They are often used to describe similar situations, as they generally refer to fires that exceed suppression capacity, put emergency crews and the public at risk, affect public health, property and ecosystems, and have major social, economic and environmental consequences.<\/p>\n\n\n\n
However, these terms do not mean exactly the same thing, and there are important nuances between them, although in some cases there is also considerable overlap. Since there is no common framework that defines them according to clearly established criteria and thresholds, their use depends to a large extent on context and expert judgement. As a result, the same wildfire may be described using different terms depending on the aspect one wishes to emphasise.<\/p>\n\n\n\n
This does not mean that some terms are more correct than others, nor that they are mutually exclusive. On the contrary, they often complement one another and make it possible to understand the same event from different perspectives.<\/p>\n\n\n\n
At the same time, this flexibility also gives rise to a certain lack of consensus. The difficulty of deciding which term to use, evident in public communication, also extends to the scientific and technical spheres, where there is still debate over the most appropriate terminology for describing these complex events.<\/p>\n\n\n\n
For this reason, and with the aim of shedding some light on the issue, this article reviews some of the most commonly used terms in order to better understand what they mean, the nuances that distinguish them, and the contexts in which they may be useful. Our aim is not to establish a rigid classification, but rather to offer a proposal based on our perspective that, as far as possible, brings together the different viewpoints of those who form part of the wildfire community.<\/p>\n\n\n\n
Large Wildfires (GIF): The Classification Used in Official Statistics<\/h2>\n\n\n\n
Of all the terms used to describe wildfires, Large Wildfire<\/em> is the only one that has an official classification in Spain. The General Wildfire Statistics (Estad\u00edstica General de Incendios Forestales<\/em>, EGIF), compiled by MITECO, group wildfire events into three broad categories: incipient fires<\/em> (conatos<\/em>), when they affect less than one hectare; wildfires<\/em>, when they burn between 1 and 500 hectares; and Large Wildfires<\/em> (GIF, from the Spanish Grandes Incendios Forestales<\/em>), when they exceed 500 hectares on the Spanish mainland or 250 hectares in island territories.<\/p>\n\n\n\n This classification is useful for organising data and comparing wildfire trends over time. However, its thresholds are not universal: they may vary between countries and even between regions within the same country, and they do not necessarily reflect the severity of an event on their own.<\/p>\n\n\n\n In this respect, although the area burned helps convey the scale of a wildfire, it does not tell the whole story. A 10,000-hectare wildfire that spreads over just a few days and affects communities located in the wildland\u2013urban interface may have very different consequences from a fire of the same size that burns for several weeks in a sparsely populated area. The area burned may be identical, but the context, rate of spread, population exposure, ecological damage and response capacity can differ substantially.<\/p>\n\n\n\n For this reason, the term Large Wildfire<\/em>, which is becoming increasingly prominent in public debate, does not refer solely to a fire that affects a large number of hectares. It is also used to describe wildfires that, for a sustained period, maintain rates of spread, fire intensity and flame lengths that exceed the suppression capacity of firefighting crews.<\/p>\n\n\n\n In this sense, GIFs constitute a broad category encompassing fires with widely differing behaviour and consequences, including Extreme Wildfire Events<\/em> (EWE).<\/p>\n\n\n\n Within this debate, the term extreme wildfires<\/em> (Extreme Wildfire Events<\/em>, EWE) is increasingly used to refer to fires that display particularly intense and difficult-to-predict behaviour. This term shares many characteristics with the concept of sixth-generation wildfires, which we will discuss later.<\/p>\n\n\n\n In these situations, fire spread can become erratic, with the emergence of isolated or widespread spot fires caused by firebrands transported over long distances. In addition, intense fire\u2013atmosphere interactions may occur, whereby the wildfire itself modifies local atmospheric conditions, generating winds, turbulence and sudden changes that make its behaviour even more unpredictable.<\/p>\n\n\n\n A significant example is the Pedr\u00f3g\u00e3o Grande wildfire in Portugal, which occurred in June 2017 and marked a turning point on the Iberian Peninsula. In just a few hours, more than 45,000 hectares burned, over sixty people lost their lives, hundreds were injured, and substantial damage was caused to infrastructure, property and essential services.