Cheap, sustainable hydrogen through solar power

Withstanding high temperatures and the light of 160 suns, a new catalyst is 10 times more efficient than previous sun-powered water-splitting devices of its kind

Peer-Reviewed Publication

UNIVERSITY OF MICHIGAN

Images and b-roll  //  Video  

A new kind of solar panel, developed at the University of Michigan, has achieved 9% efficiency in converting water into hydrogen and oxygen—mimicking a crucial step in natural photosynthesis. Outdoors, it represents a major leap in the technology, nearly 10 times more efficient than solar water-splitting experiments of its kind.

 

But the biggest benefit is driving down the cost of sustainable hydrogen. This is enabled by shrinking the semiconductor, typically the most expensive part of the device. The team's self-healing semiconductor withstands concentrated light equivalent to 160 suns.

 

Currently, humans produce hydrogen from the fossil fuel methane, using a great deal of fossil energy in the process. However, plants harvest hydrogen atoms from water using sunlight. As humanity tries to reduce its carbon emissions, hydrogen is attractive as both a standalone fuel and as a component in sustainable fuels made with recycled carbon dioxide. Likewise, it is needed for many chemical processes, producing fertilizers for instance.

"In the end, we believe that artificial photosynthesis devices will be much more efficient than natural photosynthesis, which will provide a path toward carbon neutrality," said Zetian Mi, U-M professor of electrical and computer engineering who led the study reported in Nature.

The outstanding result comes from two advances. The first is the ability to concentrate the sunlight without destroying the semiconductor that harnesses the light.

 

"We reduced the size of the semiconductor by more than 100 times compared to some semiconductors only working at low light intensity," said Peng Zhou, U-M research fellow in electrical and computer engineering and first author of the study. "Hydrogen produced by our technology could be very cheap."

 

And the second is using both the higher energy part of the solar spectrum to split water and the lower part of the spectrum to provide heat that encourages the reaction. The magic is enabled by a semiconductor catalyst that improves itself with use, resisting the degradation that such catalysts usually experience when they harness sunlight to drive chemical reactions. 

 

In addition to handling high light intensities, it can thrive in high temperatures that are punishing to computer semiconductors. Higher temperatures speed up the water splitting process, and the extra heat also encourages the hydrogen and oxygen to remain separate rather than renewing their bonds and forming water once more. Both of these helped the team to harvest more hydrogen.

 

For the outdoor experiment, Zhou set up a lens about the size of a house window to focus sunlight onto an experimental panel just a few inches across. Within that panel, the semiconductor catalyst was covered in a layer of water, bubbling with the hydrogen and oxygen gasses it separated.

 

The catalyst is made of indium gallium nitride nanostructures, grown onto a silicon surface. That semiconductor wafer captures the light, converting it into free electrons and holes—positively charged gaps left behind when electrons are liberated by the light. The nanostructures are peppered with nanoscale balls of metal, 1/2000th of a millimeter across, that use those electrons and holes to help direct the reaction. 

 

A simple insulating layer atop the panel keeps the temperature at a toasty 75 degrees Celsius, or 167 degrees Fahrenheit, warm enough to help encourage the reaction while also being cool enough for the semiconductor catalyst to perform well. The outdoor version of the experiment, with less reliable sunlight and temperature, achieved 6.1% efficiency at turning the energy from the sun into hydrogen fuel. However, indoors, the system achieved 9% efficiency.

 

The next challenges the team intends to tackle are to further improve the efficiency and to achieve ultrahigh purity hydrogen that can be directly fed into fuel cells.

 

Some of the intellectual property related to this work has been licensed to NS Nanotech Inc. and NX Fuels Inc., which were co-founded by Mi. The University of Michigan and Mi have a financial interest in both companies.

 

This work was supported by the National Science Foundation, the Department of Defense, the Michigan Translational Research and Commercialization Innovation Hub, the Blue Sky Program in the College of Engineering at the University of Michigan, and by the Army Research Office. 

