As the world burns, can we learn to live with wildfire health risks?

 

 

By Ruth Kamnitzer, via Mongabay

 

As dry brush crackled and smoke curled upward, there was a palpable feeling of satisfaction among firefighters gathered near Cranbrook in the Canadian province of British Columbia. It was a sunny day in April, and if the weather held, the multiagency team hoped to quickly finish a prescribed burn on 42 hectares (104 acres) of land adjacent to the tiny Rocky Mountains International Airport — an effort meant to protect the facility in case of a major wildfire event.

Some crew members walked diagonal lines along the fire front, lighting the grass with drip torches. Some stood along the burn’s perimeter with water bladders and hoses to douse errant sparks. Another monitored wind speed and direction, alert and ready to warn of changes. Others looked on, glad to be working with fire instead of against it.

“Should’ve bought marshmallows,” one quipped.

Last July, when a downed power line sparked a wildfire here, the mood was far different. The St. Mary’s River Fire burned 4,650 hectares (11,490 acres), destroyed homes in the Indigenous ʔaq̓am community, and put the airport and nearly 100 properties under evacuation alert. It took what the BC Wildfire Service calls a full response — water bombers, ground crews, back burning — to control it.

But without prescribed burning, things could have been far worse. That spring, three months before the St. Mary’s River Fire, the ʔaq̓am community, part of the Ktunaxa First Nation, intentionally burned a 1,200-hectare (2,965-acre) portion of their reserve.

This meant that when the St. Mary’s River Fire hit the ʔaq̓am burn, it was stopped in its tracks, says wildfire ecologist Robert Gray, who helped plan both the airport and ʔaq̓am burns. Firefighters had one less front to deal with, and the airport — essential for launching firefighting aircraft — was safeguarded.

These pragmatic burns, and the way they help prevent bigger, uncontrolled blazes, offer a clear example of how bringing fire back can actually reduce risk, Gray says.

The megafire threat

Extreme wildfires are increasing in many parts of the world, according to a 2022 United Nations Environment Programme report. The potential consequences are worrying: the release of greenhouse gases; the destruction of wildlife and ecosystems; loss of lives and property; and as emerging research shows, significant impacts to human health.

The drivers of this extreme wildfire surge are complex, and include global warming, land-use change, and increased ignition sources (including people). The solutions are just as complex.

First and foremost, we need to drastically cut emissions to limit climate change as much as possible, says Stefan Doerr, professor of wildlands fire ecology at Swansea University in the U.K. But we also need to change how we manage land and rethink how we live with the risk of fire.

Fighting fire with fire

Fire is a natural and essential part of many landscapes. It shapes species diversity, helps seeds germinate, and keeps disease in check. In many places, including Canada, Indigenous peoples historically used fire as a tool to create habitat, for ceremony and other purposes.

In the past, lightning caused fires, and intentionally set Indigenous burns created a mosaic of habitats that burned at different rates, so that when wildfires ignited they didn’t get too big or spread too far, says Gray.

But the banning of Indigenous cultural burning by colonial governments — in places like the U.S., Canada, Australia and elsewhere — along with many decades of active fire suppression to protect private property and valuable timber, effectively removed fire from the landscape.

That created a “fire deficit,” says Jen Barron, a doctoral candidate at the University of British Columbia. For example, Baron’s research shows that in the Rocky Mountain Trench in southeast BC, where the prescribed burn near the Cranbrook airport took place, most areas have now missed from one to 10 usual burn cycles.

“On the historic landscape, a lot of the research we’ve done [shows] we didn’t have big fires like we’re seeing today,” Gray says. “You take fire out of the system, you homogenize things, that fire frequency lengthens, fuels accumulate, and now we get these big ugly fires … So going forward, we have to replace that mosaic.”

Research also shows that periodic burning improves ecosystem health in fire-adapted landscapes. Indigenous fire stewardship results in greater habitat heterogeneity and biodiversity, according to a 2021 PNAS review study, while a study in Australia showed that Indigenous cultural burning increased soil and ecosystem health, even more so than other types of planned burning.

Today, there’s a resurgence in Indigenous and prescribed burns as a way to bring back more natural fire regimes and manage risk (though the two practices have different pragmatic or cultural objectives).

The Firesticks Alliance, for example, is a nonprofit network with a cultural goal, promoting Aboriginal traditional burning in Australia. In British Columbia, the provincial government is working to bring back cultural and prescribed fire as a land stewardship tool, through the Cultural and Prescribed Fire initiative.

Mitigating smoke risks

Many proponents of prescribed or cultural burning point out that these fires can be planned in a way that minimizes health risks from smoke. The idea is that these controlled fires burn at low intensity and under specific weather conditions. That means they produce less smoke, and that the spread of the smoke is more controlled.

