Heat stress for cattle may cost billions by century's end, study finds

Date: March 10, 2022

Source: Cornell University

Climate change poses a potentially devastating economic threat to low-income cattle farmers in poor countries due to increasing heat stress on the animals. Globally, by the end of this century those producers may face financial loss between $15 and $40 billion annually.

Farmers in tropical regions -- including large parts of South America, Asia and Africa -- are likely to suffer significantly, particularly when compared with producers in the world's wealthier temperate zones, according to a study by an international team of scientists and economists published in the Lancet Planetary Health.

The researchers, including Mario Herrero, professor of sustainable food systems at Cornell University, and lead author Philip Thornton, of the International Livestock Research Institute and CGIAR; published "Impacts of Heat Stress on Global Cattle Production During the 21st Century."

Escalating demand for livestock products in low- and middle-income countries, along with steadily increasing global average temperatures, is an uncomfortable mix, the researchers said. If livestock are to adapt to new thermal environments and increase their productivity, infrastructural investments or adjustments -- such as switching to more heat-tolerant cattle breeds, and improving shade, ventilation and cooling systems -- will be required.

In the paper's high greenhouse-gas emission scenario, cattle production losses from heat stress are estimated to be $39.94 billion annually, or 9.8% of the value of production of meat and milk from cattle in 2005 -- the scientists' baseline year. The low-emission scenario projects production losses at $14.9 billion annually, or 3.7% of the 2005 value.

By the end of the century, dairy and beef production in the United States is projected to decline by 6.8%, while India -- a major dairy production country -- is projected to lose more than 45% of its dairy farming due to heat stress increases.

"Resource-poor farmers in low-income countries depend heavily on their livestock for their livelihoods," Thornton said. "The adaptation needs are even higher in these countries, and those farmers are the ones where the hit is even more severe."

With climate change, farming and sustainability, Herrero suggested there is a need to create equitable adaptation practices "by design and to think intentionally on reaching the vulnerable sectors of global society," he said. "We cannot just hope that the poor will not be affected."

Technological development is key to bringing equity and social justice to poor farmers throughout the world. "Sustainability is not only about the environment and protecting biodiversity, but the human component is fundamental to sustainability," Herrero said. "We need to deal with climate change, leaving no one behind. That's the only truth."

Herrero is a fellow in the Cornell Atkinson Center for Sustainability.

Journal Reference:
Philip Thornton, Gerald Nelson, Dianne Mayberry, Mario Herrero. Impacts of heat stress on global cattle production during the 21st century: a modelling study. The Lancet Planetary Health, 2022; 6 (3): e192 DOI: 10.1016/S2542-5196(22)00002-X

People underestimate others' desire for constructive feedback

Just do it, research suggests

Date: March 24, 2022

Source: American Psychological Association

People consistently underestimate others' desire for constructive feedback and therefore don't provide it, even when it could improve another person's performance on a task, according to research published by the American Psychological Association.

"People often have opportunities to provide others with constructive feedback that could be immediately helpful, whether that's letting someone know of a typo in their presentation before a client presentation, or telling a job candidate about a stained shirt before an interview," said lead author Nicole Abi-Esber, a doctoral candidate at Harvard Business School. "Overall, our research found that people consistently underestimate others' desire for feedback, which can have harmful results for would-be feedback recipients."

Constructive feedback is instrumental for aiding learning and performance, and research has shown that people commonly report wanting this type of feedback, according to the researchers. However, despite wanting constructive feedback themselves, people often avoid giving it to others. In a pilot study conducted by the researchers, only 2.6% of participants informed a tester of a visible smudge on his or her face (e.g., chocolate, lipstick or red marker) during a survey.

The research was published in APA's Journal of Personality and Social Psychology.

Previous research suggests that people avoid giving feedback for fear of negative outcomes, such as the other person's becoming embarrassed or upset. Abi-Esber and her colleagues theorized there might be another reason people withhold feedback: They simply do not fully recognize the potential of their input to improve others' outcomes, leading them to underestimate others' desire for such feedback.

To test their theory, the researchers conducted a series of five experiments involving 1,984 participants to measure how much people underestimate others' desire for constructive feedback. In one, participants were presented with 10 hypothetical awkward social situations at work, where they could either give or receive constructive feedback. In another experiment, participants were asked to recall a situation where they could either have given or received constructive feedback. In the final experiment, participants were paired, with one practicing a speech for a competition and the other assigned to listen and provide feedback.

Across all five experiments, people in a position to give feedback consistently underestimated potential receivers' desire for it. The more consequential the feedback (e.g., telling someone they need to improve their presentation skills), the more likely participants were to underestimate the other's need for feedback and the less likely they were to offer it. The gap was smaller in more everyday, less consequential scenarios, such as when the other person had food on their face or a rip in their pants.

The researchers were surprised to find that the simple intervention of perspective taking could increase the likelihood someone would recognize the need for and provide feedback. Simply asking people to quickly reflect, "If you were this person, would you want feedback?" helped participants recognize the value of feedback to the other person and helped close the giver-receiver gap.

"Even if you feel hesitant to give feedback, we recommend that you give it," said Abi-Esber. "Take a second and imagine you're in the other person's shoes and ask yourself if you would want feedback if you were them. Most likely you would, and this realization can help empower you to give them feedback."