 

Study: Solar-to-hydrogen efficiency of >9% in photocatalytic water splitting (DOI: 10.1038/s41586-022-05399-1) 

 

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JOURNAL

Nature

DOI

10.1038/s41586-022-05399-1 

A step towards solar fuels out of thin air

Peer-Reviewed Publication

ECOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE

 

IMAGE: KEVIN SIVULA IN HIS LAB view more 

CREDIT: ALAIN HERZOG / EPFL

A device that can harvest water from the air and provide hydrogen fuel—entirely powered by solar energy—has been a dream for researchers for decades. Now, EPFL chemical engineer Kevin Sivula and his team have made a significant step towards bringing this vision closer to reality. They have developed an ingenious yet simple system that combines semiconductor-based technology with novel electrodes that have two key characteristics: they are porous, to maximize contact with water in the air; and transparent, to maximize sunlight exposure of the semiconductor coating. When the device is simply exposed to sunlight, it takes water from the air and produces hydrogen gas. The results are published on 4 January 2023 in Advanced Materials.

What’s new? It’s their novel gas diffusion electrodes, which are transparent, porous and conductive, enabling this solar-powered technology for turning water – in its gas state from the air – into hydrogen fuel.

“To realize a sustainable society, we need ways to store renewable energy as chemicals that can be used as fuels and feedstocks in industry. Solar energy is the most abundant form of renewable energy, and we are striving to develop economically-competitive ways to produce solar fuels,” says Sivula of EPFL’s Laboratory for Molecular Engineering of Optoelectronic Nanomaterials and principal investigator of the study. 

 

 

 

Inspiration from a plant’s leaf

In their research for renewable fossil-free fuels, the EPFL engineers in collaboration with Toyota Motor Europe, took inspiration from the way plants are able to convert sunlight into chemical energy using carbon dioxide from the air. A plant essentially harvests carbon dioxide and water from its environment, and with the extra boost of energy from sunlight, can transform these molecules into sugars and starches, a process known as photosynthesis. The sunlight’s energy is stored in the form of chemical bonds inside of the sugars and starches. 

The transparent gas diffusion electrodes developed by Sivula and his team, when coated with a light harvesting semiconductor material, indeed act like an artificial leaf, harvesting water from the air and sunlight to produce hydrogen gas. The sunlight’s energy is stored in the form of hydrogen bonds. 

Instead of building electrodes with traditional layers that are opaque to sunlight, their substrate is actually a 3-dimensional mesh of felted glass fibers.

Marina Caretti, lead author of the work, says, "Developing our prototype device was challenging since transparent gas-diffusion electrodes have not been previously demonstrated, and we had to develop new procedures for each step. However, since each step is relatively simple and scalable, I think that our approach will open new horizons for a wide range of applications starting from gas diffusion substrates for solar-driven hydrogen production.”

 

From liquid water to humidity in the air

Sivula and other research groups have previously shown that it is possible to perform artificial photosynthesis by generating hydrogen fuel from liquid water and sunlight using a device called a photoelectrochemical (PEC) cell. A PEC cell is generally known as a device that uses incident light to stimulate a photosensitive material, like a semiconductor, immersed in liquid solution to cause a chemical reaction. But for practical purposes, this process has its disadvantages e.g. it is complicated to make large-area PEC devices that use liquid.

Sivula wanted to show that the PEC technology can be adapted for harvesting humidity from the air instead, leading to the development of their new gas diffusion electrode. Electrochemical cells (e.g. fuel cells) have already been shown to work with gases instead of liquids, but the gas diffusion electrodes used previously are opaque and incompatible with the solar-powered PEC technology.

Now, the researchers are focusing their efforts into optimizing the system. What is the ideal fiber size? The ideal pore size? The ideal semiconductors and membrane materials? These are questions that are being pursued in the EU Project “Sun-to-X”, which is dedicated to advance this technology, and develop new ways to convert hydrogen into liquid fuels.

