Wildfires are an escalating global hazard that threaten ecosystems, air quality and societies1,2. Although tall tropical mountains have generally been considered too cool and moist to burn3, the recent occurrence of high-elevation wildfires on Africa’s highest mountains suggests the emergence of a new and potentially transformative threat. A lack of historical records of fire in these environments limits our understanding of fire activity, its environmental impacts and the resilience of Afromontane ecosystems. Here we show that a twenty-first century fire was the first to affect Afroalpine elevations (>3,800 m above sea level (a.s.l.)) over the past 12 thousand years in the Rwenzori Mountains, Central Africa. At mid-elevations (2,990 m a.s.l.), fire increased abruptly around 2 thousand years ago, coincident with regional evidence for changing human activity4, and this was followed by an increase in bamboo-dominated ecosystems. Our results highlight the role of humans as an important driver of Afromontane fire activity and show that high-elevation tropical Afroalpine fire is a new twenty-first century disturbance that could transform high-elevation tropical ecosystems.
