Friday, June 4, 2021

One Job in Twenty Was Seen as Useless

The so-called ‘bullshit jobs theory’ – which argues that a large and rapidly increasing number of workers are undertaking jobs that they themselves recognize as being useless and of no social value – contains several major flaws, argue researchers from the universities of Cambridge and Birmingham.

From: Cambridge University

June 3, 2021 -- Even so, writing in Work, Employment and Society, the academics applaud its proponent, American anthropologist David Graeber, who died in September 2020, for highlighting the link between a sense of purpose in one’s job and psychological wellbeing.

Graeber initially put forward the concept of ‘bullshit jobs’ – jobs that even those who do them view as worthless – in his 2013 essay The Democracy Project. He further expanded this theory in his 2018 book Bullshit Jobs: A Theory, looking at possible reasons for the existence of such jobs.

Jobs that Graeber described as bullshit (BS) jobs range from doormen and receptionists to lobbyists and public relations specialists through to those in the legal profession, particularly corporate lawyers and legal consultants.

Dr Magdalena Soffia from the University of Cambridge and the What Works Centre for Wellbeing, one of the authors of the article, said: “There’s something appealing about the bullshit jobs theory. The fact that many people have worked in such jobs at some point may explain why Graeber’s work resonates with so many people who can relate to the accounts he gives. But his theory is not based on any reliable empirical data, even though he puts forward several propositions, all of which are testable.”

To test Graeber’s propositions, the researchers turned to the 2005–2015 European Working Conditions Surveys (EWCS), examining reasons that led to respondents answering ‘rarely’ or ‘never’ to the statement: ‘I have the feeling of doing useful work’. The surveys – taken in 2005, 2010 and 2015 – gather measures on the usefulness of the job, workers’ wellbeing and objective data on the quality of work. The number of respondents grew from over 21,000 in 2005 to almost 30,000 in 2015.

According to Graeber, somewhere between 20% and 50% of the workforce – possibly as many as 60% - are employed in BS jobs. Yet the EWCS found that just 4.8% of EU workers said they did not feel they were doing useful work. The figure was slightly higher in the UK and Ireland, but still only 5.6% of workers.

Graeber also claimed that the number of BS jobs has been ‘increasing rapidly in recent years’, despite presenting no empirical evidence. Again the researchers found no evidence to support this conjecture – in fact, the percentage of people in BS jobs fell from 7.8% in 2005 to just 4.8% in 2015 – exactly the opposite of Graeber’s prediction.

His next hypothesis was that BS jobs are concentrated in particular professions, such as finance, law, administration and marketing, and largely absent in others, such as those linked to public services and manual labour. “Many service workers hate their jobs; but even those who do are aware that what they do does make some sort of meaningful difference in the world . . . [Whereas] we can only assume that any office worker who one might suspect secretly believes themselves to have a bullshit job does, indeed, believe this,” he wrote.

When the researchers ranked the occupations by the proportion of people who rated their job as rarely or never useful, they found no evidence for the existence of occupations in which the majority of workers feel their work is not useful.

The authors found that workers in some occupations, such as teachers and nurses, generally see themselves as doing useful jobs, while sales workers are above average in the proportion rating their job as not useful (7.7%). Even so, most of the results contradict Graeber’s assertion. For example, legal professionals and administration professionals are all low on this ranking, and jobs that Graeber rates as being examples of essential non-BS jobs, such as refuse collectors (9.7%) and cleaners and helpers (8.1%), are high on this scale.

Not everything that Graeber suggested was wrong, however. He argued, for example, that BS jobs are a form of ‘spiritual violence’ that lead to anxiety, depression and misery among workers. The team found strong evidence between the perception of one’s job as useless and an individual’s psychological wellbeing, albeit a correlation rather than necessarily a causal link. In the UK in 2015, workers who felt their job was not useful scored significantly lower on the World Health Organisation Well-Being Index than those who felt they were doing useful work (a mean average of 49.3 compared with 64.5). There was a similar gap across other EU nations.

