Uncertainty, complexity and concepts of good science in climate change modelling: Are GCMs the best tools?

Climatic Change

Volumn 38, Issue 2, 1998, Pages 159-205

  Shackley, Simon ^a   Young, Peter ^a   Parkinson, Stuart ^a   Wynne, Brian ^a  

^a LANCASTER UNIVERSITY   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

ATMOSPHERIC MODELLING; CLIMATE CHANGE; ENVIRONMENTAL PLANNING; GCMS; GENERAL CIRCULATION MODEL; MODELLING APPROACH; UNCERTAINTY;

EID: 0031887636     PISSN: 01650009     EISSN: None     Source Type: Journal    
DOI: 10.1023/A:1005310109968     Document Type: Article

References (134)

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2. Lindblom, C. and Cohen, D.: 1979, Usable Knowledge, Yale University Press, London, p. 129; Hogwood, B. and Gunn, L.: 1984, Policy Analysis For The Real World, Oxford University Press, Oxford, p. 289; Brunner, R.: 1996, 'Policy and Global Change Research: A Modest Proposal', Clim. Change32(2) 121-147.
3. Lindblom, C. and Cohen, D.: 1979, Usable Knowledge, Yale University Press, London, p. 129; Hogwood, B. and Gunn, L.: 1984, Policy Analysis For The Real World, Oxford University Press, Oxford, p. 289; Brunner, R.: 1996, 'Policy and Global Change Research: A Modest Proposal', Clim. Change32(2) 121-147.
4. Lindblom, C. and Cohen, D.: 1979, Usable Knowledge, Yale University Press, London, p. 129; Hogwood, B. and Gunn, L.: 1984, Policy Analysis For The Real World, Oxford University Press, Oxford, p. 289; Brunner, R.: 1996, 'Policy and Global Change Research: A Modest Proposal', Clim. Change32(2) 121-147.
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6. 2', Nature 280, 189-190; Stewart, T. and Glantz, M.: 1985, 'Expert Judgement and Climate Forecasting: A Methodological Critique of "Climate Change to the Year 2000"', Clim. Change 7, 159-183; Schneider, S: 1985, 'Science by Consensus: The Case of The National Defense University Study "Climate Change to the Year 2000" -An Editorial', ibid., pp. 153-157; Edwards, P.: 1996, 'Global Comprehensive Models in Politics and Policymaking', Clim. Change 32(2), 149-161; Pielke, R. Jr.: 'Usable Information for Policy: an Appraisal of the U.S. Global Change Research Program', Policy Sci. 28, 39-77; Jamieson, D.: 1991, 'The Epistemology of Climate Change: Some Morals for Managers', Soc. Natural Res. 4, 319-329.
7. 2', Nature 280, 189-190; Stewart, T. and Glantz, M.: 1985, 'Expert Judgement and Climate Forecasting: A Methodological Critique of "Climate Change to the Year 2000"', Clim. Change 7, 159-183; Schneider, S: 1985, 'Science by Consensus: The Case of The National Defense University Study "Climate Change to the Year 2000" -An Editorial', ibid., pp. 153-157; Edwards, P.: 1996, 'Global Comprehensive Models in Politics and Policymaking', Clim. Change 32(2), 149-161; Pielke, R. Jr.: 'Usable Information for Policy: an Appraisal of the U.S. Global Change Research Program', Policy Sci. 28, 39-77; Jamieson, D.: 1991, 'The Epistemology of Climate Change: Some Morals for Managers', Soc. Natural Res. 4, 319-329.
8. 2', Nature 280, 189-190; Stewart, T. and Glantz, M.: 1985, 'Expert Judgement and Climate Forecasting: A Methodological Critique of "Climate Change to the Year 2000"', Clim. Change 7, 159-183; Schneider, S: 1985, 'Science by Consensus: The Case of The National Defense University Study "Climate Change to the Year 2000" -An Editorial', ibid., pp. 153-157; Edwards, P.: 1996, 'Global Comprehensive Models in Politics and Policymaking', Clim. Change 32(2), 149-161; Pielke, R. Jr.: 'Usable Information for Policy: an Appraisal of the U.S. Global Change Research Program', Policy Sci. 28, 39-77; Jamieson, D.: 1991, 'The Epistemology of Climate Change: Some Morals for Managers', Soc. Natural Res. 4, 319-329.
9. 2', Nature 280, 189-190; Stewart, T. and Glantz, M.: 1985, 'Expert Judgement and Climate Forecasting: A Methodological Critique of "Climate Change to the Year 2000"', Clim. Change 7, 159-183; Schneider, S: 1985, 'Science by Consensus: The Case of The National Defense University Study "Climate Change to the Year 2000" -An Editorial', ibid., pp. 153-157; Edwards, P.: 1996, 'Global Comprehensive Models in Politics and Policymaking', Clim. Change 32(2), 149-161; Pielke, R. Jr.: 'Usable Information for Policy: an Appraisal of the U.S. Global Change Research Program', Policy Sci. 28, 39-77; Jamieson, D.: 1991, 'The Epistemology of Climate Change: Some Morals for Managers', Soc. Natural Res. 4, 319-329.
10. 2', Nature 280, 189-190; Stewart, T. and Glantz, M.: 1985, 'Expert Judgement and Climate Forecasting: A Methodological Critique of "Climate Change to the Year 2000"', Clim. Change 7, 159-183; Schneider, S: 1985, 'Science by Consensus: The Case of The National Defense University Study "Climate Change to the Year 2000" -An Editorial', ibid., pp. 153-157; Edwards, P.: 1996, 'Global Comprehensive Models in Politics and Policymaking', Clim. Change 32(2), 149-161; Pielke, R. Jr.: 'Usable Information for Policy: an Appraisal of the U.S. Global Change Research Program', Policy Sci. 28, 39-77; Jamieson, D.: 1991, 'The Epistemology of Climate Change: Some Morals for Managers', Soc. Natural Res. 4, 319-329.
11. For example, Hajer, M.: 1995, The Politics of Environmental Discourse, Oxford University Press, Oxford, p. 332; Haas, P.: 1992, 'Introduction: Epistemic Communities and International Policy Coordination', Int. Organ. 46(1), 1-35.
12. For example, Hajer, M.: 1995, The Politics of Environmental Discourse, Oxford University Press, Oxford, p. 332; Haas, P.: 1992, 'Introduction: Epistemic Communities and International Policy Coordination', Int. Organ. 46(1), 1-35.
13. Grotch, S. and MacCracken, M.: 1991, 'The Use of General Circulation Models to Predict Regional Climate Change', J. Clim. 4, 286-303; von Storch, H. and Hasselmann, K.: 1995, Climate Variability and Change, Report no. 152, Max-planck-Institut für Meteorologie, Hamburg, p. 26.
14. Grotch, S. and MacCracken, M.: 1991, 'The Use of General Circulation Models to Predict Regional Climate Change', J. Clim. 4, 286-303; von Storch, H. and Hasselmann, K.: 1995, Climate Variability and Change, Report no. 152, Max-planck-Institut für Meteorologie, Hamburg, p. 26.
15. Natural Science and Technology Coundl: 1996, Our Changing Planet: The FY 1996 U.S. Global Change Research Program, A report by the Subcommittee on Global Change Research, Committee of Environment and Natural Resources Research, A Supplement to the President's Fiscal Year 1996 Budget, Washington, D.C., p. 152.
