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Tag: Environmental Science

  • Something to (re)think about

    Something to (re)think about

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    By Alyssa Soucy, Ph.D. Candidate, University of Maine

    Newswise — As the spotlight cuts across the lake, intersecting with the horizon beyond, I saw the trio of Common Loons as only white floating specks surrounded by darkness. Almost like a mirage, they appeared through the fog and the gnats swirling off the surface of the water. I fixed the beam of light on one of the chicks who looked serenely unaware of our approaching boat. My body and mind launched into the sole purpose of illuminating that chick as Carl Brown, BRI’s field biologist leading this loon translocation effort, swung a net over the side of the boat. Under the starry sky that evening, we successfully captured a Common Loon chick for safe relocation and release.

    Iain Stenhouse, field biologist and director of BRI’s Marine Bird Program, is accustomed to experiencing the profoundly mesmerizing, immersive feelings that arise when working closely with wildlife. Whether on a boat off the coast of Maine tracking families of Common Eiders, or surrounded by an Arctic Tern colony in Greenland, Stenhouse is at home in the wild working with the birds. In fact, as he recalls tracking these terns, a species that claim the longest migration distance on record, he becomes awakened by the connection he has with them. “There’s not much to an Arctic Tern, it’s almost all feathers. And, to know that this bird, under its own steam, has been to Antarctica and back again since you last saw it, and it doesn’t look any different is just breathtaking.” Stenhouse describes the feeling he has when holding birds as being unlike any other, “I’ve never known anything that had that same kind of rush of excitement and fascination and just awe.”

    BRI’s field biologists seek out opportunities that put them into close contact with the natural world. In fact, those encounters captivate, awaken, and spark their motivation and passion. Evan Adams, BRI’s director of the Quantitative Wildlife Ecology Research Lab, was drawn to this career after a trip to Costa Rica. Adams recounts, “There’s a hummingbird called the Violet Sabrewing. You could hear them as they flew by you because they sounded like a Harley Davidson, you didn’t even have to look. And I thought that that was super cool, and when returned home, I thought, ‘I want to study birds’—that was kind of it.”

    Helen Yurek, another BRI wildlife biologist, spends many days and nights in remote places. “You just see really cool things; you see animals doing things that you might not have otherwise.” Sarah Dodgin, an ecological analyst for BRI, recently spotted an elusive Upland Sandpiper during fieldwork. She exclaims, “They ran out right in front of the truck and I was like ‘Oh, my gosh, here you are!’ It was a cool feeling.” Similar to my experience working with the loons, and Stenhouse’s in Greenland with Arctic Terns diving overhead, each of us recognizes that sense of awe and wholeness we feel when we are connected with the world around us.

    Through our own experiences we are all describing a concept that psychologists have been studying for decades. The term connectedness to nature refers to the emotional and cognitive connections we have with the natural world. In recent years, interest in the relationship between nature and human well-being has exploded. A growing trend of “park prescriptions” involves doctors encouraging patients to spend time outdoors. Spending time in close contact with nature can lead to positive health outcomes, including lower rates of depression and anxiety, anger and fatigue, and cardiovascular and respiratory diseases. Experimental studies have shown that being outside can even improve working memory and task performance, as well as invoke feelings of restorativeness and increase happiness. As Rachel Carson wrote in Silent Spring, “There is something infinitely healing in the repeated refrains of nature—the assurance that dawn comes after night, and spring after winter.” It is in this personal relationship with nature that we can find solace.

    Questions remain as to why spending time in nature may lead to positive health outcomes. Some answers lie in the specific chemical and biological components contained within natural environments. While others turn to the field of psychology. For example, people experience a great sense of awe in response to nature. The awe and fascination that Stenhouse describes when working closely with birds conveys a sense of fulfillment, connection, and restorativeness. As he notes, “Modern living doesn’t provide many real moments anymore. That moment—feeling that little heartbeat against your fingertips and the warmth of another little creature in the world—is very cool.” The Biophilia Hypothesis further suggests that throughout much of our two-million-year evolutionary history, humans lived in hunter-gatherer societies, coexisting with the natural world. A connection with nature, or “biophilia,” developed and became integral to human survival. A connection to nature then may be rooted in our connection to our ancestral selves.

    Weeks later, when remembering the feel of the loon’s heartbeat and the sound of its haunting call, I am transported back to that night, back to that connection I felt with the loons and the lake, and the sense of purpose that enveloped me. As a social psychologist, I study people. Rarely do I have experiences that bring me in such close physical contact with wildlife; yet, it has taken only that one night to realize that there really is no other feeling like it.

    Social psychologists continue to document feelings of a connectedness to nature that have profound effects on behaviors, attitudes, and health. In doing so, they offer solutions that address both human and environmental well-being by recognizing the interconnections between the two. Whether you experience nature in a remote place while handling an Arctic Tern, out on a lake on a clear summer night surrounded by the calls of loons, or in the local community forest during your weekly walk, a connection and restoration is there waiting for you. As Robin Wall Kimmerer writes, “As we work to heal the earth, the earth heals us.”

     

    More stories on https://briwildlife.org/bri-blog/.

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    Biodiversity Research Institute (BRI)

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  • Collision risk and habitat loss: Wind turbines in forests impair threatened bat species

    Collision risk and habitat loss: Wind turbines in forests impair threatened bat species

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    Newswise — In order to meet climate protection goals, renewable energies are booming – often wind power. More than 30,000 turbines have already been installed on the German mainland so far, and the industry is currently scrambling to locate increasingly rare suitable sites. Thus, forests are coming into focus as potential sites. A scientific team from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) now demonstrated in a new paper published in the scientific journal “Current Biology” that wind turbines in forests impair endangered bat species: Common noctules (Nyctalus noctula), a species with a high risk of colliding with rotor blades, are attracted to forest wind turbines if these are located near their roosts. Far from roosts, common noctules avoid the turbines, essentially resulting in a loss of foraging space and thus habitat for this species.

    The research results show that common noctules suffer in two ways from wind turbines in forests: If the wind turbines are built near roosts, noctules face an increasing risk of colliding with the turbines, and they lose foraging habitat because they avoid wind turbines far from roosts. In their paper the team concludes that wind power development in forests must be avoided or, if there is no alternative, should be undertaken with great care and caution. The wind turbine should be placed at least at a distance of 500 meters away from bat roosting sites, and loss of foraging habitat should be compensated for by taking forests out of use for wind power (or other anthropogenic activities) elsewhere.

    Wind energy production is an important pillar for the energy transition to renewable energies in Germany and makes a significant contribution to reducing greenhouse gas emissions. Approximately eight percent of wind turbines in Germany have already been built in forests. This number is expected to significantly increase in the coming years as suitable sites in open landscapes become increasingly scarce. “A large number of bat species occur in forests because there are many tree roosts and suitable foraging habitats with a high abundance of insects, their prey”, says Christian Voigt, head of the Department of Evolutionary Ecology at the Leibniz-IZW. “These include species such as the common noctule, which is the most common victim among the bat species of wind turbines in Germany. According to the German Federal Agency for Nature Conservation (BfN), common noctule populations are declining throughout Germany. It is therefore a matter of urgency to take a closer look at the interaction of bats with wind turbines in forests.”

    Voigt and his colleagues investigated the space-use behaviour of common noctules using miniaturised GPS loggers. These loggers recorded the flight paths of 60 bats with a high temporal and spatial resolution over 1-2 nights before the loggers automatically came off each animal. “We found that the common noctules were particularly likely to approach wind turbines if the latter were located close to bat roosts”, explains Voigt. As highly social mammals, the bats use exposed structures as meeting spots. This could be the reason why they often approach wind turbines, which rise well above the canopy, if turbines are located near roosts. This poses a high risk to the animals of colliding with the rotor blades. “Wind turbines would therefore have to be erected at a sufficient distance from existing tree roosts”, concludes Christine Reusch, first author of the paper. “As roosts can also be newly created, there is a risk that supposedly safe wind turbines, which were initially erected at a sufficiently large distance from the then existing bat roosts during the approval phase, later become death traps”, Reusch adds.

    The authors also found that further away from tree roosts, common noctules avoided wind turbines. They discovered this after they had carried out a data analysis in which all bat GPS locations in the vicinity of roosts were excluded from the analysis. This showed that bats avoid wind turbines if placed well beyond roosts. “This sounds like good news but it has a problematic side to it”, says Voigt. “Owing to their avoidance behaviour, common noctule bats essentially lose important hunting habitats.” The scientists therefore recommend, firstly, that wind turbines should not be sited in forests, and secondly, that special care should be taken if there are no alternatives. A minimum distance of 500 meters of wind turbines to known bat roosts should be taken into account during the approval procedures and the loss of foraging habitat in the vicinity of wind turbines should be compensated for elsewhere. The expansion of wind energy production into forests is therefore a major challenge to conservation in view of the complex interaction of bats with wind turbines in forests, according to Voigt and Reusch.  

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    Leibniz Institute for Zoo and Wildlife Research (IZW)

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  • Climate Change Likely to Uproot More Amazon Trees

    Climate Change Likely to Uproot More Amazon Trees

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    Newswise — Tropical forests are crucial for sucking up carbon dioxide from the atmosphere. But they’re also subject to intense storms that can cause “windthrow” – the uprooting or breaking of trees. These downed trees decompose, potentially turning a forest from a carbon sink into a carbon source.

    A new study finds that more extreme thunderstorms from climate change will likely cause a greater number of large windthrow events in the Amazon rainforest. This is one of the few ways that researchers have developed a link between storm conditions in the atmosphere and forest mortality on land, helping fill a major gap in models.

    “Building this link between atmospheric dynamics and damage at the surface is very important across the board,” said Jeff Chambers, a senior faculty scientist at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), and director of the Next Generation Ecosystem Experiments (NGEE)-Tropics project, which performed the research. “It’s not just for the tropics. It’s high-latitude, low-latitude, temperate-latitude, here in the U.S.”

    Researchers found that the Amazon will likely experience 43% more large blowdown events (of 25,000 square meters or more) by the end of the century. The area of the Amazon likely to see extreme storms that trigger large windthrows will also increase by about 50%. The study was published in the journal Nature Communications on Jan. 6.

    “We want to know what these extreme storms and windthrows mean in terms of the carbon budget and carbon dynamics, and for carbon sinks in the forests,” Chambers said. While downed trees slowly release carbon as they decompose, the open forest becomes host to new plants that pull carbon dioxide from the air. “It’s a complicated system, and there are still a lot of pieces of the puzzle that we’re working on. In order to answer the question more quantitatively, we need to build out the land-atmosphere links in Earth system models.”  