"Feedback is key to personal growth and improvement, and it can fix problems that are otherwise costly to the recipient," said co-author Francesca Gino, PhD, also of Harvard Business School. "The next time you hear someone mispronounce a word, see a stain on their shirt or notice a typo on their slide, we urge you to point it out to them -- they probably want feedback more than you think."

Journal Reference:
Nicole Abi-Esber, Jennifer Abel, Francesca Gino, Juliana Schroeder. Just Letting You Know: Underestimating Others Desire for Constructive Feedback. Journal of Personality and Social Psychology, March 24, 2022 DOI: 10.1037/pspi0000393

Scientists find that the impact of social media on wellbeing varies across adolescence

Date: March 28, 2022

Source: University of Cambridge

Summary: Girls and boys might be more vulnerable to the negative effects of social media use at different times during their adolescence, say an international team of scientists. The researchers show that, in UK data, girls experience a negative link between social media use and life satisfaction when they are 11-13 years old and boys when they are 14-15 years old. Increased social media use again predicts lower life satisfaction at age 19 years. At other times the link was not statistically significant.

In a study published today in Nature Communications, the researchers show that, in UK data, girls experience a negative link between social media use and life satisfaction when they are 11-13 years old and boys when they are 14-15 years old. Increased social media use again predicts lower life satisfaction at age 19 years. At other times the link was not statistically significant.

In just over a decade, social media has fundamentally changed how we spend our time, share information about ourselves, and talk to others. This has led to widespread concern about its potential negative impact, both on individuals and on the wider society. Yet, even after years of research, there is still considerable uncertainty about how social media use relates to wellbeing.

A team of scientists including psychologists, neuroscientists and modellers analysed two UK datasets comprising some 84,000 individuals between the ages of 10 and 80 years old. These included longitudinal data -- that is, data that tracks individuals over a period of time -- on 17,400 young people aged 10-21 years old. The researchers are from the University of Cambridge, University of Oxford, and the Donders Institute for Brain, Cognition and Behaviour.

The team looked for a connection between estimated social media use and reported life satisfaction and found key periods of adolescence where social media use was associated with a decrease in life satisfaction 12 months later. In the opposite direction, the researchers also found that teens who have lower than average life satisfaction use more social media one year later.

In girls, social media use between the ages of 11 and 13 years was associated with a decrease in life satisfaction one year later, whereas in boys this occurred between the ages of 14 and 15 years. The differences suggest that sensitivity to social media use might be linked to developmental changes, possibly changes in the structure of the brain, or to puberty, which occurs later in boys than in girls. This requires further research.

In both females and males, social media use at the age of 19 years was again associated with a decrease in life satisfaction a year later. At this age, say the researchers, it is possible that social changes -- such as leaving home or starting work -- may make us particularly vulnerable. Again, this requires further research.

At other times, the link between social media use and life satisfaction one year later was not statistically significant. Decreases in life satisfaction also predicted increases in social media use one year later; however this does not change across age and or differ between the sexes.

Dr Amy Orben a group leader at the MRC Cognition and Brain Sciences Unit, University of Cambridge, who led the study, said: "The link between social media use and mental wellbeing is clearly very complex. Changes within our bodies, such as brain development and puberty, and in our social circumstances appear to make us vulnerable at particular times of our lives."

Professor Sarah-Jayne Blakemore, Professor of Psychology and Cognitive Neuroscience at Cambridge and a co-author of the study, said: "It's not possible to pinpoint the precise processes that underlie this vulnerability. Adolescence is a time of cognitive, biological and social change, all of which are intertwined, making it difficult to disentangle one factor from another. For example, it is not yet clear what might be due to developmental changes in hormones or the brain and what might be down to how an individual interacts with their peers."

Dr Orben added: "With our findings, rather than debating whether or not the link exists, we can now focus on the periods of our adolescence where we now know we might be most at risk and use this as a springboard to explore some of the really interesting questions."

Further complicating the relationship is the fact -- previously reported and confirmed by today's findings -- that not only can social media use negatively impact wellbeing, but that the reverse is also true and lower life satisfaction can drive increased social media use.

The researchers are keen to point out that, while their findings show at a population level that there is a link between social media use and poorer wellbeing, it is not yet possible to predict which individuals are most at risk.

Professor Rogier Kievit, Professor of Developmental Neuroscience at the Donders Institute for Brain, Cognition, and Behaviour, said: "Our statistical modelling examines averages. This means not every young person is going to experience a negative impact on their wellbeing from social media use. For some, it will often have a positive impact. Some might use social media to connect with friends, or cope with a certain problem or because they don't have anyone to talk to about a particular problem or how they feel -- for these individuals, social media can provide valuable support."

Professor Andrew Przybylski, Director of Research at the Oxford Internet Institute at the University of Oxford said: "To pinpoint which individuals might be influenced by social media, more research is needed that combines objective behavioural data with biological and cognitive measurements of development. We therefore call on social media companies and other online platforms to do more to share their data with independent scientists, and, if they are unwilling, for governments to show they are serious about tackling online harms by introducing legislation to compel these companies to be more open."

The research was supported by Emmanuel College, the UK Economic and Social Research Council, the Huo Family Foundation, Wellcome, the Jacobs Foundation, the Wellspring Foundation, the Radboud UMC and the Medical Research Council.

