Wildfires (recent)

What is happening?

  • Wildfires are defined as destructive fires that quickly spread through forests or brush. Wildfires occur naturally and help the forest ecosystem remain healthy. However, uncontrollable blazes can threaten homes, infrastructure, and businesses.
  • The frequency and severity of wildfires has rapidly increased since at least 1985 (graphs below). There were 13% more wildfires globally in the year 2020 than in 2019.

Graphs with time on the horizontal axis and with the vertical axes showing the number of wildfires per year (left) and the number of acres burned per year (right; from UCSUSA, 2020).

  • Fighting wildfires is very expensive. Between 2014 and 2018 the US government spent 2.4 billion dollars on fighting wildfires, more than twice the amount spent between 1994 and 1998. 

How do wildfires affect people?

  • Wildfires also have a large impact on human health. It has been reported that over 300,000 people die prematurely every year due to wildfire smoke. As the occurrence of wildfires continues to increase, this number will only go up.
  • Additionally, wildfires clear vegetation and leave soil more vulnerable to drying out and erosion. Wind can pick up fine dust particles from the ground and carry them into the atmosphere. An accumulation of such particles can form dust storms that can last for weeks. During these dust storms, air quality becomes dangerous to human health as phosphorus, nitrogen, and iron particles can be inhaled.

Examples of Major Wildfires


  • The number of yearly wildfires in California doubled from 2019 to 2020, reaching over 8,200 separate fires. Overall, these fires burned more than 4 million acres of land. Pictured below is an image of one of the fires, and a map of wildfire locations in California. 

Image of a wildfire in California (left; from NBC News 2020), and a map of wildfire locations in California in the year 2020 (right; from Cal Fire 2020).


  • Widespread bushfires killed and displaced 3 billion animals in Australia in early 2020. Bushfires refer to wildfires in areas with lots of scrub vegetation. Pictured below is an image of the bushfires as well as a map showing their locations. 

Image of a bushfire in Australia (left; from NYT 2020), and a map of the bushfire locations in the year 2020 (right; from BBC News 2020).


  • In the summer of 2023, Canada experienced its most catastrophic wildfire season (image below left) in three decades. Hundreds of separate fires burned throughout the country, torching over 11 million hectares (27 million acres) by July. The smoke and dust from the blazes degraded air quality across the United States (image below right).

Map of the locations of wildfires across North America in summer 2023 (left; from Czachor, 2023), and a photograph of the New York City skyline covered in orange smog after a period of major wildfires in Canada (right; from Keane, 2023).

How is this related to climate?

  • While wildfires are naturally occurring, climate change has altered the many factors that lead to wildfires. Climate scientists estimate that increasing drought and warmer temperatures can make wildfires over 50% more frequent by the year 2100.
    • As average global temperatures increase, snow and ice melt sooner in the year than they do naturally. This causes the forest to remain drier for a longer period of time. A forest that is drier and hotter is far more susceptible to wildfires. 
    • Climate change and wildfires form a positive feedback loop. Wildfires destroy large carbon sinks and release copious amounts of carbon dioxide into the atmosphere. As climate change causes wildfires to increase, the carbon in the atmosphere increases, causing climate change to worsen in the long-term.

References and additional resources