Trade-offs between agricultural product carbon footprints and land use: a case study from Tanzania.

A case study comparing extensive, low-yielding smallholder maize production with an intensified, high-yielding production system (‘sustainable intensification’) is used to illustrate potential trade-offs between agricultural product carbon footprints (PCFs) and land use (LU). In the comparative analysis the extensive systems had lower PCFs so the conclusion may be that these systems should be encouraged as a climate mitigation strategy. However, if LU and the potential for land use change as a consequence of the extensive systems’ low yields are also considered, then the conclusion changes in favour of the intensified, high-yielding system. Our conclusion is that an assessment of the success of sustainable intensification with regard to climate mitigation needs to also include indirect effects at a larger spatial scale than individual farms in order to avoid misinterpreting PCF results.