    To find the link between air and land, researchers compared a map of more than 1,000 large windthrows with atmospheric data. They found that a measurement known as CAPE, the “convective available potential energy,” was a good predictor of major blowdowns. CAPE measures the amount of energy available to move parcels of air vertically, and a high value of CAPE often leads to thunderstorms. More extreme storms can come with intense vertical winds, heavy rains or hail, and lightning, which interact with trees from the canopy down to the soil.

    “Storms account for over half of the forest mortality in the Amazon,” said Yanlei Feng, first author on the paper. “Climate change has a lot of impact on Amazon forests, but so far, a large fraction of the research focus has been on drought and fire. We hope our research brings more attention to extreme storms and improves our models to work under a changing environment from climate change.”

    While this study looked at a future with high carbon emissions (a scenario known as SSP-585), scientists could use projected CAPE data to explore windthrow impacts in different emissions scenarios. Researchers are now working to integrate the new forest-storm relationship into Earth system models. Better models will help scientists explore how forests will respond to a warmer future – and whether they can continue to siphon carbon out of the atmosphere or will instead become a contributor.

    “This was a very impactful climate change study for me,” said Feng, who completed the research as a graduate student researcher in the NGEE-Tropics project at Berkeley Lab. She now studies carbon capture and storage at the Carnegie Institution for Science at Stanford University. “I’m worried about the projected increase in forest disturbances in our study and I hope I can help limit climate change. So now I’m working on climate change solutions.” 

    NGEE-Tropics is a ten-year, multi-institutional project funded by the U.S. Department of Energy’s Office of Science, Office of Biological and Environmental Research.

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    Founded in 1931 on the belief that the biggest scientific challenges are best addressed by teams, Lawrence Berkeley National Laboratory and its scientists have been recognized with 16 Nobel Prizes. Today, Berkeley Lab researchers develop sustainable energy and environmental solutions, create useful new materials, advance the frontiers of computing, and probe the mysteries of life, matter, and the universe. Scientists from around the world rely on the Lab’s facilities for their own discovery science. Berkeley Lab is a multiprogram national laboratory, managed by the University of California for the U.S. Department of Energy’s Office of Science.

    DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.

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    Lawrence Berkeley National Laboratory

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  • Let’s clear things up: how do glassfrogs achieve transparency?

    Let’s clear things up: how do glassfrogs achieve transparency?

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    Newswise — Tissue transparency—a useful skill for animals that want to hide from predators—is common in aquatic environments, but is extremely rare on land. One exception is the glassfrog, so named because its internal organs can be seen through its transparent skin and muscles. This frog is active at night and spends its days sleeping on leaves, becoming nearly invisible on the foliage. But how exactly this creature makes itself transparent has been somewhat of a mystery.

    Using state-of-the-art imaging technology, NIH-funded researchers have found the secret behind the glassfrog’s camouflage. Their findings, recently published on the cover of Science, demonstrate that glassfrogs can remove almost 90% of their red blood cells from circulation, storing them in the liver during rest. This mechanism, along with its inherently see-through tissues, allows the glassfrog to increase its transparency by two- to threefold, seemingly on demand.

    “In vertebrates like humans, tissue transparency is particularly difficult to achieve, as our circulatory systems are filled with oxygen-carrying red blood cells that strongly absorb light and render our tissues opaque,” explained NIBIB-funded researcher Junjie Yao, Ph.D., an assistant professor of biomedical engineering at Duke University. “In our study, we have discovered that the glassfrog can conceal nearly all of its red blood cells within its liver on a daily basis, resulting in a unique form of camouflage that is distinct from all other known mechanisms of tissue transparency. Understanding this blood flow mechanism in the glassfrog may provide insights into disorders related to blood clotting or stroke in humans.”

    The glassfrog’s camouflage is adaptive—the creature has peak transparency when it is asleep and at increased risk of attack. To understand the mechanism of this transparency, the researchers first used spectroscopy techniques to passively measure glassfrog’s levels of hemoglobin (a protein in red blood cells that carries oxygen and absorbs light). They found that hemoglobin levels were barely distinguishable when the frogs were sleeping, but markedly increased after exercise. This means that the glassfrog depletes its red blood cells from circulation during rest, allowing for enhanced tissue transparency and camouflage during this vulnerable time.

    But where exactly are these red blood cells going while the glassfrog is asleep? To answer this question, the researchers used an advanced technique called photoacoustic microscopy, a hybrid imaging method that takes advantage of both light and sound waves. Here’s how it works: When a tissue absorbs light, some of that absorbed energy is converted into ultrasound waves. Measuring these ultrasound waves with a specialized transducer can give detailed information about molecules and tissues under the skin’s surface. In this study, the researchers optimized this technique so that they could detect light absorbed by hemoglobin—this way, the resulting ultrasound waves would give information about glassfrogs’ red blood cell movement.

    “Photoacoustic microscopy allowed us to capture the blood flow dynamics of the glassfrogs, even though those changes occur deep inside their opaque internal organs,” explained Carlos Taboada, Ph.D., a postdoctoral associate at Duke University and one of the leading authors of this study. “This aspect of the technique was really important, because many internal organs of the glassfrog contain millions of nanocrystals that attenuate most incident light. Traditional imaging methods can’t track blood flow with such a high level of accuracy or tell us exactly where the glassfrogs are storing their red blood cells.”

    Using photoacoustic microscopy, the researchers imaged the glassfrogs while under anesthesia (which leads to red blood cells being distributed throughout the entire body), while sleeping, and after exercise. During rest, the researchers found that the glassfrogs’ circulating pool of red blood cells decreased by 80-90%, with the hemoglobin signal concentrated in the liver. Imaging the frogs after exercise revealed that the blood flows out of the liver and back into circulation during activity, with the red blood cells reaggregating in the liver within roughly an hour after movement.

    By revealing the mechanism of the glassfrog’s camouflage, a new question has surfaced: How do these creatures concentrate most of their red blood cells in their liver without triggering clotting events? “At this point, we really know very little about this important physiological function in glassfrogs, but we are actively working to understand this phenomenon, which has significant clinical implications,” said Yao. “This anti-clotting mechanism is highly relevant for treating thrombosis and stroke, as well as improving medical interventions that require removing blood from the body (like dialysis), where blood clotting is a major concern.”

    Future work in this space can take advantage of the unique ability of photoacoustic imaging to track glassfrog’s blood flow—in a safe and unobtrusive way that does not disturb the animals. “By optimizing photoacoustic imaging to specifically detect hemoglobin, the researchers were able to observe the glassfrogs’ natural blood flow dynamics without injecting contrast agents, representing a truly non-invasive approach,” said Randy King, Ph.D., a program director in the Division of Applied Science & Technology at NIBIB. “What’s more, this study highlights how photoacoustic microscopy can be tailored to investigate different aspects of blood dynamics, providing both high-resolution and real-time information.”

    This study was supported by grants from NIBIB (R01EB028143), the National Institute of Neurological Disorders and Stroke (NINDS; R01NS111039), and the NIH BRAIN Initiative (RF1NS115581).

    This Science Highlight describes a basic research finding. Basic research increases our understanding of human behavior and biology, which is foundational to advancing new and better ways to prevent, diagnose, and treat disease. Science is an unpredictable and incremental process—each research advance builds on past discoveries, often in unexpected ways. Most clinical advances would not be possible without the knowledge of fundamental basic research.

    Study reference: Carlos Taboada et al. Glassfrogs conceal blood in their liver to maintain transparency. Science (2022). DOI: 10.1126/science.abl6620

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    National Institute of Biomedical Imaging and Bioengineering

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  • Loss of glaciers faster than expected

    Loss of glaciers faster than expected

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    Newswise — How will our glaciers change during the 21st century? In a new study whose findings are published in Science (5 January), an international team1, including scientists from the CNRS and Université Toulouse III–Paul Sabatier, has demonstrated a loss of glacial mass greater than earlier projected—and specifically, 11% to 44% higher than estimates used in the most recent IPCC report. Small glaciers (<1 km2) predominate on our planet, and they are the most impacted by mass loss. In the scenario where global warming is limited to 1.5 °C, 49% of the world’s glaciers, the majority of the small ones , are expected to disappear by 2100, prompting a 9-cm sea level rise. The largest glaciers would also be affected but would not disappear. If, on the other hand, temperatures rise by 4 °C, neither small nor large glaciers will be spared: 83% would disappear and there would be a 15.4-cm sea level rise. To reach their conclusions, the team of scientists relied on the observations of a study that quantified widespread, accelerated glacial mass loss around the world between 2000 and 2019. These earlier data allowed them to calibrate their mathematical model, developed especially for the work presented in their publication, for each and every one of the >215 thousand glaciers on Earth. The model also accounts for processes not previously represented, such as mass loss due to iceberg calving and the effect of a layer of debris on the surface of a glacier. Shrinkage of the greatest glaciers, like those in Alaska, the Canadian Arctic, and around Antarctica, key to future sea level rise, may still be limited if we implement measures to mitigate global warming.

    1In France, this study incluted scientists from the Laboratoire d’étude en géophysique et océanographie spatiales (CNRS/CNES/IRD/Université Paul Sabatier Toulouse III).

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    CNRS (Centre National de Recherche Scientifique / National Center of Scientific Research)

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  • Electricity harvesting from evaporation, raindrops and moisture inspired by nature

    Electricity harvesting from evaporation, raindrops and moisture inspired by nature

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    Newswise — Raindrops, evaporating water, and even moisture in the air are all potentially sources of decentralized clean electricity generation, but many of the technologies that take advantage of this ambient and vast source of energy—many of which are inspired by the electricity harvesting techniques of plants and animals—remain at the lab-bench stage. A group of researchers and engineers have put together a survey of the opportunities and challenges this very young field face.

    Their review paper was published in the journal Nano Research Energy on November 30, 2022.

    Enormous hydroelectric dams are perhaps the first thing one thinks of when considering sustainable electricity generation, or possibly large tidal barrages. If one is very familiar with the state of play in clean energy development, one might also be aware of wave-energy converters on the sea surface or seabed that convert the energy from high-intensity waves into usable electricity.

    All of these options depend upon heavy, bulky and above all centralized forms of harvesting of the energy contained in water. Yet there are a myriad of other potential technology pathways that can harvest electricity from water in much more decentralized fashion, taking advantage of water’s ubiquitous presence almost everywhere on the Earth. These would produce usable electricity from processes of evaporation, condensation, rainfall, moisture, and even minute flows of water at the scale of a droplet falling off a leaf, and the very tiniest of waves.

    Proposed technologies along these lines take advantage of various physical phenomena, including the piezoelectric effect (whereby electric charge accumulates in response to the application of stress or pressure), triboelectricity (in which certain materials become electrically charged after they are separated from a different material with which they had been in contact), thermoelectricity (the conversion of heat to electricity and vice versa), and the hydrovoltaic effect (in which electricity is generated via interaction between water and nanomaterials).