16. Page 82, Shine, K. and Henderson-Sellers, A.: 1983, 'Modelling Climate and the Nature of Climate Models: A Reiew', J. Climatol. 3, 81-94.
17. Page 55, Henderson-Sellers, A. and McGuffie, K.: 1987, A Climate Modelling Primer, John Wiley, Chichester, p. 217.
18. Wigley, T. and Raper, S.: 1992, 'Implications for Climate and Sea Level of Revised IPCC Emissions Scenarios', Nature 357, 293-300.
19. Page 84 in [7], emphasis added.
20. Page 17, Schneider, S.: 1992, 'Introduction to Climate Modeling', in Trenberth, K. (ed.), Climate System Modeling, Cambridge University Press, Cambridge, pp. 3-26.
21. Inafurther contribution to the book, Meehl extends the concept of a model hierarchy to coupled models, relating comprehensiveness to realism and reliability of model output. (Meehl, G.: 1992, 'Global Coupled Models: Atmosphere, Ocean, Sea Ice', in Trenberth, K. (ed.), Climate System Modeling, Cambridge University Press, Cambridge, pp. 555-581; Kiehl, J.: 1992, 'Atmospheric General Circulation Modeling', in Trenberth, K. (ed.), Climate System Modeling, Cambridge University Press, Cambridge, pp. 319-369.
22. Inafurther contribution to the book, Meehl extends the concept of a model hierarchy to coupled models, relating comprehensiveness to realism and reliability of model output. (Meehl, G.: 1992, 'Global Coupled Models: Atmosphere, Ocean, Sea Ice', in Trenberth, K. (ed.), Climate System Modeling, Cambridge University Press, Cambridge, pp. 555-581; Kiehl, J.: 1992, 'Atmospheric General Circulation Modeling', in Trenberth, K. (ed.), Climate System Modeling, Cambridge University Press, Cambridge, pp. 319-369.
23. Page 760, Schlesinger, M. and Mitchell, J.: 1987, 'Climate Model Simulations of the Equilibrium Climatic Response to Increased Carbon Dioxide', Rev. Geophys. 25,760-798. Similar sentiments are expressed in the IPCC 1995 report, e.g., see Gates, L. et a.: 1996, 'Climate Models - Evaluation', in Houghton, J. et al. (eds), Climate Change 1995: The Science of Climate Change, Cambridge University Press: Cambridge, pp. 572.
24. Page 760, Schlesinger, M. and Mitchell, J.: 1987, 'Climate Model Simulations of the Equilibrium Climatic Response to Increased Carbon Dioxide', Rev. Geophys. 25,760-798. Similar sentiments are expressed in the IPCC 1995 report, e.g., see Gates, L. et a.: 1996, 'Climate Models - Evaluation', in Houghton, J. et al. (eds), Climate Change 1995: The Science of Climate Change, Cambridge University Press: Cambridge, pp. 572.
25. In evidence before the Subcommittee on Environment of the Committee on Science, Space and Technology of the U.S. House of Representatives (in 1992) the following statements have been made by research managers: ' I think we are confident in their [GCM's] fundamental physics. They are based on fundamental physical principles that we believe in. Of course there are many uncertainties associated with the parameterisations .... The clouds, the oceans, the ecosystems, and simply just a matter of resolution' (oral evidence of Dr. A. Patrinos, U.S. Department of Energy, U.S. Congress, House, 1992. Committee on Science, Space and Technology. In U.S. Global Change Research Program, Hearing before the Subcommittee on Environment, 102nd Congress, 2nd Session, 5 May, 1992, p. 91. Washington, D.C., U.S. Government Printing Office, p. 200). And: 'Right now, those GCMs incorporate the best scientific knowledge, the best understanding of the physics and transport of the atmosphere, and some coupled models include representations of the ocean as well that the science community can give you' (oral evidence of Dr. C. Riordan, U.S. Environmental Protection Agency, ibid, p. 92.) Meanwhile, in the U.K., Dr. John Houghton in a speech delivered at the opening of the Hadley Centre (at which Prime Minister Thatcher was in attendance) stated that: 'The numerical model is an effective way - in fact the only way we know - of dealing in a meaningul way with all these non-linearities involved. ... these is a good expectation of being able, through the use of models, to predict at I east i n general terms the change in climate which is likely to occur because of man's increased burning of fossil fuels' (text of speech delivered 25th May 1990).
26. Interview with a GCM er by first author, 11 October 1992. In this paper we use evidence obtained from semi-structured interviews with climate scientists and policy makers. Where quoting interviewees in this paper, we have sometimes slightly edited the verbatim statements to clarify what we perceived were the intended meanings. Where the citation is to a ' personal communication' this indicates a written communication.
27. Personal communication to first author from a GCMer, 22 May 1995.
28. He told us: 'I frequently find that when I submit a proposal or a paper which involves some of the simpler models I run into the criticism - what's the point of doing this? Why didn't you use a GCM? A GCM is obviously better!'. The same scientist told us of an application he had submitted to afunding agency which was turned down on the basis of peer-reviews, one of which assessed the proposal as using an over-simple model, whilst another thought it intended to use an over-complex model. He described a subsequent conversation with an agency official as follows: ' We had a long conversation and it was a little frustrating because he was not willing to be too explicit. ... He talked at great length about all the GCM efforts that he is supporting. ... He also mentioned that he was aware of my criticisms of GCMs and I couldn't help wondering if that had something to do with this decision'. (Interview with first author, 19April 1994.)
29. E.g., p. 18, Schneider [11]. Many well known climate scientists have devel oped and used simple models including Stephen Schneider, Martin Hoffert, Danny Harvey, Tom Wigley, and Peter Stone.
30. Interview with two climatologists by first author, 5 and 6 August 1992.
31. Ibid. Also, Land, K. C. and Schneider, S. H.: 1987, 'Forecasting in the Social and Natural Sciences: An Overview and Analysis of Isomorphisms', Clim. Change 11, 7-31. Our argument is an inevitable simplification of how GCMs are perceived and in reality perceptions of GCMs are often more finely-textured and undergoing change. For example, new relationships have been emerging between GCMers and other scientists, such as ecologists and hydrologists, in which GCMs are less predominant (e.g., Root, T. L. and Schneider, S. H.: 1995, 'Ecology and Climate: Research Strategies and Implications', Science 269, 334-341); and in the U.S.A. there are not only more research centres than in Europe, but greater diversity in the key issues pursued. However, GCMs still dominate in the U.S.A. when it comes to providing policy-relevant knowledge.
32. Ibid. Also, Land, K. C. and Schneider, S. H.: 1987, 'Forecasting in the Social and Natural Sciences: An Overview and Analysis of Isomorphisms', Clim. Change 11, 7-31. Our argument is an inevitable simplification of how GCMs are perceived and in reality perceptions of GCMs are often more finely-textured and undergoing change. For example, new relationships have been emerging between GCMers and other scientists, such as ecologists and hydrologists, in which GCMs are less predominant (e.g., Root, T. L. and Schneider, S. H.: 1995, 'Ecology and Climate: Research Strategies and Implications', Science 269, 334-341); and in the U.S.A. there are not only more research centres than in Europe, but greater diversity in the key issues pursued. However, GCMs still dominate in the U.S.A. when it comes to providing policy-relevant knowledge.
