The author talks about our "abused cropland" which opens up a lot of problems with un-regulated farming and deforestation in different places. And if we don't regulate farm land we can farm the land to the point where it has no nutrients and if we just keep moving to the next plot of land, eventually we are going to end up like the movie interstellar where the money is in crops instead of the progression of the technology.

so throughout this article it talks about how we are going to run out of oil. and then what are we going to do after that? But if you notice this has happened before. (whale oil) and even different sources of water, we just move to the next source until that source replenishes. whats to say that when oil runs out we have another resource that we use for everything. (hydrogen/ uranium)