<\/p>\n\n\n\n Beyond these figures, Pedr\u00f3g\u00e3o Grande showed just how difficult some wildfires could be to describe using the terminology available at the time. It demonstrated the capacity of certain fires to alter local atmospheric conditions and generate dynamics that are extremely difficult to predict and control, and even to favour the formation of pyrocumulus<\/a> (PyroCu<\/em>) and\/or pyrocumulonimbus<\/a> (PyroCb<\/em>) clouds\u2014convective clouds generated by the intense heat released by the fire.<\/p>\n\n\n\n The severity of its impacts also raised a key question: were we using the right words to describe these kinds of events?<\/p>\n\n\n\n It was then that approaches offering a broader understanding of these fires began to gain traction. Among them,\u00a0Tedim\u00a0et al<\/em>.<\/a>,\u00a0argued that focusing solely on fire behaviour was not enough: it was also necessary to consider how difficult a fire is to control, as well as the social and ecological impacts it may cause.<\/p>\n\n\n\n Sixth-generation wildfires can also be considered a type of Extreme Wildfire Event<\/em>, although there are some important differences to note.<\/p>\n\n\n\n Like other extreme wildfires, they release enormous amounts of energy, generate spot fires, and display behaviour that is extremely difficult to predict and control. They also interact strongly with the atmosphere and can generate fire-related clouds. In sixth-generation wildfires, however, these clouds often develop into pyrocumulonimbus clouds<\/a> (PyroCb<\/em>).<\/p>\n\n\n\n Beyond these differences in fire behaviour, the two concepts also reflect different perspectives.<\/p>\n\n\n\n One defining feature of the term is the uncertainty surrounding how the wildfire will evolve. This is due to the limited ability of current tools to predict and anticipate the development of these fires, as a result of their interaction with the atmosphere and the formation of PyroCb.<\/p>\n\n\n\n This makes decision-making particularly complex for those responsible for operational response, to the point that, at certain moments, the safety of neither emergency crews nor the population can be fully guaranteed.<\/p>\n\n\n\n The term extreme wildfire<\/em> describes these events in terms of their intensity, difficulty of control and impacts, whereas sixth-generation wildfire<\/em> approaches them from a more technical and operational perspective.<\/p>\n\n\n\n This classification was first proposed in 2005 by Marc Castellnou and Marta Miralles, from the Forest Action Support Group (GRAF) of the Fire and Rescue Service of the Government of Catalonia, as an operational planning tool.<\/p>\n\n\n\n Its purpose was to define each generation of wildfires according to the dominant factor limiting the technical capacity to control the fire. This factor is not directly linked to firefighting services, but rather to the characteristics of the landscape and its different stages of evolution, which may overlap in both time and space.<\/p>\n\n\n\n The landscape has changed considerably in recent decades. The abandonment of agricultural land, changes in land use and the expansion of forested areas have transformed the way fire spreads. These new conditions have also altered wildfire behaviour. This is why different generations of wildfires are distinguished.<\/p>\n\n\n\n Although the different generations began to be defined in the early 2000s, sixth-generation wildfires were not formally described until 2017, following the wildfire episodes recorded in Chile. In this type of wildfire, it is not only the amount of vegetation or its distribution across the landscape that matters. Atmospheric conditions and the state of forests are also key factors.<\/p>\n\n\n\n In the context of climate change, with more frequent heatwaves, more intense droughts and increasingly dry vegetation, these factors become even more decisive. Together, they create conditions that favour highly intense wildfires that are extremely difficult to anticipate and control.<\/p>\n\n\n\n This terminology therefore offers another way of describing these emerging wildfire scenarios, placing the emphasis on landscape evolution, climate change, interactions with the atmosphere and emergency response.\u00a0<\/p>\n\n\n\n Unlike other terms, referring to catastrophic wildfires<\/em> shifts the focus towards their consequences. This assessment is made from an anthropocentric perspective, that is, according to how the wildfire affects people, property, ecosystems, economic activity or the functioning of a territory.<\/p>\n\n\n\n This does not mean that all wildfires are necessarily harmful. In many landscapes, fire is part of the natural dynamics and, when it occurs at certain levels of intensity, frequency and extent, it can help renew vegetation, create clearings, recycle nutrients or promote the regeneration of certain species.