Thursday, February 01, 2024

Engineers unmask nanoplastics in oceans for the first time, revealing their true shapes and chemistry

UNIVERSITY OF NOTRE DAME

Millions of tons of plastic waste enter the oceans each year. The sun’s ultraviolet light and ocean turbulence break down these plastics into invisible nanoparticles that threaten marine ecosystems.

In a new study, engineers at the University of Notre Dame have presented clear images of nanoplastics in ocean water off the coasts of China, South Korea and the United States, and in the Gulf of Mexico. These tiny plastic particles, which originated from such consumer products as water bottles, food packaging and clothing, were found to have surprising diversity in shape and chemical composition.

The engineers’ research was published in Science Advances.

“Nanoplastics are potentially more toxic than larger plastic particles,” said Tengfei Luo, the Dorini Family Professor of Aerospace and Mechanical Engineering at the University of Notre Dame. “Their small size makes them better able to penetrate the tissues of living organisms.”

Previously, nanoplastic particles synthesized in laboratories had been used in toxicity studies to investigate their effect on marine life. Luo’s team of researchers, in collaboration with the lab of Wei Xu at Texas A&M, decided to search for actual nanoplastics in the world’s oceans, suspecting they might be significantly different from the lab-created versions, which are highly uniform in shape and composition. Any differences found may affect toxicity studies.

Nanoplastics are believed to exist at extremely low concentrations in the ocean. To find them in seawater, Luo’s team used a unique bubble deposition technique that they had previously developed to find traces of DNA molecules for early detection of cancers.

The team mixed seawater samples with silver nanoparticles and heated the solution with a laser until a bubble formed. Variations in surface tension cause the nanoplastic particles to accumulate on the bubble’s exterior. The bubble shrinks, then vanishes, depositing the particles in one concentrated spot. Electron microscopy and Raman spectroscopy are then used to reveal the nanoplastics’ shapes and chemistries.

Luo’s team found nanoplastics made of nylon, polystyrene and polyethylene terephthalate (PET) — plastic polymers used in food packaging, water bottles, clothing and fish nets — in these seawater samples. Some of the particles’ diverse shapes can be traced back to the different manufacturing techniques used to create them. Surprisingly, PET nanoparticles were found in water samples collected approximately 300 meters deep in the Gulf of Mexico, suggesting nanoplastic contamination is not restricted to the ocean surface.

Follow-up studies will focus on quantifying ocean nanoplastics, Luo said.

“The nanoplastics we found in the ocean were distinctively different from laboratory-synthesized ones,” Luo said. “Understanding the shape and chemistry of the actual nanoplastics is an essential first step in determining their toxicity and devising ways to mitigate it.”

In addition to Luo and Xu, other co-authors on this paper are Seunghyun Moon, Seongmin Kim, Qiushi Zhang and Renzheng Zhang at the University of Notre Dame, and Leisha Martin at Texas A&M.

Contact: Jessica Sieff, associate director, media relations, 574-631-3933, jsieff@nd.edu

JOURNAL

Science Advances

DOI

10.1126/sciadv.adh1675

ARTICLE TITLE

Direct observation and identification of nanoplastics in ocean water

Study shows that Rio Grande Rise was once a giant mineral-rich tropical island near Brazil

This part of the seafloor in the South Atlantic is rich in cobalt, nickel and lithium, as well as tellurium and other rare earths critical to the energy transition. The scientists plan to continue research on its natural processes

Peer-Reviewed Publication

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO

Study shows that Rio Grande Rise was once a giant mineral-rich tropical island near Brazil — IMAGE:
SAMPLES WERE COLLECTED DURING EXPEDITIONS CONDUCTED IN 2018 BY RESEARCHERS AFFILIATED WITH THE UNIVERSITY OF SÃO PAULO (BRAZIL) AND THE UNIVERSITY OF SOUTHAMPTON (UK). THIS DARK-GRAY ROCK IS A VOLCANIC BASALT DEPOSIT
view more
CREDIT: IO-USP

A study led by scientists at the University of São Paulo (USP) in Brazil has shown that the Rio Grande Rise (RGR), a possibly continental basaltic plateau and chain of seamounts now submerged in the South Atlantic Ocean some 1,200 km from the coast of Brazil, was once a giant tropical island, rich in minerals and covered with vegetation. Geologists have dated sediments from the formation to between 45 million and 40 million years ago.

