Paris-compatible National CO2 Budgets for the Six Major Emitters Based on the Regensburg Model with Converging Per Capita Emissions

CO2 accumulates in the atmosphere. Therefore, the sum of future emissions is crucial for meeting Paris climate targets. This inevitably raises the question: what are Paris-compatible national CO2 budgets, especially for the major emitters?

This paper gives an answer to this question by showing exemplary national CO2 budgets for the major emitters. The national CO2 budgets are derived top-down from a globally remaining CO2 budget with the help of the Regensburg Model, which is based on converging per capita emissions. In addition, the Regensburg Model provides an implicit weighting of the population depending on the chosen convergence level, which can be used for any country in the world, for example in our Extended Smooth Pathway Model (ESPM).

The results of the Regensburg Model are highly significant if converging per capita emissions are generally recognised as a target.

The Paris Ambition Mechanism is based on a bottom-up approach. However, if the national targets are not Paris-compatible in sum, the question arises whether national targets represent an adequate contribution to the necessary global efforts.

We expect that the discussion of Paris-compatible global framework data and different distribution keys for a remaining global CO2 budget can make a significant contribution to achieving overall Paris-compatible NDCs.

Simplified web apps for the

• Regensburg Model: http://RM.climate-calculator.info
• Extended Smooth Patway Model (ESPM): http://national-budgets.climate-calculator.info