Recent fire occurrence and associated emissions in Southern Brazil

Biomass burning affects air quality at the local and global scales. While some studies analyze biomass burning at the continental and global scales, effective mitigation of fire emissions requires detailed assessments at the regional and local scales. Due to the contrasting presence of pristine forests, intensive agriculture, and highly populated areas, Santa Catarina (SC) State in Southern Brazil offers a unique opportunity to analyze the relation between land use, climate, and fire occurrences. We combine temporal and spatial analysis of fire spot and biomass burning data from Fire Inventory from NCAR (FINN version 1.5) to evaluate the causes of recent trends in fire occurrence and associated emissions at the regional scale. Mapbiomas collection 3.1 was used for land use characterization. Our results show that fire events occurred predominantly in natural forests (37%), regions with cropland and pastures (29%), and grasslands (19%). A strong spatial correlation between agricultural productivity and fire emissions suggests that the main cause of biomass burning is anthropogenic activities. There was a substantial decrease in the number of fire spots from 2006 to 2015 that coincided with public policies and funding for fire surveillance. The fact that we could not attribute to observed climate anomalies alone the recent (2015–2017) abrupt increase in fire emissions, lead us to hypothesize that it was partly due to recent lax oversight over agricultural activities. These detailed results can provide information about environmental and land use policy, fire events, and emissions associations, while tackling climate and health issues related to air quality.