Study: Countering hate on social media

SANTA FE INSTITUTE

Research News

 

IMAGE: FIGURE 1 FROM THE PAPER: EXAMPLES OF TWITTER CONVERSATIONS (REPLY TREES) WITH LABELED HATE (RED), COUNTER (BLUE), AND NEUTRAL SPEECH (WHITE). THE ROOT NODE IS SHOWN AS A LARGE SQUARE. view more 

CREDIT: GARLAND ET AL, EMNLP 2020

The rise of online hate speech is a disturbing, growing trend in countries around the world, with serious psychological consequences and the potential to impact, and even contribute to, real-world violence. Citizen-generated counter speech may help discourage hateful online rhetoric, but it has been difficult to quantify and study. Until recently, studies have been limited to small-scale, hand-labeled endeavors.

A new paper published in the proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP) offers a framework for studying the dynamics of online hate and counter speech. The paper offers the first large-scale classification of millions of such interactions on Twitter. The authors developed a learning algorithm to assess data from a unique situation on German Twitter, and the findings suggest that organized movements to counteract hate speech on social media are more effective than individuals striking out on their own. 

The authors will present their paper, "Countering hate on social media: Large-scale classifications of hate and counter speech" during the November 20, 2020, Workshop on Online Abuse and Harms, which is running in conjunction with EMNLP 2020. 

"I've seen this big shift in civil discourse in the last two or three years towards being much more hateful and much more polarized," says Joshua Garland, a mathematician and Applied Complexity Fellow at the Santa Fe Institute. "So, for me, an interesting question was: what's an appropriate response when you're being cyber-bullied or when you're receiving hate speech online? Do you respond? Do you try to get your friends to help protect you? Do you just block the person?" 

To study such questions scientifically, researchers must first have access to a wealth of real-world data on both hate speech and counter-speech, and the ability to distinguish between the two. That data existed, and Garland and collaborator Keyan Ghazi-Zahedi at the Max Planck Institute in Germany found it in a five-year interaction that played out over German Twitter: As an alt-right group took to the platform with hate speech, an organized movement rose up to counter it.

"The beauty of these two groups is they were self-labeling," explains Mirta Galesic, the team's social scientist and a professor of human social dynamics at SFI. She says researchers who study counter-speech usually have to employ hundreds of students to hand-code thousands of posts. But Garland and Ghazi-Zahedi were able to input the self-labeled posts into a machine-learning algorithm to automate large swaths of the classification. The team also relied on 20-30 human coders to check that the machine classifications matched up with intuition about what registers as hate and counter-speech.

The result was a dataset of unprecedented size that allows the researchers to analyze not just isolated instances of hate and counter speech, but also compare long-running interactions between the two.

The team collected one dataset of millions of tweets posted by members of the two groups, using these self-identified tweets to train their classification algorithm to recognize hate and counter speech. Then, they applied their algorithm to study the dynamics of some 200,000 conversations that occurred between 2013 and 2018. The authors plan to soon publish a follow-up paper analyzing the dynamics revealed by their algorithm.

"Now we can resolve a massive data set from 2016 to 2018 to see how the proportion of hate and counter-speech changed over time, who gets more likes, who is retweeted, and how they replied to each other" Galesic says.

The quantity of data, a tremendous boon, also makes it "incredibly complex," Garland notes. The researchers are in the process of comparing tactics for both groups and pursuing broader questions such as whether certain counter-speech strategies are more effective than others.

"What I'm hoping is that we can come up with a rigorous social theory that tells people how to counter hate in a productive way that's non-polarizing," Garland says, "and bring the Internet back to civil discourse."  

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Dogmatic people seek less information even when uncertain

Peer-reviewed | observational study | people

UNIVERSITY COLLEGE LONDON

Research News

 

People who are dogmatic about their views seek less information and make less accurate judgements as a result, even on simple matters unrelated to politics, according to a study led by UCL and Max Planck Institute for Biological Cybernetics researchers.

The researchers say their findings, published in PNAS, point to differences in thinking patterns that lead people to hold rigid opinions.

First author Lion Schulz, a PhD candidate at the Max Planck Institute in Germany who began the research while at UCL, said: "Anecdotally, it seems that dogmatic people are less interested in information that might change their mind. However, it was unclear if this is because a specific opinion is of high importance to them or if more fundamental processes are at play that transcend specific opinions."

Dogmatic people are characterised by a belief that their worldview reflects an absolute truth and are often resistant to change their mind, for example when it comes to partisan issues. This tendency can have societal impacts by polarising political, scientific and religious debates. However, the cognitive drivers of dogmatism are still poorly understood.

To investigate this, the researchers asked over 700 people to perform a simple decision-making task. Participants saw two boxes with flickering dots and had to decide which box contained more of the dots. Critically, after the participants had made an initial choice, the researchers gave them the chance to view another, clearer version of the boxes. They then made a final decision.

Schulz explained: "This mirrors many real-life situations - for example, when we hear a rumour but aren't sure if it's true. Do we share it, or do we check a credible source beforehand?"

Joint first author, Dr Max Rollwage (Wellcome Centre for Human Neuroimaging at UCL and Max Planck UCL Centre for Computational Psychiatry & Ageing Research) said: "By using simple tasks, we were able to minimise motivational or social influences and pin down drivers of altered evidence processing that contribute to dogmatic beliefs."

