A Book on Megafires Risk to Natural Heritage
The landscapes we consider heritage, both for their natural and cultural value, are under increasing pressure. In particular, the risk of large-scale fires, or “megafires,” is frequent threat.
A recent talk with Tom Ribe, author of the book ‘Inferno by Committee II’, highlighted how events like the Cerro Grande Fire in New Mexico in 2000 were not isolated incidents, but symptoms of deeper issues related to land management and climate change. Understanding the causes and consequences of these fires is crucial to protecting our treasures.
From Adapted Landscape to “Powder Keg”
For centuries, areas like the Jemez Mountains and the Sangre de Cristos in New Mexico were fire-adapted landscapes. Natural, low-intensity fires, often sparked by lightning, periodically burned the ground vegetation, keeping the forests open and healthy. This natural dynamic was profoundly altered by the arrival of European settlers. The introduction of large numbers of livestock (sheep and cattle), especially after the arrival of the railroad in the 1880s, led to severe overgrazing. The cattle decimated the tall, bushy grasses that once fueled the low-intensity fires, leaving the land denuded. Meanwhile, indiscriminate logging removed the largest trees, leaving behind debris and damaged soil.
Since the early 1900s, the policy of total forest fire suppression by agencies like the US Forest Service, while well-intentioned, has further disrupted the natural fire cycle. Without frequent, low-intensity fires, tree seedlings emerging from overgrazed land have grown undisturbed, creating dense stands of trees across hundreds of thousands of acres. These “mats” of small trees, needles, and debris have transformed what were once open, fire-resistant forests into a veritable “tinderbox,” extremely vulnerable to high-severity fires.
The Climate Change Accelerator
While historical practices have created conditions for more intense fires, climate change is acting as a powerful accelerator. Since 1996, the Southwest United States (and many other regions of the world) has experienced a sharp return to drier conditions and, more importantly, warmer temperatures, a trend that continues today.
This combination of drought and high temperatures has devastating effects on vegetation. Warmer air can hold more moisture, increasing evaporation from surface water, soil, and even the plants themselves. This phenomenon, known as vapor pressure deficit (VPD), stresses trees, making it harder for their roots to deliver enough water to their leaves. Water stress weakens them and makes them more susceptible to disease and insect attacks, such as bark beetles, which have killed tens of millions of trees. Recent studies indicate that 50% of forest trees between Wyoming and northern New Mexico have died due to temperature-related mortality.
In this scenario of stressed, dry forests, conditions become ideal for extremely hot and active wildfires. The warmer atmosphere is also more unstable, leading to more frequent and intense wind events, which can quickly turn a fire into a full-blown “firestorm.”
Wounds on Cultural and Natural Heritage
Fires don’t just destroy forests; they also inflict irreparable damage on cultural and natural heritage. The Cerro Grande Fire, for example, burned about 200 homes in Los Alamos and caused the loss of historic buildings within the Los Alamos National Laboratory site, such as some at V Site, which were of crucial importance to the physical history of the Manhattan Project. The flames do not spare natural treasures, as demonstrated by the death of a thousand-year-old juniper (alligator bark juniper) in Bandelier caused by the Las Conchas Fire in 2011, or the impact on ancient redwoods in California. Entire mountain areas, such as large portions of the Jemez Mountains, once green and forested, are now transformed into shrublands after fires.
Managing Risk: Challenges and Tools
In the face of this reality, land management requires effective tools. The use of prescribed (or controlled) fire is considered a necessary and fundamental tool for public lands managers. The idea is to reintroduce fire under controlled conditions to reduce fuel accumulation (dry vegetation) and restore a healthier landscape, as it naturally occurred before the 1900s. Science and experience play a crucial role in planning and executing these interventions, carefully considering variables such as weather, vegetation type and topography.
However, implementation presents challenges. Incidents such as the Cerro Grande Fire or, more recently, the devastating Hermit Peak/Calf Canyon Fire (the largest and most destructive wildfire in the history of New Mexico, which burned over 321,000 acres and 900 structures).
Science Role in Protection
Understanding these complex phenomena relies on science, particularly research on fire ecology and climate. Agencies like the National Park Service (NPS) and the US Forest Service (USFS), despite occasional criticism of their management, are the stewards of our public lands and the heritage they contain. It is these agencies, supported by science, that develop and implement strategies to mitigate fire risk and restore landscapes.
As Tom Ribe’s text makes clear, the very idea of public land is a concept of great value if linked to the commitment, towards our ancestors and future generations, to preserve and protect these places. In the face of the growing threat of mega-fires, it is essential not to ignore the problem but to base the answers on science and support land managers and collaborate to safeguard cultural and natural heritage before it is destroyed.