Dr Alex Wood from the University of Birmingham said: “When we looked at readily-available data from a large cohort of people across Europe, it quickly became apparent to us that very few of the key propositions in Graeber’s theory can be sustained – and this is the case in every country we looked at, to varying degrees. But one of his most important propositions – that BS jobs are a form of ‘spiritual violence’ – does seem to be supported by the data.”

Given that, in absolute terms, a substantial number of people do not view their jobs as useful, what then leads to this feeling? The team found that those individuals who felt respected and encouraged by management were less likely to report their work as useless. Conversely, when employees experience management that is disrespectful, inefficient or poor at giving feedback, they were less likely to perceive their work as useful.

Similarly, individuals who saw their job as useful tended to be able to use their own ideas at work – an important element for feeling that your job provides you with the ability to make the most of your skills – was correlated with a perception of usefulness. There was a clear relationship between the extent to which people felt that they had enough time to do their job well and their rating of the usefulness of their job, suggesting that one source of feeling a job to be useless is the pace at which one is working, affecting the ability to realise one’s potential and capabilities. Other factors correlated with feeling that a job was worthwhile included support by managers and colleagues and the ability to influence important decisions and the direction of an organization.

Professor Brendan Burchell from the University of Cambridge said: “Although the data doesn’t always support David Graeber’s claims, his insightful and imaginative work played an important role in raising awareness of the harms of useless jobs. He may have been way off the mark with regards how common BS jobs are, but he was right to link people’s attitudes towards their jobs to their psychological wellbeing, and this is something that employers – and society as a whole – should take seriously.

“Most importantly, employees need to be respected and valued if they in turn are to value – and benefit psychologically as well as financially from – their jobs.”

https://www.cam.ac.uk/research/news/one-in-twenty-workers-are-in-useless-jobs-far-fewer-than-previously-thought

Thursday, June 3, 2021

Active Early Learning Affects the Adult Brain

Fralin Biomedical Research Institute, University of Pennsylvania scientists reveal effects of early learning that last decades

From Virginia Tech

May 31, 2021 -- An enhanced learning environment during the first five years of life shapes the brain in ways that are apparent four decades later, say Virginia Tech and University of Pennsylvania scientists writing in the June edition of the Journal of Cognitive Neuroscience.

The researchers used structural brain imaging to detect the developmental effects of linguistic and cognitive stimulation starting at six weeks of age in infants. The influence of an enriched environment on brain structure had formerly been demonstrated in animal studies, but this is the first experimental study to find a similar result in humans.

“Our research shows a relationship between brain structure and five years of high-quality educational and social experiences,” said Craig Ramey, professor and distinguished research scholar with the Fralin Biomedical Research Institute at VTC and principal investigator of the study. “We have demonstrated that in vulnerable children who received stimulating and emotionally supportive learning experiences, statistically significant changes in brain structure appear in middle age.”

The results support the idea that early environment influences the brain structure of individuals growing up with multirisk socioeconomic challenges, said Martha Farah, director of the Center for Neuroscience & Society at Penn and first author of the study. 

“This has exciting implications for the basic science of brain development, as well as for theories of social stratification and social policy,” Farah said. 

The study follows children who have continuously participated in the Abecedarian Project, an early intervention program initiated by Ramey in Chapel Hill, North Carolina, in 1971 to study the effects of educational, social, health, and family support services on high-risk infants. 

Both the comparison and treatment groups received extra health care, nutrition, and family support services; however, beginning at six weeks of age, the treatment group also received five years of high quality educational support, five days a week, 50 weeks a year.

When scanned, the Abecedarian study participants were in their late 30s to early 40s, offering the researchers a unique look at how childhood factors affect the adult brain.

“People generally know about the potentially large benefits of early education for children from very low resource circumstances,” said co-author Sharon Landesman Ramey, professor and distinguished research scholar with the Fralin Biomedical Research Institute and the Virginia Tech College of Science. “The new results reveal that biological effects accompany the many behavioral, social, health, and economic benefits reported in the Abecedarian Project. This affirms the idea that positive early life experiences contribute to later positive adjustment through a combination of behavioral, social, and brain pathways.”

During follow-up examinations, structural MRI scans of the brains of 47 study participants were conducted at the Fralin Biomedical Research Institute Human Neuroimaging Lab. Of those, 29 individuals had been in the group that received the educational enrichment focused on promoting language, cognition, and interactive learning. 

