[en] What is Direct Air Carbon Capture and Storage (DACCS) and can the method become a game changer in climate policy? We answer these and other questions in this policy brief.

[en] With the revision of the Climate Protection Act in 2021, Germany has, among other things, set the binding long-term target of becoming greenhouse gas neutral by 2045. This means that the use of fossil fuels is to be completely avoided, in particular by exploiting energy efficiency potentials and a complete switch to renewable energy sources. In this respect, a broad consensus has developed that a GHG-neutral energy supply, even in the case of a high degree of electrification, efficiency, flexibility, storage and sector coupling, will additionally rely on GHG-neutral gaseous energy carriers. The question therefore arises whether certain paths with regard to the use of renewable gases are preferable and how the phasing out of fossil natural gas and the future use of renewable gases can be shaped. Against this background, this study examines the gas infrastructure and the options for its development within the framework of the German government's energy and climate protection targets, and develops strategic guidelines for the necessary infrastructural course-setting for gaseous energy carriers. The aim of this study is to give an overview of the trasnformation from natural gas to hydrogen infrastructures in a compact form. In doing so, the main milestones, obstacles, regulatory and technical adaptation requirements in the course of the transformation pathway are presented, taking into account the application range of hydrogen and the timing of the arising hydrogen demand.

[en] This report presents marginal abatement cost curves (MACCs) for greenhouse gas emissions in the stationary part of the European Union Emissions Trading Scheme (EU ETS) for the years 2030 and 2040, covering all 31 countries participating in the EU ETS (including the UK) and all relevant activities/sectors with the exception of the aviation sector. The development of the EU ETS-specific MACCs was based on a system of two models: Enertile, a model to optimise the European electricity system and FORECAST-Industry, a bottom-up simulation model for the industrial sectors including refineries. In addition to a base scenario, three sensitivity analyses were carried out to verify the robustness of the results. This report contains the developed MACCs, the results of the sensitivity analyses as well as a detailed description of the models used and assumptions made to allow the interpretation of the MACCs. In addition, the results were compared with other studies and the main methodological and substantive challenges in the development of MACCs are discussed.

[en] With the Paris target of limiting global warming to well below 2 °C until 2100, at best even 1.5 °C, the question arises what this implies for the EU’s mitigation targets and strategies. In this article, the reduction of carbon intensities and energy uses in the most ambitious mitigation scenarios for the EU, France, Germany, Italy, and the UK are compared to those of the EU in global 1.5 and 2 °C scenarios. An index decomposition analysis is applied to energy supply and each end-use sector (industry, buildings, and transport) to identify the main differences. From this, we derive conclusions concerning policies and indicators for an EU mitigation strategy compatible with limiting global warming to 1.5 °C. The index decomposition shows that reducing energy use is a stronger lever in the evaluated national scenarios than in the international scenarios for all end-use sectors. The reasons for that are the lower utilization of CCS, the inclusion of additional technology options, and a detailed consideration of sufficiency in the national scenarios. The results suggest that including more ambitious demand-side mitigation options (sufficiency, energy efficiency, electrification, and fuel switching) can significantly reduce the need for negative emissions that are required in all the existing 1.5 °C-compatible global scenarios. Driving these options requires substantial enhancement of current policies for all end-use sectors. In addition, certain index decomposition approaches are shown to underrate the long-term contributions of demand-side mitigation. Accordingly, demand-side mitigation tends to be under-represented in progress indicators for the Paris Agreement, which calls for improvements.

[en] Considering the importance of national climate change mitigation scenarios for ambitious climate change mitigation policies, a profound understanding of national concepts for reducing greenhouse gas emissions and of the underlying measures is crucial. This report summarises the results of a research project which scrutinises climate change mitigation scenarios from six EU member states and elaborates a set of criteria for their evaluation. Based on two scenarios, the study exemplarily demonstrates the application of the criteria set. Building upon this, the study shows aspects which are central for establishing climate change mitigation scenarios as basis for the development of long-term strategies in the transformation towards a carbon-neutral society.

[en] Climate protection scenarios are an important basis for long-term climate protection planning. The modelling, which is often carried out in extensive studies, is a central source of information for decision makers and stakeholders in the development of climate protection strategies. This report outlines a catalog of criteria for the systematic evaluation of long-term climate protection scenarios. The criteria were selected on the basis of four guiding questions relating to the degree of reduction envisaged, the way in which this reduction is achieved, the contextual conditions and the methodological strength of the underlying modeling.

