What is a wildfire?

At its most basic, a wildfire is a chemical reaction of combustion, which requires a source of heat, oxygen, and fuel to get started. With wildfires, the fuel is the vegetation available to burn (e.g. forests, shrubs, or pastures), the oxygen is available in the air, and the heat may have various sources: a lightning, an agricultural burn which escapes, or a spark originating in an electric line.

It is important to also know that not every fire is undesirable from a social or even ecological perspective. Wildfires are complex socioecological phenomena (Tedim et al., 2016), which, in some ecosystems such as savannahs or Mediterranean forests, are a natural disturbance needed for their survival. 

Wildfire risks are increasing worldwide because of climate change and land use change. This means also that wildfires are becoming a challenge in regions where they were not a concern before, and traditionally fire-prone regions are suffering from wildfire events which surpass their suppression capacities.
 

Further reading

Pyne, S.J. 2022. The Pyrocene: How we created an age of fire, and what happens next.

Tedim et al. 2016. A wildfire risk management concept based on a social-ecological approach in the European Union: Fire Smart
Territory. International Journal of Disaster Risk Reduction, 18, 138–153. https://doi.org/10.1016/j.ijdrr.2016.06.005