The latest available scientific information is contained in the International Panel on Climate Change’s (IPCC’s) Sixth Assessment Report Climate Change 2021: The Physical Science Basis. According to the IPCC definition, 67% likelihood of a 1.5 °C increase in global temperature is ‘good’, whereas 50% likelihood is ‘fair’. The One Earth Climate Model (OECM) aims to limit the global mean temperature rise to 1.5 °C with ‘good’ likelihood. Therefore, the ‘science-based target’ for the OECM 1.5 °C pathway, in terms of the global carbon budget between 2020 and 2050, is set between 400 Gt CO2 (67% likelihood) and 425 Gt CO2 (60% likelihood). The development of sectoral targets to meet the requirements of specific countries or industries will ensure that the sum of all energy-related CO2 emissions for all countries or industry sectors does not exceed the global budget. Therefore, any approach undertaken in isolation, such as for a single industry sector, will involve the risk that one industry sector will demand a high CO2 budget and push the responsibility to reduce CO2 emissions onto other sectors.
The One Earth Climate Model
The OECM is an integrated energy assessment model that was originally developed in an interdisciplinary research project between the University of Technology Sydney (UTS), the German Aerospace Centre (DLR), and the University of Melbourne between 2017 and 2019. The task was to develop detailed 1.5 °C-targeting energy-related greenhouse gas (GHG) emissions trajectories for 10 world regions. OECM 1.0 was developed based on established DLR and UTS energy models.
Based on the OECM, the Institute for Sustainable Futures, UTS (UTS-ISF), in close co-operation with the UN-convened Net Zero Asset Owners Alliance, developed the advanced One Earth Climate Model (OECM 2.0), which has been applied to all member states of the G20 and the EU27 region, to develop energy scenarios and fair carbon budgets for each country, as well as detailed carbon budgets for key industries in each country.
The Global Industry Classification Standard (GICS) was used in OECM 2.0 to allow the design of energy and emissions pathways for clearly defined industry sectors (sectoral pathways). Developing pathways via which to reduce the CO2 emissions of industry sectors requires very high technical resolution in the calculation and projection of the future energy demand for and supply of the electricity, (process) heat, and fuels that are necessary for (for example) the steel and chemical industries. An energy model with high technical resolution must be able to calculate the energy demand based on either projections of the sector-specific gross domestic product (GDP) or market forecasts of material flows, such as the demand for steel, aluminium, or cement in tonnes per year.
Carbon budget for the EU27 Member States
The EU27 carbon budget of about 32 GtCO2 (2020-2050) has been broken down further by developing an OECM 1.5 °C pathway for each of the member states. The scenario data for all individual countries are available on the open-access project webpage (www.uts.edu.au/oecm). In this section, we present the distribution of the EU27 carbon budgets. Figure 2 shows the carbon budget for each country between 2020 and 2050 in million tonnes of carbon dioxide (CO2) and each country’s share (as a percentage) of the overall EU carbon budget of 32.1 GtCO2.
The CO2 budgets must be related to the population shares within the European Community to ensure the fairness of this distribution.
The ratio of the CO2 budget share to the population share is similar across most EU countries, within a ± 20% margin. However, some countries emit significantly higher proportions of global CO2 relative to their populations, whereas others emit lower proportions.
The ‘high-carbon’ countries, with carbon budgets 30%–50% greater than their population shares, are Cyprus, Czechia, Finland, Luxembourg, the Netherlands, and Poland.
Cyprus has an extremely carbon-intensive power-generation mix, based almost entirely on diesel and oil generators. This is not only the most polluting fossil-fuel-based technology for electricity generation but also one of the most expensive. The transition to renewables-based generation—mainly solar photovoltaic—with battery storage is expected to take more than 10 years, which explains the high carbon budget of Cyprus. Power generation in Czechia and Poland is heavily dependent on coal. Therefore, both countries start with a carbon-intensive power supply that significantly exceeds the EU average. Luxembourg and Finland have very high per capita GDPs, and relatively high energy demands per capita as well. The Netherlands has a significant chemical industry, which is a very energy-intensive industry.
The carbon shares of Germany and Italy are within ± 15% of their population shares, so they represent countries with balanced carbon budgets.
Portugal has among the lowest carbon budgets relative to its population size due to its already large share of renewable power generation.
The OECM takes the current situation of the energy demands for industries and service-based economies, the building stock, and the transport sector of each country into account and includes the status quo of the energy supply. Therefore, the carbon budgets of economies with already low carbon intensities will be smaller. However, this is not a disadvantage, but actually an advantage insofar as those countries are ahead on the road to decarbonization of countries with higher carbon intensities. Therefore, the energy transition of advanced countries and their decarbonization can be reached more rapidly.
The results of the OECM scenario for the EU27 (as a region) are compared with the EU Taxonomy. The following sections document a detailed analysis of the EU Taxonomy and how the OECM pathways can be utilized to implement and advance it in the future.
The EU taxonomy and the One Earth Climate Model
The EU Taxonomy was introduced as a classification system to help companies and investors classify sustainable investment decisions. It does not set mandatory targets, but companies falling under the Corporate Sustainability Directive (CSRD) must disclose their alignment with the Taxonomy in their annual reports.
In this research, we present the congruence between the current European Taxonomy and the 1.5 °C pathways of the OECM, to provide decarbonization pathways for real economic sectors. By integrating OECM data with the EU Taxonomy, we aim to help EU member states set ambitious targets to meet a 1.5 °C global temperature increase and to improve the reporting of their achievements, and to develop an international context for countries outside the EU.
One Earth Climate Model
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MethodologiesRead about the different methodologies used to determine energy demand, supply, how to define Scope 1, 2 and 3 emissions and renewable energy potential assessments.
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DashboardSee the OECM 1.5°C pathways for G20 members and their industry sectors. Explore energy demand and supply developments until full decarbonisation in 2050.
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Sectoral pathwaysThe OECM on the development of 1.5°C net-zero pathways for industry sectors classified under the Global Industry Classification Standard (GICS).
