Future Megacities Will Swallow Up Croplands by 2030

A new study from the Proceedings of the National Academy of Sciences has predicted that the creeping expanse of megacities around the world will begin to encroach on existing farmlands by the year 2030. It’s no secret that, as populations grow and people are increasingly flocking to live in urban areas, those cities will need to grow in order to accommodate new inhabitants. In fact, the U.N. projects that urban populations will double by 2050. Physical expansion is the only option. That spread, however, threatens the “60% of the world’s cropland which lies on the outskirts of cities — and that’s particularly worrying, the report authors say, because this peripheral habitat is, on average, also twice as productive as land elsewhere on the globe.”

Furthermore, the study predicts that global agricultural production will take a 3 or 4 percent hit due to urban growth. Numbers like that may seem inconsequential — and for certain areas, like the United States, that may be the case. But these hits to agriculture will disproportionately affect developing areas in Africa and Asia, with 80 percent of the projected losses. China alone will account for about 25 percent, with the losses concentrated in its eastern regions.

As if the developing world didn’t have enough to worry about already, with climate change affecting them first and worst, this reduction in food resources will pose a major threat to the food security of nations like Egypt and Nigeria, which are predicted to feel this loss even more acutely than their neighbors. Scarcity of resources like oil puts strain on international relations. We can only guess at what countries will do if they don’t even have enough food. Making matters even worse for farmers in places like Africa is the fact that some governments do not actually grant them land rights, meaning they can be forcibly expelled from their land with no legal resource with which to defend themselves. This is sure to spark increased tensions between rural and urban inhabitants.

Preventing this, says Felix Creutzig of the Mercator Research Institute on Global Commons and Climate Change in Berlin, who is the primary author of the study, will require a multilayered effort. Part of it, he says, will be urban farming. While insufficient on its own, he told the Guardian that it will prove “very important to maintain local supply chains and provide livelihoods and subsistence for urban farmers.” He says other measures should include “regulations on expansion, to keep urbanization as compact as possible.”

The ideal scenario may indeed heavily rely on that final suggestion: keeping urbanization as compact as possible. The study assumes that urban expansion will proceed in an outwardly direction, which due to the financial and technological limitations of building super-tall structures, may be the case for the very near future. But it doesn’t always have to be that way.

In reality vast, expansive cities aren’t necessary to house the growing population. In fact, if we wanted to take this really seriously, the entire population could be fit into an area about the size of New Zealand, provided we live as densely as people do in Manhattan. Or, if people don’t want to travel all the way to New Zealand, everyone could move to Texas instead — and yes, the math checks out on that. Texas has an area of 262,000 square miles. Divided evenly, that would leave each of the roughly 7 billion people on Earth with a 100 square meter plot of land. It’s precious little per person, but that math doesn’t factor in multi-story buildings, let alone the scale and complexity that future high rises are sure to have.

A towering megalopolis with a high population density could house the world’s population quite comfortably in that space, with plenty of room for growth. It would also leave the rest of world — more than is even currently available — free for food production. A farfetched solution, to be sure, and one that isn’t likely to occur in our lifetimes, but it could be the ultimate realization of the regulations hinted at by Creutzig. Plus, it sounds pretty goddamn cool.