An article describing the results of the study, which involved almost ten years of research, is published in the journal Scientific Reports with new information on the geology of the RGR, which has about the same area as Spain.

The researchers analyzed samples of seafloor sediment dredged at a depth of about 650 m in the western RGR and characterized its mineralogical, geochemical and magnetic properties. The samples contained mainly red clay with several minerals typical of tropical volcanic rock alterations, such as kaolinite, magnetite, oxidized magnetite, hematite and goethite.

In 2018, the group posited that the RGR was once an island, based on discoveries made by scientific expeditions to the region, where they collected the sample described in the article (read more at: agencia.fapesp.br/29617). They traveled on the Royal Research Ship (RRS) Discovery, operated by the United Kingdom’s National Oceanography Center (NOC), and the Alpha Crucis, USP’s oceanographic research vessel. The expeditions were part of a Thematic Project supported by FAPESP. The researchers were from USP’s Oceanographic Institute (IO) and the University of Southampton in the UK.

“Our research and analysis enabled us to determine that it was indeed an island, and what’s now under discussion is whether the area can be included in Brazil’s legally recognized continental shelf. Geologically speaking, we discovered that the clay was formed after the last volcanic activity occurred 45 million years ago. The formation therefore dates from between 30 million and 40 million years ago. And it must have been formed as a result of these tropical conditions,” Luigi Jovane, last author of the article and a professor at IO-USP, told Agência FAPESP.

For Jovane, who is the principal investigator for a project funded by FAPESP, the fact that a multidisciplinary team participated in the research contributed to the results. “We have a group of the highest quality including specialists in geology, geochemistry, biology, hydrodynamics, environmental impact assessment, new energies, psychology, and law. All this accumulated science can be used to deepen our understanding of the RGR and prospect the region without affecting the local system’s synergies. To know whether resources can be viably extracted from the seafloor, we need to analyze the sustainability and impacts of this extraction. The ecosystem services provided by the ocean there haven’t been studied in detail, for example. When you interfere with an area, you have to know how this will affect animals, fungi and corals, and understand the impact you’ll have on the cumulative processes involved,” Jovane said.

Priyeshu Srivastava, first author of the article and currently a professor at the University of Mumbai in India, was also supported by FAPESP via two projects (19/11364-0 and 22/02479-0).

In 2023 alone, Jovane led the production of four other articles with results of studies involving volcanic rock and ferromanganese crust samples from the RGR. The articles are published in Frontiers in Marine Science, Journal of Materials Research and Technology, Geochemistry and Marine Geology).

Seafloor discoveries

The scientists focused on the western portion of the RGR, which they reconstructed by high-resolution bathymetric mapping that showed plateaus covered with sediment and separated by a rift with a depth of more than 600 m. They used an autonomous underwater vehicle (AUV) and a remotely operated vehicle (ROV) from the Discovery to produce maps, videos and sonar surveys.

The AUV is capable of diving down to the seafloor and covering a pre-established area for a maximum of 12 hours. The ROV is connected to the ship by a cable as it moves while producing high-resolution images, and collecting samples of rocks and organisms with a robotic arm. “No one in Brazil has AUVs or ROVs, so partnering with our British colleagues at the NOC was fundamental, but the research is 100% Brazilian,” Jovane said.

The existence of tropical soil between the volcanic lava flows detected by the researchers shows that the rocks must have been exposed to open-air weathering in a warm-wet climate in a region with active volcanoes less than 40 million years ago. The soil is similar to the “red earth” (terra roxa) found in many parts of São Paulo state, according to Jovane.

