August 8, 2009

Climate Targets in an Uncertain World

by Matthias G.W. Schmidt, Alexander Lorenz, Hermann Held and Elmar Kriegler

- In this article, we explore how to base mitigation policies on climate targets when uncertainty and learning about uncertainty is being taken into account. Climate targets under uncertainty are most naturally formulated as safety constraints on the risk to violate the target. Cost-effective mitigation strategies can then be found by minimizing costs under this constraint. We show that, for very intuitive reasons, this leads to major conceptual flaws if learning is being taken into account: Costless information might be rejected and climate targets become infeasible. Therefore, we explore other ways than cost-effectiveness to base decisions on climate targets and show their respective strengths and limitations.

Schmidt, M.G.W., A. Lorenz, H. Held and E. Kriegler (2009). "Climate Targets in an Uncertain World." Potsdam Institute for Climate Impact Research, July 2009.