33. For example, the Policy makers Summary of the IPCC's 1990 report commented that: 'These models (GCMs) are based on the laws of physics and use descriptions in simplified physical terms (called parameterisations) of the smaller-scale processes ...' (IPCC, 1990: xxv). In the IPCC's 1995 report the Technical Summary states that: 'Many physical processes, such as those related to clouds, take place on much smaller spatial scales and therefore cannot be properly resolved and modelled explicitly, but their average effects must beincluded in a simple way by taking advantage of physically based relationships with the larger seale variables (a technique known as parametrization)' (p. 31, Technical Summary, IPCC 1996, Climate Change 1995: The Science of Climate Change, Cambridge University Press, Cambridge).
34. P. 19 in Schneider [11]. The IPCC' s presentation is not inconsistent with Schneider, but rather incomplete and with a different emphasis, e.g., upon the physical basis of parameterisations rather than their empirical statistical dimension.
35. Kiehl, in [12]. See also Kiehl, J. and Wlliamson, D.: 1991, 'Dependence of Cloud Amount on Horizontal Resolution in the National Center for Atmospheri c Research Community Climate Model', J. Geophys. Res. 96, 10955-10980; Singo, T.: 1990, ' Sensitivity of the Earth's Radiation Budget to Changes in Low Clouds', Nature 243, 49-51; Randall, D., Harshvardhan, Dazlich, D., and Corsetti, T.: 1989, 'Interactions among Radiation, Convection, and Large-Scale Dynamics in a General Circulation Model', J. Atmos. Sci. 46(13), 1943-1970.
36. Kiehl, in [12]. See also Kiehl, J. and Wlliamson, D.: 1991, 'Dependence of Cloud Amount on Horizontal Resolution in the National Center for Atmospheri c Research Community Climate Model', J. Geophys. Res. 96, 10955-10980; Singo, T.: 1990, ' Sensitivity of the Earth's Radiation Budget to Changes in Low Clouds', Nature 243, 49-51; Randall, D., Harshvardhan, Dazlich, D., and Corsetti, T.: 1989, 'Interactions among Radiation, Convection, and Large-Scale Dynamics in a General Circulation Model', J. Atmos. Sci. 46(13), 1943-1970.
37. Kiehl, in [12]. See also Kiehl, J. and Wlliamson, D.: 1991, 'Dependence of Cloud Amount on Horizontal Resolution in the National Center for Atmospheri c Research Community Climate Model', J. Geophys. Res. 96, 10955-10980; Singo, T.: 1990, ' Sensitivity of the Earth's Radiation Budget to Changes in Low Clouds', Nature 243, 49-51; Randall, D., Harshvardhan, Dazlich, D., and Corsetti, T.: 1989, 'Interactions among Radiation, Convection, and Large-Scale Dynamics in a General Circulation Model', J. Atmos. Sci. 46(13), 1943-1970.
38. Personal communication to first author from a GCMer, 7 February 1995.
39. Risbey has elaborated on this point: 'GCMs aim to account for physical processes from first principles, i.e., from the known laws governing the behaviour of the relevant phenomenon. Simpler models generally do not make this attempt, accepting more aggregate and empirically based representations. In practice however this distinction is not as strong as it sounds in practice, since even GCMs are highly dependent on empirical data in their parameterizations, albeit at smaller seales. This is (one reason) why the so-called "reductionist approach" of GCMs "does not automatically guarantee physical realism" ' (personal communication, September 1996).
40. Stone, P. and Risbey, J.: 1990, 'On the Limitations of General Circulation Climate Models', Geophys. Res. Lett. 17(12), 2173-2176; Stone, P. and Yao, M-S.: 1991, 'Vertica Eddy Heat Fluxes from Model Simulations', J. Clim. 4(3), 304-317.
41. Stone, P. and Risbey, J.: 1990, 'On the Limitations of General Circulation Climate Models', Geophys. Res. Lett. 17(12), 2173-2176; Stone, P. and Yao, M-S.: 1991, 'Vertica Eddy Heat Fluxes from Model Simulations', J. Clim. 4(3), 304-317.
42. Interview with a climate modeller by first author, 10 April 1994. (Michaud, R. and Derome, J.: 1991, 'On the Meridional Transport of Energy in the Atmosphere and Oceans as Derived from Six Years of ECMWF Analyses', Tellus 43A, 1-14; Oort, A. H.: 1978, 'On the Adequacy of the Rawinsonde Network for Global Circulation Studies Tested through Numerical Model Output', Mon. Wea. Rev. 106, 174-195; Oort, A. H.: 1983, Global Atmospheric Circulation Statistics, 1958-1973, NOAA Professional Paper 14, U.S. Government Printing Office, Washington, D.C.; Keith, D.W.: 1995, 'Meridional Energy Transport: Uncertainty in Zonal Means', Tell us 47A (1), 30-44; the on-going debate is reflected in Trenberth, K. and Solomon, A.: 1994, 'The Global Heat Balance: Heat Transports in the Atmosphere and Ocean', Clim. Dyn. 10, 107-134. A major comparison of models with respect to their heat transport has now been conducted (Glecker, P et al.: 1995, 'Cloud Radiative Effects on Implied Oceanic Energy Transports as Simulated by Atmospheric General Circulation Modesl', Geophys. Res. Lett. 22(7), 791-794) which reveals the extent of the probable errors).
43. Interview with a climate modeller by first author, 10 April 1994. (Michaud, R. and Derome, J.: 1991, 'On the Meridional Transport of Energy in the Atmosphere and Oceans as Derived from Six Years of ECMWF Analyses', Tellus 43A, 1-14; Oort, A. H.: 1978, 'On the Adequacy of the Rawinsonde Network for Global Circulation Studies Tested through Numerical Model Output', Mon. Wea. Rev. 106, 174-195; Oort, A. H.: 1983, Global Atmospheric Circulation Statistics, 1958-1973, NOAA Professional Paper 14, U.S. Government Printing Office, Washington, D.C.; Keith, D.W.: 1995, 'Meridional Energy Transport: Uncertainty in Zonal Means', Tell us 47A (1), 30-44; the on-going debate is reflected in Trenberth, K. and Solomon, A.: 1994, 'The Global Heat Balance: Heat Transports in the Atmosphere and Ocean', Clim. Dyn. 10, 107-134. A major comparison of models with respect to their heat transport has now been conducted (Glecker, P et al.: 1995, 'Cloud Radiative Effects on Implied Oceanic Energy Transports as Simulated by Atmospheric General Circulation Modesl', Geophys. Res. Lett. 22(7), 791-794) which reveals the extent of the probable errors).
44. Interview with a climate modeller by first author, 10 April 1994. (Michaud, R. and Derome, J.: 1991, 'On the Meridional Transport of Energy in the Atmosphere and Oceans as Derived from Six Years of ECMWF Analyses', Tellus 43A, 1-14; Oort, A. H.: 1978, 'On the Adequacy of the Rawinsonde Network for Global Circulation Studies Tested through Numerical Model Output', Mon. Wea. Rev. 106, 174-195; Oort, A. H.: 1983, Global Atmospheric Circulation Statistics, 1958-1973, NOAA Professional Paper 14, U.S. Government Printing Office, Washington, D.C.; Keith, D.W.: 1995, 'Meridional Energy Transport: Uncertainty in Zonal Means', Tell us 47A (1), 30-44; the on-going debate is reflected in Trenberth, K. and Solomon, A.: 1994, 'The Global Heat Balance: Heat Transports in the Atmosphere and Ocean', Clim. Dyn. 10, 107-134. A major comparison of models with respect to their heat transport has now been conducted (Glecker, P et al.: 1995, 'Cloud Radiative Effects on Implied Oceanic Energy Transports as Simulated by Atmospheric General Circulation Modesl', Geophys. Res. Lett. 22(7), 791-794) which reveals the extent of the probable errors).