The most widely used measure of rock weathering, known as the chemical index of alteration (CIA), was 93 for the red clay. Most alkaline rocks have a CIA of less than 50. This high value points to its origin in extreme weathering of lava flows and volcanic rocks during the Eocene (the second epoch of the Paleogene Period) between 56 million and 34 million years ago, when high temperatures favored the development of tropical forests, before the sudden climate changes that occurred when Australia split off rapidly from Antarctica. The open-air erosion was followed by thermal subsidence and submergence during the late Eocene and early Oligocene between 35 million and 25 million years ago.

The RGR has been intensely studied in recent years because of its economic potential. It is in international waters and hence governed by the International Seabed Authority (ISA). In December 2018, the Brazilian government applied for an extension of its continental shelf to include the RGR, which is well beyond the limit of 200 nautical miles established for all nations by the UN Convention on the Law of the Sea (UNCLOS).

Areas rich in cobalt, nickel and lithium, as well as tellurium and other rare earths critical to the transition from fossil fuels, one of the main drivers of global warming, to renewable energy, have been detected in the RGR.

“It’s important to understand the ecosystem services and other natural processes at work in the RGR,” Jovane said. “Only this knowledge can enable us to carry out the environmental impact assessments and calculate the mitigation measures and offsets required to protect it if economic development is permitted.”

About São Paulo Research Foundation (FAPESP)

The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.

JOURNAL

Scientific Reports

DOI

10.1038/s41598-023-46273-y

ARTICLE TITLE

Red clays indicate sub-aerial exposure of the Rio Grande Rise during the Eocene volcanic episode

WAIT, WHAT?!

Study discovers neurons in the human brain that can predict what we are going to say before we say it

Findings could be used to develop new treatments for speech and language disorders

Peer-Reviewed Publication

MASSACHUSETTS GENERAL HOSPITAL

BOSTON – By using advanced brain recording techniques, a new study led by researchers from Massachusetts General Hospital (MGH) demonstrates how neurons in the human brain work together to allow people to think about what words they want to say and then produce them aloud through speech.

Together, these findings provide a detailed map of how speech sounds such as consonants and vowels are represented in the brain well before they are even spoken and how they are strung together during language production.

The work, which is published in Nature, reveals insights into the brain’s neurons that enable language production, and which could lead to improvements in the understanding and treatment of speech and language disorders.

“Although speaking usually seems easy, our brains perform many complex cognitive steps in the production of natural speech—including coming up with the words we want to say, planning the articulatory movements and producing our intended vocalizations,” says senior author Ziv Williams, MD, an associate professor in Neurosurgery at MGH and Harvard Medical School.

“Our brains perform these feats surprisingly fast—about three words per second in natural speech—with remarkably few errors. Yet how we precisely achieve this feat has remained a mystery.”

When they used a cutting-edge technology called Neuropixels probes to record the activities of single neurons in the prefrontal cortex, a frontal region of the human brain, Williams and his colleagues identified cells that are involved in language production and that may underlie the ability to speak. They also found that there are separate groups of neurons in the brain dedicated to speaking and listening.

“The use of Neuropixels probes in humans was first pioneered at MGH. These probes are remarkable—they are smaller than the width of a human hair, yet they also have hundreds of channels that are capable of simultaneously recording the activity of dozens or even hundreds of individual neurons,” says Williams who had worked to develop these recording techniques with Sydney Cash, MD, PhD, a professor in Neurology at MGH and Harvard Medical School, who also helped lead the study. “Use of these probes can therefore offer unprecedented new insights into how neurons in humans collectively act and how they work together to produce complex human behaviors such as language.”

The study showed how neurons in the brain represent some of the most basic elements involved in constructing spoken words—from simple speech sounds called phonemes to their assembly into more complex strings such as syllables.

For example, the consonant “da”, which is produced by touching the tongue to the hard palate behind the teeth, is needed to produce the word dog.

