Deliberating beyond evidence: lessons from Integrated Assessment Modelling
Un article consacré à l'incapacité des sociétés à prendre véritablement en charge le défi du développement durable, et aux raisons expliquant ce déficit d'action. Le modèle classique ayant présidé jusque-là au fonctionnement des interfaces science-politique, fondé sur la preuve et la responsabilité, a montré ses limites ; à la logique de la justification ex-post devrait ainsi se substituer un processus de délibération ex-ante (par l'intermédiaire du modèle Integrated Assessment Modelling), permettant d'assurer la transition de la responsabilité au devoir.
Points clés [en anglais] :
CHALLENGING SCIENCE-POLICY INTERFACES
As it explores scenarios of the future, and as we will never have evidence of the future, the use of Integrated Assessment Modelling of economicclimate scenarios challenges the classical model of interface between science and policy-making. In such a classical model of social liability, the quest for ‘evidence’ serves both the validation of results in science and the justification of decisions in politics. This model can be identified as one of the causes of the inability of our societies to tackle the challenge of sustainable development.
FROM EX-POST JUSTIFICATION TO EX-ANTE DELIBERATION
A complete paradigm shift is necessary to fully apprehend the usefulness of Integrated Assessment Modelling to climate policy decisions: the logic of ex-post justification of policy-making should be replaced by the logic of ex-ante deliberation for policy-making. This would require three steps: rehabilitating the concept of policy responsibility as capacity to take position over a certain future and buy an option accordingly; accepting the divorce between rationality and evidence; and abandoning the logic of a reassuring policy control fuelled by comforting science.
THE BURDEN OF DUTY
The dominance of the logic of balancing and compensation that has permeated modelling exercises of cost-benefit analysis of climate policies should leave the floor to a new logic of political positioning. This consists in making policy values and preferences a priori explicit and open to contestation, enabling the comparison of possible future actions and commitments to explicit future benchmarks, thus changing from only a "burden of blame" to also a "burden of duty".
Under such a renovated paradigm of decision-making, the usefulness of Integrated Assessment Modelling fully appears: it consists in indicating how the future may unfold, based on specific assumptions of development of some drivers, changes and actions. Through a new operation called “reverse engineering”, the paper proposes a first exercise that allows the explicit linking of policy preferences and commitments to the future up with specific assumptions adopted in Integrated Assessment Modelling.