Bruna Alves
Research lead covering environment and sustainability
Wildfires - statistics & facts
Wildfires are among the most visible extreme weather events. Defined as unplanned and uncontrolled fires occurring in forests or wildlands, the intensity and frequency with which they appear has increased due to a rapidly warming planet. Today, wildfires affect even previously unexposed communities and natural habitats. Extreme wildfires are forecast to increase 14 percent by 2030 and 30 percent by 2050. In 2021, there were 19 large wildfire disasters worldwide, the third-highest annual figure recorded this century.
This is part of a series on the effects of climate change.
The Amazon rainforest, which stretches across northwestern Brazil and parts of its neighboring countries, has become increasingly threatened by acts of deforestation and naturally occurring wildfires. In 2022, over 145,000 wildfire outbreaks were recorded in the Legal Amazon area in Brazil, accounting for nearly three-quarters of all wildfires in the country that year. Canada, Russia, Australia, Spain, Greece, and Indonesia are also among the countries ravaged by large wildfires in recent years.
This is part of a series on the effects of climate change.
How do wildfires start?
The two most common causes for wildfires are lightning strikes and human activity, although determining the origin is not always possible. Wildfires have been documented throughout human history and usually start when weather conditions are particularly dry and hot. Areas that offer dense vegetation are more susceptible to such outbreaks, which is why indigenous people introduced controlled burns to reduce the dangers of larger uncontrollable fires. In the past decade, on average, more than five million hectares of tree cover were lost per year due to wildfires worldwide.Most affected regions
The United States is among the countries most affected by wildfires. In the past decade, between three and 10 million acres of land were burned every year. Most of these wildfires occur in the West, a region that receives minimal rainfall in the hot summer months and is home to easily flammable pine forests and shrublands. California has been hit by some of the most destructive wildfires in recent history, and its annual fire season has begun to stretch longer each year as Californian lands have become drier.The Amazon rainforest, which stretches across northwestern Brazil and parts of its neighboring countries, has become increasingly threatened by acts of deforestation and naturally occurring wildfires. In 2022, over 145,000 wildfire outbreaks were recorded in the Legal Amazon area in Brazil, accounting for nearly three-quarters of all wildfires in the country that year. Canada, Russia, Australia, Spain, Greece, and Indonesia are also among the countries ravaged by large wildfires in recent years.
The effects of wildfires
Depending on the success of early containment efforts, wildfires may cause incredible harm to humans, properties, and infrastructure, especially if they occur near densely populated areas. In the past decade, the 2018 Camp Fire in California was the most expensive wildfire for the insurance industry worldwide, with losses estimated at 12.5 billion U.S. dollars. Globally, there were around 70 deaths caused by wildfires in 2020, which is a considerably lower death toll than other extreme weather events, such as tropical cyclones and floods. Nonetheless, indirect deaths and adverse health effects from smoke pollution are estimated to be significantly higher. In addition, the burning of wildland vegetation releases climate-warming greenhouse gas emissions estimated at billions of metric tons per year, creating a vicious circle of devastation.