By recording individual neurons, the researchers found that certain neurons become active before this phoneme is spoken out loud. Other neurons reflected more complex aspects of word construction such as the specific assembly of phonemes into syllables.

With their technology, the investigators showed that it’s possible to reliably determine the speech sounds that individuals will say before they articulate them.

In other words, scientists can predict what combination of consonants and vowels will be produced before the words are actually spoken. This capability could be leveraged to build artificial prosthetics or brain-machine interfaces capable of producing synthetic speech, which could benefit a range of patients.

“Disruptions in the speech and language networks are observed in a wide variety of neurological disorders—including stroke, traumatic brain injury, tumors, neurodegenerative disorders, neurodevelopmental disorders, and more,” says Arjun Khanna who is a co-author on the study. “Our hope is that a better understanding of the basic neural circuitry that enables speech and language will pave the way for the development of treatments for these disorders.”

The researchers hope to expand on their work by studying more complex language processes that will allow them to investigate questions related to how people choose the words that they intend to say and how the brain assembles words into sentences that convey an individual’s thoughts and feelings to others.

Additional authors include William Muñoz, Young Joon Kim, Yoav Kfir, Angelique C. Paulk, Mohsen Jamali, Jing Cai, Martina L Mustroph, Irene Caprara, Richard Hardstone, Mackenna Mejdell, Domokos Meszena, Abigail Zuckerman, and Jeffrey Schweitzer..

This work was supported by the National Institutes of Health.

Link to study: https://www.nature.com/articles/s41586-023-06982-w

About the Massachusetts General Hospital

Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The Mass General Research Institute conducts the largest hospital-based research program in the nation, with annual research operations of more than $1 billion and comprises more than 9,500 researchers working across more than 30 institutes, centers and departments. In July 2022, Mass General was named #8 in the U.S. News & World Report list of "America’s Best Hospitals." MGH is a founding member of the Mass General Brigham healthcare system.

JOURNAL

Nature

DOI

10.1038/s41586-023-06982-w

ARTICLE TITLE

Single-neuronal elements of speech production in humans

ARTICLE PUBLICATION DATE

31-Jan-2024

Hiring the most qualified candidate might be unfair

Knowing about socioeconomic disparities impacts fairness perceptions, study finds

Peer-Reviewed Publication

AMERICAN PSYCHOLOGICAL ASSOCIATION

WASHINGTON — Both liberals and conservatives are more likely to believe that merit-based hiring is unfair after learning about the impacts of socioeconomic disparities, according to a study published by the American Psychological Association.

People from across the political spectrum also are more likely to support programs that encourage socioeconomic diversity after learning about the effects of social class and low income, according to the research, published online in the Journal of Experimental Psychology: General.

“Socioeconomic disadvantages early in life can undermine educational achievement, test scores and work experiences. In this way, inequality can undermine equal opportunity,” said lead researcher Daniela Goya-Tocchetto, PhD, an assistant professor of organization and human resources at the University at Buffalo-State University of New York. “Yet when we evaluate the fairness of merit-based processes, people tend to ignore this broader context and the effects of inequality.”

The researchers conducted five online experiments with a total of more than 3,300 participants. In two experiments, participants read about a merit-based hiring or promotion process where the most qualified candidate would be selected. Half of the participants weren’t given any additional information, while the other half were informed about the past socioeconomic disadvantages for one candidate and the advantages for another candidate. Both liberal and conservative participants who received the background information perceived the merit-based hiring or promotion process as less fair with less equal opportunity.

In two additional experiments, participants also found merit-based hiring or promotions to be less fair after learning how low income can hinder educational opportunities and career advancement.

A final experiment found that knowledge about socioeconomic disparities increased support for hiring programs that seek to foster social class diversity, such as removing the names of prestigious universities or companies from resumes and making prior internships a lesser requirement for being hired.

