Ottmar Edenhofer

• Potsdam Institute for Climate Impact Research

Zusammenfassung Dieser Beitrag spiegelt die in englischer Sprache gehaltene Thünen-Vorlesung von Ottmar Edenhofer auf der Jahrestagung des Vereins für Socialpolitik am 16. September 2024 in Berlin unter dem Titel „The (Missing) Third Pillar“ wider. Der Klimaökonom zeigt auf der Basis der gemeinsamen Forschung mit Matthias Kalkuhl, dass die internat...

Das ehrgeizige Ziel des Paris-Abkommens von 2015, einem Protokoll zur Klimarahmenkonvention der Vereinten Nationen von 1992, die Erderhitzung auf wesentlich unter 2°C (wenn möglich 1,5°C) zu begrenzen, ist nur noch erreichbar, wenn wir ein vorübergehendes Überschreiten dieser Grenze in Kauf nehmen. Mit dem Leuchtturmprojekt Green Deal beabsichtigen...

Net-zero commitments have become the central focal point for countries to communicate long-term climate targets. However, to this point it is not clear to what extent conventional emissions reductions and carbon dioxide removal (CDR) will contribute to net-zero. An integrated market for emissions and removals with a uniform carbon price delivers th...

Preprint of the paper: Döbbeling-Hildebrandt, Miersch, Khanna, Bachelet, Bruns, Callaghan, Edenhofer, Flachsland, Forster, Kalkuhl, Koch, Lamb, Ohlendorf, Steckel, Minx. Systematic review and meta-analysis of ex-post evaluations on the effectiveness of carbon pricing. Nat Commun 15, 4147 (2024). https://doi.org/10.1038/s41467-024-48512-w

The crises of both the climate and the biosphere are manifestations of the imbalance between human extractive, and polluting activities and the Earth’s regenerative capacity. Planetary boundaries define limits for biophysical systems and processes that regulate the stability and life support capacity of the Earth system, and thereby also define a s...

Carbon dioxide removal from the atmosphere is becoming an important option to achieve net zero climate targets. This paper develops a welfare and public economics perspective on optimal policies for carbon removal and storage in non-permanent sinks like forests, soil, oceans, wood products or chemical products. We derive a new metric for the valuat...

Zusammenfassung Steuern und Abgaben auf Produkte oder Verbrauch mit gesellschaftlichen Folgekosten (externe Kosten) – sogenannte Pigou- oder Lenkungssteuern – sind ein gesellschaftliches „Win-Win-Instrument“. Sie verbessern die Wohlfahrt und schützen gleichzeitig die Umwelt und das Klima. Dies wird erreicht, indem umweltschädigende Aktivitäten eine...

We develop a model of optimal taxation and redistribution under an ambitious climate target. We take into account vertical income differences, but also explicitly capture horizontal equity concerns by considering heterogeneous energy efficiencies. By deriving first- and second-best rules for policy instruments including carbon and labor taxes, tran...

The war in Ukraine lays bar EU’s dependence of fossil fuel imports from Russia. Here, we use a global computable equilibrium model, C3IAM/GEEPA, to estimate CO2 emission and GDP impact of embargoing fossil fuels from Russia. We find that embargoes induce more than 10% reduction of CO2 emissions in the EU, and slight increases of emissions in Russia...

To achieve the goals of the Paris Agreement, massive investments in the real economy are needed. We propose providing long-term interest subsidized loans to companies investing in sustainable projects with the primary goal of greenhouse gas neutrality. In detail, we propose linking loan interest rates to the EU Taxonomy and to future CO2 prices. Th...

Wealth inequality is rising in high-income countries. Can increased public investment financed by higher capital taxes counteract this trend? We examine how such a policy affects the distribution of wealth in a setting with distinct wealth groups: dynastic savers and life-cycle savers. Our main finding is that this policy always decreases wealth in...

Zusammenfassung Im Jahr 2021 wurde in Deutschland die sogenannte CO 2 -Bepreisung fossiler Kraft- und Brennstoffe eingeführt, um deren Verbrauch zum Zwecke des Klimaschutzes zu reduzieren. Dieser Preisaufschlag auf fossile Energieträger wird in den kommenden Jahren sukzessive erhöht. In diesem Beitrag untersuchen die Autoren die Akzeptanz der CO 2...

The stringency of the EU's Emission Trading System (ETS) is bound to be ratcheted-up to deliver on more ambitious goals as formulated in the EU's Green Deal. Tightening the cap needs to consider the interactions with the Market Stability Reserve (MSR), which will be reviewed in 2021. We analyse these issues using the model LIMES-EU. First, we exami...