The task was followed by a comprehensive set of questionnaires that allowed the researchers to measure participants' political orientation and levels of dogmatism.

Dogmatic individuals and moderates did not differ in their accuracy or confidence of their decisions. However, the researchers found that more dogmatic participants were more likely to decline the helpful additional information.

The differences between more and less dogmatic participants were especially large when participants had little confidence in a decision. Senior author Dr Steve Fleming (Wellcome Centre for Human Neuroimaging at UCL, Max Planck UCL Centre for Computational Psychiatry & Ageing Research and UCL Experimental Psychology) said: "Previous work has found that there is a close link between how confident we feel and whether or not we seek out new information. In the current study we found that this link was weaker in more dogmatic individuals."

In general, the reduced search was detrimental, with more dogmatic people being less accurate in their final judgements.

Dr Fleming added: "It is striking that we could detect links between dogmatism about issues such as politics, and information-seeking in a simple online game. This tells us that real-world dogmatism isn't just a feature of specific groups or opinions but may be associated with more fundamental cognitive processes."

The study highlights that simply having corrective information available does not necessarily mean people will consume it.

Schulz said: "This is particularly relevant today. We have never been so free to decide if we have enough evidence about something or whether we should seek out further information from a reliable source before believing it.

"It is also important to stress that the differences between more and less dogmatic people were subtle, and we don't know yet how they would manifest when considering real-world information such as news about political parties. In the end, it's a cautionary tale, whether we think of ourselves as dogmatic or not: when uncertain, it might be wise to check the information again."

The researchers are now trying to further unravel the underlying cognitive algorithms which trigger people to search for further information in situations of uncertainty.

Simple, no-cost ways to help the public care for the commons

News from the Journal of Marketing

AMERICAN MARKETING ASSOCIATION

Research News

 

Researchers from University of Wisconsin-Madison, New York Institute of Technology, University of Iowa, and Cornell University published a new paper in the Journal of Marketing that examines whether it is possible to make people feel as if the property is theirs--a feeling known as psychological ownership--and how this affects their stewardship behaviors.

The study, forthcoming in the Journal of Marketing, is titled "Caring for the Commons: Using Psychological Ownership to Enhance Stewardship Behavior for Public Goods" and is authored by Joann Peck, Colleen Kirk, Andrea Luangrath, and Suzanne Shu.

Maintaining the natural environment is a pressing issue. The intentional care of public goods, such as publicly owned parks, waterways, drinking water, and air quality, has become increasingly difficult. For example, for public parks, it has become more challenging during the pandemic as park services are reduced while the number of people spending time outside has increased. It is widely acknowledged that property that is publicly, versus individually, owned tends to be more neglected by its users - a phenomenon known in economics as the tragedy of the commons.

The most extreme solution to a tragedy of the commons problem is to convert common property into private property so that a single owner has responsibility for its care. As Peck explains, "We wondered whether it is possible to instead make people feel as if the property is theirs--a feeling known as psychological ownership--without any change to legal ownership. The hypothesis is that people who feel as if they own a public resource might be more likely to engage in stewardship behaviors." Leveraging psychological ownership, the researchers developed a series of actionable interventions that managers of public goods can implement to elicit feelings of ownership in users. Four experiments tested this hypothesis.

The first study was at a public lake with kayakers. Floating trash was set in the water where kayakers would see it. As visitors rented kayaks, half were asked to create a nickname for the lake before entering the water. Using binoculars, the researchers observed whether the kayakers tried to pick up the planted trash. Kayakers who gave the lake a nickname felt more ownership of the lake. Most importantly, they were more than five times as likely to try to pick up the planted trash (41% vs. 7% of the other kayakers).

In the second study, participants imagined taking a walk in a park. They were shown a sign at the park entrance that said either "Welcome to the Park" or "Welcome to YOUR Park." Participants who saw the "YOUR park" sign felt more ownership and responsibility for the park, were more likely to pick up trash, and would donate 34% more to the park ($32.35 vs. $24.08).

The third study tested yet a different way to elicit psychological ownership to see if it could increase actual donations. This study involved cross-country ski renters at a state park. As they rented equipment, they received a map. Half of them were asked to plan their route on the map in advance. The prediction was that this investment of time might increase the skiers' psychological ownership of the park and thus increase their donations through the addition of $1.00 to the rental fee. As expected, skiers who planned their routes and therefore felt more ownership donated to the park 2.5 times more often than those who did not plan their routes. They also reported being more likely to volunteer for the park, to donate in the future, and to promote the park on social media.

The fourth study explored whether managers of public goods may be unintentionally discouraging stewardship behaviors. Many parks tout their attendance numbers, but the intuition was that an attendance sign with a large number of people on it might diffuse users' feelings of responsibility. Research participants imagined they were visiting a park and saw either a "the park" or "YOUR park" welcome sign. Then half of them imagined seeing an attendance sign that read "This week, you are visitor #22,452". (Many U.S. parks have over a million visitors annually, so we designed an attendance sign that included an appropriately large number.) Participants were given money for participating, but also had the option to use some of that money for an anonymous donation to the park. As in the prior studies, individuals who felt more ownership of the park donated more to the park. They were also more likely to say that they would volunteer to help the park, including picking up trash. However, these effects were reduced when participants imagined the attendance sign, which possibly suggested the feeling that these other people would take responsibility for the park.

