Patterns in global food prices are indicators oftrends in the availability of food, at least for thosewho can afford it and have access to world mar-kets. Over the past century, gross food prices havegenerally fallen, leveling off in the past three dec-ades but punctuated by price spikes such as thatcaused by the 1970s oil crisis. In mid-2008, therewas an unexpected rapid rise in food prices, thecause of which is still being debated, that subsidedwhen the world economy went into recession (11).However, many (but not all) commentators havepredicted that this spike heralds a period of risingand more volatile food prices driven primarily byincreased demand from rapidly developing coun-tries, as well as by competition for resources fromfirst-generation biofuels production (12). Increasedfood prices will stimulate greater investment infood production, but the critical importance of foodto human well-being and also to social and po-litical stability makes it likely thatgovernments and other organizationswill want to encourage food pro-duction beyond that driven by sim-ple market mechanisms (13). Thelong-term nature of returns on in-vestment for many aspects of foodproduction and the importance ofpolicies that promote sustainabilityand equity also argue against purelyrelying on market solutions.So how can more food be pro-duced sustainably? In the past, theprimary solution to food shortageshas been to bring more land intoagriculture and to exploit new fishstocks. Yet over the past 5 decades,while grain production has morethan doubled, the amount of landdevoted to arable agriculture global-ly has increased by only ~9% (14).Some new land could be broughtinto cultivation, but the competi-tion for land from other human ac-tivities makes this an increasinglyunlikely and costly solution, par-ticularly if protecting biodiversityand the public goods provided bynatural ecosystems (for example,carbon storage in rainforest) aregiven higher priority (15). In recentdecades, agricultural land that wasformerly productive has been lostto urbanization and other humanuses, as well as to desertification,salinization, soil erosion, and otherconsequences of unsustainable lan