The experiments didn’t include race as a factor so the findings may have been different if race had been the focus instead of socioeconomic disadvantages, Goya-Tocchetto said. Prior research has found that learning about racial inequity can lead to defensiveness among white conservatives. Conservative participants in the current research were more likely to believe that merit-based hiring and promotion were fair in general, but they still adjusted their fairness perceptions after learning about socioeconomic disparities.

Programs meant to address racial diversity have been more polarizing with a recent U.S. Supreme Court ruling limiting affirmative action admissions policies at colleges and universities. Conservative groups also have filed lawsuits against racial diversity programs at various companies and government programs that support minority-owned businesses.

Workforce diversity programs that focus on addressing socioeconomic disadvantages may avoid some political backlash and still help increase racial diversity, Goya-Tocchetto said.

“Members of marginalized racial groups tend to experience socioeconomic disadvantages more often than members of privileged racial groups, and the negative consequences of these disadvantages can be even worse for racial minorities,” she said. “Focusing on socioeconomic considerations could garner more support and still help address racial inequality.”

Hiring managers should learn about the effects of socioeconomic inequalities on access to opportunities and consider a broader range of work experience when evaluating different candidates, Goya-Tocchetto said.

Article: “Can Selecting the Most Qualified Candidate Be Unfair? Learning About Socioeconomic Advantages and Disadvantages Reduces the Perceived Fairness of Meritocracy and Increases Support for Socioeconomic Diversity Initiatives in Organizations,” Daniela Goya-Tocchetto, PhD, University at Buffalo-State University of New York, Aaron C. Kay, PhD, Duke University, and Keith Payne, PhD, University of North Carolina-Chapel Hill, Journal of Experimental Psychology: General, published online Feb. 1, 2024.

Contact: Daniela Goya-Tocchetto, PhD, may be contacted at dgoyatoc@buffalo.edu.

The American Psychological Association, in Washington, D.C., is the largest scientific and professional organization representing psychology in the United States. APA’s membership includes over 157,000 researchers, educators, clinicians, consultants and students. Through its divisions in 54 subfields of psychology and affiliations with 60 state, territorial and Canadian provincial associations, APA works to advance the creation, communication and application of psychological knowledge to benefit society and improve people’s lives.

JOURNAL

Journal of Experimental Psychology

DOI

10.1037/xge0001525

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Can Selecting the Most Qualified Candidate Be Unfair? Learning About Socioeconomic Advantages and Disadvantages Reduces the Perceived Fairness of Meritocracy and Increases Support for Socioeconomic Diversity Initiatives in Organizations

ARTICLE PUBLICATION DATE

1-Feb-2024

New energy justice index casts spotlight on energy transition in the Global South

Can the transition to a zero-carbon society in the Global South propel sustainable development?

Peer-Reviewed Publication

RESEARCH INSTITUTE FOR SUSTAINABILITY (RIFS) – HELMHOLTZ CENTRE POTSDAM

Can the transition to a zero-carbon society in the Global South propel sustainable development? A team led by scientists from the Research Institute for Sustainability (RIFS) has developed the first quantitative approach to measure the extent to which energy transitions in the Global South incorporate elements of energy justice.

The study "An energy justice index for the energy transition in the Global South”, prepared by lead author Maria Apergi and a team of researchers, allows for a standardized, quantitative comparison of the transition processes of different countries. A quantitative measure of the extent to which energy transitions in countries outside the Global North live up to the imperative of energy justice has been lacking to date. The index presented in the journal Renewable and Sustainable Energy Reviews addresses this deficit.

The concept of energy justice
Energy justice is a concept that engages with the fairness of energy systems, taking into account the social and development implications of energy technologies, policies, and projects. A large share of the relevant studies on energy justice published to date focussed on assessing the justice implications of low-carbon transitions and renewable energy. The newly developed index provides an analytical framework for identifying injustices in energy processes and putting forward solutions. The index was composed by assigning various components of energy justice to the three core tenets of Procedural Justice, Recognition Justice, and Distributional Justice.