[en] Given that the Paris Agreement has strengthened the long-term temperature goal and that it calls for a balance of greenhouse gas (GHG) emissions and sinks within the 21st century, there is the urgent need to re-assess the long-term targets of the EU and to show how the target of GHG neutrality can be reached in the EU. The aim of this study was to design one way to realize a European Union with net-zero greenhouse gas emissions under further sustainability criteria. The scenario shows that a GHG-neutral EU is feasible, based on a fully decarbonized energy supply, without carbon capture and storage. Key components of the scenario in all energy-consuming sectors are a strong increase in energy efficiency as well as far-reaching electrification. The use of bioenergy is strongly limited.

[en] This report presents a thorough analysis of drivers for decarbonization in different scenario studies. Selected baseline and emission reduction scenarios from a range of studies on the EU, including some EU member states, were analysed to generate insights into: - Which decarbonization strategies exist? - Which sectors already show a clear decarbonization strategy? - In which sectors is the decarbonization strategy less obvious or clear as significantly different and mutually excluding strategies are researched? - Are there sectors where decarbonization is particularly difficult and which are those? - What issues have not been addressed in the existing scenarios so far? Besides a generic comparison a decomposition analysis was applied to these scenarios to identify key drivers for changes in emissions in the scenarios. The studies under consideration include at least one ambitious climate protection scenario, and provide a sufficient level of detail with regard to the quantitative results to allow for applying the framework of the analysis. In addition to an analysis of total energy-related CO${}_2$ emissions, this study analyses major energy-related sectors on the supply and demand side: electricity supply, industry, tertiary, residential and transport (where possible differentiated by passenger and freight). A comparison of findings and a synthesis along with a detailed data appendix complete the report.

[en] This document presents the final report of the project ''Efficiency and effectiveness of the EU ETS - extended analyses (EU-ETS 6)''. The project aims to deliver further contributions for the evaluation of the efficiency and effectiveness of the European Emission Trading System (ETS). In doing so, the project provides advice to the Federal Environmental Agency (UBA), as implementing authority, and the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) as the competent ministry, on methodological aspects of ex-post assessments and lessons learned for ex-ante analyses. The project builds on a previous study, titled ''Evaluierung und Weiterentwicklung des EU-Emissionshandels (EU-ETS- 5)''. The current project focusses on methodological approaches for an ex-post assessment of the effects of the EU ETS and introduces different ''Tier'' levels reflecting different scopes of complexity. The core of each analysis is to compare estimated abatement costs under the EU-ETS with cost estimates for a fictitious ''alternative policy scenario'' that aims to achieve the same total abatement but does not provide the flexibility of trading allowances. Case studies are conducted based on marginal abatement cost curves derived from a partial equilibrium model and from bottom-up models for the industry and the electricity sector respectively. Besides the different modelling approaches, the case studies differ essentially in the design and assumptions chosen with respect to the i) counterfactual scenarios, ii) alternative policy scenario, iii) sector detail, iv) abatement costs and CO₂-prices and v) temporal perspective. An efficiency analysis of the ETS always implies a trade-off between breadth and depths of the analysis. Yet, the case study analyses all reveal efficiency gains for the ETS compared to an alternative policy. For example, the Tier 2 analysis -covering a medium level of detail - investigated different sector disaggregation and different time frames for the 2^nd trading period and concluded that 15% to 50% of abatement costs were saved within the ETS compared to the alternative policy scenario. Emissions trading thus leads to important efficiency gains according to these estimates.

[en] An intensive debate has been taking place for some time about what role gaseous energy sources – natural gas as well as biogenic and renewable gases – should play in the energy transition in the longer term. A consortium made up of Fraunhofer ISI (coordinator), the Deutscher Verein der Gas- und Wasserwirtschaft e.V. (DVGW)* (association of the German gas and water industry) and the DVGW Research Centre at Engler-Bunte-Institute (EBI) of Karlsruhe Institute of Technology addressed this issue within the project “Gas Roadmap for the Energy Transition – A Sustainable Climate Contribution of the Gas Sector”. The objective was to identify upcoming challenges in the gas sector. This final report analyses the medium- and long-term contribution of the gas sector to climate protection for different levels of greenhouse gas reduction, the associated challenges in terms of infrastructure, and the resulting key measures and adaptation requirements. On this basis, strategic guidelines for policy course changes in the transformation process are summarized in a roadmap.