In the end, it’s all about space.

The elephant under the carpet of the organic discussion is and always has been: land. There’s only so much of it on the planet we can grow food on. About a billion and a half sqaure hectares by UN estimates. That’s twice the amount of productive land that was being farmed 100 years ago, though there are now about three and half times as many people. Most of them would be starving right now if we didn’t have conventional and GMO agriculture to feed them.

Farmed organically, it’s estimated that the current arable acreage of the world could sustain about 2.4 billion people. The current global population is 6.5 billion. In our lifetime we’ll see that population increase another 50% or so, to about 10 billion before, some statisticians say, global population will start to level off. Feeding all those hungry mouths will require 35% more calories than we’re producing right now.

So just clear more land, you might say. If we did — plow every available piece of park land and forest (including rain forests) — it’s thought we might be able to just feed 4 billion people. But that’s it. To feed humanity in the coming years, farmers around the world will be under consistent pressure to increase yields by 3% per year, every year. That simply won’t happen under a totally organic system.