LEFT IMAGE: NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, RIGHT IMAGE: ALBERTO SHIGUEMATSU
In the middle of the day on Monday, the sky above São Paulo, Brazil went dark.
The city, along with parts of the Brazilian states of Mato Grosso and Paraná, was blanketed by smoke from wildfires raging in the Amazon, according to local news reports.
Earlier this month, Amazonas (the largest state in Brazil) declared a state of emergency over the rising number of forest fires, reported Euro News. Fire season in the Amazon is just beginning—it runs from August through October, with its peak coming in mid-September, and the smoke is already so bad that it can be seen from space
Last week, NASA released satellite images showing the patchwork of fires and smoke in Brazil. Citing the Global Fire Emissions Database, NASA noted that though current fire levels are slightly below average compared to the last 15 years, they are higher in some states, such as Amazonas and Rondônia.
“The state of Amazonas, in particular, has seen well above average daily fire activity through August so far,” said Mark Parrington, a senior scientist working on wildfire emissions at the European Center for Medium-Range Weather Forecasts.
According to Parrington, fires in the Amazon release an average of 500-600 metric tons of carbon dioxide over the course of a typical year. In 2019 so far, they’ve already released 200 metric tons of the greenhouse gas. According to the Global Fire Emissions Database, 8,668 fires have been detected in Amazonas as of Monday. That exceeds the past few years, and falls just short of the 2016 high of 8,836.
Satellite imagery has tracked the movement of the smoke, which completely filled the air in São Paulo. Gustavo Faleiros, an editor at the environmental news group InfoAmazonia, said in an email that the air quality was even worse in the countryside than in the city.
“Countryside residents started complaining about the wildfire smoke, because the air used to be clean there and now the city is full of smoke and ashes,” Alberto Shiguematsu, a São Paulo resident who tweeted about the smoke, said.
According to Shiguematsu, the sky went “really dark” around 3:15 PM yesterday. He said that in his ten years of living in São Paulo, he’s never seen wildfire smoke like that. He’d read that there were fires in the Amazon, but didn’t think he’d be affected.
“The smoke coming here, in São Paulo, thousands of kilometers away? That hit me by surprise,” he said.
The news of these fires comes amidst reports of increased deforestation under far-right president Jair Bolsonaro, which has prompted protests at home and international concern. While the smoke from the fires threatens the health of those living nearby, more fires represent an added stressor for the Amazon rainforest as a whole.
The humidity of the Amazon has, in the past, protected it against massive fires, but drought, deforestation, and agriculture could make fires so common that they would completely alter the landscape, a 2014 study warned. According to a blog post for InfoAmazonia, Brazil’s National Institute for Space Research predicts that rainfall in the central and northern Amazon will be 40 to 50 percent below normal in the next three months.
“There is a direct relationship between increased burning and the growth of deforestation,” Faleiros wrote in the blog post. “Among the 10 municipalities that recorded the largest burnings in 2019, seven are also on the list of municipalities with the highest number of deforestation warnings.”
SMOKE OVER A SITE OF FOREST FIRE IN RYAZAN REGION, RUSSIA, IN LATE JUNE. IMAGE: GETTY/ALEXANDER RYUMIN/TASS.
Wildfires have been raging across the Arctic for over a month now, releasing huge amounts of greenhouse gases into the atmosphere. Now, scientists worry that the fires are contributing to a climate change feedback loop that could make Arctic blazes more common.
In June, unprecedented fires burned across the Arctic, breaking emissions records. The fires have continued to grow, spreading to other parts of Siberia and Alaska, according to Mark Parrington, a senior scientist working on wildfire emissions at the European Center for Medium-Range Weather Forecasts (ECMWF). As they grow, the fires are dumping so much smoke into the atmosphere that it can be seen from space.
The smoke has already blanketed some Russian cities, making it hard to breathe. According to the Moscow Times, local residents have started a Change.org petition to pressure authorities to declare a state of emergency. The petition currently has over 400,000 signatures.
The smoke-filled air is only part of the problem. The emissions spewed into the atmosphere by these massive fires contribute to a climate change feedback loop that scientists worry could mean even more Arctic blazes in the future.
The fires are burning through peatlands, filled with carbon-rich organic matter. Peatlands are usually waterlogged, which serves as natural fire protection. When a warmer climate dries them out, though, peatlands can ignite and burn for months, years, or even decades. They don’t always produce massive flames, but in terms of how much fuel they eat up, peat fires are the biggest fires we know of.