<\/p>\n\n\n\n A wildfire is therefore not considered catastrophic solely because of its magnitude or the number of hectares burned, but because of the severity of the damage it causes from an anthropocentric perspective, and because of the territory\u2019s capacity to respond, rebuild and recover..\u00a0\u00a0<\/p>\n\n\n\n In recent years, the term megafire<\/em> has become increasingly common, particularly in public communication and the media, as a way of describing fires perceived as exceeding usual scales\u2014whether because of the area they burn, the intensity of their behaviour, the impacts they cause, or a combination of all these factors. Even so, it is not a clearly defined technical category, and its meaning overlaps with other existing terms.<\/p>\n\n\n\n Its use is especially widespread in English-speaking countries, although it also appears frequently in other contexts, including that of the European Commission. In some cases, the term is used to refer to fires that exceed 10,000 hectares, whether they result from a single ignition or from several related fires.<\/p>\n\n\n\n As we have seen, each term allows us to look at these wildfires from a different perspective. Some focus on fire behaviour, others on the landscape and operational response, and others on the area burned or the severity of the impacts.<\/p>\n\n\n\n Rather than fixed labels, then, these terms serve as tools for better understanding increasingly complex wildfire events.<\/p>\n\n\n\n The question is not which of these terms is the correct one, but what each one contributes and which aspect we want to highlight in each case. The same wildfire can be described using several different terms, provided they are used precisely and the perspective from which they are being applied is made clear.<\/p>\n\n\n\n Terminology will also continue to evolve as wildfires change and our understanding of them advances. New ways of naming and classifying these events are likely to emerge, allowing us to better capture their growing complexity.<\/p>\n\n\n\n So, rather than focusing on choosing a single label, what matters is understanding which aspect of the wildfire we want to emphasise: its size, its behaviour, its interaction with the atmosphere, the difficulty of controlling it, the landscape through which it spreads, or the impacts it causes. Only then can we use each concept more precisely without losing sight of the complexity of each event.<\/p>\n\n\n\n We would like to thank Marinha Fern\u00e1ndez for her initiative, the valuable information she contributed, and for drafting the first version of this outreach article during her internship at the Foundation<\/p>\n\n\n\n Classification of wildfire generations<\/strong><\/em><\/p>\n\n\n\n Castellnou, M., & Miralles, M. (2005). El concepte de generacions d’incendis: una eina de planificaci\u00f3 i adaptaci\u00f3 al risc de grans incendis forestals. Institut de Seguretat P\u00fablica de Catalunya (ISPC), Cos de Bombers de la Generalitat de Catalunya.\u202f<\/em> <\/p>\n\n\n\n Castellnou, M., Miralles, M., Larra\u00f1aga, A., Nebot, E., Arilla, E., Castellarnau, X., Castellv\u00ed, J., Herrera, J., Pallars, J., y miembros de UT GRAF. (2021). Clasificaci\u00f3n de las generaciones de incendios forestales: actualizaci\u00f3n. Revista Incendios y Riesgos Naturales (RIyRN)<\/em>, (3). https:\/\/revistarirn.org\/wp-content\/uploads\/2023\/03\/n3_generaciones-IFs_actualizacion_Castellnou_2001.pdf\u202f<\/a> <\/p>\n\n\n\n Extreme Wildfire Events (EWE)<\/strong><\/em><\/p>\n\n\n\n Tedim, F., Leone, V., Amraoui, M., Bouillon, C., Coughlan, M. R., Delogu, G. M., Fernandes, P. M., Ferreira, C., McCaffrey, S., McGee, T. K., Parente, J., Paton, D., Pereira, M. G., Ribeiro, L. M., Viegas, D. X., & Xanthopoulos, G. (2018). Defining Extreme Wildfire Events: Difficulties, Challenges, and Impacts. Fire<\/em>, 1<\/em>(1), 9. https:\/\/doi.org\/10.3390\/fire1010009<\/a> <\/p>\n\n\n\n Large Wildfire<\/strong><\/em>s<\/p>\n\n\n\n Costa, P., Larra\u00f1aga, A., Castellnou M., Miralles M., Kraus, D. (2011). La Prevenci\u00f3n de los Grandes Incendios Forestales adaptada al Incendio Tipo. Fire Paradox Project. https:\/\/gogl.to\/4J0a<\/a> <\/p>\n\n\n\n![\"\"](\"https:\/\/www.paucostafoundation.org\/wp-content\/uploads\/2026\/08\/Pedro_Armestre_4-1024x683.webp\")
<\/a>Extreme Wildfires: An Emerging Integrative Concept<\/h2>\n\n\n\n
<\/a>Sixth-generation wildfires: landscape, fire and response<\/h2>\n\n\n\n
<\/a>Catastrophic wildfires: the scale of their impacts<\/h2>\n\n\n\n
<\/a>Megafires: a popular term for wildfires that are out of the ordinary<\/h2>\n\n\n\n
<\/a>Whatever term we use, we should not lose sight of the broader context<\/h2>\n\n\n\n
Acknowledgements<\/h2>\n\n\n\n
References<\/h2>\n\n\n\n