"This research has implications for consumers, organizations caring for public resources, policy makers, and for-profit companies by demonstrating that simple interventions based on increasing psychological ownership can enhance stewardship of public goods. The actionable interventions we designed and tested to increase psychological ownership are inexpensive, novel, and flexible solutions that successfully motivate individual stewardship behaviors" says Luangrath. By fostering visitors' individual feelings of ownership of a public resource, visitors will feel more responsible for it, take better care of it, and donate more time and money for its benefit.

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Full article and author contact information available at: https://doi.org/10.1177%2F0022242920952084

About the Journal of Marketing

The Journal of Marketing develops and disseminates knowledge about real-world marketing questions useful to scholars, educators, managers, policy makers, consumers, and other societal stakeholders around the world. Published by the American Marketing Association since its founding in 1936, JM has played a significant role in shaping the content and boundaries of the marketing discipline. Christine Moorman (T. Austin Finch, Sr. Professor of Business Administration at the Fuqua School of Business, Duke University) serves as the current Editor in Chief.

https://www.ama.org/jm

About the American Marketing Association (AMA)

As the largest chapter-based marketing association in the world, the AMA is trusted by marketing and sales professionals to help them discover what's coming next in the industry. The AMA has a community of local chapters in more than 70 cities and 350 college campuses throughout North America. The AMA is home to award-winning content, PCM® professional certification, premiere academic journals, and industry-leading training events and conferences.

https://www.ama.org

Highly efficient, long-lasting electrocatalyst to boost hydrogen fuel production

Surface oxygen adsorbed during synthesis of the single atomic alloy catalyst stabilizes the catalytic intermediate, ensuring a full cycle of water oxidation

INSTITUTE FOR BASIC SCIENCE

Research News

 

IMAGE: CRYSTAL STRUCTURE OF SURFACE OXYGEN-RICH METAL ALLOY (TOP LEFT). OXYGEN AND HYDROGEN ARE GENERATED DURING A WATER ELECTROLYSIS REACTION (TOP RIGHT). THE DESIGNED CATALYST EXHIBITS THE BEST OXYGEN EVOLUTION ACTIVITY... view more 

CREDIT: IBS

Abundant. Clean. Flexible. Alluring enough to explain why hydrogen, the most common molecule in the universe happens to have its name as part of an national Hydrogen and Fuel Cell Day. Chosen to signify hydrogen's atomic weight of 1.008, the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy celebrates advances in hydrogen-use technology every October 8 since 2015. When hydrogen is consumed in a fuel cell (which takes the water molecule H2O and seperates it into oxygen and hydrogen, a process called electrolysis), it only produces water, electricity, and heat. As a zero-carbon energy source, the range of its potential use is limitless: transportation, commercial, industrial, residential, and portable.

While traditional hydrogen production processes required fossil fuels or CO2, electrolysis produces "green hydrogen" from water molecules. Since water cannot be split into hydrogen and oxygen by itself, the electrochemical hydrogen-water conversion needs highly active electrocatalysts. The conventional water electrolysis, however, faces technological challenges to improve the efficiency of the water-splitting reaction for the sluggish oxygen evolution reaction. Noble metal-based ruthenium oxide (RuO2) and iridium oxide (IrO2) are used to enhance the oxygen generation rate. However, these noble metal catalysts are very expensive and show poor stability under long-term operation.

Led by Associate Director LEE Hyoyoung of the Center for Integrated Nanostructure Physics within the Institute for Basic Science (IBS) located at Sungkyunkwan University, the IBS research team developed a highly efficient and long-lasting electrocatalyst for water oxidation using cobalt, iron, and a minimal amount of ruthenium. "We used 'amphiphilic block copolymers' to control electrostatic attraction in our single ruthenium (Ru) atom-bimetallic alloy. The copolymers facilitate the synthesis of spherical clusters of hydrocarbon molecules whose soluble and insoluble segments form the core and shell. In this study, their tendency for a unique chemical structure allows the synthesis of the "high-performance" single atomic Ru alloy present atop the stable cobalt iron (Co-Fe) metallic composite surrounded by porous, defective and graphitic carbon shell," says LEE Jinsun and Kumar Ashwani, the co-first authors of the study.

"We were very excited to discover that pre-adsorbed surface oxygen on the Co-Fe alloy surface, absorbed during the synthesis process, stabilizes one of the important intermediates (OOH*) during the oxygen generation reaction, boosting the overall efficiency of the catalytic reaction. The pre-absorbed surface oxygen has been of little interest until our finding," notes Associate Director Lee, the corresponding author of the study. The researchers found that four hour-annealing at 750°C in an argon atmosphere is the best appropriate condition for the oxygen generating process. In addition to the reaction-friendly environment on the host metal surface, the single Ru atom, where oxygen generation takes place, also fulfills its role by lowering the energy barrier, synergistically enhancing the efficiency of oxygen evolution.

The research team evaluated the catalytic efficiency with the overvoltage metrics needed for the oxygen evolution reaction. The advanced noble electrocatalyst required only 180 mV (millivolt) overvoltage to attain a current density of 10 mA (milliampere) per cm2 of catalyst, while ruthenium oxide needed 298 mV. In addition, the single Ru atom-bimetallic alloy showed long-term stability for 100 hours without any change of structure. Furthermore, the cobalt and iron alloy with graphitic carbon also compensated electrical conductivity and enhanced the oxygen evolution rate.

