This report presents a methodology aiming to identify the greenhouse gas emission reduction levels for 2040 and the corresponding greenhouse gas emission budgets for 2030–2050 necessary to achieve the Paris targets for maximum global temperature increases of 1.5 °C and well below 2 °C.
Crucial to the Paris climate goals: higher 2040 greenhouse gas reduction targets per country
The achievement of the global climate goals of the Paris Agreement depends on the collective action by individual nations, reflected in their nationally determined contributions (NDCs). NDCs contain national mitigation targets, climate plans and measures, and were first submitted in the lead-up to the Conference of the Parties (COP) 21 in Paris (2015). To ensure continuous progress, the Paris Agreement established a ratcheting process for evaluating and enhancing the NDCs, over time. Parties were requested to submit new NDCs by 2020, as was done for COP26 in Glasgow, and will be required to do so every five years thereafter (e.g. by 2025, 2030). In this context, greenhouse gas reduction targets for 2040 become increasingly important.
Exploring greenhouse gas emission reduction levels and budgets using the IPCC scenario database
Such long-term targets can be explored with recently developed long-term low greenhouse gas emission pathways calculated from global Integrated Assessment Models. For this study, we used the least-cost mitigation scenarios for 1.5 °C and 2 °C from Integrated Assessment Models of the latest IPCC’s Sixth Assessment Report scenario database. The study focuses on five major emitting economies (the European Union 27, China, India, Japan and the United States) and the world as a whole. We have downscaled the original emission pathways at the regional level for these five major economies and further harmonised the emission data with national inventory data. The results from the study can inform policymakers on the necessary emission reductions for 2040 and greenhouse gas emission budgets for 2030–2050.
Two parts: methodology and final publication
This study will be presented in two parts, with this report intended to discuss the methodology for selecting global and regional pathways from the IPCC AR6 database with experts. The final publication will present the overall study with results based on the agreed methodology.