Journal Reference:
Amy Orben, Andrew K. Przybylski, Sarah-Jayne Blakemore, Rogier A. Kievit. Windows of developmental sensitivity to social media. Nature Communications, 2022; 13 (1) DOI: 10.1038/s41467-022-29296-3

Arts activities may improve self-control and reduce antisocial behavior among teenagers

Date: March 22, 2022

Source: University College London

Summary: Teenagers who take part in arts and cultural activities, such as dance, drama, reading and going to concerts, are less likely to engage in antisocial and criminalized behavior up to two years later, according to a new study. Researchers looked at data from more than 25,000 teenagers in the United States who had filled out questionnaires over several years.

Teenagers who take part in arts and cultural activities, such as dance, drama, reading and going to concerts, are less likely to engage in antisocial and criminalised behaviour up to two years later, according to a new study by UCL (University College London) and University of Florida researchers.

For the peer-reviewed study, published in the Journal of Youth and Adolescence (JOYO), researchers looked at data from more than 25,000 teenagers in the United States who had filled out questionnaires over several years.

They measured the teenagers' overall engagement with arts activities based on a wide range of factors, from involvement in school clubs, orchestras, choirs, and arts classes outside school, to whether they had visited museums or been to concerts, or read on their own.

They found that the more of these activities the teenagers were involved in, the less likely they were to report being engaged in antisocial behaviour -- ranging from misbehaving at school, to getting into fights, to criminalised behaviour such as stealing and selling drugs -- both at the time of the first survey and when they were asked again about antisocial behaviour one and two years later.

The team also found that teenagers and young people who were more engaged in the arts were likely to have better self-control scores and view antisocial behaviour negatively. These outcomes have previously been found to make young people less likely to engage in antisocial and criminalised behaviours.

The research was carried out as part of the EpiArts Lab, a National Endowment for the Arts Research Lab.

Senior author Dr Daisy Fancourt (UCL Institute of Epidemiology & Health Care) said: "Past research has shown that getting involved in the arts can have a big impact on teenagers' mental health and wellbeing.

"Our study adds to evidence about the wide-ranging benefits that arts and culture can have for young people, demonstrating a positive link between the arts and a lower prevalence of antisocial behaviour.

"Notably these findings remained, even when taking into account factors such as children's age, gender, ethnicity, socio-economic background, their parents' educational background, where they lived, and their previous patterns of antisocial behaviours."

Lead author Dr Jess Bone (UCL Institute of Epidemiology & Health Care) said: "Our definition of arts and cultural engagement was very broad. It included dancing and acting in school clubs, reading, going to cinemas, museums, concerts, and music classes, as well as other hobbies that teenagers took part in regularly.

"Finding ways to reduce antisocial behaviour among teenagers is important because these behaviours may become established and continue into adulthood, affecting someone's whole life.

"Our findings demonstrate the importance of making arts and cultural activities available for all young people, particularly in the wake of the Covid-19 pandemic, which has limited access to and funding for these resources."

Researchers looked at data from two US-based longitudinal studies, the National Longitudinal Study of Adolescent to Adult Health and the National Education Longitudinal Study of 1988, whose participants were nationally representative. The research team analysed questionnaires filled in by teenagers and their parents between 1988 and 2002. The average age of participants at the start of these studies was 14 to 15 years.

In one of the cohorts, about half of adolescents reported engaging in antisocial and criminalised behaviours in the last 12 months. The average number of times participants engaged in these behaviours over the year was 1.6.

Although the researchers found that arts engagement was linked to fewer positive perceptions of antisocial behaviour and better self-control scores, they could not conclude that these factors were causally responsible for the association between arts engagement and antisocial behaviour as the study was observational.

Nonetheless, in considering mechanisms through which the arts could reduce antisocial behaviour, the researchers cited previous studies showing improvements from arts engagement including increased empathy, more prosocial behaviour, reduced boredom and improved self-esteem, as well as better emotion regulation.

The research was funded in part by the National Endowment for the Arts, Bloomberg Philanthropies, the Pabst Steinmetz Foundation, and Arts Council England.

Journal Reference:
Jessica K. Bone, Feifei Bu, Meg E. Fluharty, Elise Paul, Jill K. Sonke, Daisy Fancourt. Arts and Cultural Engagement, Reportedly Antisocial or Criminalized Behaviors, and Potential Mediators in Two Longitudinal Cohorts of Adolescents. Journal of Youth and Adolescence, 2022; DOI: 10.1007/s10964-022-01591-8

Citizen divers aid understanding of fish in the Salish sea

More than half of fish species in region documented by volunteer divers, including a new species

Date: March 24, 2022

Source: University of California - Davis

Summary: Citizen scientists are increasingly playing crucial roles in understanding fish populations, according to a new study. Over the past 20 years, volunteers have helped monitor more than half of the total fish species known to occur in the Salish Sea.

Hundreds of fish species live in the Salish Sea, and many face a number of threats. Monitoring the health of these fish populations is crucial. But with nearly 5,000 miles of coastline and more than 400 islands, it's no small task.

Historically, monitoring fish populations has included fishery catch data, active trawl surveys, underwater video, satellite imagery, hydroacoustics and more. But citizen scientists are increasingly playing crucial roles, according to a study from the University of California, Davis.

The study, published in the journal Environmental Monitoring and Assessment, revealed that in just over two decades, volunteers with Reef Environmental Education Foundation (REEF)'s Volunteer Fish Survey Project helped monitor more than half of the total fish species known to occur in the Salish Sea.

