New insights on global fire extremes from object-based fire inventories

Natural ecosystems are fundamental to biodiversity and reaching net-zero, but are at increasing risk from disturbance events like drought and fire. Across many landscapes, fire responds non-linearly to drought and temperature changes, obscuring evolving fire risk until critical thresholds are breached. In particular, in the absence of natural or human-made barriers, growing fire perimeters result in non-linear increases of daily burned area over the lifetime of any individual fire. Fuel conditions and structure further determine the velocity at which fires can spread across the landscape. Predicting fire extremes remains notoriously difficult due to these non-linear responses and complex interactions of natural and managed landscapes, short observational time-series from satellites, and rapid regional trends in climate and human activity. 

 

One potential new avenue of exploring fire extremes is through the use of novel object-based fire inventories, like the Global Fire Atlas or Amazon Dashboard. Here we use these novel approaches to assess several recently unfolding fire extremes, with special attention to South America. We find that fire extremes can both unfold within a single season or drought year, as well as over the course of multiple years with continued heightened fire activity across a particular landscape. Further characterization of fire types, based on unique characteristics of each fire object, helps better separate climate and land-use driven variability and change in fire extremes. Our results provide novel insights in the underlying mechanisms driving exceptional fire activity, which can inform estimates of future change and land management strategies.