At the request of the French ministry of Food, Agriculture and Fisheries, a study was carried out in 2009 by Laurence Roudart on the current and future availability of cultivable land. The three databases she analysed indicates that the land area utilisable for rain-fed cultivation (without need of irrigation) that is not yet being farmed is, globally, very extensive – particularly in South America and Sub-Saharan Africa. On the other hand, this particular resource seems to be scarce or even to have been exhausted in the Middle East and Asia. Global warming would probably lead to a – small – increase in cultivable land, but would reduce the cultivable areas available in developing countries, particularly in South and South-East Asia, where such land is already a scarce resource.
The world’s cultivable areas seem greatly to exceed what is necessary to guarantee humanity’s food security. This conclusion remains true even if we assume relatively low growth in agricultural yields along the lines of a “sustainable, doubly green revolution” and exclude from cultivation all the currently protected zones and the forests. It is true even if we take into account the plausible effects of global warming. However, the sustainable exploitation of cultivable land resources requires appropriate public policies on agricultural prices, on access to land, and on research-and-development targeted at the needs and potential of poor producers.