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Tag: Climate Science

  • New method of monitoring shore ice could improve public safety

    New method of monitoring shore ice could improve public safety

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    Newswise — Specialized portable radar could serve as an early warning system to reduce risk for humans working on shorefast sea ice, according to a recently published study.

    The researchers suggest that use of portable interferometric radar can quickly reveal small changes that could indicate imminent movement or detachment of the ice, which is important as climate change affects ice behavior. The capability could also be useful for near-coastal navigation.

    “If you want to learn about what makes the shorefast ice go unstable and detach from the coast, we need to be able to detect some early warning signals,” said research assistant professor Andy Mahoney of the University of Alaska Fairbanks Geophysical Institute.

    Shorefast ice—also known as landfast ice—is ice that’s attached to the shore.

    “Satellites give you snapshots that are separated by hours if not days,” he said. “This portable ground-based system can be looking continuously for signs of instability.”

    The research was published in January in the journal Cold Regions Science and Technology. Former UAF graduate student Dyre Oliver Dammann is the lead author. UAF oceanography professor Mark Johnson, Mahoney and Geophysical Institute colleagues Emily Fedders, a graduate student researcher, and research professor Mark Fahnestock are among the seven co-authors.

    Imagery from a portable ground-based radar interferometer can reveal sea ice changes down to the centimeter and millimeter levels. The devices can monitor areas continuously.

    Interferometric radar differs from regular radar in that it compares two different images of an object to identify small changes in the distance to it. By collecting a near-continuous time series of data from a single location, the coast-based interferometric radar can measure the compression or stretching of sea ice before it fails. It also can detect small cracks that might go unnoticed by observers on the ice. 

    Researchers from the UAF Geophysical Institute, the UAF College of Fisheries and Ocean Sciences and institutions in Oregon, New Hampshire, Norway and Japan collected and analyzed several series of measurements in Utqiaġvik, Alaska.

    They used the portable interferometric radar to look for evidence of strain on the ice from wind and sea level change. The radar could detect displacement of as little as 1 centimeter.

    Landfast ice in shallow water depths such as that near Utqiaġvik consists of pans of smooth, floating ice anchored by ridges of deformed ice resting on the seafloor. Winds and currents alone  typically do not dislodge ice grounded in this way. Storm surges or high tides, coupled with onshore winds, can lift the grounded ice and make it more likely to detach. 

    The researchers concluded that processing radar data in near real time can reduce risk to humans on the ice by serving as an early warning system for fracturing, destabilization and break-out events. It could also serve as a warning to vessels navigating near the coast. 

    They also state that seasonal monitoring could aid in long-term strategic decision-making in response to large-scale environmental change. 

    The research is the latest in a continuing effort to better understand the behavior of coastal ice. 

    The aim is to gather interferometric images of a variety of ice interactions: landfast ice interacting with the drifting ice, landfast ice affected by wind and landfast ice during a period of higher sea level due to onshore wind, for example.

    “Through these observations, we can learn a little bit more about how landfast ice responds in these different scenarios,” Fedders said. “The eventual goal would be to incorporate that into a better prediction of land-fast ice stability.”

    Researchers were back in the area last year.

    “We saw some interesting tidal motions during a period when there wasn’t pack ice up against the landfast ice, where a lead was open,” Fedders said. “That was something we hadn’t captured with the radar before.”

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    University of Alaska Fairbanks

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  • New ways to protect food crops from climate change and other disruptions

    New ways to protect food crops from climate change and other disruptions

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    Newswise — “There’s no doubt we can produce enough food for the world’s population – humanity is strategic enough to achieve that. The question is whether – because of war and conflict and corruption and destabilization – we do,” said World Food Programme leader David Beasley in an interview with Time magazine earlier this year.    

    Indeed, projections show that we are not on track to achieve Sustainable Development Goal 2 of Zero Hunger by 2030. As climate and security crises continue to destabilise our food sources, researchers are taking a critical look not just at how we produce food – but at the entire systems behind our food supplies. In this case, the systems behind the seeds that produce our food crops.    

    “Whilst adapting crops to climate change and conserving their variation is essential for food security, these measures are meaningless if farmers do not have access to the seeds,” says crop scientist and food system expert Ola Westengen. Westengen leads the team of researchers from the Norwegian University of Life Sciences (NMBU) who recently reviewed the state of seed systems for small-holder farmers in low/middle income countries. Their findings are now published in the Proceedings of the National Academy of Sciences (PNAS).   

    What are seed systems?    

    Seed systems are the provision, management and distribution of seeds. They cover the entire seed chain, from the conservation of their diversity and variety development, to their production and distribution, and the rules that govern these activities.  In short, they are the structures that make seeds available to farmers so that crops can be sown, harvested and end up on our plates.    

    Whilst a well-functioning seed system will ensure seed security for all farmers, the researchers say that, in practice, it is rarely the case that seed systems function as well as they might. Seed systems can be disrupted by conflict and disasters, as well as by problems stemming from social inequality, lack of coordination or inappropriate policies.      

    What does this study tell us that we don’t already know?   

    “There are recent innovations and investments by governments and donors to improve farmers’ access to diverse crop varieties and quality seeds,” explains Teshome Hunduma, a seed governance researcher and co-author of the study. “For example, there are now more flexible policies and regulations that encourage diversity in the seed systems used by farmers, rather than pushing farmers to switch to commercial seed systems that focus on less diverse commodity crops – which is the norm.” Commodity crops are those grown in large volume and high intensity for the purpose of sale, as opposed to those grown by small-holder farmers for direct processing and consumption.   

    “The study highlights emerging initiatives that are helping farmers to secure food supplies, such as participatory plant breeding,” says Teshome. Participatory plant breeding is the development and selection of new crop varieties where the farmers are in control. Farmers, who know the needs of their farms best, work with researchers and others to improve crops and develop plant varieties that are in line with their household needs and culture, and that are resilient to environmental and climate challenges.    

    “Farmers prefer and need different types of seeds, based on diverse social, cultural and ecological conditions,” adds ethnobotanist and co-author Sarah Paule Dalle.       

    The study discusses various disruptions to farmer’s access to seeds. Social inequality is one such disruption. How so?   

    “A seed system that only serves a segment of a farming society contributes to seed insecurity,” replies Teshome. “For example, commercial seed systems deliver high-yielding varieties of quality hybrid seeds. Whilst wealthy farmers can afford such seeds, poor farmers can’t.”    

    “Similarly, whilst commercial seed systems that focus on commodity crops may benefit men who might primarily be interested in market value, such systems have little to offer women who want crops that provide household nutrition and meet their cultural preferences.”   

    “This means poor farmers and women do not have the same access to seeds that meet their needs. The result is seed, and thus food, insecurity due to social and economic inequality.”     

    Political-economic factors have driven the globalization of food systems over the last decades, which also includes seed systems. “Seeds have become big business”, say the researchers. According to studies quoted in the article, the four largest multinational companies in seed trade today control about 60% of the ~50 billion USD global commercial seed market. The large private actors have the power not only to shape markets, but also to influence science and innovation agendas and policy frameworks.     

    This can be problematic, say the researchers, when private sector research and development typically focuses on the most profitable crops, such as maize and soy. Crops grown and consumed by subsistence farmers are thus largely neglected, and the potential of crop diversity – the foundation of agriculture – remains largely untapped. Technology that could help develop more robust varieties remains hypothetical.   

    How does the ownership of crop diversity threaten food supplies and what can be done?      

    The term crop diversity refers both to different crops and different varieties of a crop. According to the Global Crop Diversity Trust (one of the world’s primary international organizations on crop diversity conservation), securing and making available the world’s crop diversity is essential for future food and nutrition security.      

    “Plant breeders and scientists use crop diversity to develop new, more resilient and productive varieties that consumers want to eat, that are nutritious and tasty, and that are adapted to local preferences, environments and challenges,” explains Benjamin Kilian, a plant genetics expert at the Global Crop Diversity Trust. The Crop Trust, together with the Norwegian University of Life Sciences, implements the major project from which this study emerged: Biodiversity for Opportunities, Livelihoods and Development (BOLD). Coordinated by Kilian, the project supports the conservation and use of crop diversity to strengthen food and nutrition security on a global scale. It builds on the Crop Wild Relatives project and is funded by the Norwegian government.   

    “In the BOLD project, researchers work with genebanks, plant breeders and others in the seed value chain to co-develop seed systems that are both resilient to climate stresses and inclusive of small-holder farmers on the frontline of adaptation,” adds Westengen.     

    Will access to seeds in the vulnerable areas that you are studying be improved in time to make a difference?   

    “We hope so, if we make the right moves to include small-holder farmers in seed system development,” says Dalle. “A well-functioning seed system should also be resilient. That is, it should withstand shocks such as drought or pandemics and breakdowns or disruptions such as war and conflict.”    

    “To do this, the system should promote a diversity of seeds, both local varieties and those improved to better adapt to stresses. It should also involve diverse groups of people such as farmer cooperatives/groups, and both public and private companies to increase the choice of seeds and seed sources. During lockdowns in the COVID-19 pandemic, for example, farmers’ own seed systems enabled access to seeds in developing countries when the activities of private companies and agro-dealers were restricted,” explains Dalle.   

    Westengen summarizes: “Our study highlights links between the crucial work of the Global Crop Diversity Trust and the farmers on the frontline of adapting our food systems to climate change. It is an argument for co-designing seed system development in full cooperation with farmers and other actors in the seed system. This way, efforts can meet the needs of various groups of farmers in different agroecological contexts. There is no one-size-fits-all; if there is one natural law in biology, it is that diversity is key to future evolution. That also goes for seed systems – and food system development.”   

    Navigating towards resilient and inclusive seed systems by Ola T. Westengen, Sarah Paule Dalle and Teshome Hunduma Mulesa was published in Proceedings of the National Academy of Sciences (PNAS) this week. PNAS is widely considered one of the most prestigious and highly cited multidisciplinary research journals.   

    About the Norwegian University of Life Sciences (NMBU)  
    NMBU’s research and education enables people all over the world to tackle the big, global challenges regarding the environment, sustainable development, how to improve human and animal health, renewable energy sources, food production, and land- and resource management. 

