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World on fire: looking back at the 2020 wildfires

2020 has been a challenging and unpredictable year for people all around the world. As well as being confronted by the COVID-19 pandemic, many countries have experienced their worst wildfires in decades, if not in all of recorded history.

These devastating fires are caused by a variety of factors, but there is one key thing that has undoubtedly contributed to the scale and intensity of wildfires across the globe: human-caused climate change.

The extreme temperatures and severe droughts caused by climate change have made our planet more susceptible to burning, and more severe weather conditions mean that once fires have begun, they tend to burn more intensely and widely than they have in the past.

Wildfires have a wide reaching impact, wreaking havoc on local economies, our health, and the environment. With such a vast range of short-term and long-term consequences, it’s hard to ascertain just how much damage the fires of 2020 may have caused.

Before we explore some of these impacts, it seems apt to begin by looking at some of the worst wildfires this year has seen.

Siberia: the world’s climate hotspot

In recent years, Russia’s vast Siberia region has become a climate hotspot, heating up much faster than the rest of the planet. This year, the fire season started earlier than usual following a particularly hot winter and spring. 

On the 17th June, Verkhoyansk, a town in the Arctic region of Siberia, recorded a reading of more than 38°C. This is the highest temperature ever documented north of the Arctic Circle.

According to Greenpeace International, fires have burnt through 20 million hectares of the Russian landscape since the beginning of 2020. This is an area bigger than Greece, and includes around 10.9 million hectares of forest.

Image by GreenPeace International
A fire burning through forest in Krasnoyarsk, Siberia, July 2020.

And the Arctic wildfires in Siberia this summer have set an alarming record: for releasing more pollution into the air in a single month than any other in 18 years of record keeping.

This is partly due to the fact that the substances that are burning release extremely high concentrations of pollutants into the atmosphere. Melting tundra permafrost, peat buried in bogs and resin-rich boreal forest all create large quantities of carbon dioxide (CO2), methane and toxic contaminants like mercury.  

However, it is also undeniably a result of the record-breaking heat waves at the start of the summer, which thawed parts of the tundra and made it more susceptible to burning.

Smoke from the Siberian wildfires affected citizens in nearby cities for months, with smoke spreading across the Pacific Ocean to reach Alaska. It was even responsible for creating hazes as far away as Seattle in August.

Australia: the bushfire crisis

Like Sibera, Australia’s fires have been starting earlier and becoming more rampant.

In June 2019, the Queensland Fire and Emergency Service acting director warned of the potential for an early start to the bushfire season, which normally starts in August. This was due to the exceptionally dry conditions and lack of soil moisture, combined with early fires in central Queensland. 

Throughout the summer, hundreds of fires burnt, mainly in the southeast of the country, with a peak between December and January this year.

The monstrous flames engulfed 18.6 million hectares of land, claiming the lives of 34 people, destroying thousands of homes, and killing or displacing three billion animals. Economists believe that the bushfires may have cost Australia over A$100 billion, and NASA estimated that by the 2nd January, 306 million tonnes of CO2 had already been emitted by just the New South Wales and Queensland bushfires. This is equivalent to nearly half of Australia’s total greenhouse gas emissions from the previous year.

Researchers from Canada’s University of Saskatchewan measured smoke in the upper atmosphere in the wake of pyrocumulonimbus storms (PyroCBs), which are fire-generated thunderstorms. They found that the cloud caused by Australia’s bushfires was three times larger than anything previously recorded globally. It measured 1,000km across, remained intact for three months, travelled 66,000km and soared to a height of 35km above earth.

Smoke from the fires was carried to New Zealand, where it impacted air quality and eerily darkened the snow on glacier-covered peaks. The plumes were so thick that a NASA satellite was able to capture images of it from space.

Image by NASA
NOAA-NASA’s Suomi NPP satellite captured this image of the ongoing conflagrations in New South Wales, Australia, 4th December 2019.

California: the first ‘gigafire’

This extraordinary year of wildfires reached another new distressing milestone in California – the first ‘gigafire’, a blaze spanning 1 million acres, in modern history.

At 1.03 million acres, the fire spread across seven different counties and covered an area larger than Rhode Island. It began following a series of separate fires that were sparked by lightning strikes in August. These smaller fires later morphed into the larger complex that still remains uncontained in some places.

The ‘August Complex’ follows a long list of fires that have destroyed 4 million acres of California this year, which is double the previous annual record. The 2020 fire season has also produced five of the six largest wildfires in state history, resulting in several dozen deaths and thousands of lost buildings.

