‘Megafire’ — you may not like it, but you cannot avoid it

Authors: Grant D Linley, Chris J Jolly, Tim S Doherty, William L Geary, Dolors Armenteras, Claire M Belcher, Rebecca Bliege Bird, Andrea Duane, Michael-Shawn Fletcher, Melisa A Giorgis, Angie Haslem, Gavin M Jones, Luke T Kelly, Calvin K F Lee, Rachael H Nolan, Catherine L Parr, Juli G Pausas, Jodi N Price, Adrián Regos, Euan G Ritchie, Julien Ruffault, Grant J Williamson, Qianhan Wu, and Dale G Nimmo

Published in: Global Ecology and Biogeography

Abstract

Aim: The term ‘megafire’ is increasingly used to describe large fires worldwide. We proposed a size-based definition of megafire—fires exceeding 10,000 ha arising from single or multiple related ignition events. A recent perspective in Global Ecology and Biogeography argues against a size-based definition of megafire and suggest that the term is too emotive for scientific use. We highlight that many scientific terms originate from common terms. These terms are often defined once they enter the scientific lexicon, enhancing both scientific understanding and public communication. We argue that standardised definitions facilitate better prediction, preparation, and management of fire events.

Location: Worldwide.

Time period: 2022–2023.

Methods: We conducted an updated structured review of the term ‘megafire’ and its use and definition in the peer-reviewed scientific literature, collating definitions and descriptions and identifying the criteria frequently invoked to define the term.

Results: We demonstrate an increase in the use of ‘megafire’ in the scientific literature since our original definition in 2022, with many studies adopting the > 10,000 ha size-based criterion.

Main conclusions: We contend that abandoning the term is neither practical, possible, nor beneficial. Instead, consistent usage underpinned by clear definitions is essential. Adopting a clear, size-based definition of megafire strengthens clarity and comparability across research and management practices globally. Precision in terminology is crucial for advancing research, improving communication, and informing effective fire management and policy.

Linley GD, Jolly CJ, Doherty TS, Geary WL, Armenteras D, Belcher CM, Bliege Bird R, Duane A, Fletcher M, Giorgis MA, Haslem A, Jones GM, Kelly LT, Lee CKF, Nolan RH, Parr CL, Pausas JG, Price JN, Regos A, Ritchie EG, Ruffault J, Williamson GJ, Wu Q, Nimmo DG (2025) ‘Megafire’ — you may not like it, but you cannot avoid it. Global Ecology and Biogeography PDF DOI