Associate Director Lee explains, "This study takes us a step closer to a carbon-free, and green hydrogen economy. This highly efficient and inexpensive oxygen generation electro-catalyst will help us overcome long-term challenges of the fossil fuel refining process: to produce high-purity hydrogen for commercial applications at a low price and in an eco-friendly manner."

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The study was published online on November 4 in the journal Energy & Environmental Science.

XAOS THEORY

A long distance connection: polar climate affects trade wind strength in tropics

UNIVERSITY OF HAWAII AT MANOA

Research News

 

IMAGE: THE BLUE ICE COVERING LAKE FRYXELL IN THE TRANSANTARCTIC MOUNTAINS COMES FROM MELTED GLACIER WATER. view more 

CREDIT: JOE MASTROIANNI, NATIONAL SCIENCE FOUNDATION

The impact of sea surface temperature variations in the tropical Pacific on global climate has long been recognized. For instance, the episodic warming of the tropical Pacific during El Niño events causes melt of sea ice in far-reaching parts of the Southern Ocean via its effect on the global atmospheric circulation. A new study, published this week in the journal Science Advances by an international team, demonstrates that the opposite pathway exists as well.

Using a hierarchy of climate model simulations, the authors demonstrate the physical pathways via which polar climate variations can affect the trade winds in the tropics.

"Climate signals can propagate from the polar regions to the tropics either via the atmosphere or the ocean," explained Malte Stuecker, co-author and assistant professor in the Department of Oceanography and International Pacific Research Center at the University of Hawai?i at Mānoa. "Our climate model simulations were designed to investigate the relative role of these pathways and whether their importance differs for perturbations originating from the North pole or the South pole."

The authors found that in the most complex model simulations, which include realistic representations of the ocean, atmosphere, land, and sea ice, an anomalous cooling in either hemisphere leads to a strengthening of the tropical trade winds.

Lead author Sarah Kang from the Ulsan National Institute of Science and Technology in South Korea explained the reasoning behind these experiments: "One of the largest sources of uncertainty in the current generation of climate models are biases in the representation of clouds over the cold Southern Ocean. We wanted to explore what effect too much reflection of solar radiation by these clouds to outer space might have on global climate. In addition, large emissions of aerosols in the late 20th century due to industrial activity in the Northern Hemisphere from North America, Europe, and Asia resulted in a slight, temporary reduction of the global warming rate that is due to increasing greenhouse gas emissions."

According to the authors' results, both of these effects could potentially explain why the Pacific trade winds were anomalously strong in recent decades.

"If the communication between the poles and the tropics would only occur via the atmosphere, we would see quite a distinct response in the tropics depending on whether an anomalous cooling arises from the Arctic or the Antarctic," Stuecker added. "This is because the Intertropical Convergence Zone - the largest rainband on Earth - is located to the north of the equator. It effectively blocks a communication from the Arctic to the equator via the atmosphere."

Contrasting experiments with and without a realistic ocean representation, the authors show that enhanced upwelling of cold subsurface water in the eastern tropical Pacific is able to communicate the Arctic cooling towards the tropics and thereby strengthening the trade winds.

An important implication of the results is that reducing uncertainty in simulated extratropical climate may also lead to improved simulation of climate in the tropics. The model hierarchy developed by the authors can be used to further explore two-way interactions between the tropics and polar regions both for future climate projections as well as for interpreting reconstructions of climate states in the geological past.

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GOOD NEWS

Some Amazon rainforest regions more resistant to climate change than previously thought

New observational study demonstrates that increasing air dryness does not reduce photosynthesis in certain very wet regions of the Amazon rainforest, contradicting Earth system models that show the opposite

COLUMBIA UNIVERSITY SCHOOL OF ENGINEERING AND APPLIED SCIENCE

Research News

 

IMAGE: PHOTO WAS TAKEN FROM THE TOP OF THE K34 FLUX TOWER SITE LOCATED 60KM NORTH OF MANAUS, BRAZIL. view more 

CREDIT: XI YANG/UNIVERSITY OF VIRGINIA

New York, NY--November 20, 2020--Forests can help mitigate climate change, by taking in carbon dioxide during photosynthesis and storing it in their biomass (tree trunks, roots, etc.). In fact, forests currently take in around 25-30% of our human-generated carbon dioxide (CO2) emissions. Certain rainforest regions, such as the Amazon, store more carbon in their biomass than any other ecosystem or forest but when forests become water-stressed (not enough water in the soil, and/or air is extremely dry), forests will slow down or stop photosynthesis. This leaves more CO2 in the atmosphere, and can also lead to tree mortality.

The current Earth system models used for climate predictions show that the Amazon rainforest is very sensitive to water stress. Since the air in the future is predicted to get warmer and drier with climate change, translating to increased water stress, this could have large implications not just for the forest's survival, but also for its storage of CO2. If the forest is not able to survive in its current capacity, climate change could greatly accelerate.

Columbia Engineering researchers decided to investigate whether this was true, whether these forests are really as sensitive to water stress as what the models have been showing. In a study published today in Science Advances, they report their discovery that these models have been largely over-estimating water stress in tropical forests.

The team found that, while models show that increases in air dryness greatly diminish photosynthesis rates in certain regions of the Amazon rainforest, the observational data results show the opposite: in certain very wet regions, the forests instead even increase photosynthesis rates in response to drier air.