45. Interview with a climate modeller by first author, 10 April 1994. (Michaud, R. and Derome, J.: 1991, 'On the Meridional Transport of Energy in the Atmosphere and Oceans as Derived from Six Years of ECMWF Analyses', Tellus 43A, 1-14; Oort, A. H.: 1978, 'On the Adequacy of the Rawinsonde Network for Global Circulation Studies Tested through Numerical Model Output', Mon. Wea. Rev. 106, 174-195; Oort, A. H.: 1983, Global Atmospheric Circulation Statistics, 1958-1973, NOAA Professional Paper 14, U.S. Government Printing Office, Washington, D.C.; Keith, D.W.: 1995, 'Meridional Energy Transport: Uncertainty in Zonal Means', Tell us 47A (1), 30-44; the on-going debate is reflected in Trenberth, K. and Solomon, A.: 1994, 'The Global Heat Balance: Heat Transports in the Atmosphere and Ocean', Clim. Dyn. 10, 107-134. A major comparison of models with respect to their heat transport has now been conducted (Glecker, P et al.: 1995, 'Cloud Radiative Effects on Implied Oceanic Energy Transports as Simulated by Atmospheric General Circulation Modesl', Geophys. Res. Lett. 22(7), 791-794) which reveals the extent of the probable errors).
46. Interview with a climate modeller by first author, 10 April 1994. (Michaud, R. and Derome, J.: 1991, 'On the Meridional Transport of Energy in the Atmosphere and Oceans as Derived from Six Years of ECMWF Analyses', Tellus 43A, 1-14; Oort, A. H.: 1978, 'On the Adequacy of the Rawinsonde Network for Global Circulation Studies Tested through Numerical Model Output', Mon. Wea. Rev. 106, 174-195; Oort, A. H.: 1983, Global Atmospheric Circulation Statistics, 1958-1973, NOAA Professional Paper 14, U.S. Government Printing Office, Washington, D.C.; Keith, D.W.: 1995, 'Meridional Energy Transport: Uncertainty in Zonal Means', Tell us 47A (1), 30-44; the on-going debate is reflected in Trenberth, K. and Solomon, A.: 1994, 'The Global Heat Balance: Heat Transports in the Atmosphere and Ocean', Clim. Dyn. 10, 107-134. A major comparison of models with respect to their heat transport has now been conducted (Glecker, P et al.: 1995, 'Cloud Radiative Effects on Implied Oceanic Energy Transports as Simulated by Atmospheric General Circulation Modesl', Geophys. Res. Lett. 22(7), 791-794) which reveals the extent of the probable errors).
47. Interview with a climate modeller by first author, 10 April 1994. (Michaud, R. and Derome, J.: 1991, 'On the Meridional Transport of Energy in the Atmosphere and Oceans as Derived from Six Years of ECMWF Analyses', Tellus 43A, 1-14; Oort, A. H.: 1978, 'On the Adequacy of the Rawinsonde Network for Global Circulation Studies Tested through Numerical Model Output', Mon. Wea. Rev. 106, 174-195; Oort, A. H.: 1983, Global Atmospheric Circulation Statistics, 1958-1973, NOAA Professional Paper 14, U.S. Government Printing Office, Washington, D.C.; Keith, D.W.: 1995, 'Meridional Energy Transport: Uncertainty in Zonal Means', Tell us 47A (1), 30-44; the on-going debate is reflected in Trenberth, K. and Solomon, A.: 1994, 'The Global Heat Balance: Heat Transports in the Atmosphere and Ocean', Clim. Dyn. 10, 107-134. A major comparison of models with respect to their heat transport has now been conducted (Glecker, P et al.: 1995, 'Cloud Radiative Effects on Implied Oceanic Energy Transports as Simulated by Atmospheric General Circulation Modesl', Geophys. Res. Lett. 22(7), 791-794) which reveals the extent of the probable errors).
48. Pp. 2175 and 2176 (our italics) respectively, in [26].
49. Young, P., Parkinson, S., and Lees, M.: 1996, 'Simplicity out of Complexity: Occam's Razor Revisited', J. Appl. Statis. 23, 165-210.
50. Interview by first author with a GCM modeller, 11 March 1993.
51. Some evidence for this view comes from research with relatively simple models (e.g., Marotkze, J. and Stone, P.: 1995, 'Atmospheric Transports, the Thermohaline Circulation, and Flux Adjustments in a Simple Coupled Model', J. Phys. Ocean. 25, 1350-1364; Nakamura, M., Stone, P., and Marotzke, J.: 1994, 'Destabilisation of the Thermohaline Circulation by Atmospheric Eddy Transport', J. Clim. 7, 1870-1882). Note, however, that not all GCMers would accept this evidence since simple models were used in these experiments.
52. Some evidence for this view comes from research with relatively simple models (e.g., Marotkze, J. and Stone, P.: 1995, 'Atmospheric Transports, the Thermohaline Circulation, and Flux Adjustments in a Simple Coupled Model', J. Phys. Ocean. 25, 1350-1364; Nakamura, M., Stone, P., and Marotzke, J.: 1994, 'Destabilisation of the Thermohaline Circulation by Atmospheric Eddy Transport', J. Clim. 7, 1870-1882). Note, however, that not all GCMers would accept this evidence since simple models were used in these experiments.
53. It has been suggested to us that the evaluation of climate models has become increasingly formalised since the early 1990s, with projects such as the Atmospheric Model lntercomparison Project (AMIP) and its off-shoots (Mike Hulme, personal communication, February 1997). An interesting question is the extent to which such formalisation is related to the perceived policy requirement for validation in a context of uncertain science for policy, rather than such a process being driven solely by the climate modelling community. There are generic similarities to the strategies of molecular biologists and particle physicists (Knorr-Cetina, K.: 1991, 'Epistemic Cultures: Forms of Reason in Science', Hist. Political Econ. 23, 105-122).
54. A discussion and classification of the limitations and uncertainties of climate and integrated assessment models can be found in van der Suijs, J.: 1997, Anchoring Amid Uncertainty: On the Management of Uncertainties in Risk Assessment of Anthropogenic Climate Change, Ludy Feyen, Laiden, p. 260.
55. Note that in mathematical statistics and engineering, 'over-parameterisation' is usually taken to mean that the model has more parameters (coefficients) than can be justified by the available data on which the model is based: this is, of course, quite different from the usage here.
56. Personal communication by first author with Dr. James Risbey, 6 July 1994.
57. Hempel, C. G.: 1966, Philosophy of Natural Science, Prentice-Hall, EnglewoodCliffs, NJ, p. 116; Hesse, M.: 1974, The Structure of Scientific Inference, Macmillan, London, p. 309; Popper, K.: 1959, The Logic of Scientific Discovery, Hutchinson, London, p. 480.
