What are wildfires?
A wildfire is an uncontrolled fire that burns in wild vegetation, like forests, grasslands, savannas, and other ecosystems. Unlike most natural disasters, they are not limited to a particular continent or environment and can occur both in and above the soil.
How can wildfires be classified?
Based on their incidence of occurrence:
- Ground Fires
Fires that burn vegetation under the soil are called ground fires. Typically occurring in soil rich with organic matter that helps feed the flames, these fires may burn slowly for a long time, even entire seasons until weather conditions allow them to turn into surface fires.
- Surface Fires
Unlike ground fires, surface fires burn in dead and dry vegetation present just above the ground. They are often fueled by parched grass and dry leaves and may be induced by ground fires.
Based on the cause of ignition:
For a wildfire to ignite and burn, a combination of the following elements needs to be present:
Fuel in the form of live or dead trees, vegetation and other organic matter;
Heat to ignite and burn from lightning or human sources.
The ignition can start due to natural causes like lightning strikes or human-induced causes like a spark from electric utilities and substations. Basis the cause of ignition, wildfires can be classified as:
Anthropogenic wildfiresAnthropogenic wildfires result from accidental or intentional human activities like open burning, campfires left unattended, malfunctioning electrical equipment, negligently discarded cigarettes and intentional acts of arson that end up creating a heat source sufficient to ignite a wildfire. According to the U.S. National Park Service’s, nearly 85% of wildland fires in the United States are caused by humans.
Natural wildfiresNatural wildfires are a consequence of an environmental stimulus. A majority of naturally-caused wildfires are ignited by lightning. When lightning strikes, it can create enough heat to ignite a tree or other fuel source. Volcanic, meteoric, and coal seam activities may also lead to wildfires. While natural wildfires cannot be prevented, their severity increases with the arid and dry conditions amplified by global warming and climate change.
While wildfires can start with a natural occurrence or a human-made spark. However, it is often the weather conditions that determine how much a wildfire grows. Wind, high temperatures, and little rainfall can all leave trees, shrubs, fallen leaves, and limbs dried out and primed to fuel a fire. Topography plays a big part too: flames burn uphill faster than they burn downhill.
What is a wildfire season?
A wildfire season is a duration between the first and last large fire of any given year. As wildfires are caused when conditions are hot and dry, a typical wildfire season occurs in summer and spring and typically lasts for 4-5 months. For instance, in the U.S., the peak month of wildfire season is August, with the wildfire season lasting between May and October.
What is the role of wildfires in the ecosystem?
While wildfires can endanger entire communities and result in significant ecological, economic and operational disruptions if left uncontrolled, they play a crucial role in maintaining environmental balance around various ecosystems.
Wildfires are essential to the continued survival of some plant species. For example, some tree cones need to be heated before they open and release their seeds; chaparral plants include manzanita, chamise (Adenostoma fasciculatum), and scrub oak (Quercus berberidifolia), require fire before seeds will germinate. Plants such as these depend on wildfires to pass through a regular life cycle.
Wildfires also help keep ecosystems healthy. They can kill insects and diseases that harm trees. By clearing scrub and underbrush, fires can make way for new grasses, herbs, and shrubs that provide food and habitat for animals and birds. At low intensity, flames can clean up debris and underbrush on the forest floor, add nutrients to the soil, and open up space to let sunlight through to the ground. The sunlight can then nourish smaller plants and give larger trees room to grow and flourish.
Culturally as well, fires have played a key role in sustaining communities. For instance, in the Native American culture, controlled wildfires are part of the environmental cycles and maintenance of wildlife habitats that sustained the cultures and economies of the indigenous peoples of America. In fact, wilderness in North America which colonists perceived as “untouched, pristine”, was a cumulative result of these managed fires, creating a purposeful mosaic of grasslands and forests across North America.
How have wildfires evolved?
In the last few years, the world has experienced drastic changes in wildfire patterns. The increased intensity and higher frequency of wildfires manifested by climate change are transforming fire seasons into a fire year and increasing the overall propensity of losses all around the world.
While wildfires seasons are most likely to end by October, the paradigm has slowly been shifting. As was observed in the 2020 wildfire season in California. Wildfires raged well into the later part of the year, burning a [record-setting 735,125 acres](https://www.ncdc.noaa.gov/sotc/fire/202012#:~:text=For%20December%2C%205%2C324%20fires%20(10th,fire%20(most%20on%20record).) of American land in December. Five of the six largest fires on record burned in California and Oregon saw unparalleled levels of wildfire spread and damage.
The emissions and area burnt by fires are getting larger by the year, as fires start early and end much later in the year. The erratic nature of fires and their increased occurrence spread throughout the year has made the term fire season almost obsolete.
For instance, in 2021, all continents, with the exception of Antarctica, witnessed significant wildfires throughout the course of the year - Algeria wildfires in Africa; Cyprus, Israel, and Turkey fires in Asia; France, Greece, and Russia fires in Europe; Canada, US, and Mexico fires in North America; Argentine Patagonia wildfires in South America; and Australian bushfires.
