Disentangling the environmental impacts in increasing global food production

The past few decades have seen unprecedented changes in the global agricultural system with a dramatic increase in the rates of crops production fueled by an escalating demand for food calories, as a result of demographic growth, dietary changes, and – more recently – new bioenergy policies. Food prices have become consistently higher and increasingly volatile with dramatic spikes in 2007-08 and 2010-11. The confluence of these factors has heightened demand for the natural resources needed for crop production, that is land and water so increasing the environmental burden. Solutions to feed the planet often point to agricultural intensification (i.e., increase in crop yields) as the approach that could meet the increasing human demand with the smaller environmental impacts. Indeed, intensification avoids the land use change (e.g., deforestation), habitat destruction, and increase in CO₂ emissions that would result from an expansion of cultivated land (or “extensification”). The impacts of intensification on freshwater resources, rural livelihoods, and equity, however, is often ignored. At the same time, agricultural expansion has important externalities that go beyond biodiversity losses or greenhouse gas emissions, with important ramifications to human and planetary health. We use a suite of model simulations and data analyses to evaluate the hydrological and nutritional impacts of agricultural intensification vs expansion and discuss their different suitability large scale farming vs smallholders.