Derivation of national paths based on a global path compatible with the 2°C limit
With this web application you can determine a global path which is compatible with the 2° limit. To do so you can set the following parameters:
Reduction rate of CO2 emissions in 2050 compared with 1990
Average annual change 2011 - 2019
Potential global negative emissions
In the next step you can choose a country. Using the Regensburg Formula you can derive national emission paths from a global path, gradually implementing the same per capita emissions. As a result, the reference values of the country chosen are shown for 2030 and 2050, as well as the curve of the per capita emissions.
The reference values depend on the chosen global path. Therefore, we recommend to use the detailed Excel tool in addition. There, you can make more detailed specifications to the global path and read off important features such as the cumulative emissions up to the reference points and the cumulative global negative emissions. The web application is designed to provide an easy start to the topic.
Excel tool for the Regensburg Model
For more options to influence the parameters, please use the detailed Excel tool.
E.g.: You can specify the convergence level. The convergence year arises than from the selected global path. For the global path, four types of scenarios are available. You can choose the change rate of emissions in 2020 as a starting value. Three options are available for population figures (here we have used the figures forecast).
One of the crucial questions in climate protection is who may use up how much of the remaining CO2 budget (approx. 900 Gt from 2015 onwards) in order to comply with the 2°C limit? Do the reported intended national contributions (INDCs) and in Paris agreed improvements of NDCs answer this question satisfactorily?
The Regensburg Model supplies an answer based on a criterion that Angela Merkel, the German Chancellor, postulated as early as 2007: gradually converging per capita rights. Gradually means: based on the realities of the actual emissions of a given country, a per capita distribution ratio is gradually applied until the convergence year (this web application is pre-set the convergence year: 2050), when all rights are distributed at 100% per capita.
Thus, the Regensburg Model represents an approach, seeking a comprmise between fairness and economic aspects. If the ambitions of industrialized countries are under the reference values on the Regensburg Model, then they will be hard pressed to explain what climate justice standard their propositions are based on.
On 10/30/2015 the UN Climate Change Secretariat presented its synthesis report of the INDCs concludingin the result that those are not sufficiently in compliance with the two-degree target. For this reason a process of review and revision (ratchet up mechanism) was agreed upon in Paris starting in 2018. The Regensburg model can offer valuable guidance.
Formulae used in the Regensburg Model:
The reduction rate you have chosen is too low to determine a plausible global emission path with this scenario type. This is why the reduction rate for CO2 emissions in 2050 compared with 1990 was increased to % in order to obtain a plausible curve for 2020 - 2100 with this web application. With the detailed Excel tool, you have more ways to generate a plausible global path; but basically confirm the result shown here.
If you want to use lower reduction rates for emissions in 2050 compared with 1990, you must choose a lower change rate for 2011 - 2019 and/or a higher potential of global negative emissions.
Politicians often discuss the feasibility of a reduction rate of 50% in global emissions by 2050, compared with 1990 (last the German Chancellor at the Petersberg Climate Dialogue 2015). This reduction rate applies generally to all greenhouse gases. It should be communicated more clearly that such a reduction rate applicable to CO2 would only be compatible with the cumulative budget of 2,900 Gt since the onset of industrialisation with massive global negative emissions in the second half of this century.
If you use the "close button" below, the global path with the new value is calculated.
Budget characteristics of CO2
CO2 stays in the atmosphere for a long time, so emissions are accumulated and the effect of global warming persists for years even if the emissions have been reduced. The IPCC considers a cumulative budget of 2,900 Gt CO2 compatible with the 2°C limit, with a probability of over 66% (Synthesis Paper p. 10). Upto and including 2011, abour 1,890 Gt had already been emitted. So an remaining budget of about 1,000 Gt resulting from 2012. At the moment the global emissions are approximately 40 Gt annually. You can even roughly calculate what this means.
Because they provide a more accurate data base for counties, only CO2 emissions resulting from fossile fuels (coal, gas and oil) and cement production are considered (without FOLU emissions) in this application.
Our annual change rate for the base year for the projection upto 2019
With this rate we extrapolated the emissions of the last available year upto 2019. Generally this rate is derived from available historical data (mostly average change 2010 - 2013). It was not possible to test all the resulting rates for future feasibility, so we set an upper limit of 3.5%. It may be appropriate to choose a different rate in individual cases (see separate input field below). In the database, we have deposited individual values for the following countries:
Germany: The basis is the official reduction goal of 40% in 2020 compared with 1990.
EU: The basis is the official reduction goal of 20% in 2020 compared with 1990
China, India and Japan: Based on historical values, change rates of around 8% for China and India and of 5% for Japan have been calculated. These rates no longer seem realistic for a projection upto 2019. However, the assumed rates pose a huge challenge to China and India especially.