    “Water is everywhere. It is ambiently available like no other entity. So all this clean energy is just sitting there, unused and waiting for us to take advantage of it,” said Zuankai Wang, paper author of the review and researcher with the Department of Mechanical Engineering at the City University of Hong Kong. “It makes sense for us to tap into this vast reservoir of energy not just for bulk electricity production, but for a range of applications such as sensors and wearable devices where a micro-scale of energy harvesting is much more appropriate to the use it is being put to.”

    Much of the work in the development of such distributed water-energy technologies remains very much in its infancy however. Many of these lab-bench concepts for distributed water-energy harvesting techniques suffer from poor durability, poor scalability and, worst of all, low energy conversion. This latter problem means that for all the effort put into harvesting energy out of such processes, not much is squeezed out.

    The development of generators that are driven by water vapor in the air for example uses materials that so far exhibit poor capacity for water adsorption (adhesion to the surface), resulting in incomplete interaction between the water and the material, producing low electrical output, and declining even more in the face of harsh environments.

    “And yet the rest of nature has figured out thousands of different ways to do exactly this,” added Wang. “Evolution has basically perfected the process of extracting energy from ambient hydrologic processes in ways that are extremely efficient.”

    The lotus leaf for example at the micro and nano scale enjoys an extreme hydrophobic structure that allows droplets of water to roll across its surface with extremely low resistance—essentially on a cushion of air.  This phenomenon has inspired engineers to study textured superhydrophobic surfaces. The asymmetric 3D ratchets of the Araucaria leaf causes liquids with varying surface tensions to flow in different directions. And the ability of nepenthes, the group of carnivorous plants also known as pitcher plants, to direct liquid through its surface structure, inspired the authors of the review paper to develop a ‘slippery liquid-infused porous surface’ (SLIPS) system that can repel liquid extremely efficiently. A water-energy generator with durable SLIPS allows for constant electrical output from droplets in harsh environments with high humidity, high concentrations of salt, and even ultralow temperature.

    And it’s not just plants. As water-driven electricity generators are well suited for harvesting energy from human motion due to their deformability and compact size, another group of researchers inspired by electric eel membranes developed artificial electric organs making use of hydrogel arrays (highly absorbent polymers that do not dissolve in water) that work as analogues of the eel membrane components.

    Despite the explosion in development of such bio-inspired engineering, or ‘bionics’, for water-energy harvesting, the current generation of water-driven electricity generators remains largely ad hoc. The researchers felt that a comprehensive review of the field was urgently needed to place it on a firmer theoretical foundation and identify research gaps in order to better guide design of systems and development of novel materials.

    The review covers the main mechanisms of electricity production for bio-inspired water-driven generators. It also offers a tour d’horizon of the various bio-inspired devices that have been developed, specifically evaporation, moisture, rainwater, and wave and flow-driven generators, covering three use cases: sensors, wearable electricity generators, and self-powered electronics.

    The researchers concluded that the underlying structures of water-driven electricity generation remains undertheorized, in particular that of charge transport and transfer, as well as of energy conversion. Most notably, there is no general theory of charge transfer at the interface of solid materials and water, and proposed mechanisms for this remain hotly debated.

    In addition, liquid residues on solid surfaces can significantly reduce electrical output, and so how to avoid or reduce such residues is one of the most vital avenues of research for the field. Most efforts have focussed on textural microstructures in materials that produces a super-hydrophobic surface in order to achieve an incomplete contact between liquid and solid. While this produces the desired water residue reduction, it also inevitably limits the solid-liquid contact area, reducing charge induction and thus lowering electrical output, producing the same result as a residue.

    In other areas, improving the ability to absorb water from the environment will be key to improving electricity generation. The researchers recommended that a greater focus be applied to the study of organisms that have evolved over a long period of time in extremely arid areas, such as deserts.

    Finally, the authors noted that much of the design of bio-inspired water-driven electricity generators remains at the lab-bench stage, with such devices confronting only a fairly mild experimental setting rather than the rough and tumble of real-world conditions.

    The life-span of these technologies even in the laboratory only survive a few days or at most a few months. This compares poorly to roughly 25-year life-span of a solar panel or the half-century or longer of a nuclear plant or hydro dam. There may be use cases, perhaps in medical applications, where a short lifespan poses few problems or is even desirable, but for wider adoption of the technology, such unsatisfactory lifespans will need to be overcome.

     

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    About Nano Research Energy 

    Nano Research Energy is launched by Tsinghua University Press, aiming at being an international, open-access and interdisciplinary journal. We will publish research on cutting-edge advanced nanomaterials and nanotechnology for energy. It is dedicated to exploring various aspects of energy-related research that utilizes nanomaterials and nanotechnology, including but not limited to energy generation, conversion, storage, conservation, clean energy, etc. Nano Research Energy will publish four types of manuscripts, that is, Communications, Research Articles, Reviews, and Perspectives in an open-access form.

     

    About SciOpen 

    SciOpen is a professional open access resource for discovery of scientific and technical content published by the Tsinghua University Press and its publishing partners, providing the scholarly publishing community with innovative technology and market-leading capabilities. SciOpen provides end-to-end services across manuscript submission, peer review, content hosting, analytics, and identity management and expert advice to ensure each journal’s development by offering a range of options across all functions as Journal Layout, Production Services, Editorial Services, Marketing and Promotions, Online Functionality, etc. By digitalizing the publishing process, SciOpen widens the reach, deepens the impact, and accelerates the exchange of ideas.

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    Tsinghua University Press

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  • Fathoming the hidden heatwaves that threaten coral reefs

    Fathoming the hidden heatwaves that threaten coral reefs

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    Newswise —   In April to May 2019, the coral reefs near the French Polynesian island of Moorea in the central South Pacific Ocean suffered severe and prolonged thermal bleaching. The catastrophe occurred despite the absence of El Niño conditions that year, intriguing ocean scientists around the world.

        An international research team led by Prof. Alex WYATT of the Department of Ocean Science at The Hong Kong University of Science and Technology, has investigated this surprising and paradoxical coral bleaching episode. The unexpected event was related to the passage of anti-cyclonic eddies that elevated sea levels and concentrated hot water over the reef, leading to an underwater marine heatwave that was largely hidden from view at the surface. The findings have recently been published in Nature Communications.  

        Most studies of coral bleaching patterns rely on sea-surface measures of water temperatures, which cannot capture the full picture of threats from ocean heating to marine ecosystems, including tropical coral reefs. These surface measurements conducted over broad areas with satellites are valuable, yet are unable to detect heating below the surface that influences communities living in waters deeper that the shallowest few metres of the ocean.

        Prof. Wyatt and colleagues analyzed data collected at Moorea over 15 years from 2005 to 2019, taking advantage of a rare combination of remotely sensed sea-surface temperatures and high-resolution, long-term in-situ temperatures and sea level anomalies. Results showed that the passage of anti-cyclonic eddies in the open ocean past the island raised sea levels and pushed internal waves down into deeper water. Internal waves travel along the interface between the warm surface layer of the ocean and cooler layers below, and, in a previous study also led by Prof. Wyatt, have been shown to provide frequent cooling of coral reef habitats. The present research shows that, as a result of the anti-cyclones, internal wave cooling was shut down in early 2019, as well as during some earlier heatwaves.  This led to unexpected heating over the reef, which in turn caused large-scale coral bleaching and subsequent mortality. Unfortunately for local reef biodiversity, the extensive coral death in 2019 has offset the recovery of coral communities that had been occurring around Moorea for the last decade.

        A notable observation, in contrast to the 2019 heatwave, was that the reefs in Moorea did not undergo significant bleaching mortality in 2016, despite the prevailing super El Niño that brought warm conditions and decimated many shallow reefs worldwide. The new research demonstrates the importance of collecting temperature data across the range of depths that coral reefs occupy because the capacity to predict coral bleaching can be lost with a focus only on surface conditions. Sea-surface temperature data would predict moderate bleaching in both 2016 and 2019 at Moorea. However, direct observations showed that there was only ecologically insignificant bleaching in 2016, with heating that was short in duration and restricted to shallow depths. The severe and prolonged marine heatwave in 2019 would have been overlooked if researchers only had access to sea-surface temperature data, and the resulting catastrophic coral bleaching may have been incorrectly ascribed to causes other than heating.

        “The present study highlights the need to consider environmental dynamics across depths relevant to threatened ecosystems, including those due to the passage of underwater ocean weather events.  This kind of analysis depends on long-term, in situ data measured across ocean depths, but such data is generally lacking,” Prof. Wyatt said.  

        “Our paper provides a valuable mechanistic example for assessing the future of coastal ecosystems in the context of changing ocean dynamics and climates.”

        This HKUST-led research was conducted in collaboration with a team of scientists from Scripps Institution of Oceanography at the University of California San Diego, the University of California Santa Barbara, California State University, Northbridge, and Florida State University. The data underlying this study were made possible by coupled long-term physical and ecological observations conducted at the Moorea Coral Reef Long-Term Ecological Research (LTER) site. The long-term analyses conducted here, and the concurrent monitoring of physical conditions and biological dynamics across the full range of depths of island and coastal marine communities, is a model for future research that aims to protect vulnerable living resources in the ocean. 

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    Hong Kong University of Science and Technology

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  • Nanoplastics unexpectedly produce reactive oxidizing species when exposed to light

    Nanoplastics unexpectedly produce reactive oxidizing species when exposed to light

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    Newswise — Plastics are ubiquitous in our society, found in packaging and bottles as well as making up more than 18% of solid waste in landfills. Many of these plastics also make their way into the oceans, where they take up to hundreds of years to break down into pieces that can harm wildlife and the aquatic ecosystem.

    A team of researchers, led by Young-Shin Jun, professor of energy, environmental & chemical engineering in the McKelvey School of Engineering at Washington University in St. Louis, analyzed how light breaks down polystyrene, a nonbiodegradable plastic from which packing peanuts, DVD cases and disposable utensils are made. In addition, they found that nanoplastic particles can play active roles in environmental systems. In particular, when exposed to light, the nanoplastics derived from polystyrene unexpectedly facilitated the oxidation of aqueous manganese ions and formation of manganese oxide solids that can affect the fate and transport of organic contaminants in natural and engineering water systems.

    The research, published in ACS Nano Dec. 27, 2022, showed how the photochemical reaction of nanoplastics through light absorption generates peroxyl and superoxide radicals on nanoplastic surfaces, and initiates oxidation of manganese into manganese oxide solids.

