2°C or Not 2°C?

Céline Guivarch (1) , Stéphane Hallegatte (1, 2)

1 CIRED - centre international de recherche sur l'environnement et le développement
2 CNRM - Centre national de recherches météorologiques

Political attention has increasingly focused on limiting warming to 2°C. However, there is no consensus on both questions "Is the 2°C target achievable?" and "What should be done with this target that becomes increasingly difficult to achieve?". This paper aims at disentangling the points of deep uncertainty underlying this absence on consensus. It first gives simple visualizations of the challenge posed by the 2°C target and shows how key assumptions (on the points of deep uncertainty) influence the answer to the target achievability question. It then proposes an "uncertainties and decisions tree", linking different beliefs on climate change, the achievability of different policies, and current international policy dynamics to various options to move forward on climate change.

Mots clés: feasibility of 2°C target; climate change negotiations; deep uncertainty

Domaines: Economies et finances

Céline Guivarch, Stéphane Hallegatte. 2°C or Not 2°C?. Global environmental change:Human and policy dimensions, 2013, 23 (1), pp.179-192. ⟨10.1016/j.gloenvcha.2012.10.006⟩. ⟨halshs-00750704⟩