✦Upcoming✦ 29 JUL 2026 (WED) 11:00-12:00

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Departmental Research Seminars Series

The Fire Continent: 25 Years of Hemispheric Contrasts and Climate Feedbacks in Sub-Saharan Africa

Date: 29 JUL 2026 (Wednesday)

Time: 11:00-12:00 (HKT)

Venue: CPD-3.01, The Jockey Club Tower, Centennial Campus, HKU

Registration link: https://hkuems1.hku.hk/hkuems/ec_hdetail.aspx?guest=Y&ueid=108637

Abstract:

Sub-Saharan Africa, the world's "fire continent," accounts for approximately 70% of global annual burned area, yet comprehensive long-term analyses of its fire regimes remain limited. This study analyzes 25 years (2001–2025) of MODIS-derived burned area data, revealing a pronounced hemispheric asymmetry. Southern Hemisphere Africa (SHA) burns 30% more area annually (1.4 vs. 1.1 million km²) than Northern Hemisphere Africa (NHA), with savannas and grasslands accounting for 86% of continental burned area. While most ecosystems show significant declining trends, NHA savannas declining by 40.7% and croplands by 63.0%, evergreen forest fires are increasing in both hemispheres (+52.6% in SHA), signaling climate-driven vulnerability. Fire size distribution followed a characteristic Pareto or "long-tail" pattern: the vast majority of fires were small (<1.0 km²) and contributed negligibly to total burned area, while a tiny fraction of megafires (>50 km²) disproportionately drove aggregate burned area. Notably, while total burned area declined over the 25-year period, the proportion of very small fires (<0.25 km²) increased, a pattern indicative of landscape fragmentation from agricultural expansion, which creates firebreaks that limit fire spread. Cross-correlation analysis reveals hemisphere-specific fire-precipitation feedbacks: NHA fires precede precipitation reductions (lag: -1 to -3 years), while SHA precipitation drives fire occurrence (lag: 0 to +3 years). This study underscores the complex interplay between anthropogenic fragmentation, climate variability, and fire regimes, with critical implications for carbon emissions, biodiversity conservation, and fire management across Africa.