The carbon footprint (GHG emissions) of sugar is of increasing interest to sugar users and consumers. This study considers the potential variability on a global basis of the carbon footprint of cane sugar, and investigates the key drivers affecting this variability. A mathematical model was built to represent the production of sugar from field to market. Key input values were replaced by ranges to reflect the variability and uncertainty associated with the diversity of sugar production scenarios worldwide. Monte Carlo simulation was carried out to simulate the effect of these variations on the model outputs, which were assessed against the Bonsucro method (with modifications and additions) for estimating GHG emissions. The carbon footprint of field-to-gate raw sugar ranged between 217 and 809 g CO2eq per kg sugar in 90% of simulations. The biggest drivers were the country of origin, agricultural methods, power production/export and process energy efficiency. Production of plantation white sugar and transport to a local market added another 100-150 g CO2eq/kg, split between transport and processing emissions. The carbon footprint of field-to-market factory-refined sugar ranged between 329 and 1121 g CO2eq/kg. The increase from raw sugar was mainly due to increased fossil fuel usage, and the biggest driver was process energy efficiency. The carbon footprint associated with shipping raw sugar from port, refining at a destination refinery, and transporting to market ranged between 465 and 660 g CO2eq/kg. The biggest driver was refinery energy efficiency. Finally, the carbon footprint of field-to-market destination-refined sugar ranged between 621 and 1459 g CO2eq/kg in 90% of simulations, of which the distance from factory to port was an additional significant driver. The potential variability in cane sugar carbon footprint has been shown to be large, depending on where and how it is produced. However, by focussing on areas such as irrigation, agricultural chemicals, cane yields, power generation and export, process energy efficiency and cane burning, it is realistic to achieve a negative carbon footprint for field-to-market refined sugar: a net emissions credit of 260 g CO2eq/kg was simulated, improving to 565 g CO2eq/kg with trash recovery and to 1470 g CO2eq/k9 with biomass gasification.