    “As more plastic debris accumulates in the natural environment, there are increasing concerns about its adverse effects,” said Jun, who leads the Environmental Nanochemistry Laboratory. “However, in most cases, we have been concerned about the roles of the physical presence of nanoplastics rather than their active roles as reactants. We found that such small plastic particles that can more easily interact with neighboring substances, such as heavy metals and organic contaminants, and can be more reactive than we previously thought.”

    Jun and her former student, Zhenwei Gao, who earned a doctorate in environmental engineering at WashU in 2022 and is now a postdoctoral scholar at the University of Chicago, experimentally demonstrated that the different surface functional groups on polystyrene nanoplastics affected manganese oxidation rates by influencing the generation of the highly reactive radicals, peroxyl and superoxide radicals. The production of these reactive oxygen species from nanoplastics can endanger marine life and human health and potentially affects the mobility of the nanoplastics in the environment via redox reactions, which in turn might negatively impact their environmental remediation.

    The team also looked at the size effects of polystyrene nanoplastics on manganese oxidation, using 30 nanometer, 100 nanometer and 500 nanometer particles. The two larger-sized nanoparticles took longer to oxidize manganese than the smaller particles. Eventually, the nanoplastics will be surrounded by newly formed manganese oxide fibers, which can make them easily aggregated and can change their reactivities and transport.

    “The smaller particle size of the polystyrene nanoplastics may more easily decompose and release organic matter because of their larger surface area,” Jun said. “This dissolved organic matter may quickly produce reactive oxygen species in light and facilitate manganese oxidation.” 

    “This experimental work also provides useful insights into the heterogeneous nucleation and growth of manganese oxide solids on such organic substrates, which benefits our understanding of manganese oxide occurrences in the environment and engineered materials syntheses,” Jun said. “These manganese solids are excellent scavengers of redox-active species and heavy metals, further affecting geochemical element redox cycling, carbon mineralization and biological metabolisms in nature.”

    Jun’s team plans to study the breakdown of diverse common plastic sources that can release nanoplastics and reactive oxidizing species and to investigate their active roles in the oxidation of transition and heavy metal ions in the future.

    Gao Z, Chou P-I, Liu J, Zhu Y, Jun Y-S. Oxidative Roles of Polystyrene-Based Nanoplastics in Inducing Manganese Oxide Formation under Light Illumination. ACS Nano, Dec. 27, 2022. https://doi.org/10.1021/acsnano.2c05803. 

    Funding for this research was partially provided by the National Science Foundation (CHE-1905077) and the McDonnell International Scholars Academy at Washington University in St. Louis.

    The McKelvey School of Engineering at Washington University in St. Louis promotes independent inquiry and education with an emphasis on scientific excellence, innovation and collaboration without boundaries. McKelvey Engineering has top-ranked research and graduate programs across departments, particularly in biomedical engineering, environmental engineering and computing, and has one of the most selective undergraduate programs in the country. With 165 full-time faculty, 1,420 undergraduate students, 1,614 graduate students and 21,000 living alumni, we are working to solve some of society’s greatest challenges; to prepare students to become leaders and innovate throughout their careers; and to be a catalyst of economic development for the St. Louis region and beyond.

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  • Nature conservation needs to incorporate the human approach

    Nature conservation needs to incorporate the human approach

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    Newswise — An international study led by the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) stresses the need to apply a biocultural approach in nature conservation programs.

    When deciding which aspects of nature to protect, conservationists have largely relied on ecological criteria that define the vulnerability and resilience of species. However, there is a growing call to broaden conservation criteria to include human aspects as well.

    A new article led by ICREA Professor at ICTA-UAB Victoria Reyes-García and published in the journal Proceedings of the National Academy of Science (PNAS) argues that new biocultural approaches are needed to introduce means to connect humans and other components of nature in order to achieve nature stewardship.

    “The focus on ecological criteria alone has failed to halt our biodiversity crisis,” says Victoria Reyes-García, who explains that “this has also created unintended injustices on Indigenous peoples and local communities worldwide.

    According to the researchers, the purely ecological approach, sans humans, risks perpetuating existing inequalities. For example, while proposals to safeguard 30-50% of the planet against extraction or development is sound conservation math, such proposals “face opposition”, on the grounds that they might increase the negative social impacts of conservation actions and pose immediate risks for people whose livelihoods directly depend on nature”, they say.

    “Conservation is designed to reduce or remove human impacts on species to give some breathing room to those species to recover,” noted Ben Halpern, coauthor on the study and Director of UC Santa Barbara’s National Center for Ecological Analysis & Synthesis (NCEAS). “However, if taking those actions limits opportunities for people to engage with the species that define their culture and their values, the conservation will have no sticking power and can actually harm those cultures and people.”

    To help implement this biocultural approach, the research team compiled the most comprehensive list thus far of culturally important species: 385 wild species (mostly plants) that have a recognized role in supporting cultural identity, as they are generally the basis for religious, spiritual and social cohesion, and provide a common sense of place, purpose and belonging.

    The list of species is part of a proposed framework and metric — a “biocultural status” — that combines information on the biological as well as the cultural conservation status of different components of nature.

    “We realized that prevailing classifications based on how vulnerable species are did not consider any of their cultural importance to people,” says Sandra Díaz, a researcher at CONICET and the National University of Córdoba. “Without the acknowledgement and protection of local, special relationships to nature that sustain some populations — often Indigenous — we risk losing an important dimension of conservation,” she adds.

    “When the human cultures that use and value an animal or plant species are lost, a whole body of values, of knowledge about that species is lost too, even if the organism itself does not go extinct. Our relationship with the natural world becomes impoverished,” notes Diaz.

    Conversely, according to the authors, recognizing the connections between people and nature and incorporating them into decision-making could enable actions based on both ecological conservation priorities and cultural values, while aligning with local priorities. The study’s focus on culturally important species could pave the way for mechanisms to enable the adoption of biocultural approaches, which has so far proven difficult.

    The paper comes at a timely moment, as the Convention on Biological Diversity prepares for the next set of biodiversity goals such as the post-2020 Global Biodiversity Framework.

    “As the conservation community increasingly seeks to include diverse worldviews, knowledge and values in nature management and restoration, the framework and metric proposed here offer a concrete mechanism that combines local perspectives on which species are culturally important, with scientific assessments of the biological and cultural status of those species,” Reyes-García says. “Together, they provide an actionable way to guide decisions and operationalize global actions oriented to enhance place-based practices, such as those of Indigenous people, that have supported the conservation of social-ecological systems over the long term.” To sustain culturally important species, according to the authors, society will need a more complete list of these species’ conservation status, and ultimately, direct greater support to the cultures that value them.

    According to co-author Rodrigo Cámara-Leret of the University of Zurich, one of the most important messages in this study is that conservation assessments have largely overlooked species that matter to local cultures, underscoring a big communication gap between local people and the academic community, and even between the natural and social sciences.

    “To close this communication gap and foster more equitable conservation, we need to promote more long-term engagement with local communities to develop and maintain truly collaborative conservation partnerships,” he says. “For this to happen, there are growing calls for academic institutions to recalibrate how they judge impact, and for donor agencies to step up to the challenge of supporting longer research projects that take time, but which are highly effective in knowledge generation and promoting biocultural conservation.”

    ICTA-UABs strategic research program, promoted within the framework of the María de Maeztu Unit of Excellence 2020-2023, granted by the Spanish Ministry of Science and Innovation, is structured around 5 interrelated Societal Challenges, focused on Oceans. Land. Cities, Consumption and Policies. Investigating these Societal Challenges is critical to envision a transition towards a sustainable Earth. This research is part of the Societal Challenges Land and Policy.

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  • How climate change impacts the Indian Ocean dipole, leading to severe droughts and floods

    How climate change impacts the Indian Ocean dipole, leading to severe droughts and floods

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    Newswise — PROVIDENCE, R.I. [Brown University] — With a new analysis of long-term climate data, researchers say they now have a much better understanding of how climate change can impact and cause sea water temperatures on one side of the Indian Ocean to be so much warmer or cooler than the temperatures on the other — a phenomenon that can lead to sometimes deadly weather-related events like megadroughts in East Africa and severe flooding in Indonesia.

    The analysis, described in a new study in Science Advances by an international team of scientists led by researchers from Brown University, compares 10,000 years of past climate conditions reconstructed from different sets of geological records to simulations from an advanced climate model.

    The findings show that about 18,000 to 15,000 years ago, as a result of melted freshwater from the massive glacier that once covered much of North America pouring into the North Atlantic, ocean currents that kept the Atlantic Ocean warm weakened, setting off a chain of events in response. The weakening of the system ultimately led to the strengthening of an atmospheric loop in the Indian Ocean that keeps warmer water on one side and cooler water on the other.

    This extreme weather pattern, known as a dipole, prompts one side (either east or west) to have higher-than-average rainfall and the other to have widespread drought. The researchers saw examples of this pattern in both the historical data they studied and the model’s simulation. They say the findings can help scientists not only better understand the mechanisms behind the east-west dipole in the Indian Ocean, but can one day help to produce more effective forecasts of drought and flood in the region.

    “We know that in the present-day gradients in the temperature of the Indian Ocean are important to rainfall and drought patterns, especially in East Africa, but it’s been challenging to show that those gradients change on long time-scales and to link them to long-term rainfall and drought patterns on both sides of the Indian Ocean,” said James Russell, a study author and professor of Earth, environmental, and planetary sciences at Brown. “We now have a mechanistic basis to understand why some of the longer-term changes in rainfall patterns in the two regions have changed through time.”

    In the paper, the researchers explain the mechanisms behind how the Indian Ocean dipole they studied formed and the weather-related events it led to during the period they looked at, which covered the end of the last Ice Age and the start of the current geological epoch.

    The researchers characterize the dipole as an east-west dipole where the water on the western side — which borders modern day East African countries like Kenya, Ethiopia and Somalia — is cooler than the water on eastern side toward Indonesia. They saw that the warmer water conditions of the dipole brought greater rainfall to Indonesia, while the cooler water brought much drier weather to East Africa.

    That fits into what is often seen in recent Indian Ocean dipole events. In October, for example, heavy rain led to floods and landslides in Indonesian islands of Java and Sulawesi, leaving four people dead and impacting over 30,000 people. On the opposite end, Ethiopia, Kenya and Somalia experienced intense droughts starting in 2020 that threatened to cause famine.

    The changes the authors observed 17,000 years ago were even more extreme, including the complete drying of Lake Victoria — one of the largest lakes on Earth.

