Martin Kowarsch

KlimaschutzpolitikKlimaschutz ist eine Wette: Eine ehrgeizige Verminderung klimaschädlicher Treibhausgasemissionen kann auch dann gerechtfertigt werden, wenn die Wahrscheinlichkeit katastrophaler Folgen des Klimawandels gering ist. Je niedriger die Kosten der Vermeidung und je höher die möglichen materiellen und immateriellen Schäden eines ungebremsten Klimawandels sind, umso sinnvoller ist es, eine ambitionierte Klimapolitik umzusetzen (Edenhofer/Jakob 2017). Die Klimapolitik beschränkt dabei die zuvor freie Nutzung der Atmosphäre als Treibhausgasdeponie und macht sie zu einem regulierten globalen Gemeinschaftsgut.

There are some fundamental perils for the role of the sciences in policy, which also affect economic assessments. Based on a discussion of these perils, this chapter identifies the key challenge of bridging scientific expertise and public policy. Section 3.1 provides the background for this by describing that in practice, neither scientific knowledge production nor political decision-making follow simple rationalistic and functionalist ideals. Rather, multiple (often conflicting) motives are involved in, for instance, scientific assessment-making. Yet, scientific assessments can have some desirable influence on policy-making processes if certain requirements are met. Section 3.2 introduces the fundamental problems and perils of scientific policy advice. One of the most challenging issues is the treatment of value judgements, particularly in policy assessments; this issue endangers sound science, policy-relevance and political legitimacy. Section 3.3 provides some examples in terms of existing criticism of the Intergovernmental Panel on Climate Change (IPCC), and, finally, Sect. 3.4 identifies the trade-offs between the general norms for scientific expertise in public policy as being the key challenge of scientific expertise in policy. The framework for the IPCC envisaged in this book has to successfully respond to this key challenge.

This chapter aims to analyse the normative-ethical assumptions implied in the structure and scenarios of integrated assessment models (IAMs), as well as the IAM-based studies used in the recent assessments by the Intergovernmental Panel on Climate Change (IPCC). This will be done according to the framework developed in Sect. 7.3 which claims transparency and balance. I focus particularly on aspects related to objective functions in IAMs, i.e., on welfare economic issues. Section 8.1 discusses the predominant views of the relationship between welfare economics, ethics and values. Since these views have a considerable impact on the welfare economic assumptions of IAMs, one should be aware of them. Then, some fundamental assumptions of mainstream economics underlying welfare economics – i.e., the assumed rationality of agents in markets – are examined (Sect. 8.2). Based on that, the more specific analysis of IAMs regarding welfare issues can be undertaken (Sect. 8.3). Moreover, Sect. 8.4 briefly discusses other ethically interesting aspects of IAMs that serve as additional examples of the value-laden IAM economics of climate change. It is concluded that at least some disputable ethical value judgements in IAM-based studies are still relatively opaque and one-sided – which makes life more difficult for the authors of assessment reports (Sect. 8.5).

Deepening the problem analysis of the previous parts, Part III analyses both the Working Group (WG) III contribution to the Assessment Reports (ARs) of the Intergovernmental Panel on Climate Change (IPCC) (in Chap. 10 ) and the underlying economics of climate change (in this chapter, 8 and 9 ). This chapter will introduce: (1) the economics of climate change (Sect. 7.1), while pointing out the diversity of possible problem framings (and methods) in the economics of climate change; (2) the integrated assessment models (IAMs) as its main methodical tools in the IPCC WG III AR4 and AR5 (Sect. 7.2); and (3) three evaluation criteria for the critical reflection on the IAM-based literature (Sect. 7.3), including a framework for identifying normative assumptions in economics to make them more transparent. The evaluation criteria will mainly build on the refined pragmatic model of scientific expertise in policy from Chap. 6, as the tentative ends-in-view for Part III. (4) Finally, the policy-relevance of the IAM-based literature will be briefly discussed (Sect. 7.4). IAMs can contribute a lot to the important topic of the costs, risks and benefits of global mitigation goals.

Science-policy models guide the practice of the Intergovernmental Panel on Climate Change (IPCC) and other science-policy institutions. Such science-policy models are primarily about the general competence, responsibility and legitimate role of scientific experts, policymakers and other players at the science-policy interface. The central question of Part II is how well they help tackle the key challenge at the science-policy interface, i.e. help comply with the four general norms for expertise in policy (Part I)? The results of the evaluation and refinement of the predominant science-policy models will both contribute to the envisaged framework for the IPCC assessments on a more general level, and serve as useful “lenses” for the more specific evaluation of the integrated economic assessments of the IPCC (Part III). This chapter introduces the decisionist, the technocratic, the pragmatic and the legitimisation models of the role of scientific expertise in policy; these four models are prevalent in practice. Section 4.1 explains core common characteristics of these prevalent models. The systematic analysis of the four models – particularly their philosophical assumptions on scientific knowledge – as potential tools to realise the general norms for expertise in policy follows in Sect. 4.2. Finally, Sect. 4.3 explains how the analysis and evaluation of these models can be used for the evaluation of the IPCC’s work.