The other 18 individuals received the same robust health, nutritional, and social services supports provided to the educational treatment group, and whatever community childcare or other learning their parents provided.  The two groups were well matched on a variety of factors such as maternal education, head circumference at birth, and age at scanning.

Analyzing the scans, the researchers looked at brain size as a whole, including the cortex, the brain’s outermost layer, as well as five regions selected for their expected connection to the intervention’s stimulation of children’s language and cognitive development. 

Those included the left inferior frontal gyrus and left superior temporal gyrus, which may be relevant to language, and the right inferior frontal gyrus and bilateral anterior cingulate cortex, relevant to cognitive control. A fifth, the bilateral hippocampus, was added because its volume is frequently associated with early life adversity and socioeconomic status.

The researchers determined that those in the early education treatment group had increased size of the whole brain, including the cortex. 

Several specific cortical regions also appeared larger, according to study co-authors Read Montague, professor and director of the Human Neuroimaging Lab and Computational Psychiatry Unit at the Fralin Biomedical Research Institute, and Terry Lohrenz, research assistant professor and member of the institute’s Human Neuroimaging Laboratory. 

The scientists noted the group intervention treatment results for the brain were substantially greater for males than for females. The reasons for this are not known, and were surprising, since both the boys and girls showed generally comparable positive behavioral and educational effects from their early enriched education. The current study cannot adequately explain the sex differences.  

“When we launched this project in the 1970s, the field knew more about how to assess behavior than it knew about how to assess brain structure,” said Craig Ramey, who is also a professor in the Virginia Tech College of Science. “Because of advances in neuroimaging technology and through strong interdisciplinary collaborations, we were able to measure structural features of the brain. The prefrontal cortex and areas associated with language were definitely affected; and to our knowledge, this is the first experimental evidence on a link between known early educational experiences and long-term changes in humans.”

“We believe that these findings warrant careful consideration and lend further support to the value of ensuring positive learning and social-emotional support for all children – particularly to improve outcomes for children who are vulnerable to inadequate stimulation and care in the early years of life,” Craig Ramey said.

The study was supported by a Principal Research Fellowship from the Wellcome Trust, Virginia Tech, the School of Arts and Sciences Research Fund, University of Pennsylvania, and the William N. Sternberg Fund for Human Information-Processing Research.

       https://vtx.vt.edu/articles/2021/05/learning-fralinbiomed-06012021.html

Wednesday, June 2, 2021

Advanced Method for AI Generation of Images

Applications include fields from autonomous robotics to AI training

From:  North Carolina State University

June 1, 2021 -- At issue is a type of AI task called conditional image generation, in which AI systems create images that meet a specific set of conditions. For example, a system could be trained to create original images of cats or dogs, depending on which animal the user requested. More recent techniques have built on this to incorporate conditions regarding an image layout. This allows users to specify which types of objects they want to appear in particular places on the screen. For example, the sky might go in one box, a tree might be in another box, a stream might be in a separate box, and so on.

The new work builds on those techniques to give users more control over the resulting images, and to retain certain characteristics across a series of images.

"Our approach is highly reconfigurable," says Tianfu Wu, co-author of a paper on the work and an assistant professor of computer engineering at NC State. "Like previous approaches, ours allows users to have the system generate an image based on a specific set of conditions. But ours also allows you to retain that image and add to it. For example, users could have the AI create a mountain scene. The users could then have the system add skiers to that scene."

In addition, the new approach allows users to have the AI manipulate specific elements so that they are identifiably the same, but have moved or changed in some way. For example, the AI might create a series of images showing skiers turn toward the viewer as they move across the landscape.

"One application for this would be to help autonomous robots 'imagine' what the end result might look like before they begin a given task," Wu says. "You could also use the system to generate images for AI training. So, instead of compiling images from external sources, you could use this system to create images for training other AI systems."

The researchers tested their new approach using the COCO-Stuff dataset and the Visual Genome dataset. Based on standard measures of image quality, the new approach outperformed the previous state-of-the-art image creation techniques.

"Our next step is to see if we can extend this work to video and three-dimensional images," Wu says.