    “Essentially, the dipole intensifies dry conditions and wet conditions that could result in extreme events like multi-year or decades-long dry events in East Africa and flooding events in South Indonesia,” said Xiaojing Du, a Voss postdoctoral researcher in the Institute at Brown for Environment and Society and Brown’s Department of Earth, Environmental and Planetary Sciences, and the study’s lead author. “These are events that impact people’s lives and also agriculture in those regions. Understanding the dipole can help us better predict and better prepare for future climate change.”

    The dipole the researchers studied formed from the interactions between the heat transport system of the Atlantic Ocean and an atmospheric loop, called a Walker Circulation, in the tropical Indian Ocean. The lower part of the atmospheric loop flows east to west across much of the region at low altitudes near the ocean surface, and the upper part flows west to east at higher altitudes. The higher air and lower air connect in one big loop.

    Interruption and weakening of the Atlantic Ocean heat transport, which works like a conveyor belt made of ocean and wind currents, was brought on by massive melting of the Laurentide ice sheet that once covered most of Canada and the northern U.S. The melting cooled the Atlantic and consequent wind anomalies triggered the atmospheric loop over the tropical Indian Ocean to become more active and extreme. That then led to increased precipitation in the east side of the Indian Ocean (where Indonesia sits) and reduced precipitation in the west side, where East Africa sits.

    The researchers also show that during the period they studied, this effect was amplified by a lower sea level and the exposure of nearby continental shelves.

    The scientists say more research is needed to figure out exactly what effect the exposed continental shelf and lower sea level has on the Indian Ocean’s east-west dipole, but they’re already planning to expand the work to investigate the question. While this line of the work on lower sea levels won’t play into modeling future conditions, the work they’ve done investigating how the melting of ancient glaciers impacts the Indian Ocean dipole and the heat transport system of the Atlantic Ocean may provide key insights into future changes as climate change brings about more melting.

    “Greenland is currently melting so fast that it’s discharging a lot of freshwater into the North Atlantic Ocean in ways that are impacting the ocean circulation,” Russell said. “The work done here has provided a new understanding of how changes in the Atlantic Ocean circulation can impact Indian Ocean climate and through that rainfall in Africa and Indonesia.”

    The study was supported with funding from the Institute at Brown for Environment and Society and the National Science Foundation.

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  • How do tidal marshes store carbon?

    How do tidal marshes store carbon?

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    Newswise — January 2, 2023 – Tidal marshes are wetlands that are covered with incoming tidal water twice a day. These marshes may be as small as narrow fringe along a tidal creek or miles across in estuaries with adjacent flat landscapes. There are nearly 40 million acres of tidal marshes along the Atlantic, Gulf, and Pacific shores of the US. The Soil Science Society of America’s (SSSA) January 1st Soils Matter blog explores how tidal marshes store carbon and why they are an important part of surrounding landscapes.

    Tidal marshes are also common in many estuaries such as the Chesapeake Bay and along rivers that enter these coastal estuaries. Tidal marshes are some of the most productive ecosystems on the planet. They are an important part of the landscapes because they provide flood protection, erosion control, wildlife food & habitat, water quality support, and many other benefits.

    Comparative to forest soils (that hold about 65% of the carbon held in a forest, with the rest of the carbon stored in plant life), tidal marshes store 3 to 5 times that amount in the soil.

    But why do tidal marshes store so much more carbon?

    According to Dr. Mark Stolt of University of Rhode Island, there are two major factors – the plant life, and the soil conditions.

    Marsh grasses and shrubs are drenched with full sunlight and the soils are rich in nutrients. This results in prolific plant growth above the ground. There is also growth below the ground in the form of roots and rhizomes. Marsh plants thrive in saturated conditions.

    Tidal waters that flood marshes bring in organic matter via sediment that is suspended in the flooding waters. That carbon-rich sediment is trapped by the marsh grasses. It settles to the bottom becoming part of the marsh peat.

    With twice-daily flooding, the soils are constantly under water, or saturated. Because the soil is under water, soil microbial activity is inhibited by the limited amount of oxygen. Without oxygen, soil microbes can’t decompose organic matter as well as oxygen-rich environments. This is the big reason why tidal marshes can accumulate much more carbon than forest soils.

    To read the entire blog please visit: https://soilsmatter.wordpress.com/2023/01/01/how-do-tidal-marshes-store-carbon/

    Follow SSSA on Facebook at https://www.facebook.com/SSSA.soils, Twitter at SSSA_Soils. SSSA has soils information on www.soils.org/discover-soils, for teachers at www.soils4teachers.org, and for students through 12th grade, www.soils4kids.org.

    The Soil Science Society of America (SSSA) is a progressive international scientific society that fosters the transfer of knowledge and practices to sustain global soils. Based in Madison, WI, and founded in 1936, SSSA is the professional home for 6,000+ members and 1,000+ certified professionals dedicated to advancing the field of soil science. The Society provides information about soils in relation to crop production, environmental quality, ecosystem sustainability, bioremediation, waste management, recycling, and wise land use.

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    American Society of Agronomy (ASA), Crop Science Society of America (CSSA), Soil Science Society of America (SSSA)

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  • Scientists Study How Dragonflies Catch Prey in Midair

    Scientists Study How Dragonflies Catch Prey in Midair

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    Newswise — Despite their small size, dragonflies are arguably one of the most impressive predators in the animal kingdom. According to Rachel Crane, a biologist at the University of California Davis, dragonflies often catch up to 95% of the prey they go after, a rate she describes as “wildly high compared to where most predators are.” 

    More incredible still, this prey capture all happens in midair. “Dragonflies are doing these really, really fast, high-speed aerial captures,” says Crane. 

    This ability of dragonflies to successfully intercept airborne prey—a skill many human-designed robots have yet to master—is what drew Crane and her colleagues to study them. The scientists designed a novel method to test how dragonflies adjust to aerial challenges, like catching prey that speed up unpredictably or zig-zag through the air. Crane will present their study results at the January 2023 meeting of the Society for Integrative and Comparative Biology.

    To study dragonfly flight, Crane’s team first designed a programmable pulley system that controls the movements of a bead on a string. Dragonflies are such voracious predators that they will readily attack most small objects flying through the air, even if the object is a tiny bead rather than a tasty fly. The bead’s velocity and acceleration can be set by the researchers simply by adjusting the controls, and the bead’s path can be changed by moving the string. 

    “You can make a circular track,” explains Crane, “but you can also pull that out of shape in any direction that you want, and all of a sudden, your bead is doing these really complex paths.”

    The scientists tested out their new dragonfly playground using blue dashers, a dragonfly species common throughout much of North America. They started with a relatively simple task: fly the bead in a straight line at constant velocity and record the dragonfly’s attack with a high-speed camera. They ran this test repeatedly at different bead velocities to see how dragonflies adjust their own speed in response to that of their prey. 

    Crane’s team found that regardless of how fast or slow the bead went, the dragonflies always flew about exactly one meter per second faster than the bead. This speed-matching behavior is similar to what scientists had previously observed dragonflies do while hunting insects. 

    “We’re seeing a similar thing with the beads that we would see with live prey, which is very exciting and reassuring,” says Crane.

    The next step is to examine the dragonflies’ flight patterns in more challenging scenarios, like when prey suddenly speed up or slow down, or change directions unpredictably. These tests could help scientists understand what strategies are most useful for accurately intercepting flying objects. 

    “We can see where they’re succeeding, how they’re succeeding, and how they’re failing,” says Crane, “and that can be helpful for 3D robotics challenges.”

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  • Pollution-fighting superpowers of a common roadside weed

    Pollution-fighting superpowers of a common roadside weed

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    Newswise — Plants are famous for their ability to store carbon, but that’s far from their only superpower when it comes to cleaning up the environment. Scientists have increasingly turned towards plants to help detoxify soils in areas rife with chemical contaminants. Some plants can even suck up heavy metals like lead and mercury and transfer them to their leaves, which are easy to harvest and dispose of safely. 

    This plant-based cleanup strategy, called phytoremediation, relies on finding plants that can grow quickly and easily and also have the ability to extract specific pollutants from the soil. Patrick Wright and Janet Steven, plant biologists at Christopher Newport University, recently identified horseweed as a potential candidate for the phytoremediation of heavy metals. Wright will present their research findings at the January 2023 meeting of the Society for Integrative and Comparative Biology.

    Horseweed is a common sight on roadsides and parking lots, and yet Wright never thought much about it until he was out surveying Superfund sites, which are areas contaminated with hazardous waste. “We just kind of stumbled upon this plant,” he says. 

    During the surveys, Wright carried a special handheld device that uses X-rays to measure the presence and concentrations of heavy metals. After pointing the X-ray device at the leaves of various plants, he noticed that the horseweed growing in Superfund sites had extremely high concentrations of heavy metals. 

    Based on this observation, Wright suspected that horseweed might have the metal-accumulation ability needed for phytoremediation. To test this ability, he grew horseweed plants in the lab, giving some of them clean water and others water contaminated with high concentrations of either lead, barium, zinc, copper, or chromium. Then he measured the plants’ growth and the amount of each metal that the plants accumulated in their leaves.

    Wright found that the horseweed plants were able to efficiently extract and store each of the five heavy metals. The plants grown in zinc-laden water had the most impressive results. “I saw that they accumulate a lot,” says Wright, “almost 1000 times the normal level of zinc.”

    And while plants that were watered with heavy metal solutions did grow less over the eight-week experiment than those with unpolluted water, they still grew substantially.

    The combination of its rapid growth, stress tolerance, and ability to accumulate a range of heavy metals makes horseweed an ideal candidate for phytoremediation. And Wright also points out that since horseweed is native to most of North and Central America, it can be grown throughout the region without fear of spreading a potentially invasive species. 

    Wright hopes that by sharing these findings, he will encourage more research into phytoremediation and more widespread use of this method for cleaning up pollution. “I want to continue pushing for phytoremediation,” he says, “but make sure we’re doing it in a very logical way.”

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  • Birds are Jerks Sometimes: how a Mother’s Quest to Defend her Eggs Against Invaders Influences Offspring Development

    Birds are Jerks Sometimes: how a Mother’s Quest to Defend her Eggs Against Invaders Influences Offspring Development

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    Newswise — The way people behave is influenced by processes such as mood, personality, and (curiously) our social context–it is much easier to find angry people waiting in line at the bank than cycling on Sunday afternoons. However, can the social context of parents affect the behavior of their future children? 

    Leigh Bailey, an M.S. student working with Assistant Professor Alexandra Bentz  at the University of Oklahoma, is interested in the influence that the social environment of female birds has on their offspring’s early development. 

    Tree swallows are a type of migratory bird found throughout North America. When nesting, they return to their favorite breeding grounds to find resources for their future offspring. If resources are scarce, swallows spend most of their time brawling with other birds to defend their territory. 

