In the polarized climate change debate, cost-benefit analyses of policy options are taking on an increasingly influential role. These analyses have been presented by authoritative scholars as a useful contribution to the debate. But models of climate – and especially models of the impact of climate policy – are theorists’ tools, not policy justification tools. The methods used to appraise model uncertainties at best give optimistic lower bounds on the true uncertainty, at best. Even in the finest modelling exercises, uncertainty in model structure is presented as known and manageable, when it is likely neither. Numbers arising from these modelling exercises should therefore not be presented as ‘facts’ providing support to policy decisions. Building more complex models of climate will not necessarily reduce the uncertainties. Indeed, if previous experience is a guide, such models will reveal that current uncertainty estimates are unrealistically small.

SALTELLI Andrea;  STARK Philip B.;  BECKER William Edward;  STANO Pawel; 

2015-08-10

NATL ACAD SCIENCES

JRC94904

0748-5492,   

http://issues.org/31-3/climate-models-as-economic-guides-scientific-challenge-or-quixotic-quest/,    https://publications.jrc.ec.europa.eu/repository/handle/JRC94904,