Civilisation depends on soil

There is a thesis that civilisations last about 1000 years because that's how long it takes them to deplete their soils. The exception is Egypt because the Nile constantly replenished the soil (at the expense of Ethiopia further up the river, it may be mentioned). So our planetary survival really is about looking after our soil...

You talk about Rome not as much collapsing as consuming itself. That really struck me. Are we consuming ourselves?

DM: Well you know, if we put aside the questions about consumer culture and think just in terms of soil, given that we are eroding soil on an order of magnitude that’s faster than it’s being created — that is, modern agricultural soil erosion rates are as many as 10 – 100 times faster than soil creation — a minority of farms are a net soil source, but very few, so we are consuming ourselves to death. It’s like a bank account. If you spend money 10 times faster than you make it, you go broke. Soil is no different. You produce it, you use it and then it’s lost. If erosion is faster then production, we’re running out. The question is how fast and that’s where the good news lies because the rate is so slow, a millimeter or two a year, we actually have the opportunity to turn it around but it requires farming practices that are different than what we’ve done traditionally and conventionally. If we look at the adoption of no till data, we can show like I did in the PAS paper, you can get agriculture back to the no erosion rate. You can produce food without eroding soil.