58. Hempel, C. G.: 1966, Philosophy of Natural Science, Prentice-Hall, EnglewoodCliffs, NJ, p. 116; Hesse, M.: 1974, The Structure of Scientific Inference, Macmillan, London, p. 309; Popper, K.: 1959, The Logic of Scientific Discovery, Hutchinson, London, p. 480.
59. Hempel, C. G.: 1966, Philosophy of Natural Science, Prentice-Hall, EnglewoodCliffs, NJ, p. 116; Hesse, M.: 1974, The Structure of Scientific Inference, Macmillan, London, p. 309; Popper, K.: 1959, The Logic of Scientific Discovery, Hutchinson, London, p. 480.
60. P. 234 in Hesse[36]. 38. P. 44 in Popper, K.: 1982, The Open Universe, Hutchinson, London, p. 185; Tennekes, H.: 1992, 'Karl Popper and the Accountability of Numerical Weather Forecasting', Weather 47, 343-346.
61. P. 234 in Hesse[36]. 38. P. 44 in Popper, K.: 1982, The Open Universe, Hutchinson, London, p. 185; Tennekes, H.: 1992, 'Karl Popper and the Accountability of Numerical Weather Forecasting', Weather 47, 343-346.
62. Gieryn, T.: 1995, 'Boundaries of Science', in Jasanoff, S. et al. (eds.), Handbook of Science and Technology Studies, Sage, London, pp. 393-443; Collins, H.: 1992 (1985), Changing Order: Replication and Induction in Scientific Practice, Chicago University Press, London, p. 187.
63. Gieryn, T.: 1995, 'Boundaries of Science', in Jasanoff, S. et al. (eds.), Handbook of Science and Technology Studies, Sage, London, pp. 393-443; Collins, H.: 1992 (1985), Changing Order: Replication and Induction in Scientific Practice, Chicago University Press, London, p. 187.
64. Shackley, S. and Wynne, B.: 1995, 'Integrating Knowledges for Climate Change: Pyramids, Nets and Uncertainties', Global Environ. Change5(2), 113-126.
65. Cartwright, N.: 1994, 'Fundamentalism vs. the Patchwork of Laws', Proc. Aristotelian Soc. 94, 279-292; Hacking, I.: 1992, 'The Self-Vindication of the Laboratory Sciences', in Pickering, A. (ed.), Science as Practice and Culture, Chicago University Press, Chicago, p. 474.
66. Cartwright, N.: 1994, 'Fundamentalism vs. the Patchwork of Laws', Proc. Aristotelian Soc. 94, 279-292; Hacking, I.: 1992, 'The Self-Vindication of the Laboratory Sciences', in Pickering, A. (ed.), Science as Practice and Culture, Chicago University Press, Chicago, p. 474.
67. Interview by first author with a GCMer, 10 September 1992.
68. We avoid use of the term 'reductionism' here because of its commonly- held definition by climate (and other environmental) modellers. At I east two definitions seem to be used. The more common definition of reductionism-namely that the environmental system is analytically decomposable to the governing physical laws - is widely accepted by modellers (a viewpoint we will critically explore in the next section). At the same time, however, many climate modellers are keen to distance themselves from the 'high-physics' approach to representing systems by employing a few rather abstract physical principles, a stance which they also appear to have negatively characterised as reductionism. Historically, part of the reason for the development of this second perspective may have been to counter the improper extension of a physics-derived commitment to simplicity into the subject matter of the environmental and earth sciences. Physical complexity was at least a step away from such overt reductionism. (Personal communication to first author from Dr. Naomi Oreskes, 5 February 1996.) Discussing the implications for model validation, Oreskes et al. have noted that the more sophisticated the model becomes, the more difficult it is to provide confirmation or falsification of the model (see also, Oreskes, N., Shrader-Frechette, K., and Belitz, K.: 1994, 'Verification, Validation, and Confirmation of Numerical Models in the Earth Sciences', Science 263, 641-646).
69. Palmer, T. N.: 1993, 'A Nonlinear Dynamical Perspective on Climate Change', Weather 48(10), 314-326.
70. Ibid.: 324.
71. As one modeller puts it: 'there is a view that if you are only interested in global average temperature then you don't really need GCMs-that one dimensional models will be more or less correct. And that you only need the GCM models if you are interested in homing-in on a spedfic region. But I think that is a very simplistic view of the world and you just cannot make that assumption in a non-linear system. That is really important' (interview by first author with a GCMer, 21 June 1993). A problem with Palmer's analysis, however, is that it is based on transient results only, whereas thermodynamic argument would suggest it applies much less forcefully for the case of an equilibrium response (personal communication by first author with a climate modeller, 6 June 1994).
72. A further example which possibly illustrates the need for GCMs is the model representation of the thermohaline circulation. Simple model stend to produce a much more unstable thermohaline than models with higher degrees of freedom, though the modelling evidence is somewhat mixed. The reliability of the representation of the thermohaline circulation in current coupled AOGCMs, and its sensitivity to changes i n freshwater flux and temperature, remains questionable, however (see, e.g., Rahmstorf, S.: 1995, 'Bifurcations of the Atlantic Thermohaline Circulation in Response to Changes in the Hydrological Cycle', Nature 378, 145-149).
73. Cf. Ascher, W.: 1981, 'The Forecasting Potential of Complex Models', Policy Sci. 13, 247-267.
74. 2 and the Carbon Cycle', in Houghton, J., Mera Filho, L., Bruce, J., Lee, H., Callander, B., Haites, E., Harris, N., and Maskell, K.: 1995, Climate Change 1994: Radiative Fordng of Climate Change and an Evaluation of the IPCC IS92 Emission Scenarios, Cambridge University Press, Cambridge, p. 339.
75. 2 and the Carbon Cycle', in Houghton, J., Mera Filho, L., Bruce, J., Lee, H., Callander, B., Haites, E., Harris, N., and Maskell, K.: 1995, Climate Change 1994: Radiative Fordng of Climate Change and an Evaluation of the IPCC IS92 Emission Scenarios, Cambridge University Press, Cambridge, p. 339.
76. 2 and the Carbon Cycle', in Houghton, J., Mera Filho, L., Bruce, J., Lee, H., Callander, B., Haites, E., Harris, N., and Maskell, K.: 1995, Climate Change 1994: Radiative Fordng of Climate Change and an Evaluation of the IPCC IS92 Emission Scenarios, Cambridge University Press, Cambridge, p. 339.
77. Gardner, R. H. and Trabalka, J. R.: 1985, Methods of Uncertainty Analysis for a Global Carbon Dioxide Model. Publication DOE/OR/21400-4. U.S. Dept. of Energy, Washington D.C., p. 41.
78. Schneider, E.: 1996, 'Flux Correction and the Simulation of Changing Climate', Annales Geophysicae14, 335-341.
79. Enting and Lassey [49].
80. Further details can be found in Parkinson, S.: 1995, The Application of Stochastic Modeling Techniques to Global Climate Change, Ph.D. Thesis, Lancaster University, U.K., p. 263; Young et al., 1996 [29]; Parkinson, S. and Young, P.: 1997, 'Uncertainty and Sensitivity in Global Carbon Cyd e Modelling', submitted manuscript.
