One problem we face, for exam-ple, is that the wealthier people become, the more they can afford to eat meat. But growing livestock for meat is not the most efficient or equitable — or necessarily healthy — use of grain or other agricultural resources. We need to start thinking in terms of what has to change in order for people to increase their well-being, to consume what they ought to consume and not overconsume, and to get a more equitable distribution of available food.

This is one of the most immediate interventions a government can make for a better future.

PEARCE: I agree very much. In simple terms, we already produce enough food in the world today to feed 10 billion people — the population we might expect by the end of the century. The problem is that almost half of the grain that we produce is not fed to people.

It either goes to livestock — which is a very inefficient way of feeding people — or to produce biofuels. We also waste a huge amount of food. And we also use quite a lot of our agricultural land for growing non-food crops, such as cotton, rubber and various other things.

So, in some senses, feeding 10 billion people on the planet to a reasonable level of nutrition is not too hard. We’re producing enough food already, but we have problems about wastage of food, throwing food away uneaten from the table, or wastage in warehouses in parts of the world where it simply rots before it gets anywhere near market. Rather than railing against countries that are still increasing their population, it seems to me that the best way forward is to take some real practical steps to make better uses of the resources we have.

SCHMEMANN: I’d like to delve deeper into the notion that governments should take strong action, in Asia or elsewhere. When China had an all-powerful government, they launched a campaign, the one-child campaign, which everyone now seems to think was a human rights disaster. Or we read that in India, and elsewhere as well, modern technology has led to the widespread killing of female fetuses.

PEARCE: Yes, there are issues here. Actually, in its own terms — not in human rights terms — the Chinese one-child policy was more successful than even the Chinese government claims. All the evidence from the census is that fertility rates in China really are down now to about 1.2, 1.3 — almost at the intended level. It’s almost been too successful, because China’s population is going to peak very soon, and it’s aging very fast, and aging is going to be a major problem in coming decades.

As for sex-selective abortions, that is a major problem in China and in India, and in some other parts of Asia as well, though not necessarily tied to state restrictions on family sizes. The average woman in India now has about 2.8 children; that’s half what her mother had 30 years ago, and the figures are still coming down. However, my understanding is that in much of Asia there’s still a very strong desire to make sure you have a son. And if you haven’t already got a son, there’s a very strong temptation — in the middle classes, in fact, which can access private ultrasound services — to go for sex-selective abortions.