Always interested in science as a young boy, I never wanted to use fossil energy because it is a non-renewable resource, and burning fossil fuels creates harmful gases. The first decision I took was not to drive a car as long as cars use combustion engines. Some compromises became necessary: For my academic career, I decided to take some intercontinental flights. I also started to use air travel for private holidays, once or twice a year. When I bought an old house, it took some years before I could replace the oil heating by an electric heat pump with geothermal probe. Flying remained the largest part of my personal carbon footprint.

In 2017, I decided to completely stop flying, both in my professional and my private life. When invited to an international conference which is not reachable by train and ferry, I offer to provide my talk via videoconferencing. If this is not accepted, I don’t participate. If we as researchers in the field of sustainability don’t start reducing our personal carbon emissions, who else will do it?