     About the Crop Trust 
    The Crop Trust is an international organization working to conserve crop diversity and thus protect global food and nutrition security. At the core of Crop Trust is an endowment fund dedicated to providing guaranteed long-term financial support to key genebanks worldwide. The Crop Trust supports the Svalbard Global Seed Vault and coordinates large-scale projects worldwide to secure crop diversity and make it available for use. The Crop Trust is recognized as an essential element of the funding strategy of the International Treaty on Plant Genetic Resources for Food and Agriculture.  

    About the BOLD Project 
    BOLD (Biodiversity for Opportunities, Livelihoods, and Development) is a major 10-year project to strengthen food and nutrition security worldwide by supporting the conservation and use of crop diversity. The project works with national genebanks, pre-breeding and seed system partners globally. Funded by the government of Norway, BOLD is led by the Crop Trust in partnership with the Norwegian University of Life Sciences and the International Plant Treaty. 

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    Norwegian University of Life Sciences

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  • Stones for the climate

    Stones for the climate

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    Newswise — If the cook varies the amount of ingredients when preparing a dish, a completely new taste is created. It is exactly the same with binding of CO2 in the sea – a change in the substances in the water changes everything. The so-called alkalinity, i.e. the acid binding capacity, is created by the weathering of rocks and their entry into the ocean. Increased erosion on land causes an increase in weathering of silicates and carbonates. The researchers identified the factors for more alkalinity using the model: Degree of erosion, area fraction of carbonate, temperatures, catchment size, and soil thickness.

    Method and influencing factors

    “The model we used is a statistical, not a mechanistic model. We applied it to identify the factors influencing alkalinity based on our compiled data set and to describe their interdependencies,” says Nele Lehmann of the Hereon Institute for Carbon Cycles, lead author of the study, which was an international collaboration with the Alfred Wegener Institute Helmholtz-Zentrum für Polar- und Meeresforschung (AWI) and funding from the Deutscher Akademischer Austauschdienst (DAAD).

    If warming continues slowly, alkalinity would drop by up to 68 percent by 2100, depending on the watersheds. That means the ocean’s ability to sequester CO2 would decrease significantly. Rapidly progressing warming, on the other hand, would lead to higher temperatures and thus more precipitation in temperate climate zones. This would increase alkalinity by up to 33 percent. “But that doesn’t mean that more emissions are good for the climate. The impact of alkalinity is small compared to the amounts of man-made CO2 emitted around the world. The process of weathering unfolds its effects over much longer periods of time,” Lehmann said.

    Climate change is greatly accelerating the interplay of carbon cycling and weathering that is fundamental to the development of life. The team first looked for existing data. The goal was to find as many alkalinity measurements as possible in the immediate vicinity of erosion measurement sites. To do this, the researchers searched databases and publications, and took samples themselves. They conducted the investigation of the alkalinity factors using their new model. The biggest limitation: the erosion rate measurements the researchers used have often only been taken over 20 years, are complex and expensive. This made it difficult to produce the data set. Especially in the higher latitudes, there are hardly any measurements, so the study is limited to the mid-latitudes.

    New questions in the Arctic

    Next, Lehmann would like to investigate alkalinity and the erosion rate in the Arctic. There, the data situation is patchy. And climate change is clearly being noticeable, so potentially the biggest change in alkalinity flux could also occur. Of particular importance: whether erosion itself is changing as a result of climate change.

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    Helmholtz-Zentrum Hereon

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  • Coffee plantations limit birds’ diets

    Coffee plantations limit birds’ diets

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    BYLINE: Paul Gabrielsen

    Newswise — Cast your mind back to the spring of 2020, when grocery store shelves sat bare of essential items and ingredients. For birds who live in the forests of Central America, replacement of forest land with coffee plantations essentially “clears out the shelves” of their preferred foods, causing them to shift their diets and habitats to survive.

    A new study led by researchers at the University of Utah explores a record of birds’ diets preserved in their feathers and radio tracking of their movements to find that birds eat far fewer invertebrates in coffee plantations than in forests, suggesting that the disturbance of their ecosystem significantly impacts the birds’ dietary options.

    “Growing human ecological impact on the planet, especially via habitat loss and degradation and climate change, often impacts bird diets negatively as well,” said Çağan H. Şekercioğlu, the study’s lead author and an ecology and ornithology professor in the U’s School of Biological Sciences. “These negative changes, including declines in key dietary resources like insects and other invertebrates can lead to reduced survival, especially of rapidly growing young, often leading to population declines and losses of these undernourished birds.”

    The study is published in Frontiers of Ecology and Evolution. Find the full study here.

    The forests of Costa Rica

    PHOTO CREDIT: ÇAĞAN H. ŞEKERCIOĞLU

    An Ochre-bellied Flycatcher.

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    All over the world, forests are being reduced from once-verdant havens of life to much smaller remnants, scattered amongst the agricultural land that has replaced them. Only about one percent of bird species prefer the types of habitats dominated by humans and human activity, but the rapid disappearance of natural forest habitat means that about a third of bird species now find themselves working to survive in human-dominated environments.

    In Costa Rica, the land around the Las Cruces Biological Station near the Panama border, has gone from fully forested to now 50% coffee plantations, 20% cattle pastures and 10% other human environments—only 20% of the land is still forested. The agricultural areas are drenched in pesticides, fertilizers and fungicides, drastically impacting the communities of invertebrates on which local birds feed.

    Those local birds include four species that the researchers focused on in the study: orange-billed nightingale-thrush, silver-throated tanager, white-throated thrush and ochre-bellied flycatcher. All four species can be found in both the forests and the open countryside where they feed on both fruits and invertebrates. But the invertebrates (including insects) are an important part of their diet, since they provide key nutrients including protein and nitrogen.

    Şekercioğlu and his colleagues, including researchers from the United States, Costa Rica, and Singapore, wanted to understand how the bird species they studied were obtaining their nutrients between the agricultural and forest environments, specifically during the crucial breeding season when proper nutrition is key to sustaining the species.

    An isotopic food diary

    PHOTO CREDIT: ÇAĞAN H. ŞEKERCIOĞLU

    An Orange-billed Nightingale-thrush.

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    To learn more about the birds’ diet, the researchers analyzed isotopes in their feathers. We are what we eat, and the chemical signatures of the foods we eat, in the form of isotope ratios, are incorporated into our tissues.

    Isotopes are different versions of the same element that differ only in the amount of neutrons in their nucleus – an infinitesimal difference in mass between a carbon atom with, say, six neutrons and a carbon atom with seven. But biological and physical processes can prefer either light or heavy isotopes, changing the resulting ratio in a way that can be measured and can provide valuable information.

    In humans, for example, a record of our diets is preserved in the isotopes in our hair. In a previous study, co-author Thure Cerling, a distinguished professor in the U’s Department of Geology and Geophysics, and colleagues analyzed hair clippings from barbershops and salons around the Salt Lake Valley and learned about the relative ratios of corn-fed meat and plant-based protein in the diets of local residents.

    In Costa Rica, the researchers hoped to do the same, but with the stable carbon and nitrogen isotopes in the birds’ feathers. They collected 170 feathers from the four bird species to analyze diet, and tracked 49 birds’ movements using radio tracking to see where they spent their time.

    “It’s definitely not the first time feather isotopic analysis has been used to study bird diets,” said co-author Seth Newsome of the University of New Mexico, “but it might be the first time, especially in the tropics, it has been used in conjunction with radio telemetry to examine diet composition and relative use of agricultural versus natural habitats.”

    The results showed that the birds’ habitat of choice had a significant effect on their diet. The isotopic data suggested that three of the four species studied ate significantly fewer invertebrates in coffee plantations than in forests. For silver-throated tanagers and the white-throated thrushes, the data suggested that they were eating twice as much invertebrate biomass in forests than in coffee plantations.

    “Our results suggest that coffee plantations are deficient in invertebrates preferred by forest generalist birds that forage in both native forest remnants and coffee plantations,” Şekercioğlu said.

    Consequences of habitat shifts

    PHOTO CREDIT: ÇAĞAN H. ŞEKERCIOĞLU

    A Silver-throated Tanager.

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    The coffee plantations were planted decades ago, and the researchers don’t have the data to know how the birds behaved when the forest was intact. But from what we know about the birds’ behaviors now, we can infer what the results mean for the birds’ lifestyles.

    To consume enough invertebrates, Şekercioğlu said, the birds need to forage frequently in the small forest fragments of around 7-12 acres (about the size of the parking lot at the U’s Rice-Eccles Stadium) and narrow corridors of forests alongside rivers, only around 30-60 ft wide.

    “We think that the more mobile birds like silver-throated tanager and white-throated thrush move constantly to get enough food, especially protein-rich invertebrates,” Şekercioğlu said, a hypothesis supported by a 2007 radio tracking study. “Less mobile species like orange-billed nightingale thrush that can have lifelong home range sizes as small as an acre (half a hectare) either have to adapt to coffee plantations and eat fewer invertebrates or they disappear.” The orange-billed nightingale thrush isn’t alone—a 2019 study showed that more bird species were in decline in the region than were stable.

    So for the birds of Costa Rica, and for birds in other, similar tropical regions, forest reserves can provide critical resources for birds that have shifted their habitats to the remaining forest and travel through coffee plantations to reach other forest fragments.

    “These birds’ shifting their feeding to other places may result in new ecological interactions that can themselves have negative consequences,” Şekercioğlu said. “For example, increased competition with birds in these new places or overpredation on a prey species that was formerly not consumed as much.”

    How you can help

    PHOTO CREDIT: ÇAĞAN H. ŞEKERCIOĞLU

    A White-throated Thrush.

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    If you’re a coffee drinker, you can help by choosing to buy bird-friendly coffee. According to Şekercioğlu, bird-friendly coffee is grown in plantations with more tree cover and forest remnants, which are beneficial for native birds. He recommends buying shade-grown coffee, coffee certified as Bird Friendly by the Smithsonian Migratory Bird Center, or coffee from Ethiopia which, he said, is among the bird-friendliest.

    And local governments in tropical regions can help by prioritizing the conservation of intact forest, secondary growth forests and strips of forest alongside rivers to increase the connectivity of forest remnants.

