The true carbon costs of supplying potassium fertilizer to Brazilian agriculture

Brazil is the world’s 5th largest agricultural producer, with a vital role in global food supplies. It is the world’s largest importer of potassium fertilizers. Evaluation of the carbon footprint of food production needs to include the carbon footprint of fertilizer inputs. We report, for the first time, Scope 3 emissions relating to global and local transport and distribution networks for KCl fertilizer delivered to Brazil. The average carbon footprint from 8 global manufacturers in 7 countries to 5,563 distribution hubs is 530.5 kg of CO 2 -eq per tonne of KCl. This is almost double the emissions value widely used for KCl for Brazilian agriculture (273.13 kg CO 2 -eq t -1 ). We emphasise the need for a universal mandate to ensure that all stakeholders in the supply chain comprehensively account for Scope 3 emissions relating to KCl transport from where it is produced to where it is used. The revision of the carbon footprint for K fertilizer has major implications for global producers, local distributors, supermarkets, and consumers.