In addition to contributing to erosion, pollution, food poisoning, and the dead zone, corn requires huge amounts of fossil fuel - it takes a half gallon of fossil fuel to produce a bushel of corn. ↗
Unfortunately, we haven't found many very old rocks on Earth because our planet's surface is constantly renewed by plate tectonics, coupled with erosion. ↗
This erosion of the middle class is happening all over the place. The opening of a wider gap between rich and poor is always accompanied by such a process. ↗