Fairness- and cost-effectiveness-based approaches to effort-sharing under the Paris agreement. Short study: On behalf of the German Environment Agency; Environmental Research of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety. Project No. (FKZ) 3717 41 102 0 – short study within the project „Implikationen des Pariser Klimaschutzabkommens auf nationale Klimaschutzanstrengungen“ Report No. FB000249/ZW,KURZ,ENG

Abstract

Given that the Paris Agreement (PA) has strengthened the long-term temperature goal and that it calls for a balance of greenhouse gas (GHG) emissions and sinks within the 21st century, there is the urgent need to re-assess the climate targets worldwide. On top of that, the PA stresses that contributions from the states have to reflect “the highest possible ambition” and “respective capabilities”. This study has derived national GHG emissions reduction contributions for 2030 and 2050 that are consistent with the Paris Agreements’ long-term temperature goal, both based on fairness and cost-effectiveness approaches. The analysis focuses on countries that are particularly relevant because of their share in global GHG emissions and their role in international climate policy, namely Brazil, Canada, China, the EU, India, Japan the United States of America, and Germany respectively. The comparison of these approaches yields insights whether or not a country can or should in-crease the ambition of its NDC. The data can also be taken to show how large the efforts in the country domestically should be and to indicate the need for support to or from other countries. The analysis reveals for both approaches, that the more ambitious long-term temperature goal of the Paris Agreement results in substantially higher reduction requirements for all countries compared to the former Cancun targets