Training for the new approach requires a fair amount of computational power; the researchers used a 4-GPU workstation. However, deploying the system is less computationally expensive.

"We found that one GPU gives you almost real-time speed," Wu says.

"In addition to our paper, we've made our source code for this approach available on GitHub. That said, we're always open to collaborating with industry partners."

         https://www.sciencedaily.com/releases/2021/06/210601135751.htm

Tuesday, June 1, 2021

New “Flatland” Computer Memory Approach

Currently being explored by the McKelvey School of Engineering at Washington University in St. Louis

May 21, 2021 -- Computers have a hierarchy of memory, with the memory closest to the processor performing the fastest but storing the least amount of data. Improved technology is flattening out the hierarchy, but the current practical tools and theory to understand it are not designed for this “flatland” terrain. 

Kunal Agrawal, associate professor of computer science in the McKelvey School of Engineering at Washington University in St. Louis, is joining a team of collaborators who seek to understand how the structure of memory is changing and develop new theoretical models and algorithms for the new subsystems with a four-year, $1.2 million grant from the National Science Foundation. She is collaborating with Michael Bender, professor of computer science at Stony Brook University; Martin Farach-Colton, professor of computer science at Rutgers University and lead investigator; and Jeremy Fineman, Provost's Distinguished Associate Professor and Wagner Term Chair in Computer Science at Georgetown University. Washington University’s portion of the grant is $299,997.

In this theoretical project, Agrawal and collaborators will investigate how to manage memory resources to ensure the best performance.

“Computers have many processors and cores that are all accessing this memory system, and they are fighting over the resources because some levels of the memory hierarchy are shared,” Agrawal said. “These cores could be running independent applications, the same parallel application or it could be a combination. We want to get the best performance that we can in all of these scenarios.”

“Parallelism is here to stay,” Agrawal said. “Now we have eight cores on a machine, but as we get more and more cores, this work becomes more relevant.”

While this is not a new field, it is more important now because of the changing properties of the different types of memory. The team will look at the new kinds of memory coming online: some that are fast, some that read fast but write slow, and some that can only do a certain number of writes before the memory is useless, Agrawal said.

The researchers also will look at streaming and semi-streaming applications for large data sets. 

“Previously, streaming applications often used a one-pass algorithm where you read the data only once because it was too big,” she said. “Now, you can afford to do more than one read, and this makes a big difference in algorithm design.” 

The team will build new theoretical models to help them learn how to use the memory to solve problems.

https://engineering.wustl.edu/news/2021/Exploring-the-flatland-of-computer-memory.html

Monday, May 31, 2021

Secret Childrens’ Graveyard Found in Canada

The Kamloops Indian Residential School was part of the Canadian Indian residential school system.  Located in Kamloops, British Columbia, it was once the largest residential school in Canada, with its enrolment peaking at 500 in the 1950s.

The school was established in 1890 and in operation until 1969, when it was taken over by the federal government from the Catholic Church to be used as a day school residence. It closed in 1978.  The school building still stands today, and is located on the Tk’emlúps te Secwépemc First Nation.  In May 2021, the remains of 215 children buried in a mass grave were found at the site.

History of the School

What would become the Kamloops Indian Residential School was established in 1893, after initially opening in 1890 as the Kamloops Industrial School which had the aim of acculturating Indigenous children.  D. Ross of Kamloops was awarded the $10,000 contract to erect the initial set of industrial school buildings in April 1889.  Three two-storey wooden structures were the first buildings on the site, consisting of separate living quarters for boys and girls, and the school's teachers, along with classrooms and a recreation area.  Michel Hagan served as the industrial school's first principal, resigning in 1892, at which time the government charged the Oblates of Mary Immaculate with running the school.  Father Carrion was named principal of the school in March 1893, following Hagan's departure.

In 1927, John Duplanil succeeded J. Maguire as principal of the school, following Maguire's appointment as curate of St. Patrick's Church in Lethbridge, Alberta.  G.P. Dunlop took over as head of the school in 1958, relocating from a position at the Eugene Mission Indian School in Cranbook, British Columbia.

