Dirk Messner studied at the Otto Suhr Institute of Freie Universität Berlin, where he also completed his doctorate and professorial teaching qualification (Habilitation). In 2020, he became president of the German Environment Agency. In this interview, he explains how the debate around sustainability has changed in recent years – and what it will take to keep the transition on track.

Mr. Messner, in politics and society, perceptions of the importance of the sustainability transition have changed dramatically since 2019. Although ambitious climate protection continues to be an urgent task demanding action, sustainability no longer seems to be part of the narrative of progress. To what extent is this impression accurate?

I would share that impression. The European Green Deal (EGD), championed by the conservative EU Commission President Ursula von der Leyen, was Europe’s “Man on the Moon” project at the beginning of the 2020s. Europe wanted to demonstrate how securing prosperity and social progress are possible even while staying within the limits of ecosystems. Just a few years later, the EGD is coming under immense pressure and even losing support. And you are right: environmental research worldwide shows that planetary crises are intensifying. Institutions like the German Environment Agency are once again becoming Cassandras, whereas in the early 2020s, the implementation of ambitious environmental and climate policies as the core of our economic modernization was
the primary focus.

To which factors is this development primarily attributable?

Three sets of causes are decisive here: First, the European economy is in a difficult condition; boosting the economy’s innovative capacity must be aligned with the EGD’s core objectives. In parts of the political, business, and social spheres, ambitious climate protection is now primarily viewed as an additional burden on the economy. Russia’s war against Ukraine, the Gaza conflict, and the erratic policies of the Trump administration have also led the EU to massively increase its investments in (particularly military) security, thereby limiting the scope for investment in the transition to sustainability. The dual crisis of recession and security threats creates a climate of fixation on the present, preserving the status quo, and hinders future-oriented structural change.

Second, citizens’ political priorities have shifted. From 2018 to 2020, environmental and climate policy were at the top of their agenda. Now, citizens find that other concerns are more pressing and should take precedence. The UBA Environmental Awareness Study from 2025 shows that people are now primarily concerned about the erosion of the health and education systems as well as internal security. Such shifts are also linked to the crises of democracy. Many people feel that the state is no longer fulfilling its core responsibilities. The social contract between citizens and politics is becoming fragile. As a result, environmental and climate issues seem “secondary” to many citizens.

Third, the EGD transformation has created “second-order problems” for which policymakers were not sufficiently prepared. For instance, the sustainability transformation creates a variety of distribution and equity issues that have not been adequately addressed. In Germany, for example, the “heating bill debate” was an expression of the feeling that many people cannot afford climate policy. Furthermore, the transformation places high demands on the state’s capacity to act.

Today I would say: Without a massive modernization of the public sector, the transition to sustainability cannot succeed. The debate on “reducing bureaucracy” must be steered in this direction: How can ambitious climate and environmental policy function with the leanest possible regulatory burden?

Are there also examples of successful transformation processes? If so, what can we learn from these successes?

Yes, there have also been successes. Renewable energies are on a global expansion trajectory that even many optimists could not have imagined ten years ago. Fossil fuel investments are losing significance: A solid 70 percent of new investments in the global energy sector are going into renewables. The challenge here is to phase out the existing fossil fuel infrastructure by around 2050. Yet fossil fuel capacities are being defended, in some cases very successfully, by established lobbying alliances. The debate over phasing out internal combustion engines or the pressure to maintain gas and oil heating systems fit into this context. Interests of the present and past are often better organized than those of the future.

The energy transition was once the flagship project of Germany’s sustainability transformation. How do you assess the current state of affairs, including in an international context?

The energy sector is the driving force behind climate neutrality. Our projections show that we can achieve key goals of the energy transition if we continue to work ambitiously: 80 percent renewables in the electricity mix by 2030 is achievable; a 65 percent reduction in greenhouse gas emissions between 1990 and 2030 is within reach. In addition to the continued expansion of wind and solar energy, in the energy sector the current focus is on investments in the overall energy supply system: grids, storage capacities, digital control, and green hydrogen potential as a backup to renewables. These are the levers for building a climate-neutral energy sector by 2045. However, our projections also show that if the German government’s commitment to the green transition in the energy sector wanes and supposed freedom to choose among all technologies leads to rising emissions once again, the energy transition could still fail. We can also now learn from China as a forerunner in several respects. The country is investing enormous sums to move beyond the fossil fuel foundations of its energy supply by mid-century.

