National contributions and deep decarbonization trajectories: a pragmatic approach.

Summary In contrast to the top-down approach that prevailed until the Copenhagen conference, the Paris Agreement is built on a bottom-up approach in which countries are free to set their own decarbonization targets through Intended Nationally Determined Contributions (INDCs). This text presents the carbon value implicit in each of these contributions by 2030 for the 13 countries with the highest greenhouse gas emissions, representing 75% of global emissions. These are compared to the carbon values implicit in the long-term national emissions levels of the Deep Decarbonization Pathways (DDP) project, which has enabled the development of national trajectories compatible with a global 2°C pathway. For each country, the gap between the implied carbon value of the INDCs and the emission levels of the DDP project is considerable. This shows that the ambition of national contributions will have to be significantly revised upwards in the next negotiation rounds. We also emphasize the central role that long-term national decarbonization trajectories will have to play in the definition of INDCs to ensure that the medium-term constraints of the INDCs are consistent with the long-term options incorporating the 2°C objective.