    “It is urgent,” Şekercioğlu said, “to prioritize the conservation and regeneration of forest remnants in increasingly human-dominated agricultural areas that continue to replace the world’s most biodiverse tropical forests.”

    Find the full study here.

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    University of Utah

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  • Joshua Tree Residents Pledge $4 Million Gift to CSUF to Support Desert Science

    Joshua Tree Residents Pledge $4 Million Gift to CSUF to Support Desert Science

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    Newswise — Brian and Lori Rennie have pledged a planned gift to Cal State Fullerton valued at $4 million to support desert science studies, conservation and climate change research. The couple’s gift to the university includes their Joshua Tree property and 2,500-square-foot Santa Fe pueblo-style home.

    Alumnus Brian Rennie ’70 (B.S. biological science) said the property can be used for events and research.

    “We were seeking the right organization to respect the land and the desert as much as we do, and to continue to utilize it in a way that supports our intentions,” Rennie said. “We feel confident that this will happen through our gift to the university.”

    Marie Johnson, dean of CSUF’s College of Natural Sciences and Mathematics, said this gift will allow faculty to expand their research efforts in desert environments, which will create impactful learning experiences for CSUF students.

    “We often say our university aspires to be a steward of place,” Johnson said. “Brian and Lori’s gift will allow us to fulfill that aspiration by creating the conditions for deep, meaningful engagement with desert ecosystems and our arid Southern California environment.”

    Read more about Brian and Lori Rennie’s donation at CSUF News.

    About Cal State Fullerton: The largest university in the CSU and the only campus in Orange County, Cal State Fullerton offers 110 degree programs and Division 1 athletics. Recognized as a national model for supporting student success, CSUF excels with innovative, high-impact educational practices, including faculty-student collaborative research, study abroad and competitive internships. Our vibrant and diverse campus is a primary driver of workforce and economic development in the region. CSUF is a top public university known for its success in supporting first-generation and underrepresented students, and preparing all students to become leaders in the global marketplace. Our It Takes a Titan campaign, a five-year $250 million comprehensive fundraising initiative, prioritizes investments in academic innovation, student empowerment, campus transformation and community enrichment. Visit fullerton.edu.

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    California State University, Fullerton

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  • KRICT has developed a breakthrough technology to achieve closed-loop recycling of textile wastes

    KRICT has developed a breakthrough technology to achieve closed-loop recycling of textile wastes

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    Newswise — The apparel industry accounts for 10% of global carbon emissions. The annual amount of fiber production reached 113 million tons in 2021* and the demand is increasing every year. However, almost 90% of post-consumer fiber wastes are disposed of through incineration or in landfills. Among these forms of waste, synthetic fiber has become a major threat to the environment and human health because, similar to other plastics, it is not biodegradable in nature. Owing to its low cost and durability, polyester is the most widely used synthetic fiber on the planet, accounting for more than half of all fabrics annually produced. Comprehensive recycling of polyester is thus a critical challenge for environmental sustainability and the health of future generations.

    *Source: Preferred Fiber & Materials Market Report 2022

    In practice, crude textile waste is not suitable for reuse or recycling because it is mixed with different fabric materials, colored by different dyes, and contaminated by various other impurities. Sorting it into homogeneous materials is necessary to make the waste recyclable by a chemical or mechanical method. To this end, the research team (P.I.: Dr. Joungmo Cho) in Korea Research Institute of Chemical Technology (KRICT) has developed a new chemical technology referred to as ‘chemical sorting’. This technology is applied to separate polyester from waste textiles that are disposed of in a mixed and contaminated form. In the process, a unique chemical compound, which selectively disrupts the chemical interaction between polyester and the dye used for its color, is used for the separation. The research team has also developed a new chemical recycling technology that consumes less energy than conventional methods to convert polyester into valuable monomers*, which can be repeatedly used for the synthesis of polymer materials.

    *monomer: a single molecular substance can react with other monomer molecules to form a polymer by chemical bonding

    Postconsumer clothes, made up of various materials with unknown compositions, are often discarded. They commonly comprise a variety of textiles such as cotton, wool, polyester, acrylic, nylon, elastane, and other blended fibers. Recycling cannot be achieved without sorting them into individual materials because of their incompatible chemical and physical properties. Industrially, the separation of individual materials from waste fabrics is accomplished by manual sorting, largely depending on human labor. This method has low accuracy and is unreliable and in turn fails to collect homogeneous materials, which is often critical for further steps of recycling. Recently, studies have been actively carried out to develop an automatic sorting machine, employing hyperspectral imaging technologies to acquire structural information of individual fabric targets. However, the sorting system still remains far from commercialization, mainly due to technical and economic barriers.

    The KRICT research team adopted an inexpensive and non-toxic biodegradable compound to chemically discriminate polyester from a mixture of waste fabrics. When the compound is applied to textiles. colorants only present in polyester are completely extracted while no significant changes occur in other materials. As a consequence, clean polyester can be separated from the mixture of colored fabrics. The method is applicable to select polyester from an uncolored fabric mixture as well. When uncolored fabric comes into contact with the waste colorants extracted from the sorting process, only polyester accepts the colorants while the other materials remain unchanged. As a consequence, the fabrics containing only polyester can be separated from mixed fabric waste in an inexpensive, accurate, and facile manner. The resulting sorted polyester can be used as clean feedstock for chemical recycling because the sorting method eliminates most organic impurities including intractable dyes.

    Chemical recycling, which converts polymer waste into the original building blocks, has potential to achieve circularity in recycling of polyester wastes whereas mechanical recycling can be used to produce only low quality material. In the conventional chemical recycling method, a high reaction temperature of above 200℃ is required to completely decompose polyester. Furthermore, energy-intensive purification steps are also inevitable in most commercial applications to obtain a high quality monomer product.

    The KRICT research team has developed a low-temperature glycolysis reaction system to convert chemically sorted waste polyester into pure bis(2-hydroxyethyl) terepthalate, which is an important building block monomer to produce new polymers. Monomer compounds obtained from the chemical recycling have quality equivalent to that derived from petroleum. Since the same compound as that used in ‘chemical sorting’ functions as an additive to lower the energy barrier of depolymerization, the reaction system can be easily and economically integrated with the chemical sorting technology for applications involving plastic or textile recycling where there is high demand for good product quality.

    Dr. Cho said, “Recently, the garment industry has utilized transparent and clean post-consumer PET bottles to produce recycled polyester clothes. However, this method is not sustainable because the material cannot be repeatedly recycled. In contrast, our current technology would not be limited by the complexity of the constituent materials or the initial level of impurity in the waste. Whether the targeted materials are derived from petroleum directly or recycled from waste, the technology can repeatedly process most post-consumer textile streams. Thus it will help reduce waste in landfills and substantially achieve a circular economy in the plastic and textile industries.”

    The chemical recycling technology has been licensed to Renew System Co., Ltd. (South Korea). Multidisciplinary R&D teams are now closely working together to build multi-scale facilities for the chemical recycling of waste clothing. A demonstration plant will be ready by the end of 2024 and commercial operation with an annual capacity of 10,000 tons is planned to start in 2025.

     

     

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    KRICT is a non-profit research institute funded by the Korean government. Since its foundation in 1976, KRICT has played a leading role to advance national chemical technologies in the fields of chemistry, material science, environmental science, and chemical engineering. Now, KRICT is moving forward to become a globally leading research institute tackling the most challenging issues in the field of Chemistry and Engineering and will continue to fulfill its role in developing chemical technologies that benefit the entire world and keep our earth healthy. More detailed information on KRICT can be found at https://www.krict.re.kr/eng/

    This study was supported by the Materials/Parts Technology Development Program funded by the Ministry of Trade, Industry & Energy (MOTIE, Republic of Korea) and by the Institutional Program of the Korea Research Institute of Chemical Technology (KRICT). The research was published in ACS Sustainable Chemistry & Engineering, volume 10 (51) and featured on the front cover of the volume.

    Credit: Korea Research Institute of Chemical Technology (KRICT)

    Usage Restrictions of Multimedia (Attachment File): The sources of photos and research results from KRICT must be specified

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    National Research Council of Science and Technology

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  • River deltas: Valuable and under threat

    River deltas: Valuable and under threat

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    Newswise — The livelihoods of millions of people who live in river deltas, among the world’s most productive lands, are at risk. Created where large rivers meet the ocean and deposit their natural sediment load, river deltas are often just a few meters above sea level. And while they make up less than 0.5 % of the world’s land area, river deltas contribute more than 4 % of the global GDP, 3% of global crop production, and are home to 5.5 % of the world’s population. All of these values are highly vulnerable to imminent global environmental change, according to a new Stanford University-led study.

    “It is often not rising seas, but sinking land due to human activities that puts coastal populations most at risk,” said study lead author Rafael Schmitt, a lead scientist with the Stanford Natural Capital Project. “Our research highlights that this relevant global risk is grossly understudied for all but very few coastal regions”

    Under natural conditions, deltas are subject to a number of factors that together create dynamic but stable systems. For instance, sediment supplied from upstream river basins builds new land even when sea levels are rising. Sediment supply is also critical to offset the effect that the recent, unconsolidated delta land compacts continuously under its own weight.

    Today, all of these processes are out of balance. River deltas are cut off from their natural sediment supply by dams and reservoirs, and the little sediment still reaching deltas cannot spread because of artificial levees and dikes. Additionally, groundwater pumping and extraction of hydrocarbons creates subsidence, and coastal vegetation, which can provide some protection, is lost to make space for farmland and tourism.

    Those local drivers, together with global sea level rise, lead to relative sea level rise, meaning that sinking lands amplifies the effect of rising seas, a combination that could cause significant parts of the world’s largest deltas to fall below the rising sea by the end of the century.

    Little is known about local and regional drivers of relative sea level rise. So, Schmitt’s study set out to identify key drivers of land loss and vulnerability across the world’s major deltas, and the knowledge gaps impeding more sustainable delta management, for specific deltas and on a global scale.

    In their synthesis effort, the authors find overwhelming evidence that it is not sea level rise, but sinking land, that puts global deltas most at risk. This is of great importance for managing river deltas, according to Schmitt. While climate change is increasingly recognized as a risk to coastal livelihoods and global wealth and security, this is only one part of the story.

