Séminaire NANCY – Aurélie Méjean (CNRS, CIRED)

Détails de l'événement :

“Unexpected ethical consensus for averting catastrophic climate change”

Abstract: Abrupt, extreme, irreversible changes to the climate may cause discontinuities to socio-economic systems, possibly leading to a sharp decline of human population and consumption per capita. Using an integrated assessment model, we show that even a very small risk of such catastrophic climate change warrants stringent climate policies. Our results conform with the well-known conclusion that tight carbon budgets are preferred when aversion towards inequalities between generations is low. We show that stringent policies are also optimal when inequality aversion is high. This contrasts with previous studies which typically find that with high inequality aversion, it is optimal to shift the burden of climate change mitigation towards future generations, who are assumed to be richer. Our unusual result is due to the fact that high inequality aversion makes the scenario of a small and relatively poor population (obtained when mitigation is low) especially unattractive. We also show that the size of the optimal carbon budget decreases with the social preference for large populations. We thus identify ethically-robust climate policies, as new spaces of compromise between contrasted ethical stances may emerge to set ambitious climate policies.