Fire is an important Earth system process and the primary terrestrial ecosystem disturbance agent on a global scale, and it depends on vegetation characteristics, climate, and human activities. This phenomenon generates feedback by affecting biogeochemical cycles, vegetation composition and structure, land-atmosphere, water and heat exchanges, atmospheric chemistry and composition, as well as human health and property. Thus, wildfires are a key variable in the global Earth system and are an integral part of some biomes, being an essential factor for the functioning of many ecosystems.
The Earth is vast and its ‘pyrogeography’ has varied and changed throughout its geological history. Megafires were once rare, but they are becoming increasingly common. Their occurrence is now frequent, as an isolated event or encompassed in multiple fire episodes, in various regions of the world. This development has contributed to increasing concerns, as they constitute a hard disaster phenomenon with many serious negative effects, often leading to human fatalities.
Megafires in the modern era
China’s 1987 Great Black Dragon Fire perhaps marked the beginning of the megafire phenomenon in the modern era. The wildland fire claimed the lives of over 200 people and burned approximately 1.2 million hectares.
Similar events occurred across the nineteenth and twentieth centuries. The Miramichi Fire (1825), the Peshtigo Fire (1871), the Great Fire in the United States (1910), the Black Friday Bushfire in Australia’s state of Victoria (1939), as well as the Fire in Brazil’s state of Paraná (1963) were particularly notable fires.
Recent decades have been marked by a growing concern about problems related to climate change and its direct and indirect effects on society, some of which are directly or indirectly related to natural risks and the possibility of their manifestation leading to natural disasters.
In 1989 the United Nations established the International Day for Disaster Reduction and the following years, i.e., the 1990s, were declared as the International Decade for Natural Disaster Reduction (IDNDR). The initiatives and activities developed within the framework of the IDNDR culminated in the Geneva Mandate on Disaster Reduction, adopted in 1999, which considered disaster reduction and risk management as essential elements to be included in government policies to ensure sustainable development and investment.
Despite such efforts to mitigate natural disasters, more than two decades later, in 2022, the United Nations Office for Disaster Risk Reduction (UNDRR) presented the Global Assessment Report (GAR2022), entitled “Our World at Risk: Transforming Governance for a Resilient Future”, in which it is predicted that by 2030 an average of 560 disasters will occur each year, which represents 1.5 disasters every day .
The Global Risks Report 2022 identifies that, at the environmental level, failures in mitigation and adaptation to climate change (1st), extreme weather events (2nd), biodiversity loss (3rd), human environmental damage (7th) and natural resource crises (8th), among the 10 most serious global risks for the next 10 years, some of which have been strongly enhanced by the ongoing pandemic crisis.
The report points out that, for example, extreme weather events (cold waves, wildfires, floods, heat waves, storms, etc.) will lead to an increase in losses of human life, damage to ecosystems and the destruction of property and/or financial losses on a global scale.
In fact, climate change is already rapidly manifesting itself in the form of droughts, wildfires, floods, scarcity of resources and loss of species, among other impacts, and it is known that some actions to mitigate them will also imply costs to nature.
The age of fire
Since 2015, Stephen Pyne has been warning that the intensification of wildfires, exacerbated by the climate crisis, may usher in a new era – the Age of Fire, or Pyrocene.
Although this is a provocative warning, the last decade has shown that we are facing a new generation of wildfires on a global scale of which neither territories, people or current protection and rescue systems are prepared.
This reality has forced authorities to adopt a range of risk management measures, including reinforcement of education for risk, a serious and continued commitment to territorial planning, ongoing analysis, prevention and risk management measures, and adopting novel multi-risk methodologies that are now fundamental for risk management.
Further to this, cost/benefit analysis is needed, as well as a consideration of social dynamics such as individual risk. All risk factors together – a concept known as “reaction capacity” – provides an important framework to megafire prevention and emergency planning that should be factored into megafire risk management.