Thomas Smith, professor at geography at the London School of Economics, said “there is an increased confidence” that the Arctic fires are indeed peat fires burning down into the soil, judging by their behavior.
“Peat fires burn ‘old’ carbon,” Smith said in an email, meaning that the carbon has taken thousands of years to accumulate. “So in a few weeks, a fire can burn through hundreds of years worth of carbon sequestration.”
In other words, Smith said, these fires are not carbon-neutral. More fires contribute to faster climate change, which in turn creates ideal conditions for more Arctic blazes.
“These greenhouse gas emissions (which are not offset by future regrowth) will lead to warming, and warming will increase the likelihood of peat soils being drier earlier in the summer and therefore more likely to burn…. In turn leading to more greenhouse gas emissions,” Smith said. “It is a classic positive feedback loop.”
Not only are these fires contributing to climate change, they can harm local ecosystems too, exposing vegetation to harsh chemicals and threatening animal populations, according to a 2018 paper by Smith published in the International Journal of Wildland Fire.
According to a 2013 paper in the Proceedings of the National Academy of Sciences, more forest fires are burning in the Arctic in recent years than any time in the last 10,000 years.
According to the ECMWF’s Parrington, although nobody can say for sure what will happen in the future, “it is clear that if the environmental conditions stay dry and warm the way they have this summer then we could see similar fires in the Arctic if there is an ignition.”
This year, the fires started earlier than usual and continue to break emissions records. With the positive feedback loop they’re creating, these massive arctic fires are showing worrying signs of becoming a vicious cycle.
IMAGE: WIKIMEDIA COMMONS/LAWRENCE LIVERMORE NATIONAL LABORATORY/SHAWN CAHILL
Two years ago, British Columbia suffered one of the worst wildfires in the Canadian province’s history, which consumed 1.2 million hectares and displaced 65,000 people. The 2017 blaze was so intense that scientists are using it to model the climate conditions that might be created in the fallout of nuclear war, according to a study published on Thursday in Science.
The study suggests that the smoky aftermath of a modern nuclear blast will likely persist for longer than current models predict.
A team led by Pengfei Yu at the Institute for Environment and Climate Research at Jinan University in Guangzhou, China, examined the wildfire using data from ground stations, balloons, and satellites.
In particular, they focused on the formation of a huge vertical smoke plume, made from pyrocumulonibus clouds, which rose more than 14 miles into the stratosphere and remained active for eight months.
The plume offered a real-world example of the climate effects expected from a major nuclear conflict, the team said. In that scenario, known as nuclear winter, firestorms lead to a long-term darkening of the skies and global cooling due to the accumulation of aerosols into the atmosphere.
“One of the important predictions of numerous models of nuclear winter is that smoke injected into the upper troposphere from urban fires will self-loft high into the stratosphere,” the authors wrote in the study. “The 2017 fires studied here represent the first observational evidence that such a rise actually occurs.”
Because data from the plume had been collected by so many different observation platforms—in space, in the air, and on the ground—Yu and his colleagues were able to probe the dynamics behind the plume in precise detail.
Black carbon, or soot, was found to be the main driver of its stratospheric ascent. This thick air pollutant only made up about 2% of the 0.3 teragrams of smoke from the wildfire, but it had an outsized effect on the plume because it absorbs so much solar radiation. As a result, the black carbon became heated, which in turn propelled smoke higher into the atmosphere.
In the event of a nuclear war, cities would likely burn alongside forests, and that could fuel even larger aerosol-rich plumes. The researchers estimated that about 0.05 teragrams of black carbon could be released from an urban area ravaged by a nuclear weapon, leading to sootier plumes and lower concentrations of transparent organic smoke.
“If there were a lot of organics it would make the nuclear winter last less long,” said study co-author Brian Toon, a physicist at the University of Colorado Boulder, in an email. “However, smoke from cities does not contain as much organics as smoke from a forest. Burning plastic produces smoke that is almost all black carbon, for instance.”
In other words, nuclear winter simulations may be too optimistic about the rate at which wildfire smoke will dissipate. The fact that the 2017 plume persisted for two-thirds of a year revealed that the smoky aftereffects of a nuclear war would likely last longer than originally projected in models.
