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Paths to climate neutrality in 2045

Making the energy transition cost-efficient

The new federal government is still in the process of forming, but one thing appears certain: the goal of achieving climate neutrality by 2045 remains in place. Researchers from the Kopernikus project Ariadne have calculated the costs of achieving this goal. According to their findings, the required investments will largely be offset by reduced expenditure on fossil fuels.

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Climate-damaging subsidies in transport undermine CO₂ pricing

A reward of several hundred euros for a ton of CO₂

The Ariadne calculations emphasise that Germany’s current tax system in the transport sector is still dominated by the use of fossil fuels, making it more difficult to achieve the country’s climate targets.

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Mapping variation in institutions for climate policymaking

Effective climate governance through strong climate institutions

In a report, Ariadne researchers offer reform options for German climate institutions in the context of the Klimaschutznovelle.

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Political consensus for EU emissions trading for heat and transport

Fair design and economically efficient price

In two recent publications, Ariadne experts have analysed various design options, specifically looking at the carbon pricing and relief options, and identified the advantages and disadvantages of each.

Kopernikus project Ariadne

The red thread through the energy transition

Research strategies and politicy instruments for effective climate protection

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Europe & Green Deal

Ariadne@Brussels 2025: Insights into the conference ‘EU climate and energy policy in a polarising world’

This years iteration of the Ariadne@Brussels workshop series took place in Brussels EU Quarter from 8 to 10 December 2025. Researchers from the Ariadne project presented their latest findings on EU climate and energy policy and discussed them in …

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Europe & Green Deal, Industrial transition

CO₂ pricing and subsidies alone are insufficient: Create lead markets for industrial transformation

In a new analysis, Ariadne researchers propose instruments to create lead markets for the emission-intensive basic materials cement, steel and ethylene.

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Europe & Green Deal, Transport transition

Role of hybrid vehicles in EU fleet mix questionable: very high CO₂ emissions

A real-world consumption data from around 850,000 vehicles across Europe shows that PHEVs are rarely charged, the combustion engine is used too often, and even in mainly electric mode, fuel consumption is considerable.

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Heating transition, Electricity Transition, Transport transition, Europe & Green Deal, Governance & Institutions, Industrial transition

New edition of Ariadne@Brussels launched: ‘EU climate and energy policy in a polarising world’

The Kopernikus project Ariadne invites you to this year’s edition of the Ariadne@Brussels workshop series. From 8 to 10 December 2025, researchers from the Ariadne project will present their latest findings on EU climate and energy policy and discuss …

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Industrial transition, Heating transition, Electricity Transition, Transport transition, Distributive justice, Hydrogen, Europe & Green Deal, Governance & Institutions, Scenarios, Tax reform

New Ariadne paper highlights EU climate policy from 2030 onwards

The EU is in the midst of a debate on new climate targets for 2040 and how the competitiveness of industry can be linked to decarbonization. In a new background paper, Ariadne researchers analyze the historically evolved energy and …

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Our topics

Wege zur Klimaneutralität

Paths to climate neutrality

Making climate policy work: From individual sectors to a perspective on systems, Ariadne explores options by uniquely combing systemic consistency and sectoral detail.

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Mobility of the future

Transport transition

Ariadne researches technologies and policy options for the transport transition in Germany, involving citizens from the outset.

Heliberto Arias / Unsplash

Clean and affordable energy supply

Electricity transition

Ariadne develops policy instruments and technologies for the electricity transition, taking citizens’ perspectives and goals into account.

Electricity transition

Federico-Beccari / Unsplash

Driving forward the transformation of the heating sector

Heating transition

Ariadne investigates barriers to transforming the buildings heating sector and which economic, regulatory and informational instruments can be used to overcome them.

Julian Hochgesang on Unsplash

Transformation of production processes

Industrial transition

In dialogue with stakeholders, scenario analyses and concrete options for action are developed for a climate-friendly and competitive industry in Germany.

Industrial transition

Maxim Tolchinskiy on Unsplash

An energy carrier of the future

Hydrogen

From supply potential to costs, from fields of application to uncertainties and risks, from imports to infrastructure, Ariadne provides an overview of the possible role of hydrogen for the energy transition.

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From energy tax to environmental tax

Tax reform

Stabilising the economy while directing investments toward climate protection, Ariadne explores short-term energy tax reforms and long-term restructuring of the tax system for equitable burden-sharing.

StellrWeb on Unsplash

Coordinated and effective policy management

Governance

The energy transition needs institutions for effective governance. Ariadne explores climate policy planning and coordination between the political institutions, actors and levels involved.

Governance

Moritz Lüdtke / Unsplash

Integration of the German energy transition

Europa & Green Deal

Ariadne informs policy-makers on which instruments should be reviewed and which reforms should be initiated to ensure effective carbon pricing across the EU.

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Paths to climate neutrality

Transport transition

Electricity transition

Heating transition

Industrial transition

Hydrogen

Tax reform

Governance

Europa & Green Deal

Publications

Analysis | Industrial transition | Hydrogen | Europe & Green Deal | 04.12.202504.12.2025

Analysis: Lead markets for the industrial transformation – Implementation proposals for instruments to increase demand for climate-friendly basic materials (Summary)

Lead markets, in which climate-friendly basic materials are purchased despite higher costs due to their product property, can complement the existing policy mix for a competitive and climate-neutral industry.

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Analysis | Europe & Green Deal | Transport transition | 06.11.202518.11.2025

Analysis: Real-world Fuel Consumption and Potential Future Regulation of Plug-In Hybrid Electric Vehicles in Europe – An Empirical Analysis of about one Million Vehicles

Actual real-world fuel consumption of Plug-In Hybrid Electric Vehicle (PHEV) in Europe slightly increased to around 6.0 to 6.2 l/100 km between the registration years 2021 and 2023 for both gasoline and diesel PHEVs. At the same time, type-approval fuel …

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Report: A cost-efficient energy transition: Scenarios for climate neutrality 2045 – Summary

Summary Climate change is not slowing down. In 2024, two significant records were set: for the first time, the global mean temperature exceeded +1.5 °C above pre-industrial levels (Copernicus Climate Change Service, 2024), and global CO2 emissions reached a new …

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Background: Staying the course in turbulent times – Insights on the current state and ways forward for the EU’s climate, energy and finance policy architecture

With the Fit for 55-package, the EU increased the ambition level of its energy and climate targets for 2030. The targets reflect the EU’s commitment towards an energy system transformation – or, in fact, the transformation of the entire …

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Analysis | Hydrogen | Europe & Green Deal | Industrial transition | 05.06.202505.06.2025

Ariadne-Analysis: Hydrogen in the Reformed EU ETS – Implications for Competitiveness and Emissions Reductions

The use of renewable hydrogen is considered an important element for the decarbonization of sectors that are hard to electrify, such as the steel and chemical industry or aviation (European Commission 2020, Ferrario et al. 2022). However, the volume …

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Our News

Ariadne@Brussels 2025: Insights into the conference ‘EU climate and energy policy in a polarising world’

CO₂ pricing and subsidies alone are insufficient: Create lead markets for industrial transformation

Role of hybrid vehicles in EU fleet mix questionable: very high CO₂ emissions

New edition of Ariadne@Brussels launched: ‘EU climate and energy policy in a polarising world’

New Ariadne paper highlights EU climate policy from 2030 onwards