81. Further details can be found in Parkinson, S.: 1995, The Application of Stochastic Modeling Techniques to Global Climate Change, Ph.D. Thesis, Lancaster University, U.K., p. 263; Young et al., 1996 [29]; Parkinson, S. and Young, P.: 1997, 'Uncertainty and Sensitivity in Global Carbon Cyd e Modelling', submitted manuscript.
82. Huggett, R.: 1993, Modelling the Human Impact on Nature: Systems Analysis of Environmental Problems, Oxford University Press, Oxford, p. 192.
83. See e.g., Scavia, D.: 1993, 'LakeEcosystem Modlling', in Young, P. (ed.), Concise Encyclopedia of Environmental Systems, Pergamon Press, Oxford, pp. 318-320.
84. One GCM group recently wrote a paper entitled: 'Monte Carlo climate change forecasts with a global coupled ocean-atmosphere model' (Cubasch, U., Sausen, R., Maier-Ramer, E., and Voss, R.: 1994, 'Monte Carlo Climate Change Forecasts with a Global Coupled Ocean-Atmosphere Model', Clim. Dyn. 10, 1-19). In this study they ran the AOGCM model only four times, which according to the standards of many modellers would not count as MCS at all! Nevertheless the significance of the model's initial conditions was clearly indicated, so it had some positive contribution.
85. We feel it is necessary to clarify our definitions of 'deterministic' and 'stochastic', since there appears to be some variation in their meanings. A deterministic model for us is one whose temporal evolution can be calculated exactly, given a set of initial conditions. A stochastic model, on the other hand, is one whose parameters and/or inputs are defined probabilistically, so that the model response can only be defined in probabilistic terms. Thus, a model of the global climate system can be deterministic or stochastic, depending upon the views of the model builder. But uncertainty issurely unavoidabl e in any investigation of the natural environment and it seems more appropri ate that it should be considered in stochastic terms.
86. See [53].
87. It is also possible, however, that this assumption may also lead to lower estimates of uncertainty. It depends very much upon the nature of the model being considered - see discussi on in Parkinson and Young (1997) [53].
88. See [53].
89. This empiricist approach to model evaluation would not be accepted by those using a more formal structural epistemology.
90. Schimel et al., Enting and Lassey [49]), Wigley and Raper [9], and Parkinson and Young [53]. The uncertainty in each of the deterministic exercises is due to the following: variation between different models; variation in one model due to different assumptions about feedbacks; and limited parametric uncertainty.
91. Pi is thus reduced from 275 ±15 ppmv to 275 ±7,5 ppmv which is closer to the uncertainty discussed by Schimel et al. [49] -a value published too late to be considered explicitly by this analysis.
92. Schimel et al. [49].
93. See [53].
94. Young, P.: 1984, Recursive Estimation and Time-Series Analysis, Springer-Verlag, Berlin, p. 300; Young, P.: 1985, 'The Instrumental Variable Method: A Practical Approach to Identification and System Parameter Estimation', in Barker, H. and Young, P. (eds.), Identification and System Parameter Estimation: Vol. 1 and 2, Pergamon Press, Oxford, pp. 1-16.
95. Young, P.: 1984, Recursive Estimation and Time-Series Analysis, Springer-Verlag, Berlin, p. 300; Young, P.: 1985, 'The Instrumental Variable Method: A Practical Approach to Identification and System Parameter Estimation', in Barker, H. and Young, P. (eds.), Identification and System Parameter Estimation: Vol. 1 and 2, Pergamon Press, Oxford, pp. 1-16.
96. See [53]. Note that the structural decomposition of the transfer function is ambiguous: other decompositions are possible, including feedback structures that may provide a better physical interpretation than the parallel decomposition. However, such discrimination is not important to the discussion here. 68. The input due to land-use changes is set to zero in the original model in order to carry out this comparison. Hence, a lower atmospheric carbon dioxide level than expected is seen in Figure 2 during the simulation.
97. These values come from the continuous-time reduced order model reported in Young and Parkinson(1996), which explains the EL model data a little better than the discrete-timemodel described previously in Young et al. (1996) [29]. However, the time constants of both models are quite similar and the mechanistic interpretations are the same. (Young, P. and Parkinson, S.: 1996, simplicity out of Complexity in Forecasti ng Climate Change, Technical Note Centref or Research on Environmental Systems and Statistics, Lancaster University, p. 37.) 70. This final stage of interpreting the reduced order model in physically meaningful terms is part of a technique which we term Data-Based Mechanistic (DBM) modelling; a technique which can be applied within DMA analysis to simulated data and, more generally, to real data (see Young, P. and Seven, K.: 1994, 'Data-Based Mechanistic Modelling and the Rainfall-Flow Nonlinearity', Environmetrics 5, 335-363 (Special Issue on 'Environmental Time Series Analysis')).
98. Enti ng and Lassey, Enti ng and Pearman [49].
99. The IPCC 1990 report itself stated that: 'Because running coupled ocean-atmosphere GCMs is expensive and time-consuming, many of our conclusions about global trends in future dimates are based upon simplified models' (Houghton, J., Jenkins, G., and Ephraums, J.: 1990, Climate Change: The IPCC Scientific Assessment, Cambridge University Press, Cambridge, p. 365). Henderson-Sellers has presented similar arguments to ours. (Henderson-Sellers, A.: 1996, 'Climate Modelling, Uncertainty and Responses to Predictions of Change', Mitigat. Adapt. Strat. Global Change 1, 1-21; and 'Bridging the Climate Gap', in Giambelluca, T. and Henderson-Sellers, A. (eds.) 1996, Climate Change: Devaloping Southern Hemisphere Perspectives, John Wiley, Chiehester, pp. 35-60.)
100. The IPCC 1990 report itself stated that: 'Because running coupled ocean-atmosphere GCMs is expensive and time-consuming, many of our conclusions about global trends in future dimates are based upon simplified models' (Houghton, J., Jenkins, G., and Ephraums, J.: 1990, Climate Change: The IPCC Scientific Assessment, Cambridge University Press, Cambridge, p. 365). Henderson-Sellers has presented similar arguments to ours. (Henderson-Sellers, A.: 1996, 'Climate Modelling, Uncertainty and Responses to Predictions of Change', Mitigat. Adapt. Strat. Global Change 1, 1-21; and 'Bridging the Climate Gap', in Giambelluca, T. and Henderson-Sellers, A. (eds.) 1996, Climate Change: Devaloping Southern Hemisphere Perspectives, John Wiley, Chiehester, pp. 35-60.)
101. The IPCC 1990 report itself stated that: 'Because running coupled ocean-atmosphere GCMs is expensive and time-consuming, many of our conclusions about global trends in future dimates are based upon simplified models' (Houghton, J., Jenkins, G., and Ephraums, J.: 1990, Climate Change: The IPCC Scientific Assessment, Cambridge University Press, Cambridge, p. 365). Henderson-Sellers has presented similar arguments to ours. (Henderson-Sellers, A.: 1996, 'Climate Modelling, Uncertainty and Responses to Predictions of Change', Mitigat. Adapt. Strat. Global Change 1, 1-21; and 'Bridging the Climate Gap', in Giambelluca, T. and Henderson-Sellers, A. (eds.) 1996, Climate Change: Devaloping Southern Hemisphere Perspectives, John Wiley, Chiehester, pp. 35-60.)
102. We have also observed the enthusiastic response at a meeting of IPCC advisory scientists and policy makers to Wigley's 1-D-model, because of its perceved policy-usefulness.
