Brien A. Seeley M.D., President, Sustainable Aviation Foundation
Wildfires & CO2
A wildfire is defined as an unplanned, uncontrolled, and unpredictable fire in an area of combustible vegetation. Recent boreal forest wildfires in the US, Canada, Australia, Brazil and Russia have made international headlines due to increased frequency and intensity, threatening climate goals and biodiverse habitats. Despite this alarming data, CO2 emissions caused by wildfires have generally been regarded by global climate summits as untouchable natural events (like volcanic eruptions) that are baked-in to planetary ecosystems.
When the latest data on mean global wildfire burn areas over the 20-year period from 2000 to 2020 is cumulatively multiplied by their respective net ecosystem exchange values (NEE), that first-order calculation shows wildfires to be responsible for an astonishing 101 gigatonnes of atmospheric CO2 contribution in the year 2020 alone. This value is shocking, and yet conservative for at least two reasons — It only includes the most recent 20 year period during which we have accurate data for burn areas and NEE, and It only accumulates sequestration losses for the first 50% of the burned area’s regrowth period
This 101 gigatonnes includes both the CO2 contributed via wildfire smoke directly and the 20-year accumulation of lost sequestration of CO2 globally due to their annual devastation of vegetation. This 101 gigatonnes of CO2 will increase every subsequent year that wildfires burn and is already 2.5x larger than the nearly 40 gigatonnes of annual CO2 emission caused by all global use of fossil fuels by humans. Moreover, the World Resources Institute that wildfire frequency and severity could increase by more than 200% by 2050.
This “baked-in” CO2 contribution is a huge opportunity for our CO2 mitigation goals, hiding in plain sight.
The Cost of Wildfire CO2
According to the US EPA, each gigatonne of CO2 emitted worsens global climate damage by $190 billion dollars. By that metric, 101 gigatonnes of CO2 due to wildfires amounts to $19 trillion dollars per year in loss and damages.
Kotz et al in their April 17, 2024 report in Nature offer the latest information on climate mitigation costs for already committed loss and damage, stating that “the world economy is [already] committed to an income reduction of 19% within the next 26 years independent of future emission choices… These damages already outweigh the mitigation costs required to limit global warming to 2 °C by sixfold.” Those findings urge implementing bold mitigation programs as quickly as possible.
Increased wildfire damage in the Western US has led several insurance companies to cancel the homeowners insurance on thousands of homes there, resulting in steeply rising premiums that directly transfer the costs of fire loss and damage to taxpayers. Attribution scientists are increasingly successful in applying tort law to hold individuals, corporations and government agencies liable for loss and damages due to their inaction in preventing fires and other environmental impacts.
Increasing evidence indicates that huge atmospheric CO2 emissions are hastening extreme weather events. Last summer, the United Nations found that the global average temperature during July 2023 was confirmed to be the highest on record and that coincided with the highest-ever ocean surface temperatures.
Taken together, these alarming findings demand that the world find a way to end wildfires. The enormity of that task and its urgency for saving the planet place it as the responsibility of the governments of the wealthiest nations on Earth.
A Mitigation Plan
The Sustainable Aviation Foundation (SAF) has investigated what it would take to end wildfires.
On September 2, 2020, SAF leaders met with the directors of CAL FIRE Aviation to identify the main challenges to ending wildfires. The first challenge — the extreme difficulty of getting ground crews, fire-engines and bulldozers to reach remote wildfires in time to be effective — made it obvious that direct aerial attack will be essential to ending wildfires. The directors enumerated the specific challenges to the present aerial attack system as:
- Too few pilots trained to fly air-tankers
- The inability of aerial crews to fly at night or in heavy smoke
- Excessive time for large air tankers to load, launch and arrive on-scene
- Too few air tankers (owing largely to their cost of about $24M each)
- The need for near-immediate fire detection and dispatch orders
- Excessive aircrew hazard exposures (chemical, smoke inhalation, collision, flammable avgas)
- The need to establish interoperable networked surveillance, air traffic control and persistent communications across fire zones.