    Of course, climate mitigation is important to curb global sea level rise. However, fighting overuse of local natural resources in river deltas and their contributing basins would have much greater and more immediate effects, posing both an opportunity and a responsibility for coastal nations.

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  • Discovery of novel gene to aid breeding of climate resilient crops

    Discovery of novel gene to aid breeding of climate resilient crops

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    Newswise — Researchers have revealed for the first time how a key gene in plants allows them to use their energy more efficiently, enabling them to grow more roots and capture more water and nutrients. 

    An international team of plant scientists led by Penn State University and in collaboration with the University of Nottingham have discovered this novel regulatory gene (called bHLH121) that enables corn roots to acquire more water and nutrients. The findings have been published in the Proceedings of the National Academy of Science.

    The gene controls the formation of air spaces among living root tissues (termed root cortical aerenchyma). Replacing a large percentage of root cells with airspaces saves the plant a lot of energy which is otherwise required to feed all these root cells. This makes roots metabolically more efficient, enabling them to use the resources saved to build more roots and explore the soil more effectively and capture more water and nutrients.  

    This discovery could lead to the breeding of crops that can withstand drought and low-nitrogen soil conditions and ultimately ease global food insecurity, the researchers suggest. 

    Rahul Bhosale, Assistant Professor in Crop Functional Genomics from the School of Biosciences at the University of Nottingham and BBSRC Discovery Fellow said: “Identifying this gene and how it works will enable us to create more resilient crops that can withstand water and nutrient stress conditions being experienced as a result of climate change.”

    The research team used powerful imaging tools developed in previous research at Penn State that rapidly measured cells in thousands of roots. An imaging technique called Laser Ablation Tomography was critical for this approach. This state-of-the-art approach is also now available at the University of Nottingham through BBSRC Alert Funding and support from US partners. 

    Hannah Schneider, Assistant Professor of Crop Physiology at Wageningen University & Research, Netherlands said: “We first performed the field experiments that went into this study starting in 2010, growing more than 500 lines of corn at sites in Pennsylvania, Arizona, Wisconsin and South Africa,” she said. “I worked at all those locations. We saw convincing evidence that we had located a gene associated with root cortical aerenchyma.

    This research revealed that mutant corn lines lacking the bHLH121 gene showed reduced root air space formation. In contrast, overexpressing bHLH121 caused more air space formation. 

    Characterization of these lines under suboptimal water and nitrogen availability in multiple locations revealed that the bHLH121 gene is required for root air space formation and provides a new tool for plant breeders to select varieties with improved soil exploration, and thus yield, under suboptimal conditions. 

    Professor Jonathan Lynch, who led the research at Penn State commented: “These findings are the result of many people at Penn State and beyond collaborating with us, working over many years,” he said. “We discovered the function of the aerenchyma trait and then the gene associated with it, And, it came about because of technologies that have been devised here at Penn State, such as Shovelomics — digging up roots in the field — Laser Ablation Tomography and Anatomics Pipeline. We put all those together in this work.” 

    The results are significant, Lynch continued, because finding a gene behind an important trait that’s going to help plants have better drought tolerance and better nitrogen and phosphorus capture looms large in the face of climate change. 

    “Those are super important qualities — both here in the U.S. and around the world,” he said. “Droughts are the biggest risk to corn growers and are worsening with climate change, and nitrogen is the biggest cost of growing corn, from both a financial and environmental perspective. Breeding corn lines more efficient at scavenging for the nutrient would be a major development.” 

    The U.S. Department of Energy, the Howard G Buffett Foundation, and the U.S. Department of Agriculture’s National Institute of Food and Agriculture supported this research. 

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  • 19th Century ‘dinner plate’ still useful in ocean science

    19th Century ‘dinner plate’ still useful in ocean science

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    Newswise — A simple 19th Century tool is still useful to ocean scientists in the age of satellites, new research shows.

    A Secchi disk –  historically called a “dinner plate” by sailors – is used in the open ocean to measure concentrations of microscopic algae called phytoplankton.

    It works by lowering the white disk into the water and recording the depth at which it disappears.

    In the new study, a research team including the University of Exeter, Plymouth Marine Laboratory, Vrije Universiteit (Netherlands) and the Italian Institute of Marine Sciences (ISMAR) compared the performance of Secchi disks with satellites and high-performance chromatography.

    Secchi disks performed almost as well as modern methods at monitoring phytoplankton abundance – meaning Secchi measurements going back more than a century can help scientists understand long-term changes in the ocean.

    “Phytoplankton produce half the world’s oxygen and form the base of ocean food webs, so monitoring them helps us track everything from climate change to the health of ecosystems,” said Dr Bob Brewin, from the Centre for Geography and Environmental Science on Exeter’s Penryn Campus in Cornwall.

    “New technology undoubtedly gives us new opportunities, but our study shows Secchi disks do a good job of estimating chlorophyll (a way of measuring phytoplankton abundance) – which means we should be able to integrate data from the past with modern measurements.

    “This gives us a priceless source of long-term data on how our oceans are changing.”

    Secchi disks are still used all around the world to monitor ocean biomass and water quality, and co-author Dr Jaime Pitarch, from ISMAR, said the findings support their continued use.

    “It’s a simple, cheap tool, but our research shows it’s also remarkably effective,” he said.

    In fact, researchers including Dr Brewin at Exeter, are working on a project that will use 3D-printed Secchi disks to monitor water quality in lakes in India and Africa, and coastal regions of the US.

    Prior to the 1850s, mariners used a variety of objects (in the same way as Secchi disks) to help with navigation, including cloths, pans and plates.

    It was the Vatican astronomer Angelo Secchi, invited by the Papal Navy Commander Alessandro Cialdi to join a scientific cruise to study the murkiness of the sea in 1865, who standardised the method.

    The measurements in the new study were collected on Atlantic Meridional Transect cruises, and Dr Brewin’s work is funded by a UKRI Future Leader Fellowship.

    The paper, published in the journal Frontiers in Marine Science, is entitled: “Evaluating historic and modern optical techniques for monitoring phytoplankton biomass in the Atlantic Ocean.”

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  • Humans are leaving behind a ‘frozen signature’ of microbes on Mount Everest

    Humans are leaving behind a ‘frozen signature’ of microbes on Mount Everest

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    Newswise — Almost 5 miles above sea level in the Himalayan mountains, the rocky dip between Mount Everest and its sister peak, Lhotse, lies windswept, free of snow. It is here at the South Col where hundreds of adventurers pitch their final camp each year before attempting to scale the world’s tallest peak from the southeastern side.

    According to new University of Colorado Boulder-led research, they’re also leaving behind a frozen legacy of hardy microbes, which can withstand harsh conditions at high elevations and lie dormant in the soil for decades or even centuries.

    The research not only highlights an invisible impact of tourism on the world’s highest mountain, but could also lead to a better understanding of environmental limits to life on Earth, as well as where life may exist on other planets or cold moons. The findings were published last month in Arctic, Antarctic, and Alpine Research, a journal published on behalf of the Institute of Arctic and Alpine Research (INSTAAR) at CU Boulder.

    “There is a human signature frozen in the microbiome of Everest, even at that elevation,” said Steve Schmidt, senior author on the paper and professor of ecology and evolutionary biology.

    In decades past, scientists have been unable to conclusively identify human-associated microbes in samples collected above 26,000 feet. This study marks the first time that next-generation gene sequencing technology has been used to analyze soil from such a high elevation on Mount Everest, enabling researchers to gain new insight into almost everything and anything that’s in them.

    The researchers weren’t surprised to find microorganisms left by humans. Microbes are everywhere, even in the air, and can easily blow around and land some distance away from nearby camps or trails.

    “If somebody even blew their nose or coughed, that’s the kind of thing that might show up,” said Schmidt.

    What they were impressed by, however, was that certain microbes which have evolved to thrive in warm and wet environments like our noses and mouths were resilient enough to survive in a dormant state in such harsh conditions.

    Life in the cryosphere

    This team of CU Boulder researchers—including Schmidt, lead author Nicholas Dragone and Adam Solon, both graduate students in the Department of Ecology and Evolutionary Biology and the Cooperative Institute for Research in Environmental Science (CIRES)—study the cryobiosphere: Earth’s cold regions and the limits to life in them. They have sampled soils everywhere from Antarctica and the Andes to the Himalayas and the high Arctic. Usually, human-associated microbes don’t show up in these places to the extent they appeared in the recent Everest samples.

    Schmidt’s work over the years connected him with researchers who were headed to Everest’s South Col in May of 2019 to set up the planet’s highest weather station, established by the National Geographic and Rolex Perpetual Planet Everest Expedition.

    He asked his colleagues: Would you mind collecting some soil samples while you’re already there?

    So Baker Perry, co-author, professor of geography at Appalachian State University and a National Geographic Explorer, hiked as far away from the South Col camp as possible to scoop up some soil samples to send back to Schmidt.

    Extremes on Earth, and elsewhere

    Dragone and Solon then analyzed the soil in several labs at CU Boulder. Using next-generation gene sequencing technology and more traditional culturing techniques, they were able to identify the DNA of almost any living or dead microbes in the soils. They then carried out extensive bioinformatics analyses of the DNA sequences to determine the diversity of organisms, rather than their abundances.  

    Most of the microbial DNA sequences they found were similar to hardy, or “extremophilic” organisms previously detected in other high-elevation sites in the Andes and Antarctica. The most abundant organism they found using both old and new methods was a fungus in the genus Naganishia that can withstand extreme levels of cold and UV radiation.

    But they also found microbial DNA for some organisms heavily associated with humans, including Staphylococcus, one of the most common skin and nose bacteria, and Streptococcus, a dominant genus in the human mouth.

    At high elevation, microbes are often killed by ultraviolet light, cold temperatures and low water availability. Only the hardiest critters survive. Most—like the microbes carried up great heights by humans—go dormant or die, but there is a chance that organisms like Naganishia may grow briefly when water and the perfect ray of sunlight provides enough heat to help it momentarily prosper. But even for the toughest of microbes, Mount Everest is a Hotel California: “You can check out any time you like/ But you can never leave.”