The authors emphasise that the ranking of the countries covered does not always correspond to the level of their economic development. Malaysia and Chile, for example, scored higher in terms of distributional justice, while Kenya and Jordan scored higher in terms of procedural justice. Kenya also scored higher in terms of intergenerational justice and distribution of costs and benefits of renewable energy infrastructure.

Implications for climate policy

The researchers recommend that national governments and transnational players such as multilateral institutions and investors work towards the establishment of policy frameworks and strategies that systematically integrate justice concerns. This concerns regulations addressing due process in the design of energy systems as well as access, affordability, and other distributional considerations. Policies to advance recognition justice through rural electrification programmes and microfinancing, for example, are also indispensable in the protection of vulnerable groups, the authors note. Economic instruments that encourage investment in renewable energies should also include social criteria. In addition, policymakers could benefit from introducing monitoring, reporting and data verification procedures for energy justice related indicators, so as to improve data quality and availability.
The index presented in the study will contribute to the discussion on energy justice and facilitate assessments of energy justice over time and between countries. The results illustrate the multidimensionality and complexity of the energy justice concept, especially when it is applied to the energy transition. Underpinned by a wealth of data and made accessible online, the index can become a valuable tool for researchers and decisionmakers in their efforts to systematically study and improve energy justice – in the Global South and beyond.

Publication:
Maria Apergi, Laima Eicke, Andreas Goldthau, Mustafa Hashem, Sebastian Huneeus, Renato Lima de Oliveira, Maureen Otieno, Esther Schuch, Konstantin Veit: An energy justice index for the energy transition in the global South, Renewable and Sustainable Energy Reviews 192 (2024) 114238. https://doi.org/10.1016/j.rser.2023.114238

JOURNAL

Renewable and Sustainable Energy Reviews

DOI

10.1016/j.rser.2023.114238

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

An energy justice index for the energy transition in the global South

Increased temperature difference between day and night can affect all life on earth

Peer-Reviewed Publication

CHALMERS UNIVERSITY OF TECHNOLOGY

Researchers from Chalmers University of Technology, in Sweden, have discovered a change in what scientists already knew about global warming dynamics. It had been widely accepted since the 1950s that global temperature rises were not consistent throughout the day and night, with greater nighttime warming being observed. However, the recent study reveals a shift in dynamics: with greater daytime warming taking place since the 1990s. This shift means that the temperature difference between day and night is widening, potentially affecting all life on Earth.

The rise in the global average surface temperature is one of the key characteristics of human-induced climate change. However, the temperature increase is not uniform throughout the day and night, and nighttime temperatures have increased at a faster pace than daytime temperatures in the latter half of the twentieth century. This warming pattern, with variations between day and night is termed “asymmetric warming” and could be due to both human activities and naturally occurring phenomena.

In a new study, published in Nature Communications, an international team of researchers reinvestigated the asymmetric warming phenomenon and found that the pattern has reversed. Between 1961 and 2020, global daytime warming has accelerated, while the warming rate of nighttime temperature is relatively constant. This reversed trend in asymmetric warming has led to an increasing temperature difference between day and night.

“We initially aimed to confirm the previously observed phenomenon of nighttime warming surpassing daytime warming. To our surprise, not only had the asymmetric warming trend ceased, but our analyses, based on state-of-the-art observation-based datasets, indicate a complete reversal of this original warming pattern over the past three decades”, says Ziqian Zhong, post-doctoral researcher at Chalmers.

Global brightening a potential cause

“A likely explanation to this change is a phenomenon called “global brightening”, which has been observed since the late 1980s. It is a result of less cloud cover, which causes more sunlight to reach the Earth's surface, leading to higher daytime temperatures and, as a result, a broader difference between daytime and nighttime temperatures over the recent decades”, says Ziqian Zhong.

