A new analysis shows that the world’s population is likely to rise to at least 9 billion in 2050, and 11 billion in 2100, instead of easing off at 9 billion in 2050 as was previously expected.
The increased population growth is forecast to place new pressure on the global food system over the next 40 years. Much of the population increase will come from nouveau riche developing countries, where people are likely to be wealthier, and this will create demand for a more varied, high-quality diet requiring additional resources to produce.
Over this period globalisation will continue, exposing the food system to novel economic and political pressures. Solutions from the food industry should include sustainable yield increases in agriculture, attention to the effect of globalised trade on ageing demographics in emerging markets, and policies that improve financial opportunities for farmers in Africa
Such is the reaction by experts in the food industry to a report from the United Nations and the University of Washington published in Science magazine on September 18.
“Earlier population projections were strictly based on scenarios, so there was no uncertainty,” explains University of Washington Professor Adrian Raftery, who was one of the principal authors of the research. “This work uses a Bayesian probabilistic methodology which provides a more statistically driven assessment that allows us to quantify the predictions, and offer a confidence interval that could be useful in planning.”
In other words, these are probabilistic long-term population projections, as opposed to the conventional population projections usually made by the U.N. Population Division which are scenario-based. What is new about the approach Raftery describes is that the new projection (using Bayesian probability, for the 18th-century mathematician Thomas Bayes), assigns probability to given scenarios, based on experience.
Raftery’s team used statistical methods to combine government data and expert forecasts for such things as mortality rates, fertility rates and international migration. The scientists found there’s an 80 % probability that world population in 2100 will be between 9.6 and 12.3 billion. Most of the anticipated growth is in Africa, where population is projected to quadruple from around 1 billion today to 4 billion by 2100. For the developed countries and for emerging markets, populations are set to increase at a greater extent than expected, but even the emerging markets are forecast to be faced with large ageing populations. Brazil, for example, currently has 8.6 people of working age for every person over 65, but that will fall to 1.5 by 2100, well below the current level in Japan. China and India will face the same issue as Brazil, Raftery points out.
From the perspective of the food economy, this clearly poses significant challenges. “There are more than 7 billion people on Earth now, and roughly one in eight of us doesn’t have enough to eat. The question of how many people the Earth can support is a long-standing one that becomes more intense as the world’s population—and our use of natural resources—keeps booming,” warns Jonathan Foley, head of the Institute on the Environment, University of Minnesota.
Stanford University demographer Paul Ehrlich agrees: “Population growth, for instance accelerates climate disruption, since the more people there are, the more greenhouse gases. That disruption can clobber agriculture; as billions more mouths to feed arrive. Climate-damaged food production presents a great threat to the nutritional security of our grandchildren.”
For David Tilman, a biologist at the University of Minnesota, the combination of population increase and wealth increase in emerging markets will lead to a doubling of global food demand by 2050. About a third of that’s from population, and about two-thirds from unchecked dietary growth. The Food and Agriculture Organization predicts a smaller increase, but agrees with the overall terms of Tilman’s analysis.
“The challenge for the food industry,” Tilman says, “ is that we already have nearly a billion people who go hungry, and we are adding 2 billion more people, while a couple of billion who are already here are getting richer and wanting better diets. How will that challenge be met?”
Both Tilman and Foley advocate substantial changes throughout the different elements of the food system and if food security is to be provided for the much larger global population. More food must be produced sustainably through the spread and implementation of existing knowledge, technology and best practice, and by investment in new science and innovation.
“The world can now turn its attention to increasing yields on less productive farmlands—especially in Africa, Latin America, and Eastern Europe—where there are “yield gaps” between current production levels and those possible with improved farming practices. Using high-tech, precision farming systems, as well as approaches borrowed from organic farming, we could boost yields in these places several times over,” Foley points out.
The challenge of feeding ageing populations in emerging markets in more complex than simply that of producing or trading for more food. As Christopher Baker, of the Centre for International Security Studies at the University of Sydney points out, “The increase in ageing populations in emerging markets, particularly in Asia, is combined with a movement of urbanisation. There are already large populations of elderly in the cities, and their number is increasing at the expense of rural populations. This means that demand for food from these urban areas will increase, and it will be for a richer diet than the traditional one. This demand will also bring higher food prices, and will make these urban areas dependent on the international food trade.”
What can be done in southern Africa, which is to see the largest population increase in the next 40 years? According to the World Health Organization, unless action is taken, the number of under-nourished children in Africa alone is expected to rise 10-fold by 2050. Prof Chris Leaver, the Senior Scientific Advisor to the Bioscience for Farming in Africa initiative, supported by the Templeton Foundation, advocates bringing modern farming techniques and technology to the African farmer. “Financial aid is also necessary: Enhancing opportunities for easy access to agricultural finance and insurance, facilitating markets and trade at all levels, and creating an enabling environment for private sector investment in the agriculture value chain are all critical steps to improve African agriculture.”
Policy makers and industry experts are only just coming to grips with the full consequences of the new population-growth projections. But it was clear from previous estimates that considerable adaptation of the international food supply system would be needed if most of mankind is still to eat in 2050. The need for such changes is clearly even more pressing now.
Andrew Rosenbaum is a regular contributor to MSN Money, Wall Street Journal, and The Sunday Telegraph
