Effects of climate and land‐use change scenarios on fire probability during the 21st century in the Brazilian Amazon

Abstract

The joint and relative effects of future land‐use and climate change on fire occurrence in the Amazon, as well its seasonal variation, are still poorly understood, despite its recognized importance. Using the maximum entropy method (MaxEnt), we combined regional land‐use projections and climatic data from the CMIP5 multimodel ensemble to investigate the monthly probability of fire occurrence in the mid (2041–2070) and late (2071–2100) 21st century in the Brazilian Amazon. We found striking spatial variation in the fire relative probability (FRP) change along the months, with October showing the highest overall change. Considering climate only, the area with FRP ≥ 0.3 (a threshold chosen based on the literature) in October increases 6.9% by 2071–2100 compared to the baseline period under the representative concentration pathway (RCP) 4.5 and 27.7% under the RCP 8.5. The best‐case land‐use scenario (“Sustainability”) alone causes a 10.6% increase in the area with FRP ≥ 0.3, while the worse‐case land‐use scenario (“Fragmentation”) causes a 73.2% increase. The optimistic climate‐land‐use projection (Sustainability and RCP 4.5) causes a 21.3% increase in the area with FRP ≥ 0.3 in October by 2071–2100 compared to the baseline period. In contrast, the most pessimistic climate‐land‐use projection (Fragmentation and RCP 8.5) causes a widespread increase in FRP (113.5% increase in the area with FRP ≥ 0.3), and prolongs the fire season, displacing its peak. Combining the Sustainability land‐use and RCP 8.5 scenarios causes a 39.1% increase in the area with FRP ≥ 0.3. We conclude that avoiding the regress on land‐use governance in the Brazilian Amazon (i.e., decrease in the extension and level of conservation of the protected areas, reduced environmental laws enforcement, extensive road paving, and increased deforestation) would substantially mitigate the effects of climate change on fire probability, even under the most pessimistic RCP 8.5 scenario.

Modelling the impact of climate change on Tanzanian forests

“…Future simulations should consider using the information on the spatial pattern of change, such as proximity (distance rasters) to urban centres and road networks, and density rasters of projected population growth (population data surface). Construction of road networks across forests is likely to trigger increased forest degradation and fire incidences that in turn are expected to alter regional climate (Fonseca et al., 2019; Nepstad et al., 2001). Future work also should explicitly consider the impact of sea‐level rise and geomorphology on Tanzanian mangroves to fully understand how these essential habitats might change as a result of climate change.…”

Technical note: Low meteorological influence found in 2019 Amazonia fires

“…Between September 2019 and February 2020, fires across eastern Australian temperate woodlands burnt around 18.6 million hectares, destroyed over 5,900 buildings, and killed at least 34 people (Boer et al, 2020;RFS, 2019;Sanderson and Fisher, 2020) . Unusual fire events such as these are expected to increase in frequency in the future from both changes in climate and socio-economic pressures on the landscape (Fonseca et al, 2019;Jones et al, 2020) . Given the concerns raised and the extent to which much of these fire events captured the attention of the public and press in recent months, in the aftermath it is important to look at these events objectively.…”

Persistent fire foci in all biomes undermine the Paris Agreement in Brazil

“…Brazil benefits from diverse soil and climatic conditions that are distributed among the six biomes. These biomes are prone to accidental fires and those that may occur as a result of inappropriate management practices 14,15 . Fires and the burning of biomass impacts ecosystem processes across a wide range of biomes at the regional and global scales 16 .…”