There is currently significant uncertainty regarding the reasons behind the changes in cloud cover. The “global brightening” may be attributed to a complex interplay between cloud-free and cloudy atmospheres, as well as the effect of small particles in the atmosphere, known as aerosols. These aerosols can be derived from natural processes like sea spray and wildfires, but also from human activities like fossil fuel burning, and they can have a profound effect on many aspects of the environment.

Apart from the effects from global brightening, the researchers suggest another reason for the reversed asymmetric warming. The increase in regional drought events and heatwaves suggests a potential weakening of the cooling effect due to evaporation at the Earth's surface, which would typically result in a faster increase in daytime temperatures.

The researchers found that the majority of land, 81 per cent of the total area, experienced larger nighttime warming from 1961 to 1990. However, in the subsequent period from 1991 to 2020, a shift occurred, with 70 per cent of the observed land areas experiencing larger daytime warming instead.

Affecting all life on Earth

The larger temperature difference between day and night could potentially affect crop yields, plant growth, animal well-being and human health.

For example, an increased temperature difference between daytime and nighttime is recognised as one of the environmental stressors that could lead to elevated heart rate and blood pressure, consequently increasing cardiac workload and the mortality and morbidity of cardiovascular and respiratory diseases.

“This indicates the need to adjust strategies in different areas affected by temperature variations between day and night, such as agriculture, public health, and forestry management, to address the challenges posed by this climate change”, says Ziqian Zhong.

Certain tree species in humid areas might enhance their carbon sequestration capacity due to the increased temperature difference between daytime and nighttime. However, the increased temperature difference between daytime and nighttime might prove disadvantageous for trees in dry regions, as higher daytime temperatures may increase evaporation, leading to deficiency of soil water and unfavorable conditions for tree growth.

“In the upcoming research, we will further investigate the impacts of this reversed trend in asymmetric warming on tree growth and carbon cycle”, says Ziqian Zhong.

More about the research:

The research is presented in a paper: "Reversed asymmetric warming of sub-diurnal temperature over land during recent decades", published in the journal Nature Communications.

The researchers involved in the study are Ziqian Zhong, Bin He, Hans W. Chen, Deliang Chen, Tianjun Zhou, Wenjie Dong, Cunde Xiao, Shang-ping Xie, Xiangzhou Song, Lanlan Guo, Ruiqiang Ding, Lixia Zhang, Ling Huang, Wenping Yuan, Xingming Hao, Duoying Ji and Xiang Zhao. The researchers are active at Chalmers University of Technology, University of Gothenburg, Beijing Normal University, University of California San Diego, Sun Yat-Sen University, Hohai University, Peking University and the Chinese Academy of Sciences.

This work has been supported by the Third Xinjiang Scientific Expedition Program and the State Key Laboratory of Earth Surface Processes and Resource Ecology. H.W.C. was supported by the Swedish Foundation for International Cooperation in Research and Higher Education.

For more information, please contact:

Ziqian Zhong, Researcher, Division of Geoscience and Remote Sensing, Department of Space, Earth and Environment, Chalmers University of Technology, Sweden, ziqian.zhong@chalmers.se

Hans W. Chen, Assistant Professor, Division of Geoscience and Remote Sensing, Department of Space, Earth and Environment, Chalmers University of Technology, Sweden, +46 31 772 23 44, hans.chen@chalmers.se

The researchers both speak English. Hans Chen is also fluent in Swedish and Ziqian Zhong is fluent in Chinese. They are available for live and pre-recorded interviews. At Chalmers, we have podcast studios and broadcast filming equipment on site and would be able to assist a request for a television, radio or podcast interview.

JOURNAL

Nature Communications

DOI

10.1038/s41467-023-43007-6

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Reversed asymmetric warming of sub-diurnal temperature over land during recent decades

Climate change: Fungal disease endangers wheat production

Wheat blast spread under climate change modeled for the first time

Peer-Reviewed Publication

TECHNICAL UNIVERSITY OF MUNICH (TUM)

Climate change poses a threat to yields and food security worldwide, with plant diseases as one of the main risks. An international team of researchers surrounding Prof. Senthold Asseng from the Technical University of Munich (TUM) has now shown that further spread of the fungal disease wheat blast could reduce global wheat production by 13% until 2050. The result is dramatic for global food security.