The school continued as the Kamloops Indian Residential School until 1978, located on the traditional territory of the Secwepemc (Secwépemcúl'ecw). The building was the first location of the Secwepemc Museum, which opened in 1982.  In 1991, a special edition of Secwepemc News reported that the public policy which led to the operation of the school for more than 80 years had "done its job; English is now the predominant language within the Shuswap Nation and the survival of the Shuswap language is uncertain."

The school was featured in the 1962 Christmas-themed film Eyes of the Children.  Produced by George Robertson, the film followed 400 students as they prepared for Christmas and aired on the CBC on Christmas Day.

Discovery of the Mass Grave

In May 2021, the buried remains of 215 children, some as young as three years old, were found at the school site with the assistance of a ground-penetrating radar specialist.  There had long been rumours of unmarked graves at residential schools, but none had previously been uncovered.  Tk’emlúps te Secwépemc First Nation Chief Rosanne Casimir said the finding represented "an unthinkable loss ... never documented by the school's administrators", and that work was underway to determine whether the Royal British Columbia Museum holds relevant records.  She also said the radar scanning is yet to be complete, and she expects further discoveries to be made.  The National Centre for Truth and Reconciliation has so far released official recognition of some 51 students who had died. Their dates of death range from 1919 until 1964.  The continued radar survey suggests the investigation is ongoing.

A provincial Indigenous leader said in May 2021 there were plans being made for forensic experts to exhume, identify and repatriate the remains of the children from the school.

Reactions to the Mass Grave

In a statement released by the First Nations Health Authority, CEO Richard Jock said: "That this situation exists is sadly not a surprise and illustrates the damaging and lasting impacts that the residential school system continues to have on First Nations people, their families and communities."  Premier of British Columbia John Horgan said that he was "horrified and heartbroken" at the discovery, and that he supported further efforts to bring to "light the full extent of this loss".  Federal Minister of Indigenous Services Marc Miller also offered his support.  Prime Minister Justin Trudeau called the discovery "heartbreaking" the day of the announcement, and on May 30, ordered flags on federal buildings to be flown at half-mast until further notice.  Other half-mastings included flags at the BC and Manitoba legislatures as well as individual municipalities such as Ottawa, Montreal, Edmonton, M1ississauga, Brampton, and Toronto, which also ordered the 3D Toronto sign dimmed for 215 hours.

Angela White, executive director for the Indian Residential School Survivors Society, has also called on the Canadian federal government and Catholic Church to take action and responsibility around reconciliation efforts, stating: "Reconciliation does not mean anything if there is no action to those words...[w]ell-wishes and prayers only go so far. If we are going to actually create positive strides forward there needs to be that ability to continue the work, like the Indian Residential School Survivors Society does, in a meaningful way."

Inspired by a community memorial at the Vancouver Art Gallery which laid out 215 pairs of children's shoes in rows.  Similar memorials were created across Canada, including in front of government buildings and church buildings that had been in charge of running the residential school system. At the Ontario Legislative Building, security initially ordered the shoes removed before acquiescing. The Anishinabek Nation tweeted in support of social media calls to put out teddy bears on porches on May 31, similar to what was done after the 2018 Humboldt Broncos bus crash with hockey sticks. Another popular campaign called on people to wear orange on May 31.

                 Kamloops Indian Residential School - Wikipedia

Sunday, May 30, 2021

Leading Victorian Critic John Ruskin

John Ruskin (8 February 1819 – 20 January 1900) was the leading English art critic of the Victorian era, as well as an art patron, draughtsman, watercolourist, philosopher, prominent social thinker and philanthropist. He wrote on subjects as varied as geology, architecture, myth, ornithology, literature, education, botany and political economy.

His writing styles and literary forms were equally varied. He wrote essays and treatises, poetry and lectures, travel guides and manuals, letters and even a fairy tale. He also made detailed sketches and paintings of rocks, plants, birds, landscapes, architectural structures and ornamentation.

The elaborate style that characterised his earliest writing on art gave way in time to plainer language designed to communicate his ideas more effectively. In all of his writing, he emphasised the connections between nature, art and society.

He was hugely influential in the latter half of the 19th century and up to the First World War. After a period of relative decline, his reputation has steadily improved since the 1960s with the publication of numerous academic studies of his work. Today, his ideas and concerns are widely recognised as having anticipated interest in environmentalism, sustainability and craft.