After the CAL FIRE meeting, SAF staff devoted 3 years of study to developing a proposed system called Autonomous Aerial Firefighting (AAF) that could meet all of these challenges.
The mission of AAF is to effectively contain and control any nascent wildfire within the first hour after its outbreak, 24/7, regardless of its location. To achieve that mission, AAF requires early detection dispatch and arrival on-scene followed by nearly continuous aerial drops of fire suppressing liquid by swarms of autonomous (uncrewed) electrically-powered fire-fighting aircraft. These aircraft are dispatched from a ubiquitous network of hundreds of air attack bases located so as to enable them to quickly reach wildfires. These swarms of uncrewed aircraft would carry no flammable fuel and would be fully capable of flying at night or in heavy smoke.
Today’s existing air attack bases typically occupy more than a thousand acres owing to the very long runways required by very large airtanker (VLAT) aircraft. Alternatively, AAF proposes a fleet of small electric aircraft operating from a distributed network of much smaller 3-acre air attack bases located strategically close to areas susceptible to wildfire. These thousands of small, interoperable AAF air tankers are capable of extremely short take-off and landing (ESTOL), allowing them to modularly operate in virtual teams covering large areas of wildland forest with fast deployment. In order to obtain community acceptance of the necessary frequent and nighttime aerial firefighting flight operations at close-in neighborhood airparks, these aircraft must be very quiet.
Our studies indicate that at full capacity, AAF aircraft could arrive on-scene 4 times faster and drop 20 times more liquid than present aerial attack systems.
Development of a reference design for a next-gen aircraft that can achieve the mission requirements of AAF has entailed the study and convergence of the latest technologies. These technologies include robotic assembly, machine learning, self-navigation using INS, GPS and synthetic vision, aerial agility with negligible control latency, high resolution thermographic cameras, advanced materials, swappable battery packs, swappable payload modules, circulation control in high lift systems, ballistic vehicle parachutes and more.
To maintain nearly continuous drops of fire retardant, each fire-fighting ESTOL aircraft must quickly refill with fire retardant after returning to base using robotic loading systems. Such fast turnaround times are crucial to enabling the nearly-continuous bucket–brigade-like drops of fire retardant.
The Costs To End Wildfires
AAF at full scale requires a fleet of thousands of uncrewed fire-fighting aircraft. Such a system will be costly to develop and deploy, but as covered above will mitigate billions of dollars of impending climate costs. In addition to these cost defrayals, our studies indicate that the development of AAF will yield significant second-order economic benefits during the development and operation phases. Among those benefits are:
- Potential use as passenger-carrying transit aircraft
- Potential use for last-mile cargo and logistics missions
- A revitalized small aerospace sector
- New manufacturing techniques for EVs, batteries, robotics, and composite structures
- Regional economic development through support of AAF air bases
These benefits are secondary to the primary mission of CO2 reduction, yet hold huge potential as an economic engine to fuel AAF and other climate initiatives.
Taking Action
The cumulative effects of wildfires, worsened by fossil fuel-driven climate change, and seen now to be responsible for annual CO2 emissions that surpass by 2.5-fold the emissions due to fossil fuels, can no longer be ignored as untouchable nature. The estimated $19 trillion dollars per year cost of global wildfire damage justifies large national expenditures to reduce or end that damage.
The Sustainable Aviation Foundation has proposed a feasible and affordable stepwise plan to employ a convergence of aerospace and other technologies to end wildfires by use of a system of autonomous aerial firefighting (AAF). There do not appear to be any other affordable, mass-scale solutions in sight for ending wildfires. These facts and the increasing threat of horrible extreme weather events clearly call on those responsible for national and global stewardship to address ending wildfires as soon as possible.
Please contact SAF if you are interested in advancing this solution. We are available to present a detailed study and reference design for AAF.