    The extent to which a bird acts aggressively partly hinges on its genetic makeup, similar to how some people are innately more abrasive, and others empathetic. This is information encoded in an animal’s genes since the moment they are conceived. However, other kinds of information that are not genetically encoded can also have a tremendous impact on behavior.  

    One example are sex hormones such as testosterone (T), a hormone typically associated with men’s sexual development and behavior that is also produced by females and across many species, including tree swallows. “There are two sources of testosterone,” Bailey explains; “circulatory T produced by the offspring later in development, and maternal T deposited by the mother into its eggs before they are laid.” Hormones that ‘come with the package’ communicate specific information about the environment that offspring are about to face. The influence that this information has on offspring development is referred to as a ‘maternal effect’.

    Bailey and colleagues decided to investigate maternal effects in the wild: they divided tree swallows in different groups and either gave them few or many nesting sites, a critical resource during breeding season. “We knew that swallows were territorial, so we exploited this to ramp up aggression and test how maternal T affects the offspring.” 

    Bailey’s preliminary data shows that mothers in groups with few nests behave more aggressively. Based on previous work by her group, she expects this will increase how much maternal T they allocate to their eggs. With heightened levels of maternal T, past studies showed that bird offspring grow faster, demand more food, and act more aggressively, all important traits for surviving in a competitive environment. 

    This work will allow us to understand how maternal effects prepare birds to survive in adverse conditions, but it also highlights the importance of a mother’s environment on the development of her children. “It’s remarkable how quickly these processes happen and have an impact that lasts for the offspring’s entire life.”

    The results of this research project will be presented by Leigh Bailey at SICB 2023 in Austin, TX.

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  • South Asian Black carbon aerosols accelerate loss of glacial mass over the Tibetan plateau

    South Asian Black carbon aerosols accelerate loss of glacial mass over the Tibetan plateau

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    Newswise — Black carbon aerosols are produced by the incomplete combustion of fossil fuels and biomass, and are characterized by strong light absorption. Black carbon deposition in snow/ice reduces the albedo of snow/ice surfaces, which may accelerate the melting of glaciers and snow cover, thus changing the hydrological process and water resources in the region.

    The South Asia region adjacent to the Tibetan Plateau has among the highest levels of black carbon emission in the world. Many studies have emphasized black carbon aerosols from South Asia can be transported across the Himalayan Mountains to the inland region of the Tibetan Plateau.

    Recently, a joint research team led by Prof. KANG Shichang from the Northwest Institute of Eco-Environment and Resources of the Chinese Academy of Sciences (CAS), Prof. CHEN Deliang from the University of Gothenburg, and Prof. Robert Gillies from Utah State University analyzed the influence of black carbon aerosols on regional precipitation and glaciers over the Qinghai-Tibet Plateau.

    Their findings were published in Nature Communications on Nov. 30.

    The researchers found that since the 21st century, South Asian black carbon aerosols have indirectly affected the mass gain of the Tibetan Plateau glaciers by changing long-range water vapor transport from the South Asian monsoon region.

    “Black carbon aerosols in South Asia heat up the middle and upper atmosphere, thus increasing the North­–South temperature gradient,” said Prof. KANG. “Accordingly, the convective activity in South Asia is enhanced, which causes convergence of water vapor in South Asia. Meanwhile, black carbon also increases the number of cloud condensation nuclei in the atmosphere.”

    These changes in meteorological conditions caused by black carbon aerosols make more water vapor form precipitation in South Asia, and the northward transport to the Tibetan Plateau was weakened. As a result, precipitation in the central and the southern Tibetan Plateau decreases during the monsoon, especially in the southern Tibetan Plateau.

    The decrease in precipitation further leads to a decrease of mass gain of glaciers. From 2007 to 2016, the reduced mass gain by precipitation decrease accounted for 11.0% of the average glacier mass loss on the Tibetan Plateau and 22.1% in the Himalayas.

    “The transboundary transport and deposition of black carbon aerosols from South Asia accelerate glacier ablation over the Tibetan Plateau. Meanwhile, the reduction of summer precipitation over the Tibetan Plateau will reduce the mass gain of plateau glaciers, which will increase the amount of glacier mass deficit,” said Prof. KANG.

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    Chinese Academy of Sciences

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  • Bering Land Bridge formed surprisingly late during last ice age

    Bering Land Bridge formed surprisingly late during last ice age

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    Newswise — A new study shows that the Bering Land Bridge, the strip of land that once connected Asia to Alaska, emerged far later during the last ice age than previously thought. 

    The unexpected findings shorten the window of time that humans could have first migrated from Asia to the Americas across the Bering Land Bridge. 

    The findings also indicate that there may be a less direct relationship between climate and global ice volume than scientists had thought, casting into doubt some explanations for the chain of events that causes ice age cycles. The study was published on December 27 in the Proceedings of the National Academy of Sciences. 

    “This result came totally out of left field,” said Jesse Farmer, postdoctoral researcher at Princeton University and co-lead author on the study. “As it turns out, our research into sediments from the bottom of the Arctic Ocean told us not only about past climate change but also one of the great migrations in human history.”

    Insight into ice age cycles 

    During the periodic ice ages over Earth’s history, global sea levels drop as more and more of Earth’s water becomes locked up in massive ice sheets. At the end of each ice age, as temperatures increase, ice sheets melt and sea levels rise. These ice age cycles repeat throughout the last 3 million years of Earth’s history, but their causes have been hard to pin down.

    By reconstructing the history of the Arctic Ocean over the last 50,000 years, the researchers revealed that the growth of the ice sheets — and the resulting drop in sea level — occurred surprisingly quickly and much later in the last glacial cycle than previous studies had suggested.

    “One implication is that ice sheets can change more rapidly than previously thought,” Farmer said.

    During the last ice age’s peak of the last ice age, known as the Last Glacial Maximum, the low sea levels exposed a vast land area that extended between Siberia and Alaska known as Beringia, which included the Bering Land Bridge. In its place today is a passage of water known as the Bering Strait, which connects the Pacific and Arctic Oceans.

    Based on records of estimated global temperature and sea level, scientists thought the Bering Land Bridge emerged around 70,000 years ago, long before the Last Glacial Maximum.

    But the new data show that sea levels became low enough for the land bridge to appear only 35,700 years ago. This finding was particularly surprising because global temperatures were relatively stable at the time of the fall in sea level, raising questions about the correlation between temperature, sea level and ice volume.

    “Remarkably, the data suggest that the ice sheets can change in response to more than just global climate,” Farmer said. For example, the change in ice volume may have been the direct result of changes in the intensity of sunlight that struck the ice surface over the summer.

    “These findings appear to poke a hole in our current understanding of how past ice sheets interacted with the rest of the climate system, including the greenhouse effect,” said Daniel Sigman, Dusenbury Professor of Geological and Geophysical Sciences at Princeton University and Farmer’s postdoctoral advisor. “Our next goal is to extend this record further back in time to see if the same tendencies apply to other major ice sheet changes. The scientific community will be hungry for confirmation.”

    New context for human migration

    The timing of human migration into North America from Asia remains unresolved, but genetic studies tell us that ancestral Native American populations diverged from Asian populations about 36,000 years ago, the same time that Farmer and colleagues found that the Bering Land Bridge emerged.

    “It’s generally believed that the land bridge was open for a while, and then humans crossed it at some point,” Sigman said. “But our new data suggest that the land bridge was not open, and as soon as it opened up, human populations made their way into North America.”

    The finding raises questions about why humans decided to migrate as soon as the land bridge opened, and how humans made their way across the land bridge with no previous knowledge of the landscape.

    The researchers noted that they need to be cautious when considering these implications, as the interpretation requires combining very different types of information, including the new data and the information of human geneticists and paleoanthropologists. They look forward to seeing how their results are built upon by these other scientific communities.

    A window to the past

    To reconstruct the history of the Bering Strait, Farmer and Sigman sought an ocean chemical fingerprint.

    Pacific waters carry high concentrations of nitrogen molecules that have a distinct chemical composition, known as an isotope ratio. Today, waters from the Pacific Ocean travel northwards across the Bering Strait into the Arctic Ocean, carrying a traceable nitrogen isotope ratio.

    By measuring nitrogen isotopes in sediments at the bottom of the Arctic Ocean, Farmer found that the fingerprint of Pacific Ocean nitrogen disappeared when the Bering Strait was closed during the peak of the last ice age, as expected.

    But when Farmer continued his analyses further back in time – to about 50,000 years ago – he found that the Pacific nitrogen fingerprint returned far more recently than researchers had thought possible.

    “When Jesse showed me his data, he didn’t need to explain to me what had happened,” Sigman said. “It was too large of a change to be anything other than a previous opening of the Bering Strait.”

    To understand the implications for global sea level, Farmer and Sigman collaborated with Tamara Pico, a sea level expert and professor of Earth and Planetary Sciences at UC Santa Cruz, Princeton undergraduate Class of 2014, and co-lead author on the paper. Pico compared Farmer’s results with sea level models based on different scenarios for the growth of the ice sheets.

    “When Jesse contacted me I was so excited,” Pico said. “A large part of my PhD thesis was focused on how fast global ice sheets grew leading into the Last Glacial Maximum, and much of my work suggests that they might have grown faster than previously thought.”

    Farmer’s nitrogen analyses provided a new set of evidence to back up Pico’s research about sea levels during the last ice age.

    “The exciting thing to me is that this provides a completely independent constraint on global sea level during this time period,” Pico said. “Some of the ice sheet histories that have been proposed differ by quite a lot, and we were able to look at what the predicted sea level would be at the Bering Strait and see which ones are consistent with the nitrogen data.”

    “This study brought together experts in the Arctic Ocean, nitrogen cycling and global sea level. And the outcome has consequences not only for climate and sea level but also for human prehistory,” Farmer said. “One of the thrilling aspects of paleoclimate research is the opportunity to collaborate across such a broad range of subjects.”

    “The Bering Strait was flooded 10,000 years before the Last Glacial Maximum,” by Jesse R. Farmer, Tamara Pico, Ona M. Underwood, Rebecca Cleveland Stout, Julie Granger, Thomas M. Cronin, François Fripiat, Alfredo Martínez-García, Gerald H. Haug, and Daniel M. Sigman appears in the current issue of Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.2206742119). The research was supported by the U.S. National Science Foundation (OCE-2054780 and OCE-2054757), the Tuttle and Phillips Funds of the Department of Geosciences, the Max Planck Society, and the USGS Climate Research and Development Program.

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    Princeton University

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  • Skiing over Christmas holidays no longer guaranteed – even with snow guns

    Skiing over Christmas holidays no longer guaranteed – even with snow guns

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    Newswise — For many people, holidays in the snow are as much a part of the end of the year as Christmas trees and fireworks. As global warming progresses, however, white slopes are becoming increasingly rare. Researchers at the University of Basel have calculated how well one of Switzerland’s largest ski resorts will remain snow reliable with technical snowmaking by the year 2100, and how much water this snow will consume.