The study found that the project's surveyors also expanded the known range of multiple species within the ecosystem and documented the presence of a fish species not previously known to occur in the Salish Sea -- the striped kelpfish (Gibbonsia metzi). This brings the total number of fish species known to use the Salish Sea to 261.

The research was led by SeaDoc Society, a program of the Karen C. Drayer Wildlife Health Center at the UC Davis School of Veterinary Medicine. SeaDoc has partnered with REEF for almost two decades to help train volunteer divers in the Pacific Northwest.

Citizen scientists survey Salish Sea

REEF is a marine conservation organization with a worldwide network of recreational divers and snorkelers who provide data to better understand status, trends, and distribution patterns of marine fishes and selected invertebrates and algae in oceans around the world. REEF citizen scientists have been surveying the Salish Sea since 1998. The region encompasses Puget Sound, the San Juan Islands and the waters off of Vancouver, British Columbia.

The study was also informed by a list of species published by fisheries biologists Theodore Pietsch and James Orr.

"I had so much fun exploring the REEF database and published compilation of Salish Sea fishes," said lead author Elizabeth Ashley, a UC Davis research assistant with SeaDoc Society. "This study highlights that the incredible biodiversity of the Salish Sea merits the use of a diverse set of tools, wielded by both professional and citizen scientists, to fully understand and protect these fishes."

Ashley and her co-authors compared data from 13,000 REEF surveys collected from about 800 sites in the Salish Sea over 21 years (1998-2019). Volunteers observed 138 of 261 recognized fish species in the Salish Sea and expanded the range of 18 species, meaning they were spotted in an area where they previously had not been documented to exist.

Not all fish species have an equal chance of being spotted by a scuba diver. Some might live hundreds of feet deep, expertly hide themselves, or only rarely venture into the Salish Sea. The authors took this into account and categorized each fish based on its potential for encounter by a diver.

REEF divers sighted 85% of fish species that lend themselves to visual observation. For these fishes, experienced citizen scientists can expand what scientists know about range, life history, population status, size, age, behavior, and more.

Citizen science monitoring is only minimally invasive since it relies purely on human observation. Trained divers can document what they see and enter it into the free international database housed at www.REEF.org.

"It's exciting to see that the expertise within our community of citizen scientists has expanded what is known about fish assemblages of the Salish Sea and yielded a new discovery," said co-author Christy Pattengill-Semmens, REEF's co-executive director. "Beyond providing much-needed data that can be used by researchers and management agencies, participating in citizen science programs like REEF's Volunteer Fish Survey Project creates an authentic connection to nature and empowers participants to make a difference."

Related Multimedia:
Citizen scientist observing a painted greenling in the Salish Sea, and a sailfin sculpin fish

Journal Reference:
Elizabeth A. Ashley, Christy V. Pattengill-Semmens, James W. Orr, Janna D. Nichols, Joseph K. Gaydos. Documenting fishes in an inland sea with citizen scientist diver surveys: using taxonomic expertise to inform the observation potential of fish species. Environmental Monitoring and Assessment, 2022; 194 (3) DOI: 10.1007/s10661-022-09857-1

Win-wins in environmental management hard to find

JUST LIKE IN COLLECTIVE BARGAINING

Date: March 24, 2022

Source: University of Colorado at Boulder

Summary: When a booming marine fishery can increase its shrimp catch while also reducing unintentional bycatch of turtles --t hat's an example of what environmental scientists and managers call a 'win-win.' Models often predict this ideal outcome is achievable, yet stakeholders rarely see it manifest in the real world.


When a booming marine fishery can increase its shrimp catch while also reducing unintentional bycatch of turtles -- that's an example of what environmental scientists and managers call a "win-win." Models often predict this ideal outcome is achievable, yet stakeholders rarely see it manifest in the real world. Now, a Cooperative Institute for Research in Environmental Sciences (CIRES)-led study incorporates the complexity of the real world into models, explaining the discrepancy, validating the concerns of stakeholders and providing more realistic expectations for the future of environmental management.

"If a scientist's model predicts a fishery will catch a certain amount of fish with little bycatch, or predicts a farm will harvest a certain amount of corn while cutting back on harmful fertilizer -- but fishermen and farmers on the ground report the opposite, that leads to frustration on both sides," said Margaret Hegwood, a University of Colorado Boulder graduate student in Environmental Studies working in CIRES and lead author on the new study out today in Nature Sustainability.

"We used math to show real-world complexity makes win-wins harder to achieve -- allowing scientists and stakeholders to compromise and aim for more achievable, realistic goals about environmental impact, food production, biodiversity, economic yield, etc," added Hegwood, also a USDA Food Technology and Food Security Fellow. "When you add more variables, like another species, another stakeholder, an extra regulation, the probability of the win-win starts to go down," said Hegwood.

The team also analyzed 280 previous tradeoff models and created algorithms to show how the severity of these tradeoffs might change as more variables were added. The work allows modelers to better understand what managers deal with, and allows managers to better understand the models.

"At its core, it's a study about how to bridge a communication divide," said coauthor Ryan Langendorf, a CIRES and CU Boulder Environmental Studies postdoctoral researcher. "There's this idea that there is a right and wrong, but scientists and stakeholders just think about the problem in different ways. We hope our work allows them to find common ground, so people can work together more productively."

