Web app Regensburg Model:
Calculation of Paris-compatible emission paths with converging per capita emissions
In the Regensburg Model, national emission paths are derived from a global emission path using the Regensburg Formula which leads to converging per capita emissions (see publications below).
In the results produced by the Regensburg Model, particular attention should be paid to the national CO2 budgets or the implicit weighting of the population (IWP) that results from converging per capita emissions.
In the Regensburg Model, six scenario types (RM 1 - 6) are offered to derive global emission paths that adhere to a predefined CO2 budget. Here is a brief description of the scenario types.
Important framework data in the following web app (these can be freely set in the detailed Excel tool; see below):
- Global CO2 budget 2020 - 2100 (see information in the respective app):
- 400 Gt,
- 550 Gt or
- 650 Gt.
- Separate CO2 budgets at global level 2020 - 2100:
- Land-use change (LUC): 0 Gt
- International shipping and aviation (ISA): 3% of the global remaining budget (roughly the current share of global emissions)
- Potential for global net negative emissions and thus for a volume overshoot: Minimum global CO2 emissions by 2100 -0.7 Gt (-2% of global emissions in 2019)
- Convergence level: 0.5 t per capita
When you select a country, you can see the resulting emission paths, reference values and other key figures.
In the corresponding sheet you can see the underlayed global paths.
Notes:
- The emission paths cover CO2 emissions from fossil fuel use (excluding international shipping and aviation; ISA) and cement production. ISA and land-use change (LUC) are therefore not covered. Budgets are reserved for these two fractions at the global level (see this paper on the LUC budget).
- As a budget of zero Gt was set for LUC for the period 2020 - 2100, corresponding net negative CO2 emissions must be achieved in the LUC sector in order to offset any net positive CO2 emissions in this area.
- CO2 neutrality must be achieved before climate neutrality, as net negative CO2 emissions are required to offset, for example, unavoidable methane and nitrous oxide emissions from agriculture. These net negative CO2 emissions must be provided in addition to the net negative CO2 emissions (overshoot) shown here.
- Since the focus here is on what national CO2 budgets would result for the countries in the event of converging per capita emissions and a distribution of a global CO2 budget from 2020 on, actual emissions after 2019 are not taken into account in the emission paths.
- An important indicator in the Regensburg Model is the implicit weighting of the population (IWP), which is the same for all countries depending on the scenario type chosen for the global path and the convergence level chosen. The respective IWP is specified for each scenario type in the app. In general, the more ambitious the global path at the beginning, the higher the IWP. More information on IWP can be found here. The corresponding sheet shows the national CO2 budgets resulting from the IWP for all countries in the world.
Detailed Excel tool
You can download the detailed Excel tool at: https://doi.org/10.5281/zenodo.5846043.
Some publications on the Regensburg Model
► The Regensburg Model: reference values for the (I)NDCs based on converging per capita emissions, journal 'climate policy', 
; published 2016
► Calculation of Paris-compatible emission targets for the six largest emitters with the Regensburg Model, ; published on Zenodo
► Distribution of a Global CO2 Budget - A Comparison of Resource Sharing Models, ; published on Zenodo
Global remaing CO2 budgets
Here are key statements by the IPCC on remaining global CO2 budgets.