But there’s a catch: To mitigate extreme fire risk, areas need to be burned frequently. That means nearby communities may be repeatedly exposed to low levels of smoke, says Fay Johnston, a professor at the University of Tasmania in Australia. Johnston’s research in Australia shows that, hectare for hectare, the health impacts of prescribed burning are higher than those of wildfires. That’s why it’s important that vulnerable groups are adequately protected from smoke during prescribed burns, she says.

“Fuel management is crucial, and deliberate prescribed burning is a crucial part of the mix. But we can do it a lot better, and use alternatives [more often],” she says.

Some of those alternatives have four legs and insatiable appetites: Goats, cattle, sheep and even kangaroos have all been successfully used to reduce fire risk in cities and towns. A study in Oregon, for example, found that targeted grazing by cattle was effective in creating firebreaks.

Learning to live with fire

We can’t, and shouldn’t, eliminate all fires, at least in places where ecosystems are fire-adapted, says Doerr. Instead, humanity will have to learn how to live with fire and manage risk.

“It will be one of those things … there’ll be storms, there’ll be fires, there’ll be floods,” Doerr says.

Managing the risks includes looking at the way we live, work and build in forested areas to make sure we aren’t contributing to the problem, especially as climate change dries out forests and makes them more fire-prone.

Half of the world’s population now lives in what’s called the wildlands-urban interface, according to a 2023 Nature study. These are places where home sites are nestled among trees or give way to wild olive groves or small farms. These are often desirable places to live, but risky when it comes to wildfire.

On a dry, windy day, a spark from a barbecue, or from burning garden waste, can accidently set the surrounding forest alight. And when fires do start, neighboring people and property are directly in harm’s way.

One solution is to reduce these accidental ignitions, and many countries have regulations in place to do so. For example, in Portugal, 98% of major wildfires are caused by humans, and the government now has strict controls as to when and how locals can burn agricultural and garden waste.

Another solution is to create a safe zone of nonflammable materials around homes or communities to reduce wildfire risk. The Canadian Interagency Forest Fire Centre’s FireSmart program, for example, runs programs to help communities and individuals reduce wildland fire threats.

Protecting health in a time of megafires

As extreme wildfires become more common, we’ll all have to get better at living with the smoke, says Michael Brauer, a professor at the University of British Columbia’s School of Population and Public Health. Mounting research shows that wildfire smoke, even at low to moderate levels, has wide-reaching impacts, worsening respiratory and cardiovascular health, affecting pregnancies, and more.

“I think it’s sort of a shift in philosophy,” Brauer says “People who are living in hurricane-prone regions, they all have plywood to board up their windows. It’s all about, how do we actually live with this [intensifying risk]?”

At the government or institutional level, that means protecting the groups most vulnerable to those impacts: the young, elderly, pregnant women, and people with underlying health conditions such as asthma.

This could include programs to distribute air purifiers to vulnerable households, or designing and providing access to clean-air shelters, says Carlos Gould, an assistant professor at the University of California, San Diego. The city of Penticton in British Columbia designates numerous free public spaces, including its community center, as clean-air spaces — even allowing “well-mannered dogs” on the walking track on smoky days.

But not everyone can afford to go inside, says Ira Cuello-Martinez, climate policy associate at PCUN, an advocacy group for Latino farmworkers in Oregon.

“Our members are very aware of the changing conditions and the health impacts it has on their lives, particularly when it comes to wildfire smoke. I mean, folks were coughing up black dust, having headaches, just a lot of symptoms” during recent fires, he says. “And at the same time there’s pressure to make ends meet.”

Following successful lobbying, in 2022 Oregon passed legislation that included requirements to protect outdoor workers from smoke and heat, including providing free N95 masks when smoke levels reach a certain concentration. California and Washington (which passed similar legislation this year) are the only other U.S. states that have rules to protect outdoor workers from wildfire smoke.

Changing behaviors and mindset

To better protect people from smoke, we need to be able to predict and monitor air quality.

The Copernicus Atmosphere Monitoring Service, administered by the European Space Agency, tracks the global transportation of air pollution, including wildfire smoke. Its Global Fire Assimilation System uses satellite-based sensors to monitor the location and intensity of wildfires globally, then models how emissions and smoke move around the world, in near real-time.

Numerous air quality apps use the data from Copernicus or other smoke forecasting systems to help predict air quality. For example, the IQAir app publishes global air quality forecasts.

To make the data more user-friendly, some countries use a color-coded air quality rating system, sometimes using the concentrations of multiple air pollutants including PM2.5s, ground-level ozone, nitrogen dioxide, carbon monoxide and others. For example, in the USA’s AirNow.gov rating system, the colors from green to maroon signify increasing levels of danger.