    The researchers don’t expect this microscopic impact on Everest to significantly affect the broader environment. But this work does carry implications for the potential for life far beyond Earth, if one day humans step foot on Mars or beyond.

    “We might find life on other planets and cold moons,” said Schmidt. “We’ll have to be careful to make sure we’re not contaminating them with our own.”

    Additional authors on this publication include: Anton Seimon, Department of Geography and Planning, Appalachian State University; and Tracie Seimon, Wildlife Conservation Society, Zoological Health Program, Bronx, New York.

    This work was supported by the National Geographic and Rolex Perpetual Planet Everest Expedition, the Department of Ecology and Evolutionary Biology, and the University of Colorado Boulder Libraries Open Access Fund.

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  • The world’s atmospheric rivers now have an intensity ranking like hurricanes

    The world’s atmospheric rivers now have an intensity ranking like hurricanes

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    Newswise — WASHINGTON — Atmospheric rivers, which are long, narrow bands of water vapor, are becoming more intense and frequent with climate change. A new study demonstrates that a recently developed scale for atmospheric river intensity (akin to the hurricane scale) can be used to rank atmospheric rivers and identify hotspots of the most intense atmospheric rivers not only along the U.S. West Coast but also worldwide.

    Atmospheric rivers typically form when warm temperatures create moist packets of air, which strong winds then transport across the ocean; some make landfall. The intensity scale ranks these atmospheric rivers from AR-1 to AR-5 (with AR-5 being the most intense) based on how long they last and how much moisture they transport.

    In part because some West Coast weather outlets are using the intensity scale, “atmospheric river” is no longer an obscure meteorological term but brings sharply to mind unending rain and dangerous flooding, the authors said. The string of atmospheric rivers that hit California in December and January, for instance, at times reached AR-4. Earlier in 2022, the atmospheric river that contributed to disastrous flooding in Pakistan was an AR-5, the most damaging, most intense atmospheric river rating.

    The scale helps communities know whether an atmospheric river will bring benefit or cause chaos: The storms can deliver much-needed rain or snow, but if they’re too intense, they can cause flooding, landslides and power outages, as California and Pakistan experienced. The most severe atmospheric rivers can cause hundreds of millions of dollars of damage in days in the western U.S.; damage in other regions has yet to be comprehensively assessed.

    “Atmospheric rivers are the hurricanes of the West Coast when it comes to the public’s situational awareness,” said F. Martin Ralph, an atmospheric scientist at Scripps Institution of Oceanography and a coauthor on the new study. People need to know when they’re coming, have a sense for how extreme the storm will be, and know how to prepare, he said. “This scale is designed to help answer all those questions.”

    Ralph and his colleagues originally developed the scale for the U.S. West Coast. The new study demonstrates that atmospheric river events can be directly compared globally using the intensity scale, which is how the researchers identified where the most intense events (AR-5) form and fizzle out, and how many of those make landfall.

    The researchers used climate data and their previously developed algorithm for identifying and tracking atmospheric rivers to build a database of intensity-ranked atmospheric river events around the globe over 40 years (1979/1980 to 2019/2020). The study was published in the Journal of Geophysical Research: Atmospheres, which publishes research that advances understanding of Earth’s atmosphere and its interaction with other components of the Earth system.

    “This study is a first step toward making the atmospheric river scale a globally useful tool for meteorologists and city planners,” said Bin Guan, an atmospheric scientist at the Joint Institute for Regional Earth System Science and Engineering, a collaboration between University of California-Los Angeles and NASA’s Jet Propulsion Laboratory, who led the study. “By mapping out the footprints of each atmospheric river rank globally, we can start to better understand the societal impacts of these events in many different regions.”

    The authors also found that more intense atmospheric rivers (AR-4 and AR-5) are less common than weaker events, with AR-5 events occurring only once every two to three years when globally averaged. The most intense atmospheric rivers are also less likely to make landfall, and when they do, they are unlikely to maintain their strength for long and penetrate farther inland. “They tend to dissipate soon after landfall, leaving their impacts most felt in coastal areas,” said Guan.

    The study found four “centers,” or hotspots, of where AR-5s tend to die, in the extratropical North Pacific and Atlantic, Southeast Pacific, and Southeast Atlantic. Cities on the coasts within these hotspots, such as San Francisco and Lisbon, are most likely to see intense AR-5s make landfall. Midlatitudes in general are the most likely regions to have atmospheric rivers of any rank.

    Strong El Niño years are more likely to have more atmospheric rivers, and stronger ones at that, which is noteworthy because NOAA recently forecasted that an El Niño condition is likely to develop by the end of the summer this year.

    While local meteorologists, news outlets and other West Coasters may have incorporated “atmospheric river” and the intensity scale into their lives, adoption has been slower elsewhere, Ralph said. He hopes to see, within five years or so, meteorologists on TV around the world incorporating the atmospheric river intensity scale into their forecasts, telling people whether the atmospheric river will be beneficial or if they need to prepare for a serious storm.

    #

    AGU (www.agu.org) is a global community supporting more than half a million advocates and professionals in Earth and space sciences. Through broad and inclusive partnerships, AGU aims to advance discovery and solution science that accelerate knowledge and create solutions that are ethical, unbiased and respectful of communities and their values. Our programs include serving as a scholarly publisher, convening virtual and in-person events and providing career support. We live our values in everything we do, such as our net zero energy renovated building in Washington, D.C. and our Ethics and Equity Center, which fosters a diverse and inclusive geoscience community to ensure responsible conduct.

    *****

    Notes for Journalists:

    This study is published with open access and is freely available. Download a pdf copy of the paper here.

    Paper title:

    “Global application of the atmospheric river scale”

    Authors:

    • Bin Guan (corresponding author), Duane E. Waliser, Joint Institute for Regional Earth System Science and Engineering, University of California Los Angeles, Los Angeles, California, USA
    • F. Martin Ralph, Center for Western Weather and Water Extremes, Scripps Institution of Oceanography, University of California San Diego, San Diego, California, USA

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    American Geophysical Union (AGU)

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  • Sea level rise poses particular risk for Asian megacities

    Sea level rise poses particular risk for Asian megacities

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    Newswise — Sea level rise this century may disproportionately affect certain Asian megacities as well as western tropical Pacific islands and the western Indian Ocean, according to new research that looks at the effects of natural sea level fluctuations on the projected rise due to climate change.

    The study, led by scientists at the French National Center for Scientific Research (CNRS) and University of La Rochelle in France and co-authored by a scientist at the National Center for Atmospheric Research (NCAR), mapped sea level hotspots around the globe. The research team identified several Asian megacities that may face especially significant risks by 2100 if society emits high levels of greenhouse gases: Chennai, Kolkata, Yangon, Bangkok, Ho Chi Minh City, and Manila.

    Scientists have long known that sea levels will rise with increasing ocean temperatures, largely because water expands when it warms and melting ice sheets release more water into the oceans. Studies have also indicated that sea level rise will vary regionally because shifts in ocean currents will likely direct more water to certain coastlines, including the northeastern United States.

    What’s notable about the new study is the way it incorporates naturally occurring sea level fluctuations caused by such events as El Niño or changes in the water cycle (a process known as internal climate variability). By using both a computer model of global climate and a specialized statistical model, the scientists could determine the extent to which these natural fluctuations can amplify or reduce the impact of climate change on sea level rise along certain coastlines.

    The study showed that internal climate variability could increase sea level rise in some locations by 20-30% more than what would result from climate change alone, exponentially increasing extreme flooding events. In Manila, for example, coastal flooding events are predicted to occur 18 times more often by 2100 than in 2006, based solely on climate change. But, in a worst-case scenario, they could occur 96 times more often based on a combination of climate change and internal climate variability.

    Internal climate variability will also increase sea level rise along the west coasts of the United States and Australia.

    The study drew on a set of simulations conducted with the NCAR-based Community Earth System Model that assume society this century emits greenhouse gases at a high rate. The simulations were run at the NCAR-Wyoming Supercomputing Center.

    The paper stressed that the estimates of sea level rise come with considerable uncertainties because of the complex and unpredictable interactions in Earth’s climate system. But the authors said it’s critical for society to be aware of the potential of extreme sea level rise in order to develop effective adaptation strategies.

    “The internal climate variability can greatly reinforce or suppress the sea level rise caused by climate change,” said NCAR scientist Aixue Hu, who co-authored the paper. “In a worst-case scenario, the combined effect of climate change and internal climate variability could result in local sea levels rising by more than 50% of what is due to climate change alone, thus posing significant risks of more severe flooding to coastal megacities and threatening millions of people.” 

    The study was published in Nature Climate Change. It was supported by the French Research Agency, the U.S. Department of Energy, and the U.S. National Science Foundation, which is NCAR’s sponsor.

    This material is based upon work supported by the National Center for Atmospheric Research, a major facility sponsored by the National Science Foundation and managed by the University Corporation for Atmospheric Research. Any opinions, findings and conclusions or recommendations expressed in this material do not necessarily reflect the views of the National Science Foundation.

    About the article

    Title: Increased exposure of coastal cities to sea-level rise due to internal climate variability
    Authors: M. Becker, M. Karpytchev, and A. Hu
    Journal: Nature Climate Change

    On the web: news.ucar.edu
    On Twitter: @NCAR_Science

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    National Center for Atmospheric Research (NCAR)

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  • Unique hybrid reefs deployed off Miami Beach

    Unique hybrid reefs deployed off Miami Beach

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    BYLINE: Robert C. Jones Jr. and Janette Neuwahl Tannen

    Newswise — The first piece of a series of concrete structures was lowered into the water off the coast of Miami Beach on Wednesday morning, a massive crane on the deck of a floating barge hoisting the unit into the air and sinking it to the seabed. 

    During the next six hours, crewmembers aboard the barge would repeat that process until the structures, some stacked on top of each other, were settled on the seafloor, 14 feet below the surface. 

    To casual observers onshore, the daylong operation might have seemed routine. But this maritime activity was hardly run-of-the-mill. 

