Mar 236 min read

How to Feed 10 Billion People

The global population is expected to pass 10 billion within the next few decades. That means we’ll have doubled the number of people on the planet in less than 100 years. As a result, the world faces an existential dilemma: how do we boost production to feed billions more people while reducing agriculture’s negative impact on the environment?

For thousands of years, farming has been central to human civilisation. But the looming ‘population bomb’ means we’re going to need some new ideas.

Watch my short explainer to find out more:

The population bomb

How many people can planet Earth sustain? This question has become increasingly important and often controversial.

It took around 300,000 years of human civilisation for the population to reach one billion. Just over 200 years later – in November 2022 – it reached eight billion.

When agriculture was invented around 8,000 BC, the world’s population was around 10 million. That’s roughly the number of new babies born every month today!

In many ways, this is a brilliant success story. Our population soared when the Industrial Revolution hugely improved healthcare, education, diets and living standards. Fewer people died young, more lived into old age – and the population rocketed.

And the numbers are still going up, with the UN predicting that we’ll pass 10 billion in around 30 years’ time.

Where will it end? Well, sooner than you might think.

Across the world, families today are having fewer children than in previous generations. The population may still be growing, but the brakes have been applied: before this century is out, exponential population growth is expected to screech to a halt.

Even so, billions more people mean billions more mouths to feed. Almost half of the habitable land on Earth is already used for agriculture, and we know that this is significantly damaging the planet. At the same time, more than 800 million people are going hungry. How can we hope to produce enough food for 10 billion people?

Betting on the future of humanity

"The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date nothing can prevent a substantial increase in the world death rate…"

This bleak prediction opened the 1968 bestselling book The Population Bomb, which academic Paul Ehrlich co-authored with his colleague and wife Anne. Together they believed that worldwide famines and major societal upheavals were on the way, as the world population approached a then-unprecedented four billion.

A cartoon depicting Earth attached to a bomb, with pawn-like pieces scattered all around under the words "Population Bomb"

Economist Julian Simon saw things differently. Simon believed in human ingenuity and the rapid technological advances already starting to reap benefits in agriculture. He saw population growth as a solution, not a problem. A planet with more people would generate more ideas and breakthroughs.

In 1980, they shook on a bet, pitting their two visions for the future of humanity against each other: whose prediction would be most on track in 10 years — Ehrlich’s gloomy apocalypse or Simon’s optimism?

By the time their bet was up, the global population had grown by 800 million — a record for a single decade. But the bomb had failed to detonate. Ehrlich lost.*

(* ...at least according to the measures they agreed on for their wager. This is where the story starts to get a little more messy. Ehrlich and Simon’s bet was based on what would happen to the prices of five raw materials. They agreed that if Ehrlich was correct, the cost of copper, chromium, nickel, tin, and tungsten would rocket as resources became more scarce over the decade. The opposite happened: prices actually dropped for all five metals when adjusted for inflation. However, the reality is that commodity prices, which fluctuate with economic cycles, are a bad proxy for population effects. Economists subsequently calculated that if the pair had picked a different timeframe for their bet, Ehrlich would likely have won. As David Epstein concludes in his retelling of the story in Range, they ‘might as well have flipped a coin and both declared victory’.)

More significantly, many of Ehrlich’s forecasts have been proved wrong. Some quite spectacularly. This was a man who, in 1970, famously declared: "If I were a gambler, I would take even money that England will not exist in the year 2000.”

Perhaps the best news of the 20th century was that the global death rate (the number of people per thousand who die each year) fell by almost half in the decades that followed the publication of The Population Bomb.

One innovation did more than almost anything to vindicate Simon’s optimism and stave off the threat of a global famine — a new grain of wheat.

The man who saved one billion lives

It has been said that Norman Borlaug saved more lives than any other person who has ever lived.

Borlaug was working in Mexico as a research scientist for the Rockefeller Foundation when he saw that impoverished farmers were struggling with diseased and low-producing crops. Seeking to help, he began experimenting with different kinds of wheat plants. After years of trial and error, he managed to breed a new super-strain of wheat which was resistant to disease and able to withstand the harsh Mexican climate.

Borlaug shared his game-changing discovery with developing countries, and this novel wheat helped start what has since been dubbed the ‘Green Revolution’. Across the world, previously dry and barren lands were transformed and global grain production more than doubled.

Borlaug was awarded the Nobel Peace Prize and credited with saving at least a billion lives by preventing worldwide famine.

But, just like the Ehrlich-Simon wager, Borlaug’s legacy is a little more complicated than it may first appear.

The Green Revolution led to a considerable increase in the use of pesticides. Borlaug’s high-yielding seeds required expensive fertilisers which were beyond the means of some farmers. They also needed significantly more water. Taken together, this led to the harmful pollution of water and soil which we now know has been disastrous for the environment.

Ultimately, Borlaug’s miracle discovery helped solve one existential challenge but it sowed the seeds of another.

A new green revolution?

Given what we now know about the environmental impact of agriculture and the unintended consequences of Borlaug’s Green Revolution, how will we feed 10 billion people?

Here’s a bit more about the three agricultural innovations we looked at in the video: smart farming, agroforestry, and vertical farms.

1. Smart farming:

By using technology, including sensors, satellites, and self-driving tractors, we can increase the productivity of farms, while also minimising the use of fertilisers, pesticides, and fossil fuels.

2. Agroforestry:

Instead of intensive farming with acres of monocrops, we should combine forestry and agriculture. This approach has been key to Costa Rica becoming the first country in the world to have stopped and reversed deforestation. There is a growing movement to practice this in the US and elsewhere.

3. Vertical farms:

Bring farms indoors, into high-rise production facilities within cities, where food can be safely grown right where people need to eat it. This can also be combined with fish farming (aquaponics). Dr Dickson Despommier, a vertical farming expert whose name appropriately translates to ‘of the apple tree’, argues that: “If vertical farming in urban centres becomes the norm, then one anticipated long-term benefit would be the gradual repair of many of the world’s damaged ecosystems through the systematic abandonment of farmland.”

Food for thought

Is there a maximum number of people the planet can sustain? Or is this the wrong question to be asking? Especially when there is so much more we could do to take better care of the planet and share its resources more sustainably and fairly.

More than 30 years on from losing his famous bet, Paul Ehrlich still believes he was largely right. Notable figures including Sir David Attenborough and the Dalai Lama continue to warn about the impact on the planet of an ever-growing human population.

The UN believes that we already produce enough food on the planet for 10 billion people. Some academics argue that: “Hunger is caused by poverty and inequality, not scarcity” and that one-third of all food produced for human consumption is lost or wasted.

Providing us all with a healthy, reliable, and sustainable source of food for generations to come will require more than innovations like smart farming, agroforestry, and vertical farming. But could they be an important part of the solution?

You wouldn’t bet against it…