Development of global and national climate policy pathways

For this deliverable, global and national modelling teams developed scenarios reflecting current policies, Nationally Determined Contributions (NDCs), Long Term Strategies (LTS), and mitigation trajectories to limit end-of-century global warming of 1.5 and 2C. Those scenarios are used to assess current progress in climate mitigation and to study implications of the pathways from multiple perspectives: the global level, the national level, associated energy systems and their feasibility, national sectors, and economic costs. Globally, we found that (extended) current policies lead to implementation gaps of 6.4 Gt with NDCs by 2030 and 30 Gt with LTS by 2050. Global energy systems in line with temperature targets contain high shares (32-78%) of renewable energy by 2050. However, associated feasibility concerns should be considered: models could exceed thresholds on the use of bioenergy, for instance. The analysis on economic costs found that when looking at only costs and not including avoided costs and damages, more stringent climate action can have negative effects on GDP, with varying costs or even gains identified across regions and sectors. On a national and regional level, we also found that additional policies are still needed to reach NDCs for most analysed countries, and sector level analyses demonstrated local opportunities for mitigation. Additional to the primary scope of the deliverable we aimed to contribute to future scenario development, by exploring the influence of methods extending the Current Policies and NDC scenarios towards 2100. We found major contrasts between emission pathways resulting from different methods. This version includes an enhanced dataset. The protocol that was used for the development of the scenarios, including a clarification of scenario names, can be found here.