Ruskin first came to widespread attention with the first volume of Modern Painters (1843), an extended essay in defence of the work of J. M. W. Turner in which he argued that the principal role of the artist is "truth to nature". From the 1850s, he championed the Pre-Raphaelites, who were influenced by his ideas. His work increasingly focused on social and political issues.  Unto This Last (1860, 1862) marked the shift in emphasis. In 1869, Ruskin became the first Slade Professor of Fine Art at the University of Oxford, where he established the Ruskin School of Drawing.  In 1871, he began his monthly "letters to the workmen and labourers of Great Britain", published under the title Fors Clavigera (1871–1884). In the course of this complex and deeply personal work, he developed the principles underlying his ideal society. As a result, he founded the Guild of St George, an organisation that endures today.

Social Critic and Reformer: Unto This Last

Although in 1877 Ruskin said that in 1860, "I gave up my art work and wrote Unto This Last, . the central work of my life" the break was not so dramatic or final.  Following his crisis of faith, and influenced in part by his friend Thomas Carlyle (whom he had first met in 1850), Ruskin shifted his emphasis in the late 1850s from art towards social issues. Nevertheless, he continued to lecture on and write about a wide range of subjects including art and, among many other matters, geology (in June 1863 he lectured on the Alps), art practice and judgement (The Cestus of Aglaia), botany and mythology (Proserpina and The Queen of the Air). He continued to draw and paint in watercolours, and to travel extensively across Europe with servants and friends. In 1868, his tour took him to Abbeville, and in the following year he was in Verona (studying tombs for the Arundel Society) and Venice (where he was joined by William Holman Hunt). Yet increasingly Ruskin concentrated his energies on fiercely attacking industrial capitalism, and the utilitarian theories of political economy underpinning it. He repudiated his sometimes grandiloquent style, writing now in plainer, simpler language, to communicate his message straightforwardly.

Ruskin's social view broadened from concerns about the dignity of labour to consider issues of citizenship and notions of the ideal community. Just as he had questioned aesthetic orthodoxy in his earliest writings, he now dissected the orthodox political economy espoused by John Stuart Mill, based on theories of laissez-faire and competition drawn from the work of Adam Smith, David Ricardo and Thomas Malthus.  In his four essays Unto This Last, Ruskin rejected the division of labour as dehumanising (separating the labourer from the product of his work), and argued that the false "science" of political economy failed to consider the social affections that bind communities together. He articulated an extended metaphor of household and family, drawing on Plato and Xenophon to demonstrate the communal and sometimes sacrificial nature of true economics.  For Ruskin, all economies and societies are ideally founded on a politics of social justice.  His ideas influenced the concept of the "social economy", characterised by networks of charitable, co-operative and other non-governmental organisations.

The essays were originally published in consecutive monthly instalments of the new Cornhill Magazine between August and November 1860 (and published in a single volume in 1862).  However, the Cornhill's editor, William Makepeace Thackeray, was forced to abandon the series by the outcry of the magazine's largely conservative readership and the fears of a nervous publisher (Smith, Elder & Co.).  The reaction of the national press was hostile, and Ruskin was, he claimed, "reprobated in a violent manner".  Ruskin's father also strongly disapproved.  Others were enthusiastic, including Ruskin's friend Thomas Carlyle, who wrote, "I have read your paper with exhilaration... such a thing flung suddenly into half a million dull British heads... will do a great deal of good."

Ruskin's political ideas, and Unto This Last in particular, later proved highly influential. The essays were praised and paraphrased in Gujarati by Mohandas Gandhi, a wide range of autodidacts cited their positive impact, the economist John A. Hobson and many of the founders of the British Labour party credited them as an influence.

Ruskin believed in a hierarchical social structure. He wrote "I was, and my father was before me, a violent Tory of the old school."  He believed in man's duty to God, and while he sought to improve the conditions of the poor, he opposed attempts to level social differences and sought to resolve social inequalities by abandoning capitalism in favour of a co-operative structure of society based on obedience and benevolent philanthropy, rooted in the agricultural economy.