"It's less about finding a better win-win and more about communicating what the win actually looks like," added Langendorf. That could involve adjusting goals to be more realistic: "Instead of asking, 'is it the ideal outcome for only a single objective?' we need to shift our thinking to ask, 'are we better than where we started?'" said Hegwood.

"Better" might mean sacrificing a little fish catch but reducing bycatch by a lot, which is what happened, for example, in an Australian shrimp fishery when it started adding turtle excluder devices to its trawl nets to protect sea turtles in 2001. Or "better" could mean reducing political or regulatory barriers to reaching win-wins. "If a win-win means a community needs certain resources they can't afford, they will never reach an ideal outcome. By identifying these barriers and minimizing them with proactive policies or technological advancements, you make the win-win more attainable," Hegwood said.

"Managers have always seemed to have an intuition that win-wins are harder to find in the real world than they are in models, because the real world is more complicated than models are," said Mattew Burgess, CIRES Fellow, assistant professor of Environmental Studies and Economics at CU Boulder and corresponding author on the study. "Our study shows, in a precise mathematical way, why the manager's intuition is right. By doing this, we hope that we have given modelers and managers a way to understand each other in a common language."



Story Source:

Materials provided by University of Colorado at Boulder. Note: Content may be edited for style and length.


Journal Reference:
Margaret Hegwood, Ryan E. Langendorf, Matthew G. Burgess. Why win–wins are rare in complex environmental management. Nature Sustainability, 2022; DOI: 10.1038/s41893-022-00866-z

Indian forest loss 'worse than feared' due to climate change

Forest loss from temperature and rainfall alterations adding to deforestation issue

Date: March 24, 2022

Source: University of Reading

Summary: A national-scale study of the relationship between forest loss and rainfall and temperature trends in India reveals climate change may have contributed to huge declines during last two decades, countering official reports that suggest small losses, and adding to existing concerns over deforestation.

Forest loss in India could become an even bigger problem than anticipated in the coming years, with new research revealing climate change has caused significant recent losses.

The first ever national-scale study of the relationship between forest loss and rainfall and temperature trends in India, led by the University of Reading, revealed they may have contributed to large declines since the turn of the century, exacerbating already worrying deforestation largely driven by agricultural expansion in the country.

The new research is in contrast to official reports that show relatively small decreases in forest coverage in recent years. It warns the rapid changes to the climate observed in some regions will necessitate targeted preservation action and funding to reduce the risk to biodiversity in India.

Alice Haughan, a PhD researcher at the University of Reading and lead author of the study, said: "India has seen dramatic forest loss in recent decades, with land use changes to accommodate crops, livestock and a growing population cited as causes. While the contribution of land use change to forest loss has been studied extensively, little attention has been given to the role of climate change in recent decreases.

"The rapid changes to the climate we identified suggests India's forest loss in the coming decades could be far worse than feared, as deforestation is only one part of the problem. The high levels of reduction seen are also concerning for biodiversity, as India relies on connected forests for wildlife preservation."

The new study, published in Global Change Biology, looked at forest loss between 2001 and 2018 -- a period where little data exists.

The authors calculated the velocity of changes to India's climate for the first time, a relatively new technique used to quantify climate change and reveal the rate at which it is impacting a country.

It also analysed variability in climate change impacts across different regions and seasons, revealing that the impact of climate change on forest loss varied greatly between different locations and seasons.

Far greater forest losses were seen where and when the climate was changing most rapidly. Decreases in rainfall were seen to have the strongest effect on increasing forest loss, with temperature decreases in some regions also having a negative impact.

Haughan said: "Our study of Indian tropical and subtropical regions shows that rainfall rather than temperature comes into play as the biggest factor in forest loss, in contrast to trends found in many temperate studies."

The authors argue that, because research has until now largely focused on annual changes to India's climate, this has masked more dramatic changes to temperature and rainfall within seasons, such as the monsoon seasons.

India is in the top 10 countries in the world for forest coverage, with tropical and subtropical forests covering more than a fifth of the country.

India is also one of the most biodiverse countries, containing 8% of the world's biodiversity and four recognised biodiversity hotspots. An estimated 47,000 plant species and 89,000 animal species can be found in the country, with more than 10% of each thought to be on the list of threatened species. Around 5,500 plant species are thought to be endemic to India.

Journal Reference:
Alice E. Haughan, Nathalie Pettorelli, Simon G. Potts, Deepa Senapathi. Determining the role of climate change in India’s past forest loss. Global Change Biology, 2022; DOI: 10.1111/gcb.16161

Researchers investigate development of coastal peatland in Indonesia over thousands of years

Date: March 24, 2022

Source: University of Göttingen

Tropical peatlands are one of the most efficient carbon sinks. The flipside is that they can become massive emitters of carbon if they are damaged, for instance by land use change, degradation or fire. This can lead to faster climate warming. In research led by the University of Göttingen, researchers show how peatland in the coastal areas in Sumatra and Borneo in Indonesia developed over thousands of years and how climate and sea level influenced their dynamics throughout. The results were published in Global Change Biology.