The year 2020 marks the centennial of the publication of Arthur Cecil Pigou’s mag-num opus The Economics of Welfare. Pigou’s pricing principles have had an endur-ing influence on the academic debate, with a widespread consensus having emerged among economists that Pigouvian taxes or subsidies are theoretically desirable, but politically infeasible....

Pathways toward limiting global warming to well below 2 ∘C, as used by the IPCC in the Fifth Assessment Report, do not consider the climate impacts already occurring below 2 ∘C. Here we show that accounting for such damages significantly increases the near-term ambition of transformation pathways. We use econometric estimates of climate damages on...

Der Rat für Nachhaltige Entwicklung und die Nationale Akademie der Wissenschaften Leopoldina haben angesichts der epochalen Herausforderung der Klimakrise ein gemeinsames Positionspapier erarbeitet, das ausgewählte übergeordnete Optionen für das Gelingen der notwendigen großen Transformation unserer Wirtschafts- und Lebensweise auf dem Weg zur Klim...

Voluntary participation can improve multilateral environmental governance. We model voluntary participation of states in unanimously approved federal environmental policy. A Pareto-improving federal emission price coexists with state-level emission pricing. Federal revenues are distributed equally per capita (egalitarian), in proportion to states'...

The large majority of climate change mitigation scenarios that hold warming below 2 °C show high deployment of carbon dioxide removal (CDR), resulting in a peak-and-decline behavior in global temperature. This is driven by the assumption of an exponentially increasing carbon price trajectory which is perceived to be economically optimal for meeting...

The social cost of carbon is a central metric for optimal carbon prices. Previous literature shows that inequality significantly influences the social cost of carbon, but mostly omits heterogeneity below the national level. We present an optimal taxation model of the social cost of carbon that accounts for inequality between and within countries. W...

The COVID-19 pandemic continues to strongly affect global energy systems. Global power sector CO2 emissions have shown a substantial decline, thanks to (a) the COVID-19-induced economic downturn and resulting reduction of electricity demand and (b) a decrease of carbon intensity of power generation as coal generation is decreased most strongly. The...

The Paris Agreement calls for a cooperative response with the aim of limiting global warming to well below two degrees Celsius above pre-industrial levels while reaffirming the principles of equity and common, but differentiated responsibilities and capabilities¹. Although the goal is clear, the approach required to achieve it is not. Cap-and-trade...

To measure how moral behaviour interacts with pricing regimes, we conduct highly controlled experiments in which trading creates pollution. We compare indirect pricing (here, a cap and trade mechanism) and direct pricing (a tax) in an otherwise equivalent setting in which ‘producers’ are incentivized to emit CO2. ‘Judges’ decide on central trading...

Should economic growth continue in a world threatened by the prospect of catastrophic climate change? The scientific and public debate has brought forth a broad spectrum of views and narratives on this question, ranging from neoclassical economics to degrowth. We argue that different positions can be attributed to underlying differences in views on...

Phasing out coal requires expanding the notion of a ‘just transition’ and a roadmap that specifies the sequence of coal plant retirement, the appropriate policy instruments as well as ways to include key stakeholders in the process.

Deutschland hat im Rahmen der EU-Ratspräsidentschaft die Chance, einen neuen Aufbruch der europäischen Klimapolitik einzuleiten. Die völlige Umstellung unserer Energiesysteme mit dem Ziel der Treibhausgasneutralität bis Mitte des Jahrhunderts ist dabei ein wichtiges und richtiges gesamtgesellschaftliches Projekt. Das Ziel ist leicht zu beschreiben,...

With its upcoming presidency of the EU Council, Germany has the opportunity to set European climate policy on a new path. The complete transformation of our energy systems with the aim of greenhouse gas neutrality by the middle of the century is an important and appropriate project involving our entire society. While it is easy to state the target,...

Synergistically addressing local and global environmental damages rather than optimizing a specific aspect of the policy conundrum helps to effectively foster climate action in road transport while maintaining public acceptance and socially fair outcomes.

Voluntary participation can improve multilateral environmental governance. We develop a theory of voluntary participation in federal environmental policy by states of differing wealth. Using a general equilibrium model, we formalize voluntary participation by a Pareto-improving federal emission price that coexists with state-level emission pricing....

Germany has an ambitious climate target for 2030 that cannot be achieved without reducing the high share of coal in power generation. In the face of this, the government has recently decided to directly phase out coal capacity. Yet implementing such a policy comes with two important risks: (1) the decommissioning path might actually be insufficient...

One challenge in addressing transboundary problems such as climate change is the incentive to free-ride. Transfers from multilateral compensation funds are often used to counteract such incentives, albeit with varying success. We examine how such funds can change the incentive to free-ride in a global public-goods game. In our game, self-interested...