"To our knowledge, this is the first basin-wide study to demonstrate how--contrary to what models are showing--photosynthesis is in fact increasing in some of the very wet regions of the Amazon rainforest during limited water stress," said Pierre Gentine, associate professor of earth and environmental engineering and of earth and environmental sciences and affiliated with the Earth Institute. "This increase is linked to atmospheric dryness in addition to radiation and can be largely explained by changes in the photosynthetic capacity of the canopy. As the trees become stressed, they generate more efficient leaves that can more than compensate for water stress."

Gentine and his former PhD student Julia Green used data from the Intergovernmental Panel on Climate Change's Coupled Model Intercomparison Project 5 (CMIP5) models and combined them with machine learning techniques to determine what the modeled sensitivity of photosynthesis in the tropical regions of the Americas was to both soil moisture and air dryness. They then performed a similar analysis, this time using observational remote sensing data from satellites in place of the model data, to see how the observational sensitivity compared. To relate their results to smaller-scale processes that could explain them, the team then used flux tower data to understand their results at the canopy and leaf level.

Earlier studies have shown that there are increases in greenness in the Amazon basin at the end of the dry season, when both the soil and air is drier, and some have linked this to increases in photosynthesis. "But before our study, it was still unclear whether these results translated to an effect over a larger region, and they had never been connected to air dryness in addition to light," Green, who is now a postdoctoral research associate at Le Laboratoire des Sciences du Climat et de l'Environnement in France, explained. "Our results mean that the current models are overestimating carbon losses in the Amazon rainforest due to climate change. Thus, in this particular region, these forests may in fact be able to sustain photosynthesis rates, or even increase it, with some warming and drying in the future."

Gentine and Green note, however, that this sensitivity was determined using only existing data and, if dryness levels were to increase to levels that are not currently being observed, this could in fact change. Indeed, the researchers found a tipping point for the most severe dryness stress episodes where the forest could not maintain its level of photosynthesis. So, say Gentine and Green, "our findings are certainly not an excuse to not reduce our carbon emissions."

Gentine and Green are continuing to look at themes related to vegetation water stress in the tropics. Green is currently focusing on developing a water stress indicator using remote sensing data (a dataset that can be used to identify when a forest is under stressful conditions), quantifying the effects of water stress on plant carbon uptake, and relating them to ecosystem traits.

"So much of the scientific research coming out these days is that with climate change, our current ecosystems might not be able to survive, potentially leading to the acceleration of global warming due to feedbacks," Green added. "It was nice to see that maybe some of our estimates of approaching mortality in the Amazon rainforest may not be quite as dire as we previously thought."

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About the Study

The study is titled "Amazon rainforest photosynthesis increases in response to atmospheric dryness."

Authors are: J. K. Green 1,2; J. Berry 3; P. Ciais 2; Y. Zhang 1,4; P. Gentine 1,5

1Department of Earth and Environmental Engineering, Columbia Engineering

2Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Gif sur Yvette, France

3Carnegie Institution for Science, Stanford, CA

4Department of Earth and Environmental Sciences, Lawrence Berkeley National Laboratory

5The Earth Institute, Columbia University

The study was supported by NASA Earth and Space Science Fellowship (NNX16AO16).

The authors declare that they have no competing interests.

LINKS:

Paper: https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.abb7232

DOI: 10.1126/sciadv.abb7232

http://engineering.columbia.edu/

http://advances.sciencemag.org/

https://www.engineering.columbia.edu/faculty/pierre-gentine

https://eee.columbia.edu/

https://eesc.columbia.edu

http://ei.columbia.edu/

https://www.researchgate.net/profile/Julia_Green6

Columbia Engineering

Columbia Engineering, based in New York City, is one of the top engineering schools in the U.S. and one of the oldest in the nation. Also known as The Fu Foundation School of Engineering and Applied Science, the School expands knowledge and advances technology through the pioneering research of its more than 220 faculty, while educating undergraduate and graduate students in a collaborative environment to become leaders informed by a firm foundation in engineering. The School's faculty are at the center of the University's cross-disciplinary research, contributing to the Data Science Institute, Earth Institute, Zuckerman Mind Brain Behavior Institute, Precision Medicine Initiative, and the Columbia Nano Initiative. Guided by its strategic vision, "Columbia Engineering for Humanity," the School aims to translate ideas into innovations that foster a sustainable, healthy, secure, connected, and creative humanity.

New solvent-based recycling process could cut down on millions of tons of plastic waste

UNIVERSITY OF WISCONSIN-MADISON

Research News

 

MADISON, Wis. -- Multilayer plastic materials are ubiquitous in food and medical supply packaging, particularly since layering polymers can give those films specific properties, like heat resistance or oxygen and moisture control. But despite their utility, those ever-present plastics are impossible to recycle using conventional methods.

About 100 million tons of multilayer thermoplastics -- each composed of as many as 12 layers of varying polymers -- are produced globally every year. Forty percent of that total is waste from the manufacturing process itself, and because there has been no way to separate the polymers, almost all of that plastic ends up in landfills or incinerators.

Now, University of Wisconsin-Madison engineers have pioneered a method for reclaiming the polymers in these materials using solvents, a technique they've dubbed Solvent-Targeted Recovery and Precipitation (STRAP) processing. Their proof-of-concept is detailed today (Nov. 20, 2020) in the journal Science Advances.

By using a series of solvent washes guided by thermodynamic calculations of polymer solubility, UW-Madison professors of chemical and biological engineering George Huber and Reid Van Lehn and their students used the STRAP process to separate the polymers in a commercial plastic composed of common layering materials polyethylene, ethylene vinyl alcohol, and polyethylene terephthalate.

