The carbon cost of agricultural production in the global land rush

Increases in the number of large-scale land transactions (LSLTs), commonly known as 'land grabbing' or 'global land rush,' have occurred throughout the lower-and middle-income world over the past two decades. Despite substantial and continuing concerns about the negative socio-environmental impacts of LSLTs, trade-off analysis on boosting crop yield and minimizing climate-related effects remains limited. Our study makes use of a global dataset on LSLTs for agricultural production to estimate potential carbon emissions based on different scenarios of land cover change and fertilizer use, as well as potential value of agricultural production on transacted land. We show that, if fully implemented on similar to 38 M ha of transacted land, 2.51 GtC will be emitted during land conversion, with another 24.2 MtC/year emitted from fertilizer use, assuming farming technology of investors' origin is adopted on transacted land. Comparison of different combinations of forest protection policies and agricultural intensification levels reveals that enforcing strict deforestation regulation while promoting fertilizer use rate improves the carbon efficiency of agricultural production. Additionally, positive spillovers of investors' farming technology on existing arable lands of host countries can potentially double their crop yield. Our ana-lyses thus suggest that fostering agricultural intensification and technology spillovers under strict regulation on land allocation to investors to protect forests would allow for boosting agricultural yield while minimizing carbon emissions.