Zusammenfassung Das Klimaschutzgesetz hat einen Paradigmenwechsel eingeleitet: den Einstieg in eine CO 2 -Bepreisung als künftiges Leitinstrument der Klimapolitik. Auf den ersten Blick ist der CO 2 -Preis unter einer Fülle von Fördermaßnahmen und ordnungsrechtlichen Regelungen verschüttet, deren Wirksamkeit und Kosten höchst unsicher sind. Der CO 2...

Passing federal environmental policy reform is a challenge as the approval of interest groups such as consumers and state-level governments is often a prerequisite. Among others, the burden sharing's progressivity has a large impact on reform approval. We investigate how carbon tax payments by states to a federal authority are influenced by differe...

Global mitigation efforts remain insufficient to limit the global temperature increase to well below 2 °C. While a growing academic literature analyzes this problem, perceptions of which obstacles inhibit goal attainment and which responses might be most effective seem to differ widely. This makes prioritization and agreement on the way forward dif...

We show how normative standpoints determine optimal taxation of wealth. Since wealth is not equal to capital, we find very different welfare implications of land rent-, bequest-and capital taxation. It is mainly land rents that should be taxed. We develop an overlapping generations model with heterogeneous agents and calibrate it to OECD data. We c...

Several years of very low allowance prices in the EU emissions trading scheme (ETS) have motivated calls to introduce a price floor to correct potential underlying distortions and design flaws, including (i) the political nature of allowance supply and related credibility issues, (ii) potential myopia of market participants and firms, and (iii) wat...

Economic development in sub-Saharan Africa has increased carbon emissions and will continue to do so. However, changes in emissions in the past few decades and their underlying drivers are not well understood. Here we use a Kaya decomposition to show that rising carbon intensity has played an increasingly important role in emission growth in sub-Sa...

Las reformas fscales verdes contribuirían a la mitigación del cambio climático, incrementarían la efcacia de los sistemas tributarios nacionales y generarían ingresos públicos adicionales. Algunos países en América Latina ya han dado los primeros pasos hacia ellas. Este artículo de opinión brinda una visión general de los desafíos más importantes p...

Different energy sources have different spillovers on economic development and industrialization. Pathways of economic development based on renewable energy sources might require additional policies to support industrial development.

Economic rents have long been identified as an efficient tax base. In addition, the recent literature documents that rent income is highly concentrated and that rents are quickly increasing. Rent taxation thus seems attractive for reasons of both efficiency and equity. Nevertheless, rent taxation remains a marginal topic in research and policy maki...

Over the last decade, the EU has pursued a proactive climate policy and has integrated a significant amount of renewables into the energy system. These efforts have proved successful and continuing along this pathway, increasing renewables and improving energy efficiency, would not require substantial policy shifts. But the EU now needs a deeper en...

Increasing the use of renewable energy (RE) is a key enabler of sustainable energy transitions. While the costs of RE have substantially declined in the past, here we show that rising interest rates (IRs) can reverse the trend of decreasing RE costs, particularly in Europe with its historically low IRs. In Germany, IRs recovering to pre-financial c...

Humans today face two global challenges – underprovision of basic public goods and overuse of the atmosphere. Carbon pricing could address both problems. Flipping the switch from negative to positive carbon prices could generate revenues to finance the Sustainable Development Goals (SDGs). Given the scarcity of private sources of finance in many lo...

Despite increasing empirical evidence of strong links between climate and economic growth, there is no established model to describe the dynamics of how different types of climate shocks affect growth patterns. Here we present the first comprehensive, comparative analysis of the long-term dynamics of one-time, temporary climate shocks on production...

Green fiscal reforms would contribute to climate change mitigation, increase the economic efficiency of national tax systems and provide additional public revenues. Some countries in Latin America have already taken first steps towards green fiscal reforms. This outlook article provides an overview of the major challenges for the successful impleme...

Today, more than ever, ‘Spaceship Earth’ is an apt metaphor as we chart the boundaries for a safe planet¹. Social scientists both analyse why society courts disaster by approaching or even overstepping these boundaries and try to design suitable policies to avoid these perils. Because the threats of transgressing planetary boundaries are global, lo...

Non-technical summary Global land is turning into an increasingly scarce resource. We here present a comprehensive assessment of co-occuring land-use change from 2000 until 2010, compiling existing spatially explicit data sources for different land uses, and building on a rich literature addressing specific land-use changes in all world regions. Th...

Das Kopernikus-Projekt ENavi hat im Forschungsschwerpunkt Transformation des Stromsystems untersucht, wie der Stromsektor zur Erreichung der Klimaziele beitragen kann. Aktuell gilt es, den Kohleausstieg ökonomisch effizient und ökologisch zu organisieren. Seine Ergebnisse hat das Team der von der Bundesregierung eingesetzten Kommission für Wachstum...