    In a project that could pave the way for greater efforts to protect coastlines from sea level rise and storm surge and serve as an innovative base structure to develop thriving coral reefs, a team of researchers and scientists from the University of Miami sunk 27 interlocking concrete structures that will form two hybrid reef units 1,000 feet offshore of North Beach Oceanside Park, at the northern edge of Miami Beach. 

    The units are the centerpiece of a project called Engineering Coastal Resilience Through Hybrid Reef Restoration, or ECoREEF, which combines cement- and nature-based strategies to foster coastal resilience. Supported by the University’s Laboratory for Integrative Knowledge (U-LINK) and the City of Miami Beach, the project was developed at a time when coral reefs are struggling to survive. A recent study indicates that half of the world’s living coral reefs have died since the 1950s. Meanwhile, other research has shown that healthy and complex coral reefs are able to buffer up to 97 percent of the energy from waves and can also reduce flooding frequency.

    “Coral reefs are disappearing at alarming rates throughout the world as a result of disease and warming oceans, so our reefs have lost a lot of the structure they need to reduce wave energy,” said ECoREEF lead investigator, Diego Lirman, an associate professor of marine biology and ecology at the University’s Rosenstiel School of Marine, Atmospheric, and Earth Science. “By placing these [hybrid] reefs near the shoreline and planting stress-tolerant corals on them, we hope to recover some of the lost services provided by healthy reefs, such as coastal protection, and to build a habitat for organisms like fish and lobsters.” 

    One of the hollow structures submerged this week was shaped like a trapezoid, with rocks on its outer surface to mimic the texture of coral reefs and to attract marine life. The other unit is a series of hexagons, the iconic honeycomb-like shape that is being incorporated into more and more projects, including the powerful Webb Telescope. Perforated to allow seawater to flow through them, the hollow, hexagonal SEAHIVE structures—tubes that look like honeycomb and each weighing 2,500 pounds—are stacked in a pyramid-like shape and attached to a few solid concrete SEAHIVEs to enhance the stability of the structure. 

    To build the hybrid structures, researchers also used an eco-friendly concrete mixture, with composite reinforcements instead of steel, both for durability and to attract marine life. 

    Haus and Rhode-Barbarigos peer through a six-foot-tall perforated SEAHIVE unit, which they designed with other faculty members, on the barge that lowered dozens of the units into the ocean.

    “Designing structures to dissipate wave energy while providing a hospitable environment for corals has been a challenge,” said Landolf Rhode-Barbarigos, an assistant professor in the College of Engineering, and one of the project’s lead investigators. “There are no design guidelines for nature, but hopefully this can be translated into something bigger and provide novel solutions for coastal protection.” 

    It was Rhode-Barbarigos, along with Lirman, marine biologist Andrew Baker, ocean scientist Brian Haus, sustainable architect Sonia Chao, and communications expert Jyotika Ramaprasad, who joined forces in 2018 to address challenges of coastal resilience. They hope the ECoREEF project will lead to a better understanding of the types of structures that can help protect South Florida’s vulnerable coastline from erosion and storm surge. 

    “We want to see how these two different alternatives for a hybrid, engineered structure and a natural reef compare,” Haus said. “This is a research installation, so we’ll be examining it in a variety of ways.” 

    Corals grown at the Rosenstiel School’s three nurseries will eventually be attached to the hybrid reefs, allowing them to thrive and replace some of the area’s many coral reefs lost to disease and bleaching that is the result of warming ocean temperatures. 

    “We are hoping that we can get baby corals to attach and get a community that looks similar to a natural reef developing on these structures over time,” Lirman said.  

    But for now, the reefs must get acclimated to their new underwater environment. 

    Divers and drones will help monitor the structures; and soon, researchers will install current meters and wave sensors from the U.S. Geological Survey to measure wave energy and flow on the surface of the reefs, according to Brian Haus, professor and chair of ocean sciences at the Rosenstiel School. 

    After two previous attempts to deploy the structures were called off because of inclement weather, ideal conditions—calm waters and little to no wind—made it possible for crews to sink the structures. 

    Onboard the barge which carried the hybrid reefs—after a tugboat had brought them more than 100-nautical-miles from Fort Pierce to Miami Beach—Haus and Rhode-Barbarigos helped orchestrate the deployment, directing the crane that lowered the structures into the water and making sure the reefs were positioned and stacked correctly on the seabed. A diver who patrolled the seafloor ensured the structures aligned properly.

    “We got our hands a little bit dirty today, but it was worth it,” said Haus, who oversees the Rosenstiel School’s 75-foot-long, 38,000-gallon Alfred C. Glassell, Jr. SUSTAIN Laboratory wind-wave tank, which researchers used to test small-scale versions of the hybrid reefs.  

    Should a tropical cyclone threaten or even strike South Florida this coming hurricane season, the hybrid reefs could get their first big test, which is why the team went through a meticulous permitting process, Rhode-Barbarigos said.

    A grant from U-LINK helped jump-start the project, and the group soon partnered with the City of Miami Beach. The U-LINK initiative was founded in 2018 to offer interdisciplinary faculty teams seed funding to devise novel solutions to pressing societal issues. Since then, 40 other teams have been formed, and many of them have garnered additional external funding. Last summer, Baker, Lirman, Rhode-Barbarigos and Haus, among others, received a massive grant from the Defense Advanced Research Projects Agency (DARPA), a division of the U.S. Department of Defense, to scale up their designs and help protect military and civilian infrastructure along the coast. 

    “This EcoReefs project will give us a test bed for this technology, before we do a deployment of a much larger structure for the DARPA grant elsewhere in Florida,” Lirman pointed out.   

    While the U-LINK project was evolving, Rhode-Barbarigos was also working with Haus and College of Engineering faculty members Antonio Nanni, Esber Andiroglu, and Prannoy Suraneni to develop the SEAHIVE structure through grants from the National Comparative Highway Research Program and the Florida Department of Transportation. Initially created as an alternative to traditional seawalls because of their ability to mitigate wave energy, the honeycomb-shaped SEAHIVE units are also set to be tested at two other South Florida locations. 

    Miami Beach officials are eager to see how both hybrid reefs perform in the waters off North Beach Oceanside Park. 

    “The launch of this experimental [hybrid] reef marks a pivotal moment in our efforts to protect Miami Beach from coastal erosion and restore our coral ecosystem,” said Ricky Arriola, a Miami Beach commissioner. “Not only will this innovative solution help safeguard our shores, but it will also drive ecotourism and further establish Miami Beach as a leader in sustainable coastal management.” 

    Amy Knowles, the city’s chief resilience officer, agreed. “We can’t wait to see how this hybrid reef grows,” she said. “Coral reefs are an important part of marine life, and our coastal resilience to storm surge and sea level rise for Miami Beach and our broader region.” 

    For the faculty members who worked on the project since its inception four years ago, this deployment marked an achievement.

    “It’s been a long adventure, so we’re understandably excited,” Rhode-Barbarigos said. “It’s a milestone moment because we’ll be able to learn from these units both from an engineering and ecological perspective. What we accomplished today is the end of one phase, but the beginning of another.”

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  • Shrinking age distribution of spawning salmon raises climate resilience concerns

    Shrinking age distribution of spawning salmon raises climate resilience concerns

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    Newswise — By returning to spawn in the Sacramento River at different ages, Chinook salmon lessen the potential impact of a bad year and increase the stability of their population in the face of climate variability, according to a new study by scientists at UC Santa Cruz and NOAA Fisheries.

    Unfortunately, spawning Chinook salmon are increasingly younger and concentrated within fewer age groups, with the oldest age classes of spawners rarely seen in recent years. The new study, published February 27 in the Canadian Journal of Fisheries and Aquatic Sciences, suggests changes in hatchery practices and fishery management could help restore the age structure of the salmon population and make it more resilient to climate change.

    The researchers focused on Sacramento River fall-run Chinook salmon, which contribute heavily to the salmon fisheries of California and southern Oregon. This population is particularly susceptible to the effects of increasingly severe drought conditions driven by climate change.

    “As we get more variable climate conditions, with greater extremes of rainfall and drought, we are going to see more ‘boom-and-bust’ population dynamics unless we start to restore the age structure of the population, which can spread out the effects of good and bad years across time,” said senior author Eric Palkovacs, professor of ecology and evolutionary biology and director of the Fisheries Collaborative Program at UC Santa Cruz.

    If most of the salmon return to spawn at the same age, one bad year could be devastating for the overall population. Spreading the risk over multiple years is an example of what ecologists call the “portfolio effect,” like a financial portfolio that spreads risk over multiple investments.

    First author Paul Carvalho, a postdoctoral fellow with the Fisheries Collaborative Program, explained that juvenile salmon are especially vulnerable to the effects of drought as they migrate to the ocean from freshwater rivers and streams.

    “We focused on the impacts of drought on the survival of juvenile salmon, but drought conditions can also increase mortality of returning adult salmon as they migrate upstream to spawn,” he said.

    Carvalho developed a life cycle model of the Sacramento River fall-run Chinook salmon population to simulate the effects of different drought scenarios and other variables on the population. The model was grounded in data from field studies, such as research by NOAA Fisheries scientists that quantified the relationship between river flows and survival rates of juvenile salmon.

    The model allowed the researchers to assess the effects of different mechanisms that can affect the age structure of the population. A century ago, most of the spawning salmon returning to the Sacramento River watershed were four years old, and some were as old as six years. Today, however, six-year-old fish are rarely observed and most of the spawners are three years old.

    “Historically, you would have seen huge salmon coming back at older ages, but over the past century they’ve gotten smaller and younger,” Palkovacs said. “The dominant age class is now 3 years, and there are very few even at age 5, so there’s been a big shift in the age structure.”

    Decreased size and age at maturity is a classic pattern of fisheries-induced evolution. A high mortality rate for older fish selects for fish that mature at earlier ages, because a fish that dies before it can spawn doesn’t pass on its genes. But fishing pressure is not the only factor driving changes in the age structure of the salmon population. Hatchery practices can also inadvertently select for earlier maturation.

    “It’s pretty clear that current hatchery practices are resulting in very homogeneous populations returning at age three,” Palkovacs said. “Rather than producing a uniform product, it would be better to increase the diversity of the age structure by selecting older, larger fish and making sure you get as many of them into the spawning population as possible.”