To discover more about the environment over the past 17,000 years, researchers analysed two peat cores, each over eight meters long. They carried out analyses for traces of pollen, spores and charcoal, as well as conducting carbon dating and biogeochemical investigations. Their study found that there were much higher concentrations of charcoal between 9,000 to 4,000 years ago (the mid-Holocene), when sea level was even higher than it is now. This is a sign that there were much larger forest fires at that time. Later, around 3,000 years ago, irregular periodic variations in winds and sea surface temperatures (known as El Nino-Southern Oscillation or ENSO) would have caused prolonged drought, making the forests dry and thus susceptible to fires ignited by lightning. However, even at this time, the fires were fewer than in the earlier mid-Holocene, which presented a puzzle. A clue was that during the earlier period in the mid-Holocene period, researchers found a high proportion of mangrove pollen.

The pollen grains indicate the presence of mangrove forests which grow along the coast in salty water. Their presence is a good indicator of rising sea level and an increase of salt in the otherwise freshwater peatland ecosystem. Salt is harmful to freshwater (inland) vegetation, which is likely to have resulted in more dry and dead tree leaves and branches. Salt can also reduce forest canopy cover and air humidity, which is the one important factor that can prevent fire spreading in peatland ecosystems. Furthermore, mangrove woods are high-quality fuels that can burn for a long time and reach high temperatures. The increase in dry or dead trees and the availability of high-quality firewood alongside decreased canopy cover and humidity, could all contribute to the larger fires from that time. "We were surprised to find that rising sea levels could potentially exacerbate fires in coastal areas in Indonesia," says lead author Dr Anggi Hapsari, University of Göttingen. "Our findings underline how the interaction between rising sea levels and dry climate may contribute to massive forest fires even in relatively fire-proof ecosystems, such as pristine peatlands. This reveals the potential hidden impact of sea level rise exacerbating climate warming."

"However, in contrast to the past, the primary cause of peatland fires now is human activity," adds Hapsari. "If people's behaviour continues in terms of, for instance, extensive destruction of peat swamp forests, peatland drainage, and intentional burning, when met with current rapidly rising sea level and stronger future ENSO, this could lead to catastrophic and widespread forest fires and uncontrollable carbon release," she continues.

"Our unexpected finding adds an as yet unknown threat to the survival of these valuable ecosystems," explains coauthor Dr Tim Jennerjahn, Leibniz Centre for Tropical Marine Research in Bremen. He concludes, "It demonstrates how the reconstruction of past environmental change can help improve present-day management of coastal ecosystems. It is clear that fire risk assessment in tropical peatlands deserves more attention."


Journal Reference:
K. Anggi Hapsari, Tim Jennerjahn, Septriono Hari Nugroho, Eko Yulianto, Hermann Behling. Sea level rise and climate change acting as interactive stressors on development and dynamics of tropical peatlands in coastal Sumatra and South Borneo since the Last Glacial Maximum. Global Change Biology, 2022; DOI: 10.1111/gcb.16131

Rapid glacial advance reconstructed during the time of Norse occupation in Greenland

Date:March 25, 2022

Source:Geological Society of America

The Greenland Ice Sheet is the second largest ice body in the world, and it has the potential to contribute significantly to global sea-level rise in a warming global climate. Understanding the long-term record of the Greenland Ice Sheet, including both records of glacial advance and retreat, is critical in validating approaches that model future ice-sheet scenarios. However, this reconstruction can be extremely challenging. A new study published Thursday in the journal Geology reconstructed the advance of one of the largest tidewater glaciers in Greenland to provide a better understanding of long-term glacial dynamics.

"In the news, we're very used to hearing about glacial retreat, and that's because in a warming climate scenario -- which is what we're in at the moment -- we generally document ice masses retreating. However, we also want to understand how glaciers react if there is a climate cooling and subsequent advance. To do this, we need to reconstruct glacier geometry from the past," said Danni Pearce, co-lead author of the study.

An interdisciplinary team of researchers studied the advance of Kangiata Nunaata Sermia (KNS) -- the largest tidewater glacier in southwest Greenland -- during a period of cooling when the Norse had settlements in Greenland. Differing from glaciers that are strictly on land, tidewater glaciers extend and flow all the way to the ocean or a sea, where they can then calve and break up into icebergs.

Reconstructing the advance of glaciers can be exceptionally difficult, because the glacier typically destroys or reworks everything in its path as it advances forward. The research team undertook multiple field seasons in Greenland, traveling on foot to remote sites -- many of which hadn't been visited since the 1930s -- to try and uncover the record of KNS advance.

"When we went out into the field, we had absolutely no idea whether the evidence would be there or not, so I was incredibly nervous. Though we did a huge amount of planning beforehand, until you go out into the field you don't know what you're going to find," said James Lea, the other co-lead author of the study.

By traveling on foot, the research team was able to more closely examine and explore sites that otherwise may have been missed if traveling by helicopter. The team's planning paid off, and the sedimentary sequences they studied and sampled held the clues they were looking for to date and track the advance of the glacier.

The research team found that during the twelfth and thirteenth centuries CE, KNS advanced at least 15 km, at a rate of ~115 m/yr. This rate of advance is comparable to modern rates of glacial retreat observed over the past ~200 years, indicating that when climate is cooler glaciers can advance equally as fast as they are currently retreating. The glacier reached its maximum extent by 1761 CE during the Little Ice Age, culminating in a total advance of ~20 km. Since then, KNS has retreated ~23 km to its present position.

The period when the glacier was advancing coincided with when the Norse were present in Greenland. Prior to its maximum extent during the Little Ice Age, the researchers found that KNS advanced to a location within only 5 km of a Norse farmstead.

