Search Results
Paris Climate Agreement passes the cost-benefit test
2020, Glanemann, Nicole, Willner, Sven N., Levermann, Anders
The Paris Climate Agreement aims to keep temperature rise well below 2 °C. This implies mitigation costs as well as avoided climate damages. Here we show that independent of the normative assumptions of inequality aversion and time preferences, the agreement constitutes the economically optimal policy pathway for the century. To this end we consistently incorporate a damage-cost curve reproducing the observed relation between temperature and economic growth into the integrated assessment model DICE. We thus provide an inter-temporally optimizing cost-benefit analysis of this century’s climate problem. We account for uncertainties regarding the damage curve, climate sensitivity, socioeconomic future, and mitigation costs. The resulting optimal temperature is robust as can be understood from the generic temperature-dependence of the mitigation costs and the level of damages inferred from the observed temperature-growth relationship. Our results show that the politically motivated Paris Climate Agreement also represents the economically favourable pathway, if carried out properly.
Taking stock of national climate policies to evaluate implementation of the Paris Agreement
2020, Roelfsema, Mark, van Soest, Heleen L., Harmsen, Mathijs, van Vuuren, Detlef P., Bertram, Christoph, den Elzen, Michel, Höhne, Niklas, Iacobuta, Gabriela, Krey, Volker, Kriegler, Elmar, Luderer, Gunnar, Riahi, Keywan, Ueckerdt, Falko, Després, Jacques, Drouet, Laurent, Emmerling, Johannes, Frank, Stefan, Fricko, Oliver, Gidden, Matthew, Humpenöder, Florian, Huppmann, Daniel, Fujimori, Shinichiro, Fragkiadakis, Kostas, Gi, Keii, Keramidas, Kimon, Köberle, Alexandre C., Aleluia Reis, Lara, Rochedo, Pedro, Schaeffer, Roberto, Oshiro, Ken, Vrontisi, Zoi, Chen, Wenying, Iyer, Gokul C., Edmonds, Jae, Kannavou, Maria, Jiang, Kejun, Mathur, Ritu, Safonov, George, Vishwanathan, Saritha Sudharmma
Many countries have implemented national climate policies to accomplish pledged Nationally Determined Contributions and to contribute to the temperature objectives of the Paris Agreement on climate change. In 2023, the global stocktake will assess the combined effort of countries. Here, based on a public policy database and a multi-model scenario analysis, we show that implementation of current policies leaves a median emission gap of 22.4 to 28.2 GtCO2eq by 2030 with the optimal pathways to implement the well below 2 °C and 1.5 °C Paris goals. If Nationally Determined Contributions would be fully implemented, this gap would be reduced by a third. Interestingly, the countries evaluated were found to not achieve their pledged contributions with implemented policies (implementation gap), or to have an ambition gap with optimal pathways towards well below 2 °C. This shows that all countries would need to accelerate the implementation of policies for renewable technologies, while efficiency improvements are especially important in emerging countries and fossil-fuel-dependent countries.