To make matters worse, it’s not just California that has been affected, with several major blazes occurring in other Western parts of the US including Oregon and Washington.


Image by Neal Waters / Anadolu Agency
A firefighter battles against the Creek Fire in Fresno County, California, 6th September 2020.

The threat of travelling wildfire smoke

It is extremely worrying to see just how far the smoke from wildfires can travel. It can hang in the atmosphere for days, weeks or even months depending on how long the fires burn. 

And PyroCBs provide a pathway for smoke to reach the stratosphere, enabling it to travel thousands of miles from its source and affect global atmospheric conditions.

What is even more alarming is that the toxicity of smoke particles also appears to increase as they get further away from the site of a fire. 

As smoke travels through the air, the methoxyphenols within it react with ozone and hydroxyl radicals to become oxidized. This converts the particles into highly reactive compounds that have an even greater capacity to damage cells and tissue than when they were first produced at the source of the fire.

A study showed that the toxicity of smoke compounds can double in the hours after they are first emitted from a fire, and can become up to four times as toxic throughout the following days. Athanasios Nenes, an atmospheric chemist who led the study explained:

“Even if someone is far away from a fire source, they may still experience adverse health outcomes from the inhalation of highly diluted and oxidised smoke. We have seen that the oxidative potential of wildfire smoke can be up to four times higher when smoke has been atmospherically processed.”

Image by Joshua Stevens / NASA
Camp Fire in Butte County, California as seen from the Landsat 8 satellite on the morning of 8th November 2018. 

The short-term impacts wildfire smoke has on our health

Wildfire smoke is made up of a variety of gases and particles from the materials that fuel the fire. This includes ozone, carbon monoxide, polycyclic aromatic compounds and nitrogen dioxide.

The smoke also contains particulate matter, including PM2.5 and even finer nanoparticles. These particles are particularly harmful when inhaled, as they can penetrate our lung membranes, damage our respiratory system, and pass into our bloodstream.

In the short-term, particulate matter causes coughing and shortness of breath, and can exacerbate existing health conditions like asthma.

One study estimated that between 2004 and 2009, around 46 million people in the western US were exposed to at least one wave of smoke from wildfires. On days where smoke caused high PM2.5 levels, there was a 7.2% increase in hospital admissions due to respiratory illnesses.

Similarly, during the bushfires at the end of 2019 in Australia, hospital admissions due to breathing problems increased by 34% in the state of New South Wales.

Image by Noah Berger / Associated Press
Medical personnel evacuate patients from the Feather River Hospital as the Camp Fire rages through Paradise, California, in 2018.

The concerning long-term health issues

There are also some significant long-term health issues to consider. Particulate matter has been linked to a range of problems, including chronic inflammatory response, and a greater risk of heart disease and strokes. 

And wildfire smoke itself carries unique risks, as it is filled with reactive chemical compounds that can be carcinogenic, and that can also lead to premature births. Exposure to the smoke is thought to be shortening the life expectancies of populations that experience fire seasons regularly.

A study found that particulate matter from wildfire smoke was especially harmful to a type of immune cell in our lungs called macrophages. Researchers found that wildfire particulates were four times more toxic than particulate matter from other types of air pollution.

It is estimated that wildfire smoke causes over 339,000 premature deaths a year globally. People with pre-existing respiratory conditions tend to be the ones who are most affected by wildfire smoke, and it is thought that some may never completely recover after experiencing just one severe wildfire season. 

However, it is newborn babies that may face the most life-altering impacts, as their lungs are still developing, making them particularly vulnerable to smoke toxicity.

When wildfires and a global pandemic combine

The health risks associated with wildfire smoke have been exacerbated this year with the unwelcome addition of COVID-19. This is because smoke can stress the respiratory tract, leaving it more vulnerable to respiratory pathogens.

Sarah Henderson, from the British Columbia Centre for Disease Control, explains:

“Your body perceives that smoke as a foreign threat, the same way it would perceive a virus or a bacterium. And it mounts an immunological response against the smoke, trying to kill it, basically. And what this serves to do is kind of distract your immune system.”

The smoke also makes cilia – tiny hair-like organelles that help keep our lungs and airways clean – less effective. This puts our bodies in a more vulnerable position to fight off COVID-19.

It is estimated that a moderate episode of wildfire smoke could potentially increase the effect of a COVID-19 outbreak by approximately 10%

While the virus remains a global health threat, it’s more important than ever for people in fire-prone regions to take precautions to minimise their exposure to smoky air as much as possible.

