As birth announcements go, it was a pretty big one. Sometime around the end of October last year, the world’s population officially reached seven billion people.
Seemingly, it is the kind of celebration we should get used to. By 2050, an extraordinary nine billion people are expected to call Earth home. But these are milestones we cannot yet afford to celebrate, because as the population swells, our ability to feed everyone diminishes. Globally, one billion people are undernourished at present, especially in sub-Saharan Africa and Asia.
By around 2050, the swelling global population and affluence is expected to increase demand for food production by 70%, with a 100% increase expected in some developing countries. Yet most of the globe’s best farmland is already planted or grazed. And when you factor in climate change, limited fresh water supplies and competition for harvests from biofuel makers, it is clear the world faces a major challenge.
One note of reassurance is that we have been in a similar fix before, and our ingenuity proved to be up to the challenge. In the mid-20th Century, when the global demand for food outpaced supply and famine was routine in places such as India and Pakistan, what helped save the day was the so-called “Green Revolution”. The movement was spearheaded by American agronomist Norman Borlaug, who cleverly bred wheat to be shorter but sturdier and better at producing the parts we eat.
Borlaug’s approach drew its fair share of critics, in part through its reliance on pesticides and fertilisers. But breeding high-yield crops in this manner more than doubled farm field yields globally in 50 years, particularly in Latin America and Asia, and helped to avert mass famines - an achievement that earned Borlaug the 1970 Nobel Peace Prize.
Recently, however, the trend toward higher yields has flattened, and the world finds itself in need of another revolution. This time, however, there is no obvious blueprint. Green Revolution 2.0 is possible, scientists say, but it will be engineered using tools that were unavailable to Borlaug and others in their pioneering days. Instead of relying on traditional breeding techniques and the lavish use of chemicals, the machinery sowing this new revolution includes supercomputers, molecular biology and arrays of sensors.
Here, BBC Future profiles four areas of research to discover how close they are to feeding the coming nine billion.
Squeezing more from the sun
In a corner of Illinois, they are trying to improve on billions of years of evolution. A group led by British-born plant scientist Stephen Long is trying to improve the ability of plants to harness energy from the sun. Their aim is to turbocharge photosynthesis, the fundamental process that allows plants to use the light they capture to convert carbon dioxide into organic necessities like sugar and starch - or food, as we like to call it.
According to Long, plants currently operate at about one third of their potential efficiency when it comes to photosynthesis, which hints that if you can find a way to ramp it up, you can also produce more food. In 2006, Long and his colleagues described how climate-change experiments have shown that rising atmospheric levels of carbon dioxide lead to higher rates of photosynthesis in plants. When this happens, yields can improve by 15% in vital crops like wheat, rice and soybean.
Increasing atmospheric carbon dioxide further is hardly a practical or desirable way to boost crops, so the team set about looking for the genetic switches that could mimic the action and ramp up the plant’s ability to harness the sun.
That is easier said than done. More than 100 different proteins play a role in photosynthesis, interacting in countless different permutations, Long says. Trying to work out which ones could boost photosynthesis through trial and error would take years. But there is a shortcut: supercomputers.