"Even though KNS was rapidly coming down the fjord, it did not seem to affect the Norse, which we found really unusual," said Pearce. "So the team started to think about the surrounding environment and the amount of iceberg production in the fjord during that time. At the moment, the fjord is completely filled with icebergs, making boat access challenging, and we know from historical record that it has been like this for the last 200 years while the glacier has been retreating. However, for KNS to advance at 115 m/yr, it needed to hang onto its ice and could not have been producing a lot of icebergs. So we actually think that the fjord would have looked very different with few icebergs, which allowed the Norse far more easy access to this site for farming, hunting, and fishing."

In the 1930s, archaeologists who visited the site hypothesized that conditions in the fjord must have been different from the present day in order for the Norse to have occupied the site, and this current research study provides data to support these long-held ideas.

"So we have this counterintuitive notion that climate cooling and glacier advance might have actually helped the Norse in this specific circumstance and allowed them to navigate more of the fjord more easily," said Lea.

The Norse left Greenland during the fifteenth century CE, and these results are consistent with the idea that a cooling climate was likely not the cause of their exodus; rather, a combination of economic factors likely led the Norse to abandon Greenland.

The results from this research reconstructing rapid glacial advance are also shown to be consistent with the ways ice sheet models work, which brings confidence to the projections from these models. Having accurate models and projections are crucial in understanding and preparing for future scenarios of continued retreat of the Greenland Ice Sheet and associated sea-level rise.

"Melt from Greenland not only impacts sea-level change but also the ecology around the ice sheets, fisheries, the biological productivity of the oceans -- how much algae is growing. And also because the types of glaciers we're looking at produce icebergs these can cause hazards to shipping and trade, especially if the Northwest Passage opens up as it is expected to," said James Lea.

Pearce added, "Our research shows that climate cooling can change iceberg calving behavior and drive glacier advance at rates just as rapid as current retreat. It also shows how resilient the Greenlandic Norse were to the changing environmental conditions. Such adaptation can give us hope for the changes we may face over the coming century.''

Journal Reference:
Danni M. Pearce, James M. Lea, Douglas W.F. Mair, Brice R. Rea, J. Edward Schofield, Nicholas A. Kamenos, Kathryn M. Schoenrock, Lukasz Stachnik, Bonnie Lewis, Iestyn Barr, Ruth Mottram. Greenland tidewater glacier advanced rapidly during era of Norse settlement. Geology, 2022; DOI: 10.1130/G49644.1

Nature-based carbon removal can help protect us from a warming planet

Date: March 29, 2022

Source: Simon Fraser University

A new study finds that temporary nature-based carbon removal can lower global peak warming levels but only if complemented by ambitious fossil fuel emission reductions.

Nature-based climate solutions aim to preserve and enhance carbon storage in terrestrial or aquatic ecosystems and could be a potential contributor to Canada's climate change mitigation strategy. "However, the risk is that carbon stored in ecosystems could be lost back to the atmosphere as a result of wildfires, insect outbreaks, deforestation or other human activities," says Kirsten Zickfeld, a distinguished professor of climate science in Simon Fraser University's Department of Geography who is on the research team.

The researchers used a global climate model to simulate temperature change through two scenarios ranging from weak to ambitious greenhouse gas emissions reductions. In the relatively weak emissions reduction scenario, carbon emissions continue through 2100. In the ambitious scenario carbon emissions reach net-zero by 2050.

In order to meet the Paris Agreement's climate goals, the world will need to reach net-zero CO2 emissions around or before mid-century, according to the United Nations' Intergovernmental Panel on Climate Change.

In both scenarios, it is assumed that carbon storage through nature-based climate solutions is temporary as forests are vulnerable to both natural and human disturbances. Therefore, nature-based climate solutions are anticipated to withdraw carbon from the atmosphere over the next 30 years then slowly release the carbon during the second half of the century.

The team found that in a scenario with carbon emissions decreasing rapidly to net-zero, temporary nature-based carbon storage can decrease the level of peak warming. However, in a scenario with continued carbon emissions temporary nature-based carbon storage would serve only to delay the temperature increase.

"Our study shows that nature-based carbon storage, even if temporary, can have tangible climate benefits, but only if implemented alongside a rapid transition to zero fossil-fuel emissions," says Zickfeld.

The findings are published in Communications Earth & Environment.

Zickfeld is also the lead author of the recent United Nations' Intergovernmental Panel on Climate Change (IPCC) Working Group I contribution to the Sixth Assessment Report released in summer 2021, and the IPCC's 2018 special report on the global warming of 1.5 degrees.

The researchers also note that investing in protecting and restoring nature offers social and environmental benefits for local and Indigenous communities beyond storing carbon to mitigate climate change. They add that biodiversity, water and air quality are inherently valuable and that efforts to enhance these can also help to build community resilience to climate change.

Related Multimedia:
YouTube video: Nature-based carbon removal can help protect us from a warming planet

Journal Reference:
H. Damon Matthews, Kirsten Zickfeld, Mitchell Dickau, Alexander J. MacIsaac, Sabine Mathesius, Claude-Michel Nzotungicimpaye, Amy Luers. Temporary nature-based carbon removal can lower peak warming in a well-below 2 °C scenario. Communications Earth & Environment, 2022; 3 (1) DOI: 10.1038/s43247-022-00391-z

Drought alters Mammoth Mountain’s carbon dioxide emissions

Date: March 29, 2022

Source: Stanford University

Summary:  A study suggests the weight of snow and ice atop the Sierra Nevada affects a California volcano's carbon dioxide emissions, one of the main signs of volcanic unrest.