With a global cultivation area of 222 million hectares and a harvest volume of 779 million tons, wheat is an essential food crop. Like all plant species, it is also struggling with diseases that are spreading more rapidly compared to a few years ago because of climate change. One of these is wheat blast. In warm and humid regions, the fungus "Magnaporthe oryzae" has become a serious threat to wheat production since it was first observed in 1985. It initially spread from Brazil to neighboring countries. The first cases outside of South America occurred in Bangladesh in 2016 and in Zambia in 2018. Researchers from Germany, Mexico, Bangladesh, the USA and Brazil have now modeled for the first time how wheat blast will spread in the future.

Regionally up to 75% of total wheat acreage affected

According to the researchers, South America, southern Africa and Asia will be the regions most affected by the future spread of the disease. Up to 75% of the area under wheat cultivation in Africa and South America could be at risk in the future. According to the predictions, wheat blast will also continue to spread in countries that were previously only slightly impacted, including Argentina, Zambia and Bangladesh. The fungus is also penetrating countries that were previously untouched. These include Uruguay, Central America, the south-eastern USA, East Africa, India and eastern Australia. According to the model, the risk is low in Europe and East Asia - with the exception of Italy, southern France, Spain and the warm and humid regions of south-east China. Conversely, where climate change leads to drier conditions with more frequent periods of heat above 35 °C, the risk of wheat blast may also decrease. However, in these cases, heat stress decreases the yield potential.

Dramatic yield losses call for adapted management

The affected regions are among the areas most severely impacted by the direct consequences of climate change. Food insecurity is already a significant challenge in these areas and the demand for wheat continues to rise, especially in urban areas. In many regions, farmers will have to switch to more robust crops to avoid crop failures and financial losses. In the Midwest of Brazil, for example, wheat is increasingly being replaced by maize. Another important strategy against future yield losses is breeding resistant wheat varieties. CIMMYT in collaboration with National Agricultural Research Systems (NARs) partners have released several wheat blast-resistant varieties which have been helpful in mitigating the effect of wheat blast. With the right sowing date, wheat blast-promoting conditions can be avoided during the ear emergence phase. Combined with other measures, this has proven to be successful. In more specific terms, this means avoiding early sowing in central Brazil and late sowing in Bangladesh.

First study on yield losses due to wheat blast

Previous studies on yield changes due to climate change mainly considered the direct effects of climate change such as rising temperatures, changing precipitation patterns and increased CO2 emissions in the atmosphere. Studies on fungal diseases have so far ignored wheat blast. For their study, the researchers focused on the influence of wheat blast on production by combining a simulation model for wheat growth and yield with a newly developed wheat blast model. Environmental conditions such as the weather are thus included in the calculations, as is data on plant growth. In this way, the scientists are modeling the disease pressure in the particularly sensitive phase when the ear matures. The study focused on the influence of wheat blast on production. Other consequences of climate change could further reduce yields.

Publication:

Pequeno D., Ferreira T., Fernandes J., Singh P., Pavan W., Sonder K., Robertson R., Krupnik T., Erenstein O., Asseng A. Production vulnerability to wheat blast disease under climate change. Nature Climate Change (2024). https://www.nature.com/articles/s41558-023-01902-2

Further information:

The study was conducted by researchers from:

CIMMYT (Mexico and Bangladesh)
Technical University of Munich (Germany)
University of Florida (USA)
Brazilian Agricultural Research Corporation (Brazil)
International Fertilizer Development Center (USA)
International Food Policy Research Institute (USA)

JOURNAL

Nature Climate Change

DOI

10.1038/s41558-023-01902-2

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Production vulnerability to wheat blast disease under climate change

ARTICLE PUBLICATION DATE

1-Feb-2024