Since the very beginning in 1951, the Lindau meetings were dedicated to medicine, chemistry and physics. But when the Royal Swedish Academy of Sciences and the Nobel Foundation in 1968 agreed to take on a new prize in economic sciences to the memory of Alfred Nobel, the Laureates of this prize were also invited to Lindau. Ragnar Frisch, one of the two co-Laureates who received the new prize when it was given for the first time in 1969, lectured at the Lindau meeting already 1971. During the 1970’s, several of the new economic Laureates visited the meetings, but the second to give a formal lecture was Tjalling Koopmans 1982. By the time he came to Lindau he had regained his gold medal, which was mixed up with the medal of his co-Laureate Leonid Kantarovich in 1975 and which spent four years in the Soviet Union before returning to the west! Koopmans was a former theoretical physicist who seemed to feel at home with the physicists at the 1982 meeting. Among many other things, he had acted as chairman of the Modelling Resource Group of the Committee on Nuclear and Alternative Energy Systems of the National Academy of Sciences of the US. This committee had the task of making long-range projections well into the 21st century. One of Koopmans’ specialities was the application of the techniques of optimization over time, in this case as applied to the field of the supply of energy, and this was the topic of his talk in Lindau. It is a pity that we don’t have access to his viewgraphs, but from the spoken word it is clear that many of the questions that are at the forefront today were already present some 30 years ago. This goes, e.g., for the side effects of using fossil fuels, which is discussed by Koopmans mainly in economic terms. In particular the emission of CO2 into the atmosphere, leading to the greenhouse effect, was already there in this 1982 lecture! Anders Bárány