What role will the ETS 2 emissions trading system, planned for 2027, play in future climate protection?

The ETS 2 system will introduce emissions pricing in the building and mobility sectors. Unfortunately, it was recently postponed until 2028 because many EU member states are concerned that sufficient mechanisms have not yet been developed to cushion the costs for citizens, particularly for vulnerable groups. The UBA has proposed solutions for a socially equitable design of ETS 2. We propose a socially differentiated climate allowance, supplemented by targeted support for particularly vulnerable groups, both of which could be financed from the revenues of CO2 pricing. We should promise the bottom 50 percent of the income pyramid that they will not be financially worse off as a result of the introduction of ETS 2. The ETS 2 toolkit is very important for climate protection, because we have not been meeting our climate targets in the building and mobility sectors so far. That could change with ETS 2, but only if the social design is successful in all member states. There is still much to be done.

In your opinion, which areas of action are the largest causes for concern?

I have already mentioned mobility and buildings. Beyond that, I am highly concerned about ecosystems. A large portion of emissions is stored in the oceans and terrestrial ecosystems. If these ecosystems fail to act as “sinks,” it will further accelerate global warming. Studies worldwide show that ecosystems in many places are themselves becoming sources of greenhouse gases or that their capacities as sinks are eroding. This could apply, for example, to the Amazon rainforest region. Another potential risk lies in the tipping points within the Earth system. These include, for example, the melting of the Greenland ice sheet, the collapse of the monsoon system, or the thawing of permafrost. A decade ago, most of these tipping points were thought to lie beyond the three-degree warming threshold. New studies point to increasing probabilities that tipping points could already be triggered at around two degrees. Such a change in the Earth system represents a challenge for future generations that is still largely misunderstood.

How can science and universities help address the problems identified? In particular, what special challenges do you see for science communication?

Without research, we cannot understand the dynamics of climate and Earth system change. Research is our telescope into conceivable futures. Research is also the foundation for solutions to address planetary crises. At the same time, university education in these fields is indispensable for societies to remain capable of taking action. Science communication is becoming even more important. We have seen that technocratic transformation strategies fail because people cannot understand what they are intended to achieve. Science must make itself understandable to society and policymakers. “Science for scientists,” which neglects to communicate research findings to society, undermines research’s shared responsibility for society’s problem-solving capabilities.

You have served on a number of high-level political Advisory Committees on sustainability transformation. If you could travel back in time, would you advise policymakers differently with the knowledge you have today?

I have drawn three lessons from 30 years of scientific policy advising: First, I mentioned ‘second-order problems of the transition to sustainability.’ Today, I would attribute significantly greater importance to them. Second, environmental and climate challenges can only be solved through interdisciplinary, transdisciplinary, and international collaboration. I would say that there is significant room for improvement in all three dimensions. Third, in the sustainability transformation community, we assumed that planetary issues would represent the central challenge of the 21st century. Now we see three further, profound dynamics of change (tectonic plates, so to speak) that have begun to shift. It appears as though we are dealing with four ‘major transformations’ that must be understood and addressed in their interplay. In addition to the sustainability transformation, we observe: the comprehensive crisis of democracy in the core countries of democracy; the erosion of the international system, in an age of global interconnectedness, which could lead to a renaissance of imperial structures in world politics; the power and reach of AI-driven disruptions, which challenge all subsystems of our local, national, and global societies and the role of humans in the process of civilization. There is still much work to be done in the field of scientific policy advising.

Judith Hübner, Katrin Schweigel, and Andreas Wanke conducted the interview on March 12, 2026.
It first appeared in Freie Universität Berlin’s 2026 Sustainability Report.