That seems like a strange conclusion to draw from this article. It even says "But in fact, more than enough grain is already grown to meet humanity’s needs."
Seems more like the number of people isn't the biggest problem, but the lifestyle of a part of those people is. To me it look like the problem will be solved if North America and Europe drastically reduce their meat consumption.
So someone gives an argument which involves less than 1/4 of the world population merely having to change their consumption patterns by eating less meat, but still you see a better solution in 'cutting our population' by more than that? Wouldn't it be better to first focus on the lowest hanging fruit in which we tackle the problem by focussing on those people using a disproportionate amount of resources, instead of indiscriminately reducing the whole population? Not to mention the fact that there are not really any ways to quickly 'cut our pupulation' to this level short of killing people.