“We are currently working on some new simulations of nuclear conflicts, and we will consider the impacts of the organics in this new work,” Toon said.
Nuclear warfare could lead to even worse outcomes for humanity than originally expected, and it’s not as if it was looking very positive before this research anyway. Wildfires exacerbated by human-driven climate change are bad enough without our species escalating them with weapons of mass destruction.
Update: This article has been updated to include comments from co-author Brian Toon.
THE ATHABASCA GLACIER, IN CANADA’S ROCKY MOUNTAINS IN 1917 AND 2011. IMAGE: HISTORICAL IMAGE BY ARTHUR O. WHEELER, 1917, COURTESY OF LIBRARY AND ARCHIVES CANADA / BIBLIOTHÈQUE ET ARCHIVES CANADA. MODERN IMAGE COURTESY OF THE MOUNTAIN LEGACY PROJECT
Striking photographs from the Mountain Legacy Project, an initiative to retake and compare images made by early surveyors, show how Canada’s mountain environments have become less icy and more uniform over time.
These changes, researchers say, spell trouble for alpine birds and could mean a greater number of severe forest fires in the future.
The historic images date as far back as 1861, when surveyors clambered up mountains to make maps of the area. Their age makes them valuable to researchers because it allows them to see the kinds of environmental changes, including melting glaciers, that happen over a century. Satellite images would only cover a few decades.
Environmental scientist Julie Fortin categorized the types of land cover in 46 pairs of historic and modern photographs taken in Alberta’s Willmore Wilderness Park, a rugged landscape only accessible by hiking or horseback trails.
She painstakingly outlined areas of forest (dark green), alpine meadows (light green and light yellow), ice (light blue), and wetlands (periwinkle) in digital versions of the images to quantify how much of each habitat there was in the early 1900s compared to today.
She saw forests growing bigger, creeping into other habitats like alpine meadows or wetlands—such as this area across the valley from Bury Ridge, where sparsely covered slopes are now obscured with dense green foliage: Because Willmore is so inaccessible and resource extraction is forbidden, any landscape changes are likely due to climate change or wildfire management.
Although trees help sequester carbon from the atmosphere, helping lower global temperatures, more trees aren’t necessarily a good thing, Fortin explained to me over the phone.
“I got out here [from Montreal] and I realized more forest is good for some species but there are some species that rely on other kinds of habitats that are being negatively impacted,” she said.
Using a computer model that related the type of habitat to the likelihood of particular bird species living there, Fortin showed that birds that breed or live in alpine areas—like the American Pipit—have declined in numbers over the past century.
Other birds, not investigated by Fortin, could also see a drop in numbers, according to the recent State of the Mountains report by the Alpine Club of Canada. Close to 35 percent of Canada’s birds use high mountains for migration stopovers to fatten up before flying on, the report states, and a quarter of those birds are on national conservation lists. Scientists are unsure how the birds will deal with shrinking alpine areas, or whether they’ll be able to cope at all.
The way we manage fires is also part of what contributes to the changing alpine landscape, Fortin explained.
Almost 100 years ago this site—15 kilometers southeast of Mount Persimmon—had more natural breaks in the landscape, seen on the right side of the image above, which served as a roadblock for spreading fires. Partly, those breaks came from sections of the forest that were allowed to burn. As communities moved closer to alpine forest areas and fires were controlled, the breaks have almost completely closed up.
Vast swaths of forest make the parks more vulnerable to forest fires. “It’s basically just this big tinderbox that when it lights it’s hard to stop,” Fortin said. This means British Columbia may not have seen the last of its record-breaking wildfires, which burned close to 13,000 square kilometres of the province and forced 65,000 people out of their homes over the course of three months.
“Mountains create their own particular type of fire risk,” added ecologist Eric Higgs, who has taken some of the modern photographs for the Mountain Legacy Project to understand how to restore mountain habitats.
“They provide you with a visual argument,” said Higgs. “The interplay of our values at present and what we’re seeing from the past shapes where we ought to go.”
Higgs argued that environmental restoration initiatives must consider controlled burning and include community awareness. Fortin is now using the images from her project to show locals in Grande Cache, a town directly bordering the Willmore Wilderness Park, how their mountain neighbourhood has changed. The photos also help inform controlled-burning projects in the area.
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