    Carvalho noted that improving the age structure of the population by selecting for fish that spend more years at sea (delayed maturation) would be most effective in combination with reduced harvest rates.

    “Because the fish remain in the ocean longer, they are exposed to the fishery and other causes of mortality for a longer period, so that reduces the number returning to spawn if you don’t reduce fishing pressure on those older age classes,” he said.

    Overall, the results show that maintaining or increasing the age structure through reduced mortality and delayed maturation improves the stability of the salmon population, buffering against the adverse effects of drought and making the population more resilient in an increasingly variable climate.

    “Regardless of the mechanism, whether it’s reduced mortality or delayed maturation that’s driving it, increasing the diversity of the age structure will increase the stability of the population,” Carvalho said.

    In addition to Carvalho and Palkovacs, the coauthors of the paper include William Satterthwaite, Michael O’Farrell, and Cameron Speir at the NOAA Southwest Fisheries Science Center. This work was supported by the Cooperative Institute for Marine, Earth, and Atmospheric Systems (CIMEAS) and the NOAA Quantitative Ecology and Socioeconomics Training (QUEST) Program.

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    University of California, Santa Cruz

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  • The claim that U.S. temperatures are not trending upward is false

    The claim that U.S. temperatures are not trending upward is false

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    Fact Check By:
    Newswise

    Truthfulness: False

    Claim:

    Zero US warming in 18 years, per US Climate Reference Network temp stations. That’s no US warming despite 30% of total manmade CO2. Emissions-driven warming is a hoax.

    Claim Publisher and Date: Steve Milloy on 2023-02-26

    A tweet shared by thousands by Steve Milloy, founder of Junk Science and former member of the EPA transition team under the Trump Administration, says, “Zero US warming in 18 years, per US Climate Reference Network temp stations. That’s no US warming despite 30% of total manmade CO2.” This claim is similar to ones in the past where skeptics of human-caused climate change cherry-pick data (using a fraction of the data to prop up claims that are false globally) to suit their ideology. It is simply false to claim that data from the Climate Reference Network show no warming over the last 18 years. There is a warming trend. Even if it was true, the US represents only 1.9 % of the Earth’s surface. It’s hard to extrapolate much about global temperature change from an 18-year period in 2% of the globe.

    According to data from the National Oceanic and Atmospheric Administration (NOAA), nine of the top 10 warmest years on record for the contiguous 48 states have occurred since 1998, and 2012 and 2016 were the two warmest years on record. Some parts of the United States have experienced more warming than others. According to NOAA, the North, the West, and Alaska have seen temperatures increase the most, while some parts of the Southeast have experienced little change. This warming trend is consistent with the long-term trend of global warming, primarily driven by human activities, particularly the burning of fossil fuels that release greenhouse gases into the atmosphere. 

    Chris Cappa, chair of the Department of Civil and Environmental Engineering, University of California, Davis has this to say…

    As usual, Steve Milloy is contributing to a disinformation campaign about the reality and seriousness of climate change through selective cherry picking of information. He conveniently ignores the undeniable global trend in surface temperatures to mention only the continental US, which is only 2% of the total Earth surface area. He misleads the public here by spinning a tale that is the equivalent of someone living in Chicago and saying they don’t believe that hurricanes are real because they’ve never seen one. Milloy peddles this same nonsense year after year and refuses to engage with the actual science.

    Note to Journalists/Editors: The expert quotes are free to use in your relevant articles on this topic. Please attribute them to their proper sources.

     

     

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    Newswise

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  • Researchers find several oceanic bottom circulation collapses in the past 4.7 million years

    Researchers find several oceanic bottom circulation collapses in the past 4.7 million years

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    Newswise — Antarctic bottom water (AABW) covers more than two-thirds of the global ocean bottom, and its formation has recently decreased. However, its long-term variability has not been well understood.

    Researchers led by Prof. DENG Chenglong from the Institute of Geology and Geophysics (IGG) of the Chinese Academy of Sciences (CAS) and their collaborators have reconstructed AABW history back to approximately 4.7 million years ago (mya). They found that AABW has collapsed several times and such collapses might have induced moisture transport to fuel the Northern Hemisphere glaciation (NHG).

    This work was published in Science Advances on Feb. 24.

    The study was based on a 36-mm-diameter Fe-Mn nodule from the Eastern Pacific, located 5,050 m below sea level. The nodule was collected by Guangzhou Marine Geological Survey, China Geological Survey.

    Magnetic scanning was an important factor in providing precise dating results. “This is a key, though the final dating was obtained by an integration with 10Be/9Be, flux of metal Co, and astronomical tuning,” said Dr. YI Liang from Tongji University, first author of the study and a postdoc at IGG/CAS.

    “Since AABW is the main provider of oxygen in the ocean bottom region, we used various scientific methods to identify the relation between metal accumulation in the Fe-Mn nodule and oceanic redox conditions,” said Prof. DENG. “Ni, Mn, and Cu contents are used to indicate AABW changes.”

    These results show that seawater oxygen has experienced a linear increase in the Eastern Pacific since around 3.4 mya. This trend agrees with the observation of the Antarctic Ice Sheet (AIS), suggesting a covariation between them.

    Comparing the AABW record with other geological records from the past million years, the researchers found a glacial enhancement of oceanic bottom circulation. This observation implies that atmospheric CO2 may have been regularly stored in the deep ocean when Earth’s climate was cold, e.g., during past glacial periods.

    The comparisons clearly highlighted seven intervals of poor seawater oxygen, suggesting AABW influence was reduced to a much lower level. These periods are known as AABW collapse and accompanied an enhancement of North Atlantic Deepwater (NADW) as well as key stages of NHG history, such as when NHG became intensified or amplified.

    Although we don’t know what will happen in response to ongoing AIS melting and AABW slowing, AABW collapse might have pulled the Earth into a harsher glacial climate several times in the past.

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    Chinese Academy of Sciences

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  • Feedback loops make climate action even more urgent, scientists say

    Feedback loops make climate action even more urgent, scientists say

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    Newswise — CORVALLIS, Ore. – An international collaboration led by Oregon State University scientists has identified 27 global warming accelerators known as amplifying feedback loops, including some that the researchers say may not be fully accounted for in climate models.

    They note that the findings, published today in the journal One Earth, add urgency to the need to respond to the climate crisis and provide a roadmap for policymakers aiming to avert the most severe consequences of a warming planet.

    In climate science, amplifying feedback loops are situations where a climate-caused alteration can trigger a process that causes even more warming, which in turn intensifies the alteration. An example would be warming in the Arctic, leading to melting sea ice, which results in further warming because sea water absorbs rather than reflects solar radiation.

    OSU College of Forestry postdoctoral scholar Christopher Wolf and distinguished professor William Ripple led the study, which in all looked at 41 climate change feedbacks.

    “Many of the feedback loops we examined significantly increase warming because of their connection to greenhouse gas emissions,” Wolf said. “To the best of our knowledge, this is the most extensive list available of climate feedback loops, and not all of them are fully considered in climate models. What’s urgently needed is more research and modeling and an accelerated cutback of emissions.”

    The paper makes two calls to action for “immediate and massive” emissions reductions:

    • Minimize short-term warming given that “climate disasters” in the form of wildfires, coastal flooding, permafrost thaw, intense storms and other extreme weather are already occurring.
    • Mitigate the possible major threats looming from climate tipping points that are drawing ever-closer due to the prevalence of the many amplifying feedback loops. A tipping point is a threshold after which a change in a component of the climate system becomes self-perpetuating.

    “Transformative, socially just changes in global energy and transportation, short-lived air pollution, food production, nature preservation and the international economy, together with population policies based on education and equality, are needed to meet these challenges in both the short and long term,” Ripple said. “It’s too late to fully prevent the pain of climate change, but if we take meaningful steps soon while prioritizing human basic needs and social justice, it could still be possible to limit the harm.”

    Ripple, Wolf and co-authors from the University of Exeter, the Potsdam Institute for Climate Impact Research, the Woodwell Climate Research Center and Terrestrial Ecosystems Research Associates considered both biological and physical feedbacks. Biological feedbacks include forest dieback, soil carbon loss and wildfire; physical feedbacks involve changes such as reduced snow cover, increased Antarctic rainfall and shrinking arctic sea ice.

    Even comparatively modest warming is expected to heighten the likelihood that the Earth will cross various tipping points, the researchers say, causing big changes in the planet’s climate system and potentially strengthening the amplifying feedbacks.

    “Climate models may be underestimating the acceleration in global temperature change because they aren’t fully considering this large and related set of amplifying feedback loops,” Wolf said. “The accuracy of climate models is crucial as they help guide mitigation efforts by telling policymakers about the expected effects of human-caused greenhouse gas emissions. While recent climate models do a much better job of incorporating diverse feedback loops, more progress is needed.”

    Emissions have risen substantially over the last century, the researchers note, despite several decades of warnings that they should be significantly curbed. The scientists say interactions among feedback loops could cause a permanent shift away from the Earth’s current climate state to one that threatens the survival of many humans and other life forms.

    “In the worst case, if amplifying feedbacks are strong enough, the result is likely tragic climate change that’s moved beyond anything humans can control,” Ripple said. “We need a rapid transition toward integrated Earth system science because the climate can only be fully understood by considering the functioning and state of all Earth systems together. This will require large-scale collaboration, and the result would provide better information for policymakers.”

    In addition to the 27 amplifying climate feedbacks the scientists studied were seven that are characterized as dampening – they act to stabilize the climate system. An example is carbon dioxide fertilization, where rising concentrations of atmospheric CO2 lead to increasing carbon uptake by vegetation.

    The effects of the remaining seven feedbacks, including increased atmospheric dust and reduced ocean stability, are not yet known.

    The paper in One Earth has a corresponding website that features more about climate feedback loops, including infographics and interactive animations.

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    Oregon State University

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  • UMD Smith to Add MS Climate Finance Track

    UMD Smith to Add MS Climate Finance Track

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    Newswise — The University of Maryland’s Robert H. Smith School of Business will offer a new track in climate finance to students in the Master of Finance and Master of Quantitative Finance degree programs, starting in spring 2024. 

