While several studies have reported a recent decline in area burned in Africa, the causes of this decline are still not well understood. In this study, we found that from 2002 to 2016 burned area in Africa declined by 18.5%, with the strongest decline (80% of the area) in the Northern Hemisphere. One third of the reduction in burned area occurred in croplands, suggesting that changes in agricultural practices (including cropland expansion) are not the predominant factor behind recent changes in fire extent. Linear models that considered interannual variability in climate factors directly related to biomass productivity and aridity explained about 70% of the decline in burned area in natural land cover. Our results provide evidence that despite the fact that most fires are human‐caused in Africa, increased terrestrial moisture during 2002–2016 facilitated declines in fire activity in Africa.

Burned area estimates are an essential component of cropland management systems, inventory-based fire emission calculations, and air quality models, and any inaccuracies in these estimates propagate into the final outputs and decision-making process. While satellite-based global burned area and fire emission datasets (e.g., GFED, FireCCI51, and MCD64A1) are frequently cited in the scientific literature and are employed by a range of users from atmospheric and carbon modelers to policy-makers, they are generally not optimized for cropland burning – a quintessential small-fire type. Here we describe a new dataset (GloCAB; global cropland area burned) which represents the first attempt at a global cropland-focused burned area product. The GloCAB dataset provides global, monthly cropland burned area at 0.25^∘ spatial resolution from July 2002 to December 2020. Crop-specific burned area conversion factors for several widespread burnable crops (winter wheat, spring wheat, maize, rice, and sugarcane) were calculated from extensively mapped cropland reference regions spanning 191 560 fields over 5 different countries. We found global annual cropland burned area (2003–2020) ranged between 64 Mha (2018) and 102 Mha (2008) with an average of 81 Mha using our lower-bound estimates, which are substantially higher than the annual average of 32 Mha in the MCD64A1 C6 product. Region-specific trend analysis found some areas with significant increasing trends (northwest India), while the heterogeneity of many other regions showed no burned area trends. The GloCAB product is freely accessible at https://doi.org/10.5281/zenodo.7860452 (Hall et al., 2023).

The global extent of the amount of burned area seems to have changed substantially in the last two decades. Discussions regarding the main force behind the current trends have dominated research in recent years, with several studies attributing the global decline in wildfires to socio-economic and land-use changes. This review discusses the uncertainties and limitations of remotely sensed data used to determine global trends in burned areas and changes in their potential drivers. In particular, we quantify changes in the amount of burned area and cropland area and illustrate the lack of consistency in the direction and magnitude of the trend in cropland land cover type specifically within sub-Saharan Africa, the region where data show a strong trend in the amount of burned area. We state the limitations of remote-sensed fire and land cover products. We end by demonstrating that based on the currently available data and research methods applied in the literature, it is not possible to unequivocally determine that cropland expansion is the primary driver of the decline in fire activity.

It has been 10 years since the start of the Syrian uprisings. While relative stability is improving overall, a new disaster, wildfires, impacted an already food-insecure population by burning through key production areas, damaging crops, soil, and livestock and causing air quality to deteriorate. As observed with remotely sensed data, fire affected 4.8% of Syria in 2019, as compared with the average 0.2%, and most fires were observed within agricultural land in the northeast. Abnormal amounts of rainfall during the 2019 growing season and, consequently, high soil moisture explained about 62% of the drastic increase in the burned area extent. In contrast, in 2020, fires continued despite the average amount of rainfall. Extremely high temperature could partially explain a 10-fold increase in the extent of burned area in 2020 but only within forested regions in the northwest. We argue that the abrupt changes in Syria’s fire activity were driven by the complex interactions among conflict, migration, land use, and climate. On one side, the ongoing conflict leads to a drastic increase in the number of accidental and deliberate fires and reduced capacity for fire response. On the other side, years of insecurity, widespread displacement, and economic instability left no choice for locals other than exploiting fires to remove natural vegetation for expanding farming, logging, and charcoal trading. The loss of agricultural production and natural vegetation to fire can have serious implications for food security, soil property, biodiversity, and ecosystem services, which can further exacerbate the already unstable economy and make ongoing violence even more intense.

Despite the widespread use of the “fire regime” concept for describing spatial and temporal patterns and ecosystem impacts of fire, this concept lacks an unambiguous, quantitative definition. By adopting from the ecological literature the concept of climate niche, that is, the environmental conditions that allow a specie to exist, we propose a new framework where variables that promote fuel accumulation and desiccation were used to define the environmental space at the continental level, later divided into regions (“fire regions”) with distinct fire potential. Our proposed approach emphasizes climate controls on fire patterns, distinct from the controls that humans exert on observed fire activity. By applying this framework, we identified nine fire regions in Africa and eight in Australia, distinguishing differences in fire patterns between continents as a result of changes in environmental gradient. Not only did we find that fire size and intensity varied significantly between continents, but biomes at a continental level were also found to be heterogeneous in terms of fire frequency, size, and intensity. For example, within African tropical savannas, the total annual rainfall and tree cover change drastically North and South of the equator, resulting in fire regions with significantly different fire characteristics. Meanwhile, in Australia, a strong gradient of annual temperature and precipitation seasonality was observed within tropical savannas and xeric shrublands, which was recognized by dividing those biomes into five regions with statistically different fire activity. Additionally, human presence led to some heterogeneity of fire patterns within delineated fire regions that also varied across biomes.