Where There’s Fire, There’s Smoke…

The tragic aftermath of our burning bush

Tue 20 Jun 23


Black Summer will go down as one of the deadliest bushfires on record.

From September 2019 to March 2020, more than 18 million hectares, 5.4 million alone in NSW, were burnt, with 26 fatalities directly related to fires.

But the smoke from the fires across NSW, eastern Victoria and the ACT caused more than 450 deaths.

Earlier this month, Wood Central reported that Australian crews have joined hundreds of firefighters from South Africa, New Zealand, France, Portugal and Spain to battle wildfires raging across Canada.

The hidden deathtrap in forest fires

But as each wildfire is eventually (hopefully) extinguished and many lives are saved, the aftermath of deaths from smoke is yet to be assessed.

An international team of researchers has calculated that short-term exposure to wildfire smoke is attributable to around 440 deaths in Canada and more than 33,000 deaths globally each year.

The study, published by Monash University, examined the connection between wildfire pollution and deaths in 749 cities across 43 countries.

As trees, their leaves and other ground vegetation burn, small particles of solid carbon, water vapour and gases, including carbon monoxide, are released.

Ultrafine particles of less than 2.5 micrometres (referred to as PM2.5) pose the biggest health risk; they can bury deep into the lungs and even enter the bloodstream. The risks are irritation, infection and an increased chance of heart attacks and lung disease.

The thick orange haze that has dominated New York City’s skyline these past weeks was caused by a high concentration of these fine particles. The key factors for the intensity of these toxic particulates are the severity of the wildfire producing them and wind, which can help disperse them.

Footage courtesy of @CBSNews

According to laboratory experiments, a given amount of wildfire smoke causes more inflammation and tissue damage than the same amount of air pollution, according to Kent Pinkerton, co-director of the Centre for Health and the Environment at the University of California.

He says studies have linked wildfire smoke with higher rates of heart attacks, strokes and cardiac arrests, increased emergency room visits for respiratory conditions, and a weakened immune defence. The effects of exposure can persist for years.

The increase in forest fire frequency has been linked to climate change

Smoke is still shifting across Canada into the United States and winds are expected to drive smoke further north to northeast Ontario this week.

Canada’s fire season extends from May through October, but these fires are abnormally prolific for this time of year.

The country is on track to have its worst wildfire season on record, according to the US National Environmental Satellite, Data, and Quebec has reported 446 fires this year. Over the last 10 years, the average number of fires for this date is 212.

Smoke rises from the Stoddart Creek wildfire in British Columbia, Canada. (Photo credit: British Columbia Wildfire Service/Reuters)
Smoke rises from the Stoddart Creek wildfire in British Columbia, Canada. (Photo credit: British Columbia Wildfire Service/Reuters)

The fires have collectively burned over 3.3 million hectares of land across the country, around 12 times more than the average over the last 10 years.

Experts have pointed to a warmer and drier spring than normal as the reason behind this trend.

These warm and dry conditions are projected to continue throughout the summer, fuelling a high risk of wildfires from the west coast province of British Columbia to Atlantic Canada in the east.

If the trend continues, the country could see its largest area burned by wildfires on record and its worst spread of smoke.

Footage courtesy of @globalnews

“Climate change is increasing the frequency and intensity of wildland fires and creating longer fire seasons in Canada,” says Michael Norton, director-general of the Northern Forestry Centre at Canada’s Department of Natural Resources.

According to Professor McKitrick rates of forest fire is trending downward

But Ross McKitrick, a Professor of Economics and CBE Fellow in Sustainable Commerce at the University of Guelph in Ontario, where he specialises in environment, energy and climate policy, and is a Senior Fellow of the Fraser Institute, responds:

“Before the truth about forest fires goes up in smoke, we need to address the postulations of politicians, reporters and climate activists rushed in to exploit this unusual event by pushing their agenda.

“They made a lot of glib claims about climate change causing wildfires to become more common. For instance, Prime Minister Trudeau tweeted: ‘We’re seeing more and more of these fires because of climate change”.

“That statement is false,” says McKitrick.

“Amid the smokescreen of untrue claims, nobody seems to have bothered looking up the numbers.

“Canadian forest fire data are available from the Wildland Fire Information System. Wildfires have been getting less frequent in Canada over the past 30 years. The annual number of fires grew from 1959 to 1990, peaking in 1989 at just over 12,000 fires that year, and has been trending down since.

“From 2017 to 2021 (the most recent interval available), there were about 5500 fires each year, half the average from 1987 to 1991.

The annual area burned also peaked 30 years ago. It grew from 1959 to 1990, peaking in 1989 at 7.6 million ha before declining to the current average of 2.4 million ha a year over 2017-21. And 2020 marked the lowest point on record with only 760,000 ha burned.”

McKitrick says record show that the fraction of fires each year that become major (more than 200 hectares in size) peaked back in 1964 at 12.3%. From 1959 to 1964, it averaged 8.7%, then dropped to 3.4% in the early 1980s.

“As of the 2017-21 interval, it had climbed again to 6%, but that’s still well below the average 60 years ago.”

McKitrick adds: “At the global level, satellite data from the European Space Agency also show that wildfire activity has been trending downward in recent decades and is approaching its lowest level since records began in the early 1980s.”

The topic of climate change and its link to forest fires is hotly debated worldwide. Footage courtesy of @CBCNews

And closer to home … in the haze days of a Black Summer in Sydney

Waking up to a city full of smoke. It’s the new norm in Sydney,” came an ABC News report on the Black Summer bushfires on December 3, 2019.

“The spate of bushfires burning across NSW has given people in the Harbour City a taste of what it’s like to live in a smog-choked megacity.”

Black Summer will go down as one of the deadliest bushfires on record. From September 2019 to March 2020 more than 18 million ha, 5.4 million alone in NSW, were burnt with 26 fatalities directly related to fires. But smoke from the fires caused more than 450 deaths.

NSW Department of Environment data that day showed Sydney’s air quality was already three times worse than at any moment in the previous five years.

The photo shows the extent of harmful pollutants in Greater Sydney’s air since the start of the season’s bushfire.

While the NSW government measures several different categories of “particulate matter”, one of the most concerning to people’s health is PM2.5. This is also the smallest size the government measures — about 3% of the diameter of human hair.

“In the past five years, albeit when there were fewer monitoring sites, there were only five recorded instances of a daily maximum AQI above 100, indicating ‘poor’ air quality in Greater Sydney,” said the ABC report/

In November and December of that year, there had already been about 80. Over a quarter of those readings were above 200, which indicates ‘hazardous’ air quality.

In health terms, the toxicity of the air in some parts of Sydney had gone from smoking half a cigarette to between four and 10 a day. On Tuesday, December 3, 2019, the AQI hit 669 – the equivalent of smoking 30 cigarettes.


  • Jim Bowden

    Jim Bowden, senior editor and co-publisher of Wood Central. Jim brings 50-plus years’ experience in agriculture and timber journalism. Since he founded Australian Timberman in 1977, he has been devoted to the forest industry – with a passion.


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