"The ever-increasing-yield per acre, by the way, is the result of heavy fertilizer use. And most fertilizers are commodities, too (potassium, for example). So there's no infinite supply of fertilizers, either."
The other 13 graphs in the article (about oil, metals, crop yields) are also going in the wrong direction.
This Grantham dude is bumming me out.
Business Insider: We're Headed For A Disaster Of Biblical Proportions