    A Climate Finance Track Informational Webinar, 9-10 a.m. Tuesday Feb. 21, 2023, will preview the track, which adds four new elective courses to Smith’s current MS curriculum.

    These courses will teach students how to use climate modeling and analytics tools to assess climate change financial risks, how to navigate accounting rules around climate and carbon disclosures, and techniques used by asset and fund managers for valuing companies and assets based on their exposure to climate-related risks.

    The track also will incorporate an experiential learning project engaging small groups of students with a corporate or government sponsor on a consulting project related to climate finance and risk management.

    Financing projects to mitigate climate risk for companies and individuals and finding mechanisms to incent the transition from a fossil fuels-based economy to a green economy requires direct engagement with the financial services industry, says Professor of the Practice and Executive-in-Residence Clifford Rossi, one of the faculty members who will teach courses in the track. 

    “Asset management, banking, insurance, and other nonbank financial companies are critical stakeholders in these efforts,” he says. “The Federal Reserve, Bank of England, Securities and Exchange Commission and other regulatory agencies are developing rules and requirements for financial disclosures of climate-related risks for publicly traded corporations and scenario analysis for banking institutions.”

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    University of Maryland, Robert H. Smith School of Business

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  • First steps towards a more climate-friendly streaming

    First steps towards a more climate-friendly streaming

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    Newswise — In recent years, video streaming has increased significantly. While every German spent an average of 42 minutes a day watching online videos on YouTube, Netflix, Facebook or other platforms in 2019, a year later it was already 55 minutes – in the group of 14- to 29-year-olds even 130 minutes.

    This is bad news for the climate, since streaming requires enormous computer capacity and thus energy, which rarely comes from renewable sources. According to a 2019 study, video streaming activity accounted for about 60 percent of global data traffic in 2018, emitting 306 million tons of CO2, which was comparable to Spain’s annual emissions.

    Study in the Journal of Consumer Policy

    How can users reduce their energy consumption? This was investigated by a team of scientists from the Julius-Maximilians-Universität Würzburg (JMU). Dr. Benedikt Seger, research associate at the Institute of Psychology at JMU, was responsible for the study. The team has now published the results in the Journal of Consumer Policy.

    “Over a period of seven weeks, we investigated how people can reduce CO2 emissions when watching videos on the Internet,” explains Seger. Seger and his team used three different approaches t o help users change their streaming habits.
    First, they informed participants about the carbon footprint of online videos and showed them ways to improve it – for example, by switching from smart TVs to laptops, selecting a lower resolution, or turning off the Autoplay function. In a second step, they set a CO2 reduction target of 20 percent for some of them. In the third step, some of the study participants received additional weekly feedback on the carbon footprint of their streaming activities and whether they had met the agreed target.

    Information is the key to success

    The results were unequivocal: “It turned out that providing information at the end of the first week already led to a drop in CO2 consumption of up to 30 percent in the following weeks,” explains Seger. In contrast, the two subsequent stimuli – the 20 percent reduction target and the weekly feedback – had no additional effect.

    Reducing the streaming duration as well as choosing lower resolutions were responsible for the decrease. “From this, we conclude that individuals can improve the carbon footprint of their digital activities if they are provided with appropriate problem and action knowledge and keep a kind of diary of their activities,” Seger says.

    The study is part of the research focus “Climate Communication, Attitude and Behavior Change” at the Institute of Psychology at the University of Würzburg. Last year, the team already published a highly regarded study, according to which references on menus to the carbon footprint of dishes persuade people to reach for the more climate-friendly alternative more often. “With the present study, we want to direct the focus of the public climate discourse more strongly than before to digital areas of life,” says the psychologist.

    Streaming platforms can also make their contribution

    However, Seger does not see the responsibility resting solely with users. Rather, in his opinion, platform providers can also make a significant contribution to energy saving, for example by switching to climate-friendly default settings. Anyone who then calls up the respective website or opens an app would, in principle, be shown the videos in a low resolution. For higher quality, users have to take action. A deactivated Autoplay function should also be part of these standard settings. Then the next movie would not start automatically and immediately after the end of one.

    “Of course, it would be even more effective to convert the data centers to renewable energies,” says Seger. However, local, national and international decision-making bodies would have to set favorable framework conditions for this.

    https://www.uni-wuerzburg.de/en/news-and-events/news/detail/news/erste-schritte-zu-klimafreundlicherem-streamen/

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    University of Wurzburg

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  • Record low sea ice cover in the Antarctic

    Record low sea ice cover in the Antarctic

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    Newswise — There is currently less sea ice in the Antarctic than at any time in the forty years since the beginning of satellite observation: in early February 2023, only 2.20 million square kilometres of the Southern Ocean were covered with sea ice. Researchers from the Alfred Wegener Institute and the University of Bremen analyse the situation for the Sea Ice Portal. January 2023 had already set a new record for its monthly mean extent (3.22 million square kilometres), even though the melting phase in the Southern Hemisphere continues until the end of February. The current expedition team on board RV Polarstern has just reported virtually ice-free conditions in its current research area, the Bellingshausen Sea.

    “On 8 February 2023, at 2.20 million square kilometres, the Antarctic sea ice extent had already dropped below the previous record minimum from 2022 (2.27 million square kilometres on 24 February 2022). Since the sea ice melting in the Antarctic will most likely continue in the second half of the month, we can’t say yet when the record low will be reached or how much more sea ice will melt between now and then,” says Prof Christian Haas, Head of the Sea Ice Physics Section at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), with regard to the current developments in the Antarctic. “The rapid decline in sea ice over the past six years is quite remarkable, since the ice cover hardly changed at all in the thirty-five years before. It is still unclear whether what we are seeing is the beginning of a rapid end to summer sea ice in the Antarctic, or if it is merely the beginning of a new phase characterised by low but still stable sea ice cover in the summer.”

    The melting has progressed since December 2022, especially in the Bellingshausen and Amundsen Seas in the West Antarctic; the former is virtually ice-free. That is also where the research vessel Polarstern currently is, exploring the evidence left behind of past glacials and interglacials. According to expedition leader and AWI geophysicist Prof Karsten Gohl, who is now in the region for the seventh time, having first come in 1994: “I have never seen such an extreme, ice-free situation here before. The continental shelf, an area the size of Germany, is now completely ice-free. Though these conditions are advantageous for our vessel-based fieldwork, it is still troubling to consider how quickly this change has taken place.”

    In the course of the year, the Antarctic sea ice generally reaches its maximum extent in September or October and its minimum extent in February. In some regions, the sea ice melts completely in summer. In winter, the cold climate throughout the Antarctic promotes the rapid formation of new sea ice. At its maximum, the sea ice cover in the Antarctic is generally between 18 and 20 million square kilometres. In summer, it dwindles to roughly 3 million square kilometres, displaying far more natural annual variability than ice in the Arctic.

    Further, Antarctic sea ice is much thinner than its Arctic counterpart and appears only seasonally – which explains why, for a very long time, its development was considered impossible to predict beyond a matter of days. In recent years, however, science has uncovered several mechanisms for predicting the development of sea ice on seasonal time scales. Knowing the sea ice presence weeks to months in advance is of great interest to Antarctic shipping.

    Analyses of the current sea ice extent, conducted by the Sea Ice Portal team, show that, for the entire month of January 2023, the ice was at its lowest-ever extent recorded for the time of year since the beginning of record-keeping in 1979. The monthly mean value was 3.22 million square kilometres, ca. 478,000 square kilometres (an area roughly the size of Sweden) below the previous minimum from 2017. With regard to its long-term development, the Antarctic sea ice shows a declining trend of 2.6 percent per decade. This is the eighth consecutive year in which the mean sea-ice extent in January has been below the long-term trend.

    This intense melting could be due to unusually high air temperatures to the west and east of the Antarctic Peninsula, which were ca. 1.5 °C above the long-term average. In addition, the Southern Annular Mode (SAM) is in a strongly positive phase, which influences the prevailing wind circulation in the Antarctic. In a positive SAM phase (like today), a low-pressure anomaly forms over the Antarctic, while a high-pressure anomaly develops over the middle latitudes. This intensifies the westerly winds and causes them to contract toward the Antarctic. As a result, upwelling of circumpolar deep water on the continental shelf intensifies in the Antarctic, promoting sea-ice retreat. More importantly, it also intensifies the melting of ice shelves, an essential aspect for future global sea-level rise.

    Unravelling the geological evolution of the West Antarctic Ice Sheet, i.e., the massive glaciers that cover the Antarctic continent and fuel the ice shelves, is the proclaimed goal of the current Polarstern expedition. Doing so, it is hoped, will allow us to make more accurate statements on the ice sheet’s future development, and therefore on sea-level rise in the face of constant climate change. For example, the last interglacial, 120,000 years ago, and a prolonged warm period in the Pliocene roughly 3.5 million years ago, are considered analogous to today. In both past periods, the warming was exclusively due to gradual changes in Earth’s orbit – today, these are supplemented by carbon dioxide emissions, which are produced by the use of fossil fuels and accumulate in the atmosphere. The insights gleaned from the ice sheets’ history are intended to help estimate how rapidly and extensively they will melt when certain tipping points of today’s rapid anthropogenic climate change are exceeded. In this regard, researchers use geophysical and geological methods to investigate marine sediments at the sea floor, which, as archives of past ice-sheet movements, hold valuable information.

    Historical records also reflect the tremendous changes. For example, in the Antarctic summer 125 years ago, the Belgian research vessel Belgica was trapped in the massive pack ice for more than a year – in exactly the same region where the Polarstern can now operate in completely ice-free waters. The photographs and diaries of the Belgica’s crew offer a unique chronicle of the ice conditions in the Bellingshausen Sea at the dawn of the industrial age, which climate researchers often use as a benchmark for comparison with today’s climate change.

    You can find more detailed analyses at the Sea Ice Portal: https://www.meereisportal.de/.

    For the latest news from the Polarstern expedition, check out the Polarstern app https://follow-polarstern.awi.de/ or the Polarstern blog https://blogs.helmholtz.de/polarstern/en/ , not to mention the blog on the 125th anniversary of the Belgica expedition (English only): https://125yearsbelgica.com/

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    Alfred Wegener Institute for Polar and Marine Research

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