We are hearing ever more frequent mention of ‘Megafires’. The word is an emerging concept commonly used to describe fires that are extreme in terms of size, behaviour, and/or impacts.

In describing ‘Megafires’, it is clear that fire size thresholds vary round the world from > 100 to more 100,000 ha. In Australia, a mega fire year is defined as the cumulative burned area of forest over one year of more than 1 million hectares. Fires greater than 100,000 hectares have also been increasing – check this list for details.

A new research paper (What do you mean, ‘megafire’?, available here) proposes a uniform definition be used around the world.  The authors suggest megafire be described as fires > 10,000 ha arising from single or multiple related ignition events. They also introduce two additional terms – gigafire (fires greater than 100,000 ha) and terafire (> 1,000,000 ha) – for fires of an even larger scale than megafires. Australia has experienced at least six fires greater than 1 million hectares since 1851.

Check here for details on the growing risk of large fires and how to deal with them.