Part IV identifies (in this chapter), and reflects on (in Chap. 12 ), some elements of a more specific guideline for improving the integrated economic assessments by the Intergovernmental Panel on Climate Change (IPCC). This is based on the preceding analysis of the challenges faced by these assessments (Parts I–III). A short check list for integrated economic assessments summarises the key recommendations (Sect. 11.1). Section 11.2 addresses the question of what information we want the IPCC to provide in its next assessments. The IPCC should map alternative policy pathways and their implications even more comprehensively and specifically. More specific proposals for the appropriate treatment of disputed value judgements and uncertainties in IPCC assessments are given next (Sect. 11.3). It is also argued that the multi-scenario analyses should more explicitly explore disputed ethical viewpoints. Then, potential improvements of the IPCC’s processes, formats and public participation are discussed (Sect. 11.4). Finally, Sect. 11.5 argues that the scientific community could better support the IPCC assessments.

The decisionist and technocratic models of scientific expertise in policy are critically evaluated in this chapter regarding their potential to address the major pitfalls of scientific expertise in policy. The mistaken philosophical assumption of a fact/value dichotomy, which is underlying these two traditional science-policy models, is identified as the main weakness of these models. The assumption that factual statements and (ethical) value judgements can be neatly separated in policy-relevant research is crucial for these models and a necessary precondition for their understanding of scientific objectivity. However, there is an inevitable fact/value entanglement in scientific statements; values, including ethical ones, permeate all experience and scientific knowledge. Hence, the decisionist and technocratic models cannot ensure that expertise in policy-making processes is reliable for everyone. Instead, due to their mistaken assumption of fact/value separability, they often lead to a misguided use or even misuse of expertise in policy in terms of the legitimisation model. Consequently, the decisionist and technocratic models are unable to realise the general norms developed in Sect. 2.1.

KlimaschutzpolitikKlimaschutz ist eine Wette: Eine ehrgeizige Verminderung klimaschädlicher Treibhausgasemissionen kann auch dann gerechtfertigt werden, wenn die Wahrscheinlichkeit katastrophaler Folgen des Klimawandels gering ist. Je niedriger die Kosten der Vermeidung und je höher die möglichen materiellen und immateriellen Schäden eines ungebremsten Klimawandels sind, umso sinnvoller ist es, eine ambitionierte Klimapolitik umzusetzen (Edenhofer/Jakob 2017). Die Klimapolitik beschränkt dabei die zuvor freie Nutzung der Atmosphäre als Treibhausgasdeponie und macht sie zu einem regulierten globalen Gemeinschaftsgut.

While economic and other social science expertise is indispensable for successful public policy-making regarding global climate change, social scientists face trade-offs between the scientific credibility, policy-relevance, and legitimacy of their policy advice. From a philosophical perspective, this book systematically addresses these trade-offs and other crucial challenges facing the integrated economic assessments of the Intergovernmental Panel on Climate Change. Based on John Dewey’s pragmatist philosophy and an analysis of the value-laden nature and reliability of climate change economics, the book develops a refined science-policy model and specific guidelines for these assessments of climate policy options. The core idea is to scientifically explore the various practical implications of alternative climate policy pathways in an interdisciplinary manner, together with diverse stakeholders. This could facilitate an iterative, deliberative public learning process concerning disputed policy issues. This volume makes novel contributions to three strands of the literature: the philosophy of science in policy; the philosophy of economics; and debates about the design of scientific assessments, including the continuous IPCC reform debate. This work is thus interesting for philosophers and other scholars reflecting on the science-policy interface, but also for assessment practitioners, climate policy-makers, and economists. The science-policy approach developed in this volume has already influenced the recent socio-economic IPCC assessment.

This chapter identifies some challenges, strengths and weaknesses of Working Group (WG) III contributions to the Assessment Reports (ARs) of the Intergovernmental Panel on Climate Change (IPCC). The focus is on the Fourth (AR4) and Fifth (AR5) assessment cycle of the IPCC. For this purpose, the evaluation criteria and heuristic tools developed in Part II are employed, along with the results of the critical analysis of the underlying economics in Chaps. 7, 8 and 9. Evaluating the IPCC WG III contributions in this way will help us identify the appropriate means of improving IPCC assessments. This chapter argues that in the AR4, both the policy-relevance and the transparency of ethically relevant assumptions could have been higher. This may partly result from the adherence to misguided science-policy models. The AR5 was an improvement in these regards, but faced challenges inter alia in terms of (i) considerable research gaps regarding retrospective, social-science policy analysis, and (ii) political disputes over value-laden findings with far-reaching implications for domestic policies. All things considered, however, both the AR4 and the AR5 did a good job. In contrast to some existing criticisms, there is no clear case of a considerable hidden bias in these WG III ARs, for instance towards more ambitious global mitigation goals.

