Energy and Environment in the 21st Century

Close Icon
These competencies are explicitly fostered and described in Competence View.
These competencies are fostered in this course but are not explicitly described in Competence View. Please contact the responsible person for further information. Competencies in grey are fostered in this course but are generally not the focus of Competence View, which focusses on cross-disciplinary competencies.

The fundamentals of physics make a constructive contribution to the discussion of energy and environmental problems. With the help of up-to-date data and publications, this course takes a very interdisciplinary look at our unsustainable way of life. Students contribute actively, learn to ask the right questions and discover the options for dealing with undesired realities and problems for which no solutions currently exist. They become more aware what their place is and how they can contribute toward the transition to a sustainable future.

The topic has interested me since my high school days in Hamburg and by around 2004, I thought that I had collected enough material to develop a full lecture course at ETH.

Including fundamentals of physics in the energy discussion

The energy and environmental problems (and not just the issues surrounding CO2 emissions) have become a particularly important topic in our society, but I felt that discussions usually did not touch on some of the fundamentals of physics and that this gap needed to be closed.
The course goal is to use scientific methods, and especially the methods used in physics, to define and analyze the future energy problems and, more generally and interdisciplinarily, the problem of our unsustainable way of life.

Avoiding wishful thinking
A key learning objective is how to avoid and reduce subjective and wishful thinking when assessing which unsolved problems can and cannot be solved. Predefined solutions are not provided. Students have to learn to formulate their own arguments and question (hidden) assumptions. This involves a holistic approach and system thinking plays an important role here.


Students must be interested in energy and environmental problems and have a high-school understanding of physics. They also need to be willing to accept facts and undesired realities – which can be a challenge.

At their core, the lectures are based on facts and use a great deal of up-to-date data and numerous publications on the current energy system and its problems and limitations. The standard weekly two-hour lecture (with slides) is accompanied by a one-hour exercise/discussion session

Engaged students due to challenging questions and self-awareness

After overcoming their initial shyness, the students started to ask challenging questions and make constructive comments during the lecture and in doing so made the lecture relatively interactive.

This is highly encouraged by the lecturer and also motivates the lecturer to discuss the topics in much more detail.

  • By being consistent when analyzing the selection and assessment possibilities, students develop integrity and a work ethic.
  • By motivating and inspiring others about the topics discussed, students also develop in terms of their leadership initiative and responsibility
  • The ability to make the right decisions is another key component of the course. This is important when analyzing the proposed and realistic options for the future use of energy.
  • In addition, students can become more service-oriented by showing compassion for others in line with the motto of “we all share the same planet”

Apply physics to socially relevant questions

During the examination, the students present a topic or problem of their choice from the field of energy/the environment. They are then asked various questions to check whether they have considered the topic logically and from all sides. It is important to be able to apply the knowledge of physics to socially relevant questions and to recognise unrealistic promises for the future as such.

Finally, a few more in-depth questions are asked to check whether they have really dealt independently and critically with their own attitude and the different points of view.


We observed a growing number of students (started the autumn lectures in 2005 with around 15 students – record participation in autumn semester 2019 with more than 50 subscribed students).

Students provided positive feedback on the lectures and several students even continue to engage in an active exchange with the faculty years after taking the course.

Lessons learned

  • The course thrives on the active participation of many students during the lectures. They are encouraged to develop their critical thinking skills. The students, however, still find it really challenging to accept the undesired realities.
  • The teacher is required to cover the various discussed topics in greater detail every year. This has resulted in trying to present too much information in most lectures.
  • Such personal exchanges and discussions become more difficult and even impossible to implement on a larger scale. The topics are, on the other hand, interesting for much larger audiences and with different backgrounds to those of natural science students.
  • In conclusion, the current course is designed for groups of 30–40 active participants, however it is also suitable for interested students/participants of all ages and from all backgrounds.
  • There is no need for any special resources. All that is needed is a standard lecture room for at most 30–40 students with a good setup to encourage discussions.

Future plans

Hopefully, the general content of the lectures will be maintained after the upcoming retirement (2021).

Course Description

Energy and Environment in the 21st Century (Part I & II)
Part I: The energy problems and the related environmental issues, the physics principles of using energy and the various real and hypothetical options are discussed from a physicist’s point of view. The lecture is intended for students of all ages with an interest in a rational approach to the energy problem of the 21st century.

Part II: Despite the concepts of sustainability and sustainable development being widely used, there is a clear lack of a scientific definition. In this lecture, we will discuss the various concepts proposed for a move toward sustainability using the laws of nature and scientific methods as a basis.
Part I: Scientists and particularly physicists are often confronted with questions related to the problems of energy and the environment. These lectures try to address the physical principles of the current and future use of energy and the resulting global consequences for the world climate.

Part II: Questions such as the following will be discussed in detail: What is a scientifically useful definition of sustainability? Which aspects of our lifestyles and society are unsustainable? What can we learn from historical examples of societal collapses?
402-0737-00 V & 402-0742-00 V
Lectures & exercises/discussions
D-PHYS students
Teaching Power:
Session examination, oral exam (20 minutes)