Extreme wildfires have repeatedly made headlines in recent years. Fuelled by increasing temperatures, changing precipitation patterns and extended drought periods, extreme wildfires are affecting more and more local communities and regional economies and threatening vulnerable ecosystems across the globe. The 2019-20 wildfires wreaked havoc in Australia, with environmental damages that may well last for decades. The 2018 Camp Fire became the deadliest in California’s history and caused economic costs amounting to USD 19 billion, without taking into account the indirect impacts. The consequences of wildfires also go beyond affected countries’ borders. Extreme wildfires in the Amazon region, such as those experienced in 2016, may trigger critical tipping points. These could result in abrupt shifts in vegetation cover, which in turn affect global carbon cycles.

The frequency and severity of wildfires, as well as the duration of the fire season, are increasing in many regions of the world. The occurrence of extreme wildfires – i.e. wildfire events that are particularly severe in terms of their size, duration, intensity and impacts – is also on the rise. In Australia, the average wildfire frequency has doubled since 1980. In the forests of the western United States, wildfire severity, i.e. the degree of ecosystem impacts caused by a fire, increased eightfold between 1985 and 2017. The duration of the fire weather season has increased by 27% globally since 1979.

Recent extreme wildfire events have caused unprecedented damages and had impacts on human communities, economies and the environment. Climate change is a key driver behind the growing occurrence of extreme wildfires. Under projected warming, wildfire frequency and severity are set to increase, calling for a fundamental shift in wildfire management towards enhanced wildfire prevention. This chapter summarises the main findings of this report, outlining observed and projected patterns in extreme wildfire activity as well as the emerging policy solutions to address them. The recommendations aim to inform countries’ policy progress towards building climate resilience to extreme wildfires.

This chapter provides an overview of the state-of-the-art scientific knowledge on wildfires, shedding light on the key factors that influence wildfires and their characteristics, as well as on how wildfire trends are changing globally. It discusses how anthropogenic climate change and human activity influence such changes, exacerbating the conditions for the occurrence of extreme wildfires. The chapter provides a comprehensive assessment of the environmental and socio-economic impacts caused by wildfires.

This chapter provides an overview of the trends in countries’ policies and practices in response to the growing occurrence of extreme wildfires. The analysis is informed by the findings of five in-depth country case studies conducted in Australia, Costa Rica, Greece, Portugal and the United States, in addition to a desk review of policies and practices adopted by countries globally. The chapter assesses whether and how countries have adapted their policies and practices in light of the growing occurrence of extreme wildfires. In doing so, it highlights the indispensable and growing role prevention measures play in limiting the impacts and costs of extreme wildfires. The chapter identifies good practices and highlights findings and recommendations for designing a conducive enabling environment.