This chapter concludes the enquiry of this book into a new guideline for integrated economic assessments. The proposals for future integrated economic assessments made in Chap. 11 are briefly evaluated (Sect. 12.4) in light of the assumed direct effects of these proposals regarding the general norms for scientific expertise in policy from Part I (Sect. 12.1), risks and unwanted side effects (Sect. 12.2), and possible co-benefits (Sect. 12.3). This discussion can be regarded as Step 4 of a Deweyan enquiry; it is about evaluating (1) the means proposed for overcoming the problems of current integrated economic assessments by the Intergovernmental Panel on Climate Change (IPCC), and (2) perhaps even the underlying general norms for scientific expertise in policy themselves – in light of the possible practical implications of these means. It is argued that realising the proposals from Chap. 11 may have several valuable positive effects, including on deliberative policy learning, while perhaps also facing some remaining challenges regarding feasibility and acceptance. Gaps in research and potential applications of the proposals to institutions other than the IPCC are discussed in Sect. 12.4. Finally, the thoughts on a philosophy-based framework for future integrated economic assessments developed in the present book are summarised (Sect. 12.5).

Can the pragmatic science-policy model cluster that emphasises democratic public participation and deliberation ensure reliable, politically legitimate and useful scientific assessments, despite the implied ethical and social value judgements? Section 6.1 will analyse the weaknesses of some variations of the pragmatic model cluster, including substantial open questions with regard to scientific objectivity. In order to philosophically substantiate the possibility of objective knowledge despite the value judgements involved, Sect. 6.2 will introduce pragmatist philosophy in the tradition of John Dewey and Hilary Putnam as a fundamental, convincing philosophy of science, epistemology and meta-ethics. Pragmatism combines anti-scepticism with fallibilism and fact/value entanglement. Some implications of this philosophy are discussed in Sect. 6.3, before Sect. 6.4 develops a refined variation of the pragmatic science-policy model based on this Deweyan-Putnamian pragmatism. In a highly interdisciplinary manner, and jointly with stakeholders and the public, this refined pragmatic model suggests (i) careful exploration of alternative problem framings and (ii) critical reflection on different policy ends and means in light of the practical implications of the means (while making disputed ethical assumptions transparent). This may require a substantial revision of initial policy goals if the best available means have severe side effects. The four general norms for scientific expertise in policy (Sect 2.1.3 ) may be realisable when employing this refined pragmatic model.

This chapter provides an overview of the book, with its essential relevance and approach (Sect. 1.1). The novelty and timeliness of this study are also highlighted (Sect. 1.2). Scientific assessments are valuable as tools to inform the public on complex policy issues such as climate change where so much is at stake for so many people. However, guidance is still lacking at the science-policy interface where there are perils lurking. These include the treatment of disputed normative implications in much of the social-science evaluation of policy options. Currently, taking account of this and other challenges, a central open question for many large-scale scientific assessments is whether and how to strengthen and extend social-science policy evaluation to appropriately inform public policy. This book develops a novel philosophical framework for the appropriate role of social-science expertise, particularly economics, in climate policy. The focus is on the integrated economic assessments of the Intergovernmental Panel on Climate Change. The work mainly adds to the existing body of literature by refining John Dewey’s pragmatist philosophy of scientific expertise in public policy, and systematically applying this philosophy to integrated economic assessments.

This chapter evaluates the scientific and epistemic quality of integrated assessment models (IAMs) and related economic studies in light of Deweyan-Putnamian pragmatism. This is mainly done by analysing the treatment of three different types of uncertainty (in a broad sense), explained in Sect. 9.1. Section 9.2 discusses technical and methodological uncertainties in IAM-based economic studies. Next, the fundamental methodology underlying IAM-based economic studies is critically discussed from an epistemological perspective, and some refinements are proposed from a Deweyan perspective (Sect. 9.3). The conclusion (Sect. 9.4) regarding the overall reliability of IAM-based results is neither that IAM-based studies provide us with absolutely true knowledge, nor that we, from an epistemological perspective, should completely disregard such economic results in policy-making. Instead, a more enlightened use of uncertainty-laden economic models including IAMs is the goal, based on a revision of economic methodology in light of Deweyan-Putnamian pragmatism. A critical reflection on the predominant viewpoints in economic methodology is indispensable because it is in a worrisome state; economists often cannot compellingly explain what their results mean from a philosophical-epistemological perspective. Pragmatism (Sect. 6.2 ) might help overcome the disorientation of current economic methodology in several regards, without returning to the dogmatism of positivist methodology.

This chapter indicates the need for appropriate integrated economic assessments to support climate policy-making. A normative point of departure for this is John Dewey’s concept of a scientifically well-informed, collective regulation of indirect consequences of human actions – as the essence of “the public” (Sect. 2.1). From this Deweyan philosophy of deliberative democracy, a few (widely accepted) general norms for the role of the desired scientific expertise in policy can also be derived: sound science, policy-relevance, good communication and political legitimacy. Employing Dewey’s political philosophy, I argue that integrated economic expertise, if it complies with the general norms for expertise in policy, is urgently needed to adequately understand and design complex climate policy where so much is at stake for so many (present and future) people (Sect. 2.2). This is particularly, although not exclusively, true for climate change mitigation where many socially relevant aspects are still poorly understood. Section 2.3 introduces the highly influential Intergovernmental Panel on Climate Change (IPCC) and its integrated economic assessments, particularly those of IPCC Working Group III, on which this book will focus.