Image by Noah Berger / Associated Press
Flames from the LNU Lightning Complex fires burn in unincorporated Napa County, California, on 18th August 2020. Click here to find out how Berger took this remarkable photo.

Are we safe indoors?

The general recommendation when wildfires are raging outside is to stay indoors to avoid the smoke. But indoor spaces can be problematic, too.

When outdoor air particle concentrations increase, so do concentrations indoors. This is particularly the case in our homes, as they don’t usually have particle filtration systems in place.

A study looked into the impact wildfires in the US have on indoor air quality. It found that increases in indoor concentrations of particles from wildfires are about 50% of the increases in outdoor particle concentrations. And due to the fact that the average person spends 90% of their time indoors, around 80% of total exposure to particles from wildfires will occur indoors. 

This means that we need to do everything we can to optimise indoor air quality, including closing windows, investing in air purifiers with HEPA filters, and avoiding activities that create more pollution indoors.

Considering the limited ability to suppress wildfires, it’s clear that making indoor air cleaner needs to be a priority in order to mitigate the effects of wildfire smoke.

Image by Apu Gomes / Agence France-Presse
The Ranch Fire in Azusa, California, August 2020.

The potential impact on the property market

As buyers and renters become more aware of the risks associated with intense fire seasons, it seems likely that they will start to seek homes in new destinations that are less prone to wildfires.

According to analysts, California is losing ground as the most-desirable place to dwell. For the first time in a decade, more people left California last year for other states than arrived,  and the devastation caused by wildfires undoubtedly has a role to play in this.

With the knowledge that wildfires are predicted to worsen in the coming years, there will inevitably be shifts in how and where we live, potentially impacting real estate prices around the world.

Climate change and wildfires: a vicious cycle

Wildfires not only have a long-term impact on human health, but also on the health of our planet. These destructive blazes are not only a result of climate change, but also contribute to it.

Burning forests release enormous amounts of CO2 and other greenhouse gases (GHGs) into the atmosphere. This leads to a vicious cycle: GHGs emitted by fires feed climate change, which in turn brings warmer, dryer summer conditions that create the perfect conditions for more fires.

Peat fires have an especially adverse impact on the environment as they emit legacy carbon which has been built up over thousands of years in a matter of hours or days. 

A study estimated that during the 2015 fire season in Indonesia, biomass fires that included a significant amount of peat released 1.5 billion tonnes of CO2 into the atmosphere. The soil in places like Russia, Alaska and Canada contain around 30 times the amount of peat found in Indonesia’s soil. As climate change causes these Arctic territories to warm faster than the rest of the planet, the number of peat fires spewing huge quantities of CO2 will only increase.

Image by Mike Lewelling / NPS Climate Change Response
The Alder Fire in Yellowstone National Park, 2013.

These areas are also regularly experiencing ‘zombie fires’, which are fires from a previous growing season that smoulder under the ground for long periods of time. When the weather warms, they can quickly roar back to life, as seen in Siberia this year.

More recently, NASA researchers have also discovered another effect wildfire smoke may be having on the climate. They found that the Earth is surrounded by a haze of old smoke that hangs in the troposphere over places like Antarctica. 

On a global scale, these smoke particles cool the Earth slightly. But on a regional scale and in places like the Arctic that are especially sensitive to climate change, these particles can cause a regional warming effect. 

One reason for this is that the black and brown carbon found in smoke absorbs heat, and causes the air temperature to rise and warm the area below. In areas like the Arctic, this could serve to make wildfires even more likely.

Can we break the cycle?

In this ever-warming warming world, wildfires are only going to become more frequent and devastating. The climate-driven threats that experts thought would get worse in the coming decades are already much worse than anticipated. Wade Crowfoot, the California Secretary for Natural Resources, has said:

“Frankly, we’re alarmed because this wildfire destruction that we’re seeing in 2020 is the type of destruction that we anticipated experiencing later in the century.”

It is safe to say that it is truly worrying to consider what the coming years hold for fire-prone regions. But what we need to do now is to focus on the things we can do to make a difference.

To have any chance of restricting the rise in global temperatures to 1.5°C in line with the Paris Agreement, more needs to be done to cut carbon emissions from governments, businesses, communities and individuals.

And to reduce the ferocity of wildfires, we need to reinvest in prevention, clarify governance and coordinate policies, and use a science-based approach to risk and interventions.

There are no two ways about it: we need to come together as a matter of urgency to fight wildfires and climate change. If we act now, we have the power to break the cycle and move towards a more sustainable future.