Ever since Malthus and Ricardo, all discussions of the pressure on food supplies have started from the assumption that population is the active factor and nature the fixed. This interpretation, however, can hardly be reconciled with modern scientific thought, especially if the problem is viewed in the long term. It is not necessary to go to other geological periods in order to discover great changes in nature. Two changes have occurred in Sweden in the course of the last few thousand years which have radically altered the living conditions of human beings: the great land-elevation which followed the melting of the inland ice, and the climatic fluctuations which have occurred continually. The former was a gradual change and is still proceeding; the latter have made themselves felt at irregular intervals and with varying intensity.

I have suggested in an earlier article that the development of population in Scandinavia and the Baltic regions during the first half of the eighteenth century, far from supporting the Malthusian theory of population, can only be explained by exogenous factors, in particular by the fact that a period of unusually mild climate occurred in the early decades of the century until it was brought to a close about 1740 by a return to more extreme conditions. Even the later surges of population growth seem to have been made possible above all by a mild climate. This prompts the question whether earlier climatic fluctuations might not also have played a decisive part in the development of population – perhaps not only in Scandinavia but in central and western Europe as well.