The result? The separated polymers appear chemically similar to those used to make the original film.

The team now hopes to use the recovered polymers to create new plastic materials, demonstrating that the process can help close the recycling loop. In particular, it could allow multilayer-plastic manufacturers to recover the 40 percent of plastic waste produced during the production and packaging processes.

"We've demonstrated this with one multilayer plastic," says Huber. "We need to try other multilayer plastics and we need to scale this technology."

As the complexity of the multilayer plastics increases, so does the difficulty of identifying solvents that can dissolve each polymer. That's why STRAP relies on a computational approach used by Van Lehn called the Conductor-like Screening Model for Realistic Solvents (COSMO-RS) to guide the process.

COSMO-RS is able to calculate the solubility of target polymers in solvent mixtures at varying temperatures, narrowing down the number of potential solvents that could dissolve a polymer. The team can then experimentally explore the candidate solvents.

"This allows us to tackle these much more complex systems, which is necessary if you're actually going to make a dent in the recycling world," says Van Lehn.

The goal is to eventually develop a computational system that will allow researchers to find solvent combinations to recycle all sorts of multilayer plastics. The team also hopes to look at the environmental impact of the solvents it uses and establish a database of green solvents that will allow them to better balance the efficacy, cost and environmental impact of various solvent systems.

The project stems from UW-Madison's expertise in catalysis. For decades, the university's chemical and biological engineering researchers have pioneered solvent-based reactions to convert biomass -- like wood or agricultural waste -- into useful chemicals or fuel precursors. Much of that expertise translates into solvent-based polymer recycling as well.

The team is continuing its research on STRAP processing through the newly established Multi-University Center on Chemical Upcycling of Waste Plastics, directed by Huber. Researchers in the $12.5 million U.S. Department of Energy-funded center are investigating several chemical pathways for recovering and recycling polymers.

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This research was supported by a grant from the U.S. Department of Energy (DE-SC0018409).

--Jason Daley, jgdaley@wisc.edu

...SO BELOW

New Chinese submersible reaches Earth's deepest ocean trench

Issued on: 20/11/2020 - 

The Mariana Trench AFP


Beijing (AFP)

China livestreamed footage of its new manned submersible parked at the bottom of the Mariana Trench on Friday, part of a historic mission into the deepest underwater valley on the planet.

The "Fendouzhe", or "Striver", descended more than 10,000 metres (about 33,000 feet) into the submarine trench in the western Pacific Ocean with three researchers on board, state broadcaster CCTV said.

Only a handful of people have ever visited the bottom of the Mariana Trench, a crescent-shaped depression in the Earth's crust that is deeper than Mount Everest is high and more than 2,550 kilometres (1,600 miles) long.

The first explorers visited the trench in 1960 on a brief expedition, after which there had been no missions until Hollywood director James Cameron made the first solo trip to the bottom in 2012.

Cameron described a "desolate" and "alien" environment.

Video footage shot and relayed by a deep-sea camera this week showed the green-and-white Chinese submersible moving through dark water surrounded by clouds of sediment as it slowly touched down on the seabed.

Fendouzhe, which has made multiple dives in recent days, had earlier this month set a national record of 10,909 metres for manned deep-sea diving after landing in the deepest known point of the trench, Challenger Deep, just shy of the 10,927-metre world record set by an American explorer in 2019.

The mission on November 10 beamed up the world's first live video from Challenger Deep.

- Deep sea resources -

The submersible, equipped with robotic arms to collect biological samples and sonar "eyes" that use sound waves to identify surrounding objects, is making repeated dives to test its capabilities.

It is carrying so much equipment that engineers added a bulbous forehead-shaped protrusion containing buoyant materials to the vessel to help maintain its balance.

Fendouzhe, China's third deep-sea manned submersible, is observing "the many species and the distribution of living things on the seabed", scientists on board told CCTV.

The water pressure at the bottom of the trench is a crushing eight tons per square inch, around a thousand times the atmospheric pressure at sea level, yet scientists have found the dark, frigid waters of the trench to be teeming with life.

The Chinese researchers will collect specimens for their work, CCTV said.

Previous studies have found thriving communities of single-cell organisms surviving on organic waste that had settled on the ocean floor, but very few large animals.

The mission will also conduct research on "deep-sea materials," CCTV said, as China pushes ahead in deep-sea mining.

Beijing this month set up a joint training and research centre with the International Seabed Authority, which will train professionals on deep-sea technology as well as conducting research on mining for valuable minerals at the bottom of the ocean.

Fendouzhe is expected to set standards for China's future deep-sea vessels.

"It takes more than two trials before we can call it a real success," Zhu Min, a researcher at the Chinese Academy of Sciences involved in the mission, told CCTV on Tuesday.

© 2020 AFP

AS ABOVE...

Researchers find microplastics on top of the world at Everest

Issued on: 20/11/2020 - 

Traces of microplastics have been found as high as 8,440 metres on Mount Everest, just short of the summit Jewel SAMAD AFP/File

Kathmandu (AFP)

Traces of microplastics have been found close to the top of Mount Everest, a study showed Friday, likely originating from equipment used by the hundreds of climbers who summit the world's highest peak every year.

Fluorescent tents, discarded climbing equipment, empty gas canisters and even frozen excrement have long littered the well-trodden route to the 8,848-metre (29,029-feet) high summit, earning it the name of "the highest dumpster in the world".

