With the world's population expected to grow from 6.8 billion today to 9.1 billion by 2050, a certain Malthusian alarmism has set in: how will all these extra mouths be fed? The world's population more than doubled from 3 billion between 1961 and 2007, yet agricultural output kept pace — and current projections (see page 546) suggest it will continue to do so. Admittedly, climate change adds a large degree of uncertainty to projections of agricultural output, but that just underlines the importance of monitoring and research to refine those predictions. That aside, in the words of one official at the Food and Agriculture Organization (FAO) of the United Nations, the task of feeding the world's population in 2050 in itself seems “easily possible”. Easy, that is, if the world brings into play swathes of extra land, spreads still more fertilizers and pesticides, and further depletes already scarce groundwater supplies. But clearing hundreds of millions of hectares of wildlands — most of the land that would be brought into use is in Latin America and Africa — while increasing today's brand of resource-intensive, environmentally destructive agriculture is a poor option. Therein lies the real challenge in the coming decades: how to expand agricultural output massively without increasing by much the amount of land used.
What is needed is a second green revolution — an approach that Britain's Royal Society aptly describes as the “sustainable intensification of global agriculture”. Such a revolution will require a wholesale realignment of priorities in agricultural research. There is an urgent need for new crop varieties that offer higher yields but use less water, fertilizers or other inputs — created, for example, through long-neglected research on modifying roots (see page 552) — and for crops that are more resistant to drought, heat, submersion and pests. Equally crucial is lower-tech research into basics such as crop rotation, mixed farming of animals and plants on smallholder farms, soil management and curbing waste. (Between one-quarter and one-third of the food produced worldwide is lost or spoiled.)