How do you grow more food? One answer that makes sense is with bigger farms and more farmers. But if you look at the last half century-or-so worth of data, that's not at all what's been happening.
The USDA in the US put together this curious little chart of what the United States has been putting into its farms since 1948, versus what they've been getting out of them. Most immediately striking is the huge rise in how much food being produced at farms today. But look a little closer and you may notice something odd. The strange thing about this data is not the fact that farm production almost doubled, it's just how steady that light blue line ("agricultural inputs") stays.
Top image: Scott Bauer / ARS; Chart: USDA/ERS
Why is it so weird? Because we actually have much less farmland today than we did in 1948, and we certainly have far fewer farmers. So shouldn't the chart be even more dramatic, with a strong dip in what we're putting into farms, even while what we're getting out of them rises? The answer to why we don't see that actually also explains why the rise was so quick.
The last six decades or so have been huge in terms of figuring out how to use basic farm technologies -- ranging from the big machinery that overtook farms (making most farm laborers obsolete), to the more modern incarnation of plants hybridised in the lab to suit specific needs. Figuring out how to do that was a big enough investment that it almost completely balanced out the dip we would have seen from the loss of all those farm workers and farmland
In a lot of ways, the message is comforting: If we could figure out ways to grow less with more before using technology, then can't we simply keep doing it? In some ways we can, although changing climates are tightening resources (water, topsoil) in ways that were never a problem before. A lot of the jump that we see in the chart was from farm technology like automatic sprinklers, for instance.
Certainly, there are still ways out there to keep upping the amount of food we grow, but it's just as likely that we can expect that the increases of the future will be much more modest -- and come at a higher price.