103. Interview by first author with a government official, 23 February 1993.
104. Such dependency could have serious implications vis-à-vis the commitment of devaloping countries to climate change as a policy issue. Given a context of distrust between policy makers in the North and South, the question must be asked of whether GCM climate change scenarios devaoped in the North will be trusted, especially given the difficulty of independently evaluating the judgement which goes into construction of those scenarios.
105. Polanyi, K.: 1958, Personal Knowledge, Routledge and Kegan Paul, London, p. 428.
106. Leading scientists themselves may prefer the level of control over scientific assessment offered by fewer centres. For example, a previous director of the U.K. Meteorological Office, Sir John Mason, stated before the House of Lords Select Committee on Sustainable Devalopment in 1994 that: '... the number of people or the number of groups around the world involved in dimate modelling has increased rather dramatically in the last two or three years and not wholly for the better in my view. It is easier when you have only three or four major groups, particularly if one of them is in the United Kingdom, to make judgments than when there are a lot of people in the field and perhaps introducing more turbulence into the subject' (p. 15, Minutes of Evidence taken before the Select Committee on Sustainable Development, Tuesday 3 May 1994, London, HMSO, HL Paper 66-ii).
107. Interview by first author with a GCMer, 11 April 1994. The episode is mentioned in Gore, A.: 1992, Earth in the Balance, Houghton Miflin Company, New York, p. 407. A similar point is made by Parsons, E.: 1995, 'Integrated Assessment and Environmental Policy Making: I n Pursuit of Usefulness', Energy Policy 23, 463-476.
108. Interview by first author with a GCMer, 11 April 1994. The episode is mentioned in Gore, A.: 1992, Earth in the Balance, Houghton Miflin Company, New York, p. 407. A similar point is made by Parsons, E.: 1995, 'Integrated Assessment and Environmental Policy Making: I n Pursuit of Usefulness', Energy Policy 23, 463-476.
109. Technology Review: 1992, 'The Political Pleasures of Engineering: An Interview with John Sununu', Technol. Rev. 95, August/September, 22-28.
110. Research results do not clearly indicate the effects of changes in the THC on the take-up of heat, and subsequent feedbacks upon surface temperature and precipitation. See, e.g., Harvey, L. D. Danny: 1994, 'Transient Temperature and Sea Level Response of a Two-Dimensional Ocean-Climate Model to Greenhouse Gas Increases', J. Geophys. Res. 99(C9), 18,447-18,466.
111. A further example is theargument by Schlesinger and Jiang that a ten year delay in greenhouse gas emission reductions would have a minimal effect on potential warming. Schlesinger and Jiang were criticised by Risbey, Handel and Stone for basing strong policy conclusions on simple climate models which failed to take account of non-linear, possibly abrupt climate change, as well as probably under-recognising the extent of regional climate change. The debate between Schlesinger and Jiang and Risbey, Handel and Stone subsequently revolved, however, around different and conflicting interpretations of the same GCM model runs, indicating that it was, in practice, difficult to divorce the evaluation of the simple models from more complex ones, and vice versa. A further difference between Schlesinger and Jiang and Risbey, Handel and Stone was the degree to which models, whether simple or GCMs, were held to be sufficiently robust to act as the basis of policy-decisions to delay action. Schlesinger and Ji ang defended the use of both types of modäs for this purpose, whilst Risbey, Handel and Stone implied that neither simple models nor GCMs were currently adequate to act as the basis for such decisions. (Schlesinger, M. and Jiang, X.: 1991, 'Revised Projection of Future Greenhouse Warming', Nature 350, 219; Schlesinger, M. and Jiang, X.: 1991, 'A Phased-ln Approach to Greenhouse-Gas-Induced Climatic Change and Climatic Response to Increasing Greenhouse Gases', Eos Trans. A.G.U. 72(53), 596-597; Risbey, J., Handel, M., and Stone, P.: 1991, 'Should We Delay Responses to the Greenhouse Issue?' and 'Do We Know What Difference a Delay Makes?', Eos Trans. A.G.U. 72 (53), 593.)
112. A further example is theargument by Schlesinger and Jiang that a ten year delay in greenhouse gas emission reductions would have a minimal effect on potential warming. Schlesinger and Jiang were criticised by Risbey, Handel and Stone for basing strong policy conclusions on simple climate models which failed to take account of non-linear, possibly abrupt climate change, as well as probably under-recognising the extent of regional climate change. The debate between Schlesinger and Jiang and Risbey, Handel and Stone subsequently revolved, however, around different and conflicting interpretations of the same GCM model runs, indicating that it was, in practice, difficult to divorce the evaluation of the simple models from more complex ones, and vice versa. A further difference between Schlesinger and Jiang and Risbey, Handel and Stone was the degree to which models, whether simple or GCMs, were held to be sufficiently robust to act as the basis of policy-decisions to delay action. Schlesinger and Ji ang defended the use of both types of modäs for this purpose, whilst Risbey, Handel and Stone implied that neither simple models nor GCMs were currently adequate to act as the basis for such decisions. (Schlesinger, M. and Jiang, X.: 1991, 'Revised Projection of Future Greenhouse Warming', Nature 350, 219; Schlesinger, M. and Jiang, X.: 1991, 'A Phased-ln Approach to Greenhouse-Gas-Induced Climatic Change and Climatic Response to Increasing Greenhouse Gases', Eos Trans. A.G.U. 72(53), 596-597; Risbey, J., Handel, M., and Stone, P.: 1991, 'Should We Delay Responses to the Greenhouse Issue?' and 'Do We Know What Difference a Delay Makes?', Eos Trans. A.G.U. 72 (53), 593.)
113. A further example is theargument by Schlesinger and Jiang that a ten year delay in greenhouse gas emission reductions would have a minimal effect on potential warming. Schlesinger and Jiang were criticised by Risbey, Handel and Stone for basing strong policy conclusions on simple climate models which failed to take account of non-linear, possibly abrupt climate change, as well as probably under-recognising the extent of regional climate change. The debate between Schlesinger and Jiang and Risbey, Handel and Stone subsequently revolved, however, around different and conflicting interpretations of the same GCM model runs, indicating that it was, in practice, difficult to divorce the evaluation of the simple models from more complex ones, and vice versa. A further difference between Schlesinger and Jiang and Risbey, Handel and Stone was the degree to which models, whether simple or GCMs, were held to be sufficiently robust to act as the basis of policy-decisions to delay action. Schlesinger and Ji ang defended the use of both types of modäs for this purpose, whilst Risbey, Handel and Stone implied that neither simple models nor
114. In this section we draw upon theories developed in the field of social studies of science. See, for example, Callon, M.: 1986, 'Some Elements of a Sociology of Translation: Domestication of the Scallops and of the Fisherman of St. Brieuc Bay', in Law, J. (ed.), Power, Action and Belief, Methuen, London, pp. 196-233; Latour, B.: 1988, The Pasteurisation of France, Harvard University Press, London, p. 273; Latour, B.: 1992 (1987), Science in Action, Harvard University Press, London, p. 274.
