Can We Keep Feeding a Growing Population? Don't Bet on it

In 2011, Professor David Lam of the University of Michigan was the President of the Population Association of America and in his presidential address at the Annual Meeting that year in Washington, DC, he predicted that there should be plenty of food to go around even as the world added another 4 billion people. [Like all presidential addresses, this was published later that year in the journal Demography.] Professor Lam updated some of these ideas in a recent article in the online news magazine of the International Union for the Scientific Study of Population (IUSSP). This was followed yesterday by a sort of rebuttal of that optimism from Richard Grossman, a retired gynecologist and public health physician.

As a demographer, it is appropriate that Lam should focus on humans. However, I fear that he has largely ignored the environment in which we live when he wrote this essay. I have difficulty accepting his statement: “An important source of optimism about the world’s ability to support an additional 4 billion people is the success in supporting the previous 4 billion.” My concern is that the past 4 billion have degraded natural world upon which we depend, and that this degradation will make the world much less welcoming to the next 4 billion.

If you've read Chapter 11 of my Population text you will know that I too worry about this same issue, and you won't find anything really new or exciting in what Grossman is saying. Rather, it is very troubling. Grossman also reminds us that Lam's optimism back in 2011 was subsequently challenged by Professor Stan Becker of Johns Hopkins University: 

In 2013, Professor Stan Becker challenged Professor Lam after his presidential address at the Population Association of America in 2011 in which he forecast “I expect that it [the world] will have improved in many ways, including lower poverty, higher levels of education, and plenty of food to go around” (Lam 2011:1259). Drs. Lam and Becker have a wager on food prices (collected by FAO) over the period 2001-10 to 2011-2020, with Lam predicting they will go down and Becker predicting they will go up. Half of the period of interest has passed (2011 to 2016), and prices have risen, by about 51% globally (Table 1).

And, of course, prices are going up because we have essentially used up all the available good farmland, we have to apply new and expensive technologies to get more food out of each acre of land, and we waste a lot of land and food on animals that are killed for humans to eat.