This is Brian Czech on the “trophic theory of money”:
Due to the fundamental structure of the economy, the size of the economy – as measured by GDP – is a perfectly valid indicator of environmental impact. Agricultural and extractive sectors form the base, which must expand to support the growth of manufacturing and service sectors – yes even the “information economy.” This structure, which is the closest thing in economics to an inescapable law of physics, gives us the “trophic theory of money,” which says that the level of expenditure (GDP, in other words) is proportionate to environmental impact including such tangibles as biodiversity loss, climate change, and pollution in the aggregate.
It makes perfect sense that the overall scale of human activity is proportional to environmental impact, at least for a given level of technological knowledge, which doesn’t change very fast. Where I think he is wrong is the idea that money is a good measure of that impact. If you drew a pyramid showing the environmental impact of various sectors of the economy, starting with the lowest “trophic levels” like agriculture, forestry, and mining, and continuing up to the service and information sectors, it would indeed be a pyramid – agriculture, forestry, and mining would have the biggest ecological footprints, then the footprint of various sectors would decrease as you worked your way up the scale.
However, if you drew the same pyramid based on the contribution of each sector to GDP, it would be inverted, with agriculture, forestry, and mining representing much smaller numbers of dollars changing hands, and higher-tech sectors much more. The reason, I think, is that agriculture and mining have been around forever, and have become very efficient from an economic perspective (although we certainly don’t count their true costs in an environmental sense). The rate of technological change is low in those sectors, and we have turned them over to a small number of firms that know how to operate very efficiently and drive costs down, making small profit margins on a large scale. Relative to historical levels, prices are low enough in these sectors that we can largely take these goods and services for granted, and the majority of us have some money left over to spend on more frivolous goods like electronics.
The high-tech industries are rapidly evolving and have many players competing against each other to come up with novel things that we have just figured out we are willing and able to pay for. The profit margins in these sectors, and the total number of dollars changing hands, are much larger. This allows a larger number of players to compete at smaller scales.
A fun place to look at these statistics yourself is the U.S. Bureau of Economic Analysis’s interactive tables.