiological processes appear to be more related to relative water content than to water potential. Finally, more accurate and more timely, (e.g., in situ) measurements of plant/soil nutrient status are sorely needed to take advantage of the promise of precision agriculture.