But in the first study of microplastics on Everest, by a research team part of the 2019 National Geographic and Rolex Perpetual Planet Everest Expedition, the tiny pollutants were found as high as 8,440 metres above sea level, although concentration levels were higher at the mountain's base camp.

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The findings, which reveal the potential threat to Everest posed by plastic pollutants, were published in the environmental journal One Earth on Friday.

"The samples showed significant quantities of polyester, acrylic, nylon, and polypropylene fibres," author Imogen Napper, a National Geographic explorer and scientist based at the University of Plymouth in Britain, said in a statement.

"It really surprised me to find microplastics in every single snow sample I analysed. Mount Everest is somewhere I have always considered remote and pristine. To know we are polluting near the top of the tallest mountain (in the world) is a real eye-opener."

- Environmental scourge -

A majority of outdoor clothing worn by trekkers and climbers on Everest is made of synthetic fabrics. Tents, climbing ropes and other gear also use the materials.

"We highly suspect that these types of items are the major source of pollution rather than things like food and drink containers," Napper said, referring to the trash accumulation on the peak after decades of commercial mountaineering.

Last year, a 14-member team spent six weeks scouring for litter at Everest base camp and at Camp 4 -- nearly 8,000 metres up.

They cleared the mountain of four bodies and more than 10 tonnes of plastic bottles, cans and climbing equipment.

The study also suggests it is possible that microplastics found on Everest are blown there from elsewhere in the strong Himalayan winds.

Researchers also found microplastics in streams below the famous Himalayan peak, but the concentration was lower than in snow.

Last year, scientists reported tiny particles of plastic settled every day on each square metre of an uninhabited, high-altitude area in the Pyrenees straddling France and Spain.

Plastic litter, and the tiny particles that it breaks down into, has emerged in the last few years as a major environmental scourge.

Up to 12 million tonnes of plastics are thought to enter the world's oceans every year, and millions more clog inland waterways and landfills.

Scientists are only now beginning to measure the damage to wildlife and potential impacts on human health.

© 2020 AFP

There are microplastics near the top of Mount Everest too

CELL PRESS

Research News

 

IMAGE: THIS IMAGE SHOWS A VIEW OF THE NATIONAL GEOGRAPHIC AND ROLEX PERPETUAL PLANET EVEREST EXPEDITION CLIMBERS' TENTS, MADE FROM WATERPROOF ACRYLIC MATERIAL, AT CAMP IV/SOUTH COL. IN THE BACKGROUND, CLIMBERS... view more 

CREDIT: MARIUSZ POTOCKI/NATIONAL GEOGRAPHIC

Researchers analyzing snow and stream samples from the National Geographic and Rolex Perpetual Planet Everest Expedition have found evidence of microplastic pollution on Mount Everest. While the highest concentrations of microplastics were around Base Camp where hikers and trekkers spend the most time, the team also found microplastics as high up as 8,440 meters above sea level, just below the summit. The findings appear November 20 in the journal One Earth.

"Mount Everest has been described as 'the world's highest junkyard,'" says first author Imogen Napper (@Imogennapper), a National Geographic Explorer and scientist based at the University of Plymouth who is described by her colleagues as a "plastic detective." "Microplastics haven't been studied on the mountain before, but they're generally just as persistent and typically more difficult to remove than larger items of debris."

Microplastics--tiny particles of plastic that come from the slow breakdown of larger litter--pose a huge ecological threat because they are easily consumed by animals and are so small that they are difficult to clean up. Microplastics are common in the ocean, but are not as carefully studied on land, especially remote mountaintops.

"I didn't know what to expect in terms of results, but it really surprised me to find microplastics in every single snow sample I analyzed. Mount Everest is somewhere I have always considered remote and pristine. To know we are polluting near the top of the tallest mountain is a real eye-opener."

While some members of the research team climbed the mountain collecting samples during the Everest expedition in the spring of 2019, much of the work was done in a lab many miles away, where Napper and her team analyzed the samples. "The closest I got to Mount Everest was in my lab at University of Plymouth in the UK," Napper jokes. She wanted to determine not only whether there was plastic on the mountain, but what type of plastic was there. This is an important step in figuring out where the pollution originated.

"The samples showed significant quantities of polyester, acrylic, nylon, and polypropylene fibers," says Napper. "Those materials are increasingly being used to make the high-performance outdoor clothing climbers use as well as tents and climbing ropes, so we highly suspect that these types of items are the major source of pollution rather than things like food and drink containers."

While this study clearly demonstrated the presence of microplastics on Mount Everest, the best way to clean this pollution remains to be seen.

"Currently, environmental efforts tend to focus on reducing, reusing, and recycling larger items of waste. This is important, but we also need to start focusing on deeper technological solutions that focus on microplastics, like changing fabric design and incorporating natural fibers instead of plastic when possible," she says.

The researchers also hope that their work will help clarify the extent to which plastic pollution jeopardizes all environments, not just the ocean.

"These are the highest microplastics discovered so far," says Napper. "While it sounds exciting, it means that microplastics have been discovered from the depths of the ocean all the way to the highest mountain on Earth. With microplastics so ubiquitous in our environment, it's time to focus on informing appropriate environmental solutions. We need to protect and care for our planet."