    The future for ski sports in Switzerland looks anything but rosy – or rather white. Current climate models predict that there will be more precipitation in winter in the coming decades, but that it will fall as rain instead of snow. Despite this, one investor recently spent several million Swiss francs on expanding the Andermatt-Sedrun-Disentis ski resort. A short-sighted decision they will regret in future?

    A research team led by Dr. Erika Hiltbrunner from the Department of Environmental Sciences at the University of Basel has now calculated the extent to which this ski resort can maintain its economically important Christmas holidays and a ski season of at least 100 days with and without snowmaking. The team collected data on the aspects of the slopes, where and when the snow is produced at the ski resort and with how much water. They then applied the latest climate change scenarios (CH2018) in combination with the SkiSim 2.0 simulation software for projections of snow conditions with and without technical snowmaking. The results of their investigations were recently published in the International Journal of Biometeorology.

    No guarantee of a white Christmas

    According to the results, the use of technical snow can indeed guarantee a 100-day ski season – in the higher parts of the ski resort (at 1,800 meters and above), at least. But business is likely to be tight during the Christmas holidays in coming decades, with the weather often not cold enough at this time and in the weeks before. In the scenario with unabated greenhouse gas emissions, the Sedrun region in particular will no longer be able to offer guaranteed snow over Christmas in the longer term. New snow guns may alleviate the situation to a certain extent, say the researchers, but will not resolve the issue completely.

    “Many people don’t realize that you also need certain weather conditions for snowmaking,” explains Hiltbrunner. “It must not be too warm or too humid, otherwise there will not be enough evaporation cooling for the sprayed water to freeze in the air and come down as snow.” Warm air absorbs more moisture and so, as winters become warmer, it also gets increasingly difficult or impossible to produce snow technically. In other words: “Here, the laws of physics set clear limits for snowmaking.”

    540 million liters

    The skiing will still go on, however, because technical snowmaking at least enables resort operators to keep the higher ski runs open for 100 consecutive days – even up until the end of the century and with climate change continuing unabated. But there is a high price to be paid for this. The researchers’ calculations show that water consumption for snowmaking will increase significantly, by about 80% for the resort as a whole. In an average winter toward the end of the century, consumption would thus amount to about 540 million liters of water, compared with 300 million liters today.

    But this increase in water demand is still relatively moderate compared with other ski resorts, the researchers emphasize. Earlier studies had shown that water consumption for snowmaking in the Scuol ski resort, for example, would increase by a factor of 2.4 to 5, because the area covered with snow there will have to be largely expanded in order to guarantee snow reliability.

    For their analysis, the researchers considered periods of 30 years. However, there are large annual fluctuations: In addition, extreme events are not depicted in the climate scenarios. In the winter of 2017 with low levels of snow, water consumption for snowmaking in one of the three sub-areas of Andermatt-Sedrun-Disentis tripled.

    Conflicts over water use

    Today, some of the water used for snowmaking in the largest sub-area of Andermatt-Sedrun-Disentis comes from the Oberalpsee. A maximum of 200 million liters may be withdrawn annually for this purpose. If climate change continues unabated, this source of water will last until the middle of the century, at which point new sources will have to be exploited. “The Oberalpsee is also used to produce hydroelectric power,” says Dr. Maria Vorkauf, lead author of the study, who now works at the Agroscope research station. “Here, we are likely to see a conflict between the water demands for the ski resort and those for hydropower generation.”

    At first, this ski resort may even benefit from climate change – if lower-lying and smaller ski resorts are obliged to close, tourists will move to larger resorts at higher altitude, one of which is Andermatt-Sedrun-Disentis.

    What is certain is that increased snowmaking will drive up costs and thus also the price of ski holidays. “Sooner or later, people with average incomes will simply no longer be able to afford them,” says Hiltbrunner.

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    University of Basel

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  • Slime for the climate, delivered by brown algae

    Slime for the climate, delivered by brown algae

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    Newswise — Brown algae are true wonder plants when it comes to absorbing carbon dioxide from the air. They even outcompete forests on land in this, and thus play a decisive role for the atmosphere and our climate. But what happens to the carbon dioxide after the algae have absorbed it? Researchers at the Max Planck Institute for Marine Microbiology now report in the Proceedings of the National Academy of Sciences (PNAS) that the brown algae can remove large amounts of carbon dioxide from the global cycle in the long term and thus can counteract global warming.

    Fucoidan: Brown algae slime is not a favourite dish

    Algae take up carbon dioxide from the atmosphere and use the carbon to grow. They release up to a third of the carbon they absorb back into the seawater, for example in the form of sugary excretions. Depending on the structure of these excretions, they are either quickly used by other organisms or sink towards the seafloor.

    “The excretions of brown algae are very complex and therefore incredibly complicated to measure,” says first author Hagen Buck-Wiese from the Max Planck Institute for Marine Microbiology in Bremen. “However, we have managed to develop a method to analyse them in detail.” With this method, the researchers scrutinised a large number of different substances. The so-called fucoidan turned out to be particularly exciting. “Fucoidan made up about half of the excretions of the brown algae species we studied, the so-called bladderwrack,” says Buck-Wiese. Fucoidan is a recalcitrant molecule. “The fucoidan is so complex that it is very hard for other organisms to use it. No one seems to like it.” As a result, the carbon from the fucoidan does not return to the atmosphere quickly. “This makes the brown algae particularly good helpers in removing carbon dioxide from the atmosphere in the long term – for hundreds to thousands of years.”

    Brown algae could bind almost all of Germany’s carbon dioxide emissions

    Brown algae are remarkably productive. It is estimated that they absorb about 1 gigaton (one billion tons) of carbon per year from the air. Using the results of the present study, this would mean that up to 0.15 gigatons of carbon, equivalent to 0.55 gigatons of carbon dioxide, are sequestered by brown algae each year in the long term. For comparison: Germany’s annual greenhouse gas emissions currently amount to about 0.74 gigatons of carbon dioxide, according to the Federal Environment Agency (Umweltbundesamt, estimation for 2020).

    “And even better: The fucoidan does not contain any nutrients such as nitrogen,” Buck-Wiese explains further. Thus, the growth of the brown algae is not affected by the carbon losses.

    More species and sites

    For the current study, Buck-Wiese and his colleagues from the MARUM MPG Bridge Group Marine Glycobiology, which is based at both the Bremen Max Planck Institute and MARUM – Centre for Marine and Environmental Sciences at the University of Bremen, conducted their experiments at the Tvärminne Zoological Station in southern Finland. “Next we want to look into other brown algae species and other locations,” says Buck-Wiese. “The great potential of brown algae for climate protection definitely needs to be further researched and utilised.”

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    Max Planck Institute for Marine Microbiology

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  • Model analysis of atmospheric observations reveals methane leakage in North China

    Model analysis of atmospheric observations reveals methane leakage in North China

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    1. Background

    Natural gas is a relatively clean burning fossil fuel, that causes less air pollution than coal and is widely used in the world. Recent studies have shown that the natural gas leaks from production, supply chain, and end-use facilities are a large source of atmospheric methane (CH4), and the leaking budget is underestimated in many places by bottom-up inventories. CH4 is the second most important greenhouse gas (GHG) contributing to global warming after carbon dioxide (CO2), with a relatively shorter lifetime, making the reduction of CH4 emission a suitable target for implementing rapid and achievable mitigation strategies of the Paris Agreement.

    Over the last decade, natural gas has become the fastest-growing fossil energy source in China due to the coal-to-gas government initiative that has been implemented to reduce air pollution and CO2 emissions. Natural gas consumption has increased dramatically from 108.5 billion standard cubic meters (bcm) (4% of primary energy consumption) in 2010 to a record level of 280 bcm (7.6% of primary energy consumption) in 2018. In addition, according to China’s energy plan, the share of primary energy from gas will keep increasing and is likely to reach 15% by 2030, while coal and oil consumption will decline. From 2010 to 2018, the length of gas supply pipelines in urban areas of China increased approximately three-fold from 298 to 842 thousand kilometers. However, CH4 leakage from those pipelines has not been actively reported, and there is limited publicly available data on upstream emissions and local distribution of natural gas emissions in China.

    2. Research Outline and Results

    In this study, we used nine years (2010–2018) of CH4 observations by the Greenhouse gases Observing SATellite “IBUKI” (GOSAT) and surface station data from the World Data Centre for Greenhouse Gases (WDCGG) to estimate CH4 emissions in different regions of China. GOSAT observes the column-averaged dry-air mole fractions of CH4 in the atmosphere, and the surface stations monitor CH4 concentrations near surface. The observation data were used for simulations by the high-resolution inverse model NTFVAR (NIES-TM-FLEXPART-variational) to infer the surface flux of CH4 emissions. Inverse modelling optimizes prior flux estimates, which are constrained so that an acceptable agreement between the simulated and observed atmospheric concentrations is achieved.

    Figure 1 shows the model-estimated CH4 fluxes in four regions of China. The four regions, North China (NE), South China (SE), North-west China (NW), and the Qinghai-Tibetan Plateau (TP), vary with respect climate, geographical features, types of agriculture, major economic activities, and CH4 emission sources. The model-estimated average CH4 emissions from the four subregions over the period 2010–2018 are 30.0±1.0 (average ± standard deviation) Tg CH4 yr-1 from the SE region, 23.3±2.7 Tg CH4 yr-1 from the NE region, 2.9±0.2 Tg CH4 yr-1 from the NW region, and 1.7±0.1 Tg CH4 yr-1 from the TP region. The trends in CH4 emissions have varied in the different regions of China over the last nine years, with significant increase trends detected in the NE region and the whole China.

    We focused our analysis on the NE region where natural gas production and consumption have increased dramatically and are likely one of the main contributors to the increase estimated in regional total CH4 emissions. The CH4 emissions from natural gas, including leakage from fuel extraction, processing, transport, and the end-use stage, were estimated using an approach that combined data for the province-level emissions inventory and published inverse model studies. The model-estimated total CH4 emissions and the estimated natural gas emissions both increased significantly during 2010–2018 (Figure 2). The total amount of natural gas emissions due to leakages constitutes a significant waste of energy and value. For example, in 2018, natural gas consumption in the NE region was 101.5 bcm and the estimated total natural gas emissions were 3.2%–5.3% of regional consumption.