 

 

Making transparent, gas-diffusion electrodes

 

In order to make transparent gas diffusion electrodes, the researchers start with a type of glass wool, which is essentially quartz (also known as silicon oxide) fibers and process it into felt wafers by fusing the fibers together at high temperature. Next, the wafer is coated with a transparent thin film of fluorine-doped tin oxide, known for its excellent conductivity, robustness and ease to scale-up. These first steps result in a transparent, porous, and conducting wafer, essential for maximizing contact with the water molecules in the air and letting photons through. The wafer is then coated again, this time with a thin-film of sunlight-absorbing semiconductor materials. This second thin coating still lets light through, but appears opaque due to the large surface area of the porous substrate. As is, this coated wafer can already produce hydrogen fuel once exposed to sunlight.

 

The scientists went on to build a small chamber containing the coated wafer, as well as a membrane for separating the produced hydrogen gas for measurement. When their chamber is exposed to sunlight under humid conditions, hydrogen gas is produced, achieving what the scientists set out to do, showing that the concept of a transparent gas- diffusion electrode for solar-powered hydrogen gas production can be achieved.

 

While the scientists did not formally study the solar-to-hydrogen conversion efficiency in their demonstration, they acknowledge that it is modest for this prototype, and currently less than can be achieved in liquid-based PEC cells. Based on the materials used, the maximum theoretical solar-to-hydrogen conversion efficiency of the coated wafer is 12%, whereas liquid cells have been demonstrated up to 19% efficient.

 

 

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JOURNAL

Advanced Materials

DOI

10.1002/adma.202208740 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Transparent Porous Conductive Substrates for Gas-Phase Photoelectrochemical Hydrogen Production

ARTICLE PUBLICATION DATE

4-Jan-2023

Over 330 fish species – up to 35 new to science – found in Bolivian national park

Study confirms the fish richness of the megadiverse Madidi National Park, Bolivia

Peer-Reviewed Publication

WILDLIFE CONSERVATION SOCIETY

 

IMAGE: STERNARCHORHYNCHUS HAGEDORNAE -- ONE OF 330 SPECIES IDENTIFIED IN A NEW SURVEY OF FRESHWATER FISH DIVERSITY OF MADIDI NATIONAL PARK IN BOLIVIA view more 

CREDIT: ROB WALLACE/WCS

The number of fish species recorded in Madidi National Park and Natural Integrated Management Area (PNANMI), Bolivia has doubled to a staggering 333 species – with as many as 35 species new to science – according of a study conducted as part of the Identidad Madidi expedition led by the Wildlife Conservation Society. The results are described in the latest issue of Neotropical Hydrobiology and Aquatic Conservation.

The study lists the fish species whose presence in Madidi has been confirmed, including those recorded during the Identidad Madidi expeditions, and a compilation of species occurrences listed in previous studies, providing an estimate of the total ichthyological richness for this protected area. The species list for the Madidi protected area includes 35 possible new species for science.

Species range in size from the invasive arapaima (Arapaima gigas), a mouth breathing giant weighing in at more than 200 kg and more than 3 m long, to the seasonally abundant killifish (Anablepsoides beniensis) from the Rivulidae family found in pools in natural savannas that are just 1.5 cm long. The list also includes the most attractive gamefish from the Amazon, the golden dorado (Salminus brasiliensis), as well as migratory catfish from the Amazonian goliath catfish (Brachyplatystoma filamentosum) to the tiny chipi chipi pencil catfish whose massive collective migration is a local phenomenon (Trichomycterus barbouri). Another killifish (Orestias sp.) is found in some of the highest Andean lakes at 4,300 m in Madidi, whilst in the stagnant ponds of the wonderful Amazon electric knife fish (Gymnotus carapo) and the swamp eel (Synbranchus madeirae), and in the fast-flowing streams of the Amazon headwaters, several species of naked catfish (Astroblepus spp.), including probable several new species for science.

The 35 possible new species for science includes candidates of the genus Knodus, Microgenys, Moenkhausia, Characidium, Apareiodon, Brachyhypopomus, Ernstichthys (genus reported for the first time in Bolivia), Astroblepus, Trichomycterus (including one species recently described and named in honor of a pioneer French ichthyologist in Bolivia), and a three-barbled catfish (Cetopsorhamdia), a striking pike cichlid (Crenicichla) and a charming bumblebee catfish (Microglanis), among others.