115. In this section we draw upon theories developed in the field of social studies of science. See, for example, Callon, M.: 1986, 'Some Elements of a Sociology of Translation: Domestication of the Scallops and of the Fisherman of St. Brieuc Bay', in Law, J. (ed.), Power, Action and Belief, Methuen, London, pp. 196-233; Latour, B.: 1988, The Pasteurisation of France, Harvard University Press, London, p. 273; Latour, B.: 1992 (1987), Science in Action, Harvard University Press, London, p. 274.
116. In this section we draw upon theories developed in the field of social studies of science. See, for example, Callon, M.: 1986, 'Some Elements of a Sociology of Translation: Domestication of the Scallops and of the Fisherman of St. Brieuc Bay', in Law, J. (ed.), Power, Action and Belief, Methuen, London, pp. 196-233; Latour, B.: 1988, The Pasteurisation of France, Harvard University Press, London, p. 273; Latour, B.: 1992 (1987), Science in Action, Harvard University Press, London, p. 274.
117. Interviews by first author with global vegetation dynamics modalers, 15 December 1993 and 16 September 1993.
118. Compare, Perry, J.: 1992, The United States Global Change Research Program: Early Achievements and Future Directions, National Academy Press, Washington D.C., p. 20.
119. As a senior scientist at a GCM modelling centre put it: 'This (modelling centre) of course, is in a sense the tip of an iceberg though. It depends on a community of international and national research to actually achieve its task ... if you don't have something like (the modelling centre), you actually run the risk that you make a lot of investment but as a nation, actually, you lack perhaps the primary benefit of that integrated output. ... And I think that's one of the frustrations, perhaps, of some of the smaller European nations, that they actually contribute quite a bit to the science base of it, but they don't get the high profile of the actual prediction activity'. (Interview by first author with a research manager, 6 May 1993.)
120. Interview by first author with a GCM research manager 5 April 1993.
121. Interview by first author with an observational climatologist, 10 February 1993.
122. This was done by Parkinson and Young [53] in generating the results quoted in Section 5.
123. Parry, M.: 1990, Climate Change and World Agriculture, Earthscan, London, p. 157; Carter, T., Holopainen, E., and Kanninen, M. (eds): 1993, 'Techniques for Developing Regional Climatic Scenarios for Finland', Publications of the Academy of Finland 2/93, Painatuskeskus, Helsinki, p. 63; Viner, D. and Hulme, M.: Climate Change Scenarios for Impact Studies in the U.K., Climatic Research Unit, University of East Anglia, p. 70.
124. Parry, M.: 1990, Climate Change and World Agriculture, Earthscan, London, p. 157; Carter, T., Holopainen, E., and Kanninen, M. (eds): 1993, 'Techniques for Developing Regional Climatic Scenarios for Finland', Publications of the Academy of Finland 2/93, Painatuskeskus, Helsinki, p. 63; Viner, D. and Hulme, M.: Climate Change Scenarios for Impact Studies in the U.K., Climatic Research Unit, University of East Anglia, p. 70.
125. Parry, M.: 1990, Climate Change and World Agriculture, Earthscan, London, p. 157; Carter, T., Holopainen, E., and Kanninen, M. (eds): 1993, 'Techniques for Developing Regional Climatic Scenarios for Finland', Publications of the Academy of Finland 2/93, Painatuskeskus, Helsinki, p. 63; Viner, D. and Hulme, M.: Climate Change Scenarios for Impact Studies in the U.K., Climatic Research Unit, University of East Anglia, p. 70.
126. Admittedly, economists also make extensive use of simple models. Nordhaus, W. D.: 1994, Managing the Global Commons: The Economics of Climate Change, MIT Press, London, p. 213.
127. It might be objected that this is a circular argument, since the status of GCMs in policy derives itself in part from the prominence and credibility of GCMs within science. However, what we are proposing is a process of mutual reinforcement of status in which both processes occur concurrently. (Shackley, S. and Wynne, B.: 1995, 'Global Climate Change: The Mutual Construction of an Emergent Science-Policy Domain', Sci. Publ. Pol. 22(4), 218-230.)
128. It could be countered that versions of the science emphasising the climate system's chaotic nature might act to strengthen the rationale for global environmental policy action, especially if the precautionary principle is accepted. Note, however, that adominant response to the suggestion that the climate system might face abrupt, chaotic and unexpected changes, has been model-based analyses of whether this feature affects our ability to find an optimal solution to the problem of managing climate change. Hence it attempts to re-impose a control and management ethos at a subsequent level, (e.g., see: Lempert, R., Schlesinger, M., and Hammitt, J.: 1994, 'Thelmpact of Potential Abrupt Climate Changes on Near-Term Policy Choices', Clim. Change 26, 351-376). Nevertheless, as James Risbey points out, Palmer's analysis may point to a happy marriage between chaos and GCMs, since the latter are needed to represent regime structure, identify climate attractors and perform ensemble climate forecasts. A similar point has been made by a GCM modeller, who noted that: 'GCMs provide the most practical means of investigating instability, given that the details of the "mean" climate or attractor determine the nature of the instability. ... to get the right answer the detailed shape of the attractor may be important' (personal communication, November 1995).
129. An alternative argument, suggested by one of our referees, is that policy makers are not so much interested in 'good science' as in 'good scientists'. Although we can think of a few scientists who do not personally use GCMs and are also considered within the IPCC to be amongst the leading scientists, they still draw extensively upon GCMs in their provision of scientific advice. Moreoever, none that we can think of departs from the consensus view that GCM s are the 'best' amongst climate models (for the reasons discussed in Section 2.4). This cursory observation does not confirm the argument ether way, but raises the significant question of whether the evaluation of scientists can be divorced from the methods and tools used by those scientists.
130. Many scientists would agree with this of course and it appears to be a major rationale for the development of new integrated assessment models (IAMs) as heuristic tools. However, IAMs are still considered by many scientists to be primitive when compared to GCMs and the extent to which they should be trusted as a aid to decision-making in climate negotiations surely needs to be critically discussed. See also van der Sluijs [33].
131. Young et al. [29].
132. Van Asselt, M.: 1994, Global Integrated Assessment Models as Policy Support Tools, Masters Thesis, University of Twente, Netherlands, p. 94.
133. For example, there is good reason to believe that the overwhelmingly technical framing of the climate change issue structures the policy agenda in a way which fails to engage with the diverse constituencies (such as local government, industry and lay members of the public) whose commitment would be necessary for any serious policy on global climate change. (Macnaghten, P., Grove-White, R., Wynne, B., and Jacobs, M.: 1995, Public Perceptions and Sustainability in Lancashire: Indicators, Institutions and Participation, Lancashire County Council, Preston, p. 96; Macnaghten, P. and Jacobs, M.: 1997, ' Public Identification with Sustainable Development: Investi gating Cultural Barriers to Participation', Global Environ. Change 7(1), 5-24.)
134. For example, there is good reason to believe that the overwhelmingly technical framing of the climate change issue structures the policy agenda in a way which fails to engage with the diverse constituencies (such as local government, industry and lay members of the public) whose commitment would be necessary for any serious policy on global climate change. (Macnaghten, P., Grove-White, R., Wynne, B., and Jacobs, M.: 1995, Public Perceptions and Sustainability in Lancashire: Indicators, Institutions and Participation, Lancashire County Council, Preston, p. 96; Macnaghten, P. and Jacobs, M.: 1997, ' Public Identification with Sustainable Development: Investi gating Cultural Barriers to Participation', Global Environ. Change 7(1), 5-24.)