Between the world's increasing population and its growing food consumption as poverty declines, experts predict we will need 70-100% more food by 2050.
How we might be able to produce that food is the subject of a report published in the journal Science called "Food Security: The Challenge of Feeding 9 Billion People."
The paper, written by Britain's chief scientific adviser, John Beddington, and nine other experts, does not offer specific recommendations, though the authors are working on those. They note that climate change and its impact on agriculture, soil and water resources will further complicate the task of feeding a world population estimated to hit 9 billion by 2050.
"Here, we are raising broad strategies to address food security," says lead author and University of Oxford professor Charles Godfray.
1) Closing the yield gap: The wide variation of agricultural productivity, even in regions with comparable climates, is known as the yield gap. The variation can be the result of factors like technical constraints and economic issues.
"Straight agronomic research can help hugely in choosing which of the spectrum of currently available crops/technologies are most appropriate to which particular site," Godfray says. "Second, the yield gap is not static, but can increase as pests and diseases are introduced or evolve; scientific innovation is constantly needed to counter these challenges."
2) Increasing production limits: Growing more food on existing farmland may require genetically modified crops, which the authors call a "potentially valuable technology," though they note that GM foods still need to gain greater public trust.
3) Reducing waste: Roughly 30-40% of food in both the developed and developing world is wasted. In the latter case, the problem may be pests and inadequate storage; in the developed world, the waste is usually post-retail: in restaurants and homes.
4) Changing diets: Demand for meat is on the rise, especially as consumer wealth increases in India and China, but meat production brings some undesirable environmental impacts, including methane production and deforestation for land. Still, the authors point out that to say all meat consumption is bad is too simplistic.
"Of the five strategies we explore, assessing the value of this one is the most difficult," Godfray says. "I think all we are saying at the moment is that this cannot be ignored but needs further study."
5) Expanding aquaculture: Aquatic products supply almost three billion people with at least 15% of their animal protein intake, but aquaculture practices need improvement. Better stock selection, larger-scale production technologies, aquaculture in open seas and larger inland water bodies, and cultivating a wider range of species are some of the paper's suggestions. GM technologies may play a role here too, as research looks at factors like salinity tolerance, disease resistance and fish feed with enhanced nutrition.
Focusing on the yield gap is key — and so is being practical about approaching food security, says food security researcher Molly Brown of the Biospheric Sciences Branch of NASA and an author of the study "Declining Global Per Capita Agricultural Production and Warming Oceans Threaten Food Security," published last summer in the journal Food Security.
"It's important to keep in mind a goal that's achievable in the next two or three decades," she says. During that time, Brown's paper predicts that per capita cereal production could decline 14% as population growth outpaces yield increases.
"What we need to do is invest in yield gains in places that are inefficient. West Africa is the top of the list," she says. "You don't need to spend trillions of dollars. We need to provide tools to very vulnerable places so they can feed themselves."
Of course climate change will affect agriculture there — and everywhere — in ways that are still largely uncertain.
"Much of the scientific innovation in agriculture that we will need in the coming decades will be to maintain and increase yields in the face of changing environments," Godfray says.
In tropical areas, Brown predicts two primary effects of climate change on agriculture. The first is on temperatures, which could push the limits of plants' tolerance if they rise five or 10 degrees. In fact, some researchers think temperature changes will have more harmful effects than water cycle transformations. "Temperature effects are also what we know least about," Brown says.
The second major issue will be the effects of what Brown calls "weird weather" on the global commodity system.
In 2008, a huge price spike in commodities was caused by droughts in some areas of the world combined with a bad rice harvest and lots of grains going into biofuels. "People panicked and prices went up," Brown says. "We expect to see these much more volatile prices and more variation in production." As a result, the markets will get less predictable.
All of these threads will come together over the next 20 or 30 years, she says — and the challenges don't end there. In the final paragraphs of the Godfray paper, he and his co-authors write,
"Any optimism must be tempered by the enormous challenges of making food production sustainable while controlling greenhouse gas emissions and conserving dwindling water supplies. ... Together, these challenges amount to a perfect storm."