Some cities are also incorporating fire and smoke warnings into their hazard warning systems. And in future, these types of 24-hour advance wildfire smoke early-warning systems — carried out over the internet, via news outlets and government — will likely become more essential. And these systems needn’t be expensive. For example, in Colombia, the Early Warning System of Medellín and the Aburrá Valley (SIATA), a low-cost natural-hazard warning system developed in 2011 in response to catastrophic flooding, now also includes air quality monitoring. As part of the program, local authorities, private companies and volunteers work together to monitor environmental conditions, disseminate information through social media, apps and other channels, and manage risks.

The hope is that these types of warning systems will lead people to reduce their exposure to smoke by changing their behavior, for example by cutting back on outdoor activities, staying home and turning on air filters.

Some behavior changes can be seen in the hospital admissions data in the U.S., says Gould. On heavy smoke days, emergency room visits for respiratory problems like asthma skyrocket, but visits for other reasons decline. That’s because people are staying home; kids aren’t out playing. Gould’s research also shows that people move around less on smoky days, and there are more Google searches for air quality and for air purifiers.

Experts say more research is needed on what types of interventions are most effective, and how to make them accessible.

We also need a change in mindset, so people start taking precautions during wildfire smoke events much as they do for bad weather, Johnston says.

“Extreme cold, extreme UV rays … we need to get air quality to that level. We’re a long way from that now,” she says.

That means getting educated about smoke. Most public health consequences occur when smoke is at mild to moderate levels, Johnston says, so it’s important to take action before the sky turns orange. And as wildfires increase, and smoke becomes a recurring event for many communities, it’s important that people know how to manage their exposure.

“We really need to give people the everyday tools to manage intermittent smoke, [and] to think about reducing the load through the year,” Johnston says.

Banner image: BC wildfire service crew and partners conduct a prescribed burn in southeastern British Columbia in April 2024. Prescribed and Indigenous cultural burning helps to reduce fuel loads and create habitat heterogeneity to make landscapes more resilient to wildfires. Image by Ruth Kamnitzer.

 

Citations:

Baron, J. N., Gergel, S. E., Hessburg, P. F., & Daniels, L. D. (2022). A century of transformation: Fire regime transitions from 1919 to 2019 in southeastern British Columbia, Canada. Landscape Ecology, 37(10), 2707-2727. doi:10.1007/s10980-022-01506-9

Hoffman, K. M., Davis, E. L., Wickham, S. B., Schang, K., Johnson, A., Larking, T., … Trant, A. J. (2021). Conservation of Earth’s biodiversity is embedded in Indigenous fire stewardship. Proceedings of the National Academy of Sciences, 118(32), e2105073118. doi:10.1073/pnas.2105073118

Murramarang Country, Davis, J., Simmons, J., Snelson, S., Channell, V., Haynes, K., … Dosseto, A. (2024). Quantitative assessment of the effect of agency-led prescribed burns and cultural burns on soil properties in southeastern Australia. Fire, 7(3), 75. doi:10.3390/fire7030075

Boyd, C. S., O’Connor, R. C., Ranches, J., Bohnert, D. W., Bates, J. D., Johnson, D. D., … Doherty, K. E. (2023). Using virtual fencing to create fuel breaks in the sagebrush steppe. Rangeland Ecology & Management, 89, 87-93. doi:10.1016/j.rama.2022.07.006

Schug, F., Bar-Massada, A., Carlson, A. R., Cox, H., Hawbaker, T. J., Helmers, D., … & Radeloff, V. C. (2023). The global wildland-urban interface. Nature, 621(7977), 94-99. doi:10.1038/s41586-023-06320-0

Gould, C. F., Heft-Neal, S., Johnson, M., Aguilera, J., Burke, M., & Nadeau, K. (2024). Health effects of wildfire smoke exposure. Annual Review of Medicine, 75, 277-292. doi:10.1146/annurev-med-052422-020909

Burke, M., Heft-Neal, S., Li, J., Driscoll, A., Baylis, P., Stigler, M., … Gould, C. F. (2022). Exposures and behavioural responses to wildfire smoke. Nature Human Behaviour, 6(10), 1351-1361. doi:10.1038/s41562-022-01396-6

Heft-Neal, S., Gould, C. F., Childs, M. L., Kiang, M. V., Nadeau, K. C., Duggan, M., … Burke, M. (2023). Emergency department visits respond nonlinearly to wildfire smoke. Proceedings of the National Academy of Sciences, 120(39), e2302409120. doi:10.1073/pnas.2302409120

Kreider, M. R., Higuera, P. E., Parks, S. A., Rice, W. L., White, N., & Larson, A. J. (2024). Fire suppression makes wildfires more severe and accentuates impacts of climate change and fuel accumulation. Nature Communications, 15(1), 2412. doi:10.1038/s41467-024-46702-0