    Figure 3 shows the changes in estimated CH4 emissions from natural gas and the model-estimated total CH4 emissions for 2010-2018 compared to previous years in the NE region. The year-over-year change in the model-estimated total CH4 emission closely follows the changes in CH4 emissions from natural gas. In January 2016, record cold wave hit the region causing a sudden increase in natural gas use, and natural gas suppliers recorded an increase in natural gas loss (i.e., the difference between the amount of gas purchased and the amount of gas sold). Simultaneously, the atmospheric observations also captured the emission changes, as reflected in our inverse estimates (Figure 3). The analysis shows a strong correlation between trends in natural gas use and the increase in the atmospheric CH4 concentration over the NE region, which is indicative the ability of GOSAT to monitor variations in regional anthropogenic sources.

    3. Future Perspectives

    The findings of our study highlight that the increase in natural gas use threatens China’s carbon reduction efforts. The increase in CH4 leaks from natural gas production and the supply chain will adversely affect the interests of diverse stakeholders, despite the introduction of carbon reduction measures. Given that the large natural gas distribution pipelines span more than 900 thousand kilometers in China, natural gas leaks constitute a significant waste of energy and value. The year-over-year changes in regional emissions and trends were detected by satellite and surface observations in this study. In the future, additional observations using high-resolution satellites will help to more accurately quantify emissions and provide scientific directions for emission reduction measures. There is also a need to further detect and locate such leaks using advanced mobile platforms in order to effectively mitigate CH4 emissions in China and bring about economic, environmental, and health benefits.

    4. Data Availability

    GOSAT data used in this study are available from the GOSAT Data Archive Service https://data2.gosat.nies.go.jp/index_en.html

    In-situ methane observation data are archived on the WDCGG Global Network: https://gaw.kishou.go.jp/

    Emissions Database for Global Atmospheric Research (EDGAR) emission inventories are available for download at

    https://edgar.jrc.ec.europa.eu/

    Global Fire Assimilation System (GFAS) fire emissions Database are from https://www.ecmwf.int/en/forecasts/dataset/global-fire-assimilation-system

    Wetland emission by Vegetation Integrative SImulator for Trace gases (VISIT) model are available at

    https://www.nies.go.jp/doi/10.17595/20210521.001-e.html

    The NIES airborne and Japan-Russia Siberian Tall Tower Inland Observation network (JR STATION) data are available at

    https://db.cger.nies.go.jp/ged/en/index.html

    The Japanese 55-year Reanalysis (JRA-55) data from the Japanese Meteorological Agency (JMA) are available at

    https://search.diasjp.net/en/dataset/JRA55

    5. Supplementary Information

    ○ Greenhouse gases Observing SATellite “IBUKI” (GOSAT)

    The Greenhouse Gases Observing Satellite “IBUKI” (GOSAT) is the world’s first spacecraft to monitor the concentrations of the two major GHGs CO2 and CH4 from space. NIES has promoted the GOSAT series projects for GHG observation from space, together with the Ministry of the Environment, Japan (MOE) and the Japan Aerospace Exploration Agency (JAXA). GOSAT (IBUKI) is the first satellite in the series and has been observing column-averaged concentrations of CO2 and CH4 for more than 13 years since its launch in 2009. The second satellite, GOSAT-2 (IBUKI-2) was launched in 2018 and started observing carbon monoxide in addition to CO2 and CH4. Furthermore, the third satellite, Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW) is under development and due for launch in Japanese fiscal year 2023.

    ○ Lifetime of methane in the atmosphere

    Methane is the second most important well-mixed GHG contributing to human-induced climate change after CO2. The lifetime of CH4 in the atmosphere refers to the time that CH4 stays in the air after being emitted from a variety of sources. CH4 is removed from the atmosphere mostly by chemical reactions. The atmospheric lifetime of CH4 is 10 ± 2 years, which is relatively shorter than that of CO2 (approximately 5 to 200 years) (IPCC, 2013).

    ○ Methane emission sources

    Methane is emitted from a variety of anthropogenic and natural sources. Approximately 60% of all CH4 emissions come from anthropogenic sources, such as agricultural activities, waste treatment, oil and natural gas systems, coal mining, stationary and mobile combustion, and certain industrial processes. Natural emissions include wetlands, freshwater bodies such as lakes and rivers, and geological sources such as terrestrial and marine seeps and volcanoes. Other smaller sources include ruminant wild animals, termites, hydrates and permafrost.

    ○ Underestimation of methane emissions from oil and gas using bottom-up inventories

    Methane can leak into the atmosphere from upstream/downstream natural gas operations (i.e., extraction and gathering, processing, transmission and storage, and distribution) and end-use combustion. Atmospheric measurement studies have shown that a large amount of CH4 emissions from oil and gas production are unaccounted for in bottom-up inventories. Using high-resolution satellite observations, Zhang et al. (2020) estimated a leakage equivalent to 3.7% (~60% higher than the national average leakage rate) of all the gas extracted from the largest oil-producing basin in the United States. Chan et al. (2020) reported eight-year estimates of CH4 emissions from oil and gas operations in western Canada and found that they were nearly twice that from inventories. Weller et al. (2020) used an advanced mobile leak detection (AMLD) platform combined with GIS information of utility pipelines to estimate CH4 leakage from pipelines of local distribution systems in the United States. They found that the leakage from those pipelines was approximately five times greater than that reported in inventories compiled based on self-reported utility leakage data.

    ○ High-resolution inverse model NIES-TM-FLEXPART-variational (NTFVAR)

    Inverse modeling is an important and essential method for estimating GHGs emissions. The model uses atmospheric observation data as a controller in atmospheric models to optimize bottom-up emission inventories (prior fluxes).

    The NIES-TM-FLEXPART-variational (NTFVAR) global inverse model was developed by Dr.Shamil Maksyutov’s group at NIES. NTFVAR is combined with a joint Eulerian three-dimensional transport model, the National Institute for Environmental Studies Transport Model (NIES-TM) v08.1i, and a Lagrangian model, the FLEXPART model v.8.0. The transport model is driven by JRA-55 meteorological data from JMA. The prior fluxes include gridded anthropogenic emissions from the EDGAR database, such as energy, agriculture, waste and other sectors; wetland emissions estimated by the Wetland emission by the VISIT model; biomass burning emissions estimated by GFAS; and climatological emissions from oceanic, geological, and termite sources. The inverse modeling problem is formulated and solved to find the optimal value of corrections to prior fluxes minimizing mismatches between observations and modelled concentrations. Variational optimization is applied to obtain flux corrections to vary prior uncertainty fields at a resolution of 0.1° × 0.1° with bi-weekly time steps. A variational inversion scheme is combined with the high-resolution variant of the transport model and its adjoint described by Maksyutov et al. (2021).

    References:

    Chan, E. et al. Eight-Year Estimates of Methane Emissions from Oil and Gas Operations in Western Canada Are Nearly Twice Those Reported in Inventories. Environmental Science & Technology 54, 14899-14909, doi:10.1021/acs.est.0c04117 (2020).

    IPCC 2013: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. [Stocker, T. F. Q. et al.]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

    Maksyutov, S. et al. Technical note: A high-resolution inverse modelling technique for estimating surface CO2 fluxes based on the NIES-TM – FLEXPART coupled transport model and its adjoint. Atmospheric Chemistry Physics 21, 1245–1266 doi:10.5194/acp-21-1245-2021(2021).

    Weller, Z., Hamburg, S. & von Fischer, J. A National Estimate of Methane Leakage from Pipeline Mains in Natural Gas Local Distribution Systems. Environmental Science & Technology 54, 8958-8967, doi:10.1021/acs.est.0c00437 (2020).

    Zhang, Y. et al. Quantifying methane emissions from the largest oil-producing basin in the United States from space. Science Advances 6, doi:10.1126/sciadv.aaz5120 (2020).

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    National Institute for Environmental Studies

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  • Microplastics deposited on the seafloor triple in 20 years

    Microplastics deposited on the seafloor triple in 20 years

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    Newswise — The total amount of microplastics deposited on the bottom of oceans has tripled in the past two decades with a progression that corresponds to the type and volume of consumption of plastic products by society. This is the main conclusion of a study developed by the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) and the Department of the Built Environment of Aalborg University (AAU-BUILD), which provides the first high-resolution reconstruction of microplastic pollution from sediments obtained in the northwestern Mediterranean Sea.

    Despite the seafloor being considered the final sink for microplastics floating on the sea surface, the historical evolution of this pollution source in the sediment compartment, and particularly the sequestration and burial rate of smaller microplastics on the ocean floor, is unknown.

    This new study, published in the journal Environmental Science and Technology (ES&T), shows that microplastics are retained unaltered in marine sediments, and that the microplastic mass sequestered in the seafloor mimics the global plastic production from 1965 to 2016. “Specifically, the results show that, since 2000, the amount of plastic particles deposited on the seafloor has tripled and that, far from decreasing, the accumulation has not stopped growing mimicking the production and global use of these materials,” explains ICTA-UAB researcher Laura Simon-Sánchez.

    Researchers explains that the sediments analysed have remained unaltered on the seafloor since they were deposited decades ago. “This has allowed us to see how, since the 1980s, but especially in the past two decades, the accumulation of polyethylene and polypropylene particles from packaging, bottles and food films has increased, as well as polyester from synthetic fibres in clothing fabrics,” explains Michael Grelaud, ICTA-UAB researcher. The amount of these three types of particles reaches 1.5mg per kilogram of sediment collected, with polypropylene being the most abundant, followed by polyethylene and polyester. Despite awareness campaigns on the need to reduce single-use plastic, data from annual marine sediment records show that we are still far from achieving this. Policies at the global level in this regard could contribute to improving this serious problem.

    Although smaller microplastics are very abundant in the environment, constraints in analytical methods have limited robust evidence on the levels of small microplastics in previous studies targeting marine sediment. In this study they were characterised by applying state-of-the-art imaging to quantify particles down to 11 µm in size.

    The degradation status of the buried particles was investigated, and it was found that, once trapped in the seafloor, they no longer degrade, either due to lack of erosion, oxygen, or light. “The process of fragmentation takes place mostly in the beach sediments, on the sea surface or in the water column. Once deposited, degradation is minimal, so plastics from the 1960s remain on the seabed, leaving the signature of human pollution there,” says Patrizia Ziveri, ICREA professor at ICTA-UAB.

    The investigated sediment core was collected in November 2019, on board the oceanographic vessel Sarmiento de Gamboa, in an expedition that went from Barcelona to the coast of the Ebro Delta, in Tarragona, Spain. The research group selected the western Mediterranean Sea as a study area, in particular the Ebro Delta, because rivers are recognized as hotspots for several pollutants, including microplastics. In addition, the influx of sediment from the Ebro River provides higher sedimentation rates than in the open ocean.

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    Universitat Autonoma de Barcelona

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