Pre-harvest sugarcane burning emission inventories based on remote sensing data in the state of São Paulo, Brazil

- Annual emissions associated with the sugarcane burning practice were estimated.
- Emissions were estimated in the state of São Paulo, Brazil, from 2006 to 2011.
- Sugarcane straw burning emission inventories were built with a new approach.
- Emissions from sugarcane burning were compared to bottom-up emission inventories.
- The expansion of sugarcane cultivation has not entailed increased pollutant emissions.

The state of São Paulo is the largest sugarcane producer in Brazil, with a cultivated area of about 5.4 Mha in 2011. Approximately 2 Mha were harvested annually from 2006 to 2011 with the pre-harvest straw burning practice, which emits trace gases and particulate material to the atmosphere. The development of emission inventories for sugarcane straw burning is crucial in order to assess its environmental impacts. This study aimed to estimate annual emissions associated with the pre-harvest sugarcane burning practice in the state of São Paulo based on remote sensing maps and emission and combustion factors for sugarcane straw burning. Average estimated emissions (Gg/year) were 1130 ± 152 for CO, 26 ± 4 for NOx, 16 ± 2 for CH4, 45 ± 6 for PM2.5, 120 ± 16 for PM10 and 154 ± 21 for NMHC (non-methane hydrocarbons). An intercomparison among annual emissions from this study and annual emissions from four other different approaches indicated that the estimates obtained by satellite fire detection or low spatial resolution approaches tend to underestimate sugarcane burned area, due to unique characteristics of this type of biomass fire. Overall, our results also indicated that government actions to reduce sugarcane straw burning emissions are becoming effective.