The biodiversity surveys and field research were conducted between 2015 to 2018 by specialists from the Wildlife Conservation Society (WCS), the Institut de Recherche pour le Développement de Montpellier (France) and the National Museum of Natural History and the Ecology Institute of the Universidad Mayor de San Andrés. Madidi is probably the world’s most biologically diverse protected area due to a unique altitudinal gradient of almost 6,000 m spanning the Tropical Andes and the Amazon.

For four years, the specialists conducted extensive ichthyological sampling at 13 sites in Madidi National Park, using different sampling techniques: electrofishing, gill nets, trawls, hook and line, and ichthyoplankton nets. Ichthyoplankton species were identified by genetic characterization (metabarcoding). A total of 333 species distributed in 43 families and 13 orders were recorded. This number doubles the previously known ichthyofauna (161) in Madidi.

The largest number of species are found in the order Characiformes (139 species; 41.7 percent), followed by Siluriformes (137 species; 41.1 percent), and Cichliformes (19 species; 5.7 percent), which together represent 88.6 percent of species richness. The remaining 11.4 percent is distributed in 10 other orders. The families with the highest number of species are the characids (73 species; 21.9 percent), loricariids (36; 10.8 percent), heptapterids (21; 6.3 percent), pimelodids (21; 6.3 percent) and cichlids (19; 5.7 percent).

Lead author of the study, Guido Miranda, of the Wildlife Conservation Society said “With an extension of 18,957.5 square kilometers (7,319 square miles), Madidi covers 1.3 percent of the Madeira River basin, but conserves 25 percent of the known species in the basin. Madidi also represents only 1.8 percent of the Bolivian territory, but it conserves almost 40 percent of the ichthyofauna recorded in Bolivia. This study has more than doubled our knowledge about fish diversity in this incredible protected area, but with several sub-basins yet to sample in the park, this is only the beginning”.

Dr. Rob Wallace, Senior Conservation Scientist at the Wildlife Conservation Society, leader of the Identidad Madidi expeditions, and coauthor, said “Due to its great diversity of habitats, mostly as a result of the altitudinal gradient from 184 meters (Heath River) to 6,044 meters (Chaupi Orko Peak), Madidi is considered the most biodiverse protected area on the planet. The Identidad Madidi initiative aimed to firmly establish this record-breaking status for the park, whilst communicating the importance of Madidi to the Bolivian people. This is the first of several biodiversity summary articles that the Bolivian scientists on the expedition are systematizing to share the results of our efforts with Bolivia and the world”.

Study authors include: Guido Miranda-Chumacero1, 3, Jaime Sarmiento2, Soraya Barrera2, Martin Velasco2, Jorge Molina-Rodriguez1,3, Gabriel Tarifa3, Camila Ramallo3, Oscar Ayala3, Kelvin Herbas3, Erick Loayza3, Débora Alvestegui3, Gustavo Alvarez1, Jean-François Renno4, Cédric Mariac4 & Robert B. Wallace1

1Wildlife Conservation Society, Bolivia Program, La Paz.

2Museo Nacional de Historia Natural, La Paz, Bolivia.

3Unidad de Ecología Acuática, Instituto de Ecología, Universidad Mayor de San Andrés, La Paz, Bolivia.

4Institut de Recherche pour le Development, Montpellier, France.

 

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JOURNAL

Neotropical Hydrobiology and Aquatic Conservation

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Ichthyofauna of the megadiverse Madidi National Park in the Bolivian Andean Amazon

Multidisciplinary, cross-border collaboration and stable levels of funding extend knowledge of the oceans

The authors analyzed 300 projects completed since 1972, of which 46 were supported under the auspices of the FAPESP Research Program for Biodiversity Characterization, Conservation, Restoration and Sustainable Use (BIOTA-FAPESP).