CAPTION

This image high-elevation expedition climbers and Sherpa wear 'Himalayan suits' made of waterproof acrylic fibers at the Balcony (~8,440 m.a.s.l.), the highest from which microplastics were collected during the National Geographic and Rolex Perpetual Planet Everest Expedition. Behind them rest disused metal oxygen canisters and other waste which is a regular sight at this common resting point. www.NatGeo.com/Everest

 

This work was supported by the National Geographic Society and Rolex. To learn more about the 2019 Everest Expedition, please visit: https://www.nationalgeographic.org/projects/perpetual-planet/everest/.

One Earth, Napper et al.: "Reaching new heights in plastic pollution - preliminary findings of microplastics on Mount Everest" https://www.cell.com/one-earth/fulltext/S2590-3322(20)30550-9

One Earth (@OneEarth_CP), published by Cell Press, is a monthly journal that features papers from the fields of natural, social, and applied sciences. One Earth is the home for high-quality research that seeks to understand and address today's environmental Grand Challenges, publishing across the spectrum of environmental change and sustainability science. A sister journal to Cell, Chem, and Joule, One Earth aspires to break down barriers between disciplines and stimulate the cross-pollination of ideas with a platform that unites communities, fosters dialogue, and encourages transformative research. Visit http://www.cell.com/one-earth. To receive Cell Press media alerts, contact press@cell.com.

CAPTION

This image shows a selection of microfibers found in snow samples from Mt. Everest Balcony (8,440 m), collected during the National Geographic and Rolex Perpetual Planet Everest Expedition, which are consistent with fibers from outdoor clothing. www.NatGeo.com/Everest

Microplastics in the death zone

Scientists find plastic fibres in snow samples from Mount Everest

UNIVERSITY OF PLYMOUTH

Research News

 

IMAGE: HIGH-ELEVATION CLIMBERS AND SHERPA AT THE BALCONY DURING THE NATIONAL GEOGRAPHIC AND ROLEX PERPETUAL PLANET EVEREST EXPEDITION view more 

CREDIT: BAKER PERRY, NATIONAL GEOGRAPHIC

Scientists have identified the highest recorded microplastics ever found on Earth - at an altitude of more than 8,000metres, close to the summit of Mount Everest.

Samples collected on the mountain and in the valley below it revealed substantial quantities of polyester, acrylic, nylon, and polypropylene fibres.

The materials are increasingly being used to make the high performance outdoor clothing commonly used by climbers, as well as the tents and climbing ropes used in attempts to climb the mountain.

As a result, researchers have suggested the fibres - the highest of which were found in samples from the Balcony of Mount Everest, 8,440 metres above sea level - could have fragmented from larger items during expeditions to reach the summit.

However, they have also surmised the plastics could have been transported from lower altitudes by the extreme winds which regularly impact the mountain's higher slopes.

The research, published in One Earth, was led by researchers from the University of Plymouth's International Marine Litter Research Unit, working with colleagues from the UK, USA and Nepal. It was supported by the National Geographic Society and Rolex.

Research Fellow and National Geographic Explorer Dr Imogen Napper, the study's lead author, said: "Microplastics are generated by a range of sources and many aspects of our daily lives can lead to microplastics entering the environment. Over the past few years, we have found microplastics in samples collected all over the planet - from the Arctic to our rivers and the deep seas. With that in mind, finding microplastics near the summit of Mount Everest is timely reminder that we need to do more to protect our environment."

The samples were collected in April and May 2019, as part of National Geographic and Rolex's Perpetual Planet Everest Expedition, and then analysed in specialist facilities in Plymouth.

Of 19 high elevation samples collected from the Mount Everest region for microplastic analysis, 11 were snow and eight stream water. This included streams along the trekking routes close to the Khumbu Glacier, in the snow at Everest Base Camp, and high into the Death Zone near the mountain's summit.

The highest quantities (79 microplastic fibres per litre of snow) were found at Base Camp, where summit expeditions are based for periods of up to 40 days. However, evidence was also found at Camps 1 and 2 on the climbing route, with 12 microplastic fibres per litre of snow recorded from the Balcony.

There were lower quantities in streams leading down from the mountain to the Sagarmatha National Park, with scientists saying this could be due to the continuous flow of water created by the region's glaciers.

CAPTION

Samples are collected near Everest Base Camp during the National Geographic and Rolex Perpetual Planet Everest Expedition

CREDIT

Brittany Mumma, National Geographic

The first confirmed summiting of Mount Everest in 1953 coincided with the global rise to prominence of plastics and their use in society.

From a time in the 1950s when it had very few visitors, the Sagarmatha National Park (which includes the mountain) welcomed more than 45,000 visitors in 2016, while in 2019, climbing permits for Everest were issued in Nepal.

Over the same period, the versatility of plastic materials has resulted in a substantial increase in their use from five million tonnes globally in the 1950s to over 330 million tonnes in 2020.

Professor Richard Thompson OBE FRS, Head of the International Marine Litter Research Unit, said: "Since the 1950s, plastics have been increasingly used in all kinds of products because of their practicality and durability. However, it is those qualities which are, in large part, creating the global environmental crisis we are seeing today. There is now global recognition of the need to take action, with Nepal itself imposing regulations on climbing expeditions to try and curb the environmental problems created by waste. This study and our continued research only emphasises the importance of designing materials that have the benefits of plastics without the lasting and harmful legacy."

CAPTION

Dr Imogen Napper working in the laboratories at the University of Plymouth

CREDIT

University of Plymouth