If there be any one point insisted on throughout my works more frequently than another, that one point is the impossibility of Equality. My continual aim has been to show the eternal superiority of some men to others, sometimes even of one man to all others; and to show also the advisability of appointing such persons or person to guide, to lead, or on occasion even to compel and subdue, their inferiors, according to their own better knowledge and wiser will.

— John Ruskin, Unto This Last: Cook and Wedderburn 17.34

       https://en.wikipedia.org/wiki/John_Ruskin

Saturday, May 29, 2021

Important New Data for Climate Models

A fiery past sheds new light on the future of global climate change.  Ice core samples reveal significant smoke aerosols in the pre-industrial Southern Hemisphere

From: Harvard (the John A. Paulson School of Engineering and Applied Sciences)

May 28, 2021 -- Centuries-old smoke particles preserved in the ice reveal a fiery past in the Southern Hemisphere and shed new light on the future impacts of global climate change, according to new research published in Science Advances.

"Up till now, the magnitude of past fire activity, and thus the amount of smoke in the preindustrial atmosphere, has not been well characterized," said Pengfei Liu, a former graduate student and postdoctoral fellow at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and first author of the paper. "These results have importance for understanding the evolution of climate change from the 1750s until today, and for predicting future climate."

One of the biggest uncertainties when it comes to predicting the future impacts of climate change is how fast surface temperatures will rise in response to increases in greenhouse gases. Predicting these temperatures is complicated since it involves the calculation of competing warming and cooling effects in the atmosphere. Greenhouse gases trap heat and warm the planet's surface while aerosol particles in the atmosphere from volcanoes, fires and other combustion cool the planet by blocking sunlight or seeding cloud cover. Understanding how sensitive surface temperature is to each of these effects and how they interact is critical to predicting the future impact of climate change.

Many of today's climate models rely on past levels of greenhouse gasses and aerosols to validate their predictions for the future. But there's a problem: While pre-industrial levels of greenhouse gasses are well documented, the amount of smoke aerosols in the preindustrial atmosphere is not.

To model smoke in the pre-industrial Southern Hemisphere, the research team looked to Antarctica, where the ice trapped smoke particles emitted from fires in Australia, Africa and South America. Ice core scientists and co-authors of the study, Joseph McConnell and Nathan Chellman from the Desert Research Institute in Nevada, measured soot, a key component of smoke, deposited in an array of 14 ice cores from across the continent, many provided by international collaborators.

"Soot deposited in glacier ice directly reflects past atmospheric concentrations so well-dated ice cores provide the most reliable long-term records," said McConnell.

What they found was unexpected.

"While most studies have assumed less fire took place in the preindustrial era, the ice cores suggested a much fierier past, at least in the Southern Hemisphere," said Loretta Mickley, Senior Research Fellow in Chemistry-Climate Interactions at SEAS and senior author of the paper.

To account for these levels of smoke, the researchers ran computer simulations that account for both wildfires and the burning practices of indigenous people.

"The computer simulations of fire show that the atmosphere of the Southern Hemisphere could have been very smoky in the century before the Industrial Revolution. Soot concentrations in the atmosphere were up to four times greater than previous studies suggested. Most of this was caused by widespread and regular burning practiced by indigenous peoples in the pre-colonial period," said Jed Kaplan, Associate Professor at the University of Hong Kong and co-author of the study.

This result agrees with the ice core records that also show that soot was abundant before the start of the industrial era and has remained relatively constant through the 20th century. The modelling suggests that as land use changes decreased fire activity, emissions from industry increased.

What does this finding mean for future surface temperatures?

By underestimating the cooling effect of smoke particles in the pre-industrial world, climate models might have over-estimated the warming effect of carbon dioxide and other greenhouse gasses in order to account for the observed increases in surface temperatures.

"Climate scientists have known that the most recent generation of climate models have been over-estimating surface temperature sensitivity to greenhouse gasses, but we haven't known why or by how much," said Liu. "This research offers a possible explanation."

"Clearly the world is warming but the key question is how fast will it warm as greenhouse gas emissions continue to rise. This research allows us to refine our predictions moving forward," said Mickley.

       https://www.sciencedaily.com/releases/2021/05/210528152517.htm