Heavy footprint weighs down U.S. empire

Is the decline of the status of the United States a result of its heavy ecological footprint? A strong argument can be made that the fading of the American empire is fundamentally an environmental issue.

In his book The Upside of Down, Canadian political scientist Thomas Homer-Dixon devotes a lot of space to an environmental analysis of the decline and fall of the Roman Empire. Interesting in itself, it is also meant as a cautionary tale, not only for the U.S., but also for all industrialized nations.


The main source of energy for Rome was biomass — grain for people, fodder for oxen and fuels like wood and olive oil. Indirectly, all are forms of solar energy. As the city of Rome expanded, more and more energy was needed to support the growing urban population and build infrastructure. (The book includes a particularly fascinating study of the embodied energy in the Coliseum.) Thus, Rome had to expand its empire in order to control enough land to produce all the biomass energy it needed for its capital.

In order to build an empire, soldiers were needed, more and more as the empire expanded. All had to be fed and provisioned. The empire also needed tax gatherers and civil servants. These armies and bureaucrats had to be supported by the empire. Expansion was also necessary to get booty and other forms of wealth, such as gold, to pay for the Roman lifestyle and the costs of expansion itself.

All this supported a vicious cycle of expansion to gain land followed by a build-up of soldiers, civil servants and debt, then more expansion.

Meanwhile, the intensive farming and forestry resulted in a deterioration of the environment, particularly through erosion and salination, meaning lower productivity. Once again, the land base had to be expanded to make up for lost productivity. This meant more soldiers and longer supply lines. Gradually, the whole environmental-military-political-financial system became exhausted and the barbarians had their day.

The StarPhoenix