Energy Consumption in the Roman World

The energy system of the ancient Mediterranean civilisations was the same as that of all agrarian societies between the 5th millennium B.C. and the 19th century, and the level of per head consumption of energy was the same too. This system was based on food, firewood, and fodder for working animals. Despite the increase in useful knowledge and the extensive development of the agrarian energy basis, supported by a favourable climatic phase, this system was finally unable to support the increasing population. Per capita availability of energy began to diminish. An unfavourable climatic phase, from the 2nd century A.D., contributed to this decline.