Infographic: Wildfires and Climate Change

Table of Contents

Every year, millions of acres of land are consumed by fire in the United States. By raising temperatures, melting snow sooner, and drying soils and forests, climate change is fueling the problem. Here’s what we know.

#1: Wildfires are getting worse

A bar chart showing an increase in the number of wildfires — Data from the Monitoring Trends in Burn Severity program. MTBS only includes large fires in the United States (>500 acres for the eastern US, >1000 acres for the west). Prescribed fires removed.

A bar chart showing acreage burned by wildfires — Data from the Monitoring Trends in Burn Severity program. MTBS only includes large fires in the United States (>500 acres for the eastern US, >1000 acres for the west). Prescribed fires removed.

Since 2015, the United States has experienced, on average, roughly 100 more large wildfires every year than the year before. This changes region by region, and year to year, but generally we’re seeing more wildfires, more acres burned, and longer, more intense fire seasons.

#2 Wildfires are causing more harm

The perimeter of the Camp Fire overlayed on Chicago for scale — On left, the perimeter of the massive Camp Fire is overlayed on Chicago. Federal suppression costs from the National Interagency Fire Center.

A bar chart showing the rising federal cost to fight wildfire — On left, the perimeter of the massive Camp Fire is overlayed on Chicago. Federal suppression costs from the National Interagency Fire Center.

Wildfires are dangerous and destructive. The historically large Camp Fire of 2018 caused at least ninety deaths, destroyed more than 18,000 structures, and covered an area roughly the same size as the Chicago metropolitan area.

They're also expensive. Between 2014 and 2018, the federal government spent an average of 2.4 billion dollars fighting wildfires every year. Even when adjusted for inflation, that’s more than twice what we spent 20 years earlier (1994-1998).

And as the forests burn, they release carbon dioxide and other global warming gases, worsening climate change. As wildfires burn more land, emissions go up.

#3: Climate change is a key driver

A flow chart showing how global warming relates to forest fires. As temps go up, snow melts sooner and forests stay drier, longer. — Data shown are from John T. Abatzoglou and A. Park Williams, Impact of anthropogenic climate change on wildfire across western US forests, which models forest fire area as a function of fuel dryness both with and without climate change.

A stacked line area chart showing how climate change has increased the numbers of acres burned by wildfire. — Data shown are from John T. Abatzoglou and A. Park Williams, Impact of anthropogenic climate change on wildfire across western US forests, which models forest fire area as a function of fuel dryness both with and without climate change.

Fire has historically been a natural part of many wild landscapes. But global warming has changed some of the underlying variables that make wildfires more or less likely to occur every year.

Warmer temperatures increase the likelihood that fires will burn more intensely. They also cause snow to melt sooner, and lead to drier soils, forests, and plants, which act as kindling. Increased droughts, unusual rain patterns, and insect outbreaks that lead to large stands of dead trees are also connected with climate change—and they all make wildfires more likely.

#4 Management matters

Other factors also influence wildfire risk—especially management and development decisions in fire-prone areas near forests.

In the western United States, forests historically evolved with frequent, low-intensity fires that removed underbrush, debris, and fallen timber. This allowed for larger trees and made massive fires much less common.

But for the past century, almost all fires have been suppressed, even small ones. This has allowed forests to maintain denser growth and more potential fuel, leading to larger and more intense wildfires.

In addition, development near and into previously wild areas has increased fire risk and made fire-fighting more costly, challenging, and dangerous.

Government agencies have tried to lower forest density through prescribed burning (purposefully lit, low-intensity fires) and thinning (the physical removal of brush, vegetation and dead trees), but have struggled to do so at scale.

On smaller landscapes in the southeast, land managers conduct far more frequent prescribed burns. These fires bring their own risks, including poor air quality, and the chance of growing to be a damaging wildfire. But by mimicking smaller "natural" fires, prescribed burns can benefit forest ecology, and help mitigate at least some of the increased wildfire risk presented by climate change.

Climate change protester carries a sign that says 'Don't burn my future'

#5 Action is possible

In the near term, ecologically-sound forest and fire management could help limit fire risks.

But in the long-term, climate action is the best tool we have. When we reduce global warming emissions, we slow the growth of climate risks, including wildfire. Until then, summers will continue getting hotter, forests will get drier, and more and more people will face the threat of wildfire.

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