The evolution of wildfire threat globally can be encapsulated through the following statistics that paint a jarring picture of where we stand today:
According to the European Space Agency, fire affects an estimated 4 million square kilometres (1.5 million sq miles) of Earth’s land each year. To put that in context, that is about half the size of the United States, larger than India, or roughly four times the size of Nigeria.
Source: European Space Agency, August 18, 2021
According to the Congressional Research Service of the U.S., since 2000, an annual average of 70,600 wildfires have burned an annual average of 7.0 million acres. This figure is more than double the average annual acreage burned in the 1990s (3.3 million acres)
According to the National Aeronautics and Space Administration, 13 of California’s 20 most destructive wildfires have occurred in the past five years. They collectively destroyed 40,000 homes, businesses and pieces of infrastructure.
California wildfires since 1970 Source: NASA Earth Observatory
According to a project under NASA’s Earth Science Applied Sciences program, the total area burned by fires each year and the average size of fires in California increased over the past two decades. About 3% of the state’s land surfaces burned between 1970-1980; between 2010-2020, this number was about 11%.
According to a study, forests in Australia experienced an annual average increase of 350% in burned area between the first (1988-2001) and second (2002-2018) half of the record, and an increase of 800% when including 2019.
According to the Center for Research on the Epidemiology of Disasters, at least 470 wildfire disasters – incidents that killed 10 or more people or affected more than 100 – have been reported globally since 1911, causing at least $120bn in damages. Additionally, wildfires have killed at least 4,545 people, injured 11,379 and affected more than 17 million around the world in the same time frame.
Brazil had more than 222,000 wildfires last year, the highest number since 2010, according to the Brazilian space agency INPE, with swaths of the Amazon rainforest affected
“It’s the lengthening fire season. It’s giving us more days that are burning at a higher intensity. And the result of that is massive fires. They’re more intense, and they’re producing more extreme fire weather. The changes point to the dominant role of heat and a warming climate.”
_—Neil Lareau, atmospheric scientist and professor at the University of Nevada._
What is the role of Climate Change?
Research shows that changes in climate have amplified drought and heat, two factors that play crucial roles in driving bigger blazes.
As shrubbery shrivels due to amplified heat and the dense layer of damp vegetation dries much more quickly than before, the landscape is prone to burn much earlier than in typical years. This creates a tinderbox effect that leaves the landscape more prone to flames.
This, coupled with a lack of adequate precipitation, increases the risk of turning small ignitions into massive infernos.
Adding that to the devastatingly hot temperatures induced by climate change makes wildfires more intense. Once a fire starts, warmer temperatures and drier conditions can help it spread and make it harder to put out.
Where are we headed next?
Undeniably, climate change’s most apparent connection with uncontrollable wildfires is warming air temperatures. The planet has been heating up nearly continuously since the late 1800s, the advent of the Industrial Revolution. Since then, the global average temperatures have only gone up– by approximately 1 degree Celsius. To put that into perspective, for much of the Western U.S., projections from a study show that an average annual 1 degree C temperature rise would increase the median burned area per year by as much as 600%.
According to a study funded by NOAA, climate warming from increasing greenhouse gases emissions is predicted to dramatically increase the risk of very large, very damaging wildfires over the next several decades. The climate models used in the study took rapidly increasing climate change-induced GHG emissions into an assumption while warming average temperatures substantially and markedly decreasing precipitation and humidity. The results were drastically reduced soil moisture and extreme tinderbox conditions, clearly illuminating the role climate change would play if untethered. A recent report from Environmental Protection Agency also predicted twice as much land burning per year by the end of the century, representing an area exceeding the size of Massachusetts.
What is the Impact on the business?
The impact of this trend of increased frequency and intensity of wildfires is not only limited to ecological aspects but also invariably increases the exposure of businesses to material financial losses across the corporate value chain. Analysing the economic implications of wildfires involves accounting for the cost of damages as well as other indirect costs, i.e., costs resulting from power shut-offs, business closures, insurance payouts, supply chain disruptions, real estate valuation changes and much more.
For instance, when we account for the costs of California’s 2018 wildfire season, it amounts to a total of $148.5bn (0.7% of the country’s annual GDP) which includes the state incurred damages of $102.6bn; indirect losses through economic disruption to 80 industries amounting to $42.7bn; and the indirect losses caused to the U.S. economy amounting to $45.9bn outside California due to economic links between California and the rest of the U.S. Indirect financial losses thereby accounted for 41.5% of the state-wide total damages.
These implications are, in turn, triggering a pressing need for businesses to better understand wildfire risk and re-evaluate the status quo.
What is the way forward?
As per a report released by the U.N. based on their analysis of the IPCC report, many have agreed to the worst— wildfires could be "the new normal". Wildfire weather is expected to become more frequent and strike more regions – even where extreme heat and fires have been less common.
Wildfires essentially produce one of the most severe negative feedback loops as more wildfires cause higher carbon emissions leading to faster global warming and in turn setting the stage for even more wildfires.
This has propagated the need to re-evaluate the entire approach to managing fires. Preempting the impact of fires needs to take centre stage in institutional and business risk assessment models with high quality and real time data becoming the holy grail. Together with data and decision-useful insights, businesses and institutions worldwide can become more resilient and better prepared.