Thirty years ago, on the flanks of a volcano in California's Sierra Nevada range, trees began to die en masse, suffocated at their roots by carbon dioxide seeping up from the mountain's depths after a swarm of small earthquakes.

The wave of tree deaths on Mammoth Mountain, which lies within one of the nation's largest active volcanic systems, prompted scientists to start monitoring the volcano's emissions more closely.

Now, researchers led by Stanford University geologist George Hilley have made a surprising discovery in the long-running record: The ebb and flow of carbon dioxide emissions from Mammoth Mountain are strongly linked to the weight of snow and ice atop the Sierra Nevada, and to the amount of water that percolates from ground level down into the volcano's plumbing.

"This really shows how the solid Earth is coupled to climate and the things that go on at the surface," said Hilley, professor of geological sciences in Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth). "Droughts can change the way in which volcanoes breathe."

The research, published March 9 in Geophysical Research Letters, comes amid a dry winter that has left California snowpack well below average for this time of year, with less than a week remaining in the state's wet season and no major snowstorms in the forecast.

By the end of this century, state officials predict the Sierra Nevada snowpack will decline by 48 to 65 percent from the historical April 1 average. "Changes in Earth's hydrology due to climate change could actually impact something like the tempo at which gases are emitted from volcanic systems," Hilley said.

Horseshoe Lake

Hilley and coauthors analyzed measurements of carbon dioxide emissions taken every 30 minutes for six years from Horseshoe Lake, the best-studied tree kill area on Mammoth Mountain. The mountain rises along the southwest rim of Long Valley Caldera, a crater formed by a supervolcano eruption 760,000 years ago.

The results reveal a persistent 20 percent reduction in the amount of carbon dioxide seeping up from the ground during the spring of 2017. The downshift coincides with the region's emergence from intense drought and the pileup of the biggest Sierra Nevada snowpack in decades.

The study builds upon research by USGS volcanologist Jennifer Lewicki showing that carbon dioxide emissions in the Horseshoe Lake tree-kill area changed seasonally and across multiple years for reasons unrelated to a brewing eruption.

Seeking an explanation for these variations, Lewicki and Hilley -- with coauthor Curtis Baden of Stanford -- developed mathematical models to test out plausible mechanisms. Snowmelt and rainfall can wash away carbon dioxide that might otherwise seep from the ground, for example. But their calculations show Mammoth Mountain receives far too little precipitation to account for the low springtime CO2 levels observed in 2017.

The most likely explanation for the seasonal changes in Mammoth Mountain's carbon dioxide emissions has to do with an underground crack, or fault, which to a trained eye is evident in the vegetation patterns and topography of the landscape. Changes in the distribution of stress across the whole mountain range seem to open and close the fault like a valve, or like the tiny gaps between old floorboards that flex under shifting weight.

Using GPS data and snow depth measurements, the authors found compressive force on the fault between 2014 and 2020 generally peaked in winter as snowpack accumulated across the Sierra Nevada and eased during snow-free summer months. Carbon dioxide emission levels dipped during periods when the weight of snow and water in the mountains flexed Earth's crust, squeezing together the rocks on either side of the Mammoth Mountain fault.

One limitation of the study is that it does not provide a physics-based model of the fault's movement and how gas flows through it. "We're using stress changes as proxies for the opening and closing of a conduit," Hilley said. "An interesting study would run a three-dimensional model of gas transport through a conduit that you could actually open and close, and then run that model many times to see if its predictions quantitatively match the carbon dioxide measurements we're making."

Predicting future eruptions

The ability to distinguish between CO2 fluctuations driven by climate from those driven by an impending eruption will enable better hazard forecasts, which are based partly on signs that rising magma is triggering earthquakes, deforming the ground surface or ushering gases upward. "The alignment of all three of those is generally a clue that an eruption might be about to happen," Hilley said.

For decades, ground deformation and seismicity around some of the United States' active volcanoes have been monitored continuously using GPS and satellites, and scientists can view the data in close to real time. But they have a murkier view on volcanic gas. "In the past, at most volcanoes, scientists had to go into a volcanic area in advance of an eruption, or even between eruptions, and go collect this gas for later analysis. It's real Indiana Jones-type stuff," said Hilley.

The difficulty of collecting volcanic gases has resulted in limited records, sometimes with only a single snapshot of a volcano's degassing in any given year, which makes it challenging to detect changes that may warn of an eruption -- or to understand patterns linked to Earth's climate system.

The new study offers a glimpse of insights to come as scientists gain access to more volcanic emission data, thanks in part to the development of less expensive and more durable instruments.

"The hope is, in the next couple years, we can have a record of what the gas is doing in near real time," Hilley said. "When you look in detail, you can see there are seasonal fluctuations that probably have nothing to do with the actual volcanic state."


Journal Reference:
George E. Hilley, Jennifer L. Lewicki, Curtis W. Baden. Seasonal and Multiyear Changes in CO 2 Degassing at Mammoth Mountain Explained by Solid‐Earth‐Driven Fault Valving. Geophysical Research Letters, 2022; 49 (6) DOI: 10.1029/2021GL096595