Peer-Reviewed Publication

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO

 

IMAGE: LOW TIDE AT PRAIA DA FORTALEZA, UBATUBA, SÃO PAULO STATE: MOST OCEANOGRAPHIC RESEARCH FOCUSES ON COASTAL AREAS view more 

CREDIT: MARIANA CABRAL DE OLIVEIRA/USP

The oceans are still less known than the Moon, but scientists have been exploring them more intensely in recent decades. Much of the research has been conducted with FAPESP’s support, as shown by a review of the literature produced by researchers at the University of São Paulo (USP), the Federal University of the ABC (FABC) and São Paulo State University (UNESP), and published in the journal Biota Neotropica. The article is part of a special issue dedicated to FAPESP’s sixtieth anniversary, which was commemorated in 2022. 

The authors analyzed 300 projects completed since 1972, of which 46 were supported under the auspices of the FAPESP Research Program for Biodiversity Characterization, Conservation, Restoration and Sustainable Use (BIOTA-FAPESP). Launched in 1999, BIOTA has significantly increased the number of ocean exploration research projects. The increase has been particularly strong since 2010, thanks to a 2009 call for proposals in this area.  

Another important contribution has come from 13 projects funded by the FAPESP Research Program on Global Climate Change (RPGCC), launched in 2008. 

“We can’t claim to have reviewed the state of the art in Brazilian ocean research. We focused on a specific angle. We didn’t analyze all the oceanographic studies conducted in Brazil, or even in São Paulo state, because we didn’t include projects funded by CNPq [the National Council for Scientific and Technological Development, an agency of the Ministry of Science, Technology and Innovation, MCTI] or by other funding agencies. On the other hand, to some extent the review does reflect all the work done in São Paulo and the rest of Brazil,” said Mariana Cabral de Oliveira, last author of the article. Oliveira is a professor at USP’s Institute of Biosciences and a former member of BIOTA’s steering committee (2009-18). 

As the oldest university in the state, USP already existed when FAPESP was set up, in 1962. It still accounts for a majority of the oceanographic projects funded by FAPESP: 66%, followed by UNESP and the State University of Campinas (UNICAMP), with 9% each; and the Federal University of São Paulo (UNIFESP), with 6%.

Until the 1980s, however, the differences were greater, with USP accounting for 82% of the total. The increase in the share of other institutions was partly due to the creation of new centers, such as UNESP’s São Paulo State Coast Campus (CLP) at São Vicente, established in 2002; UFABC, established in 2005; and UNIFESP’s Institute of Marine Sciences (IMAR), established in 2007. Historically, 47 public and private institutions have had marine research projects funded by FAPESP. 

Future challenges 

For the authors, FAPESP’s importance to oceanographic research reflects its strength in all research areas in São Paulo state and its influence on science nationally and globally, thanks to its commitment to multidisciplinary and cross-border collaboration, provision of research infrastructure, and relatively stable levels of funding. 

“The launch of a funding line for Thematic Projects in 1990 was important because it provided support for long-term projects involving larger networks of researchers who seek answers to questions that can’t be addressed by regular projects, which last two years,” Oliveira said.  

This vision, which was also reflected by the Genome Project (1997-2008), BIOTA, and RPGCC, together with bilateral cooperation agreements with foreign institutions, helped change the incremental approach prevalent hitherto by fostering an approach that was more ambitious both theoretically and in terms of being oriented to problem-solving. The most noteworthy feature of BIOTA, for example, is its integrated view of biodiversity as connecting biological and cultural elements.

For the future, the authors identify deep-sea research as a gap to be filled. Brazil has one of the world’s largest marine economic exclusive zones, mostly in waters deeper than 1,000 meters, and urgently needs a comprehensive program to support research projects targeting this enormous and complex ecosystem in all its dimensions. Most ongoing research projects focus on coastal waters. 

Although FAPESP has funded two oceanographic research vessels (the Alpha Crucis and Alpha Delphini), they are used less than they should be owing to high running costs. The problem could be solved by more collaboration among researchers from different institutions to share the expenses and train more people to do oceanographic research.  

Besides Oliveira (20/09406-3), the authors of the article are Antonio C. Marques (IB-USP), Alvaro Migotto and Marcelo V. Kitahara, (Center for Marine Biology, CEBIMAR-USP) (21/06866-6); Gustavo Muniz Dias (Center for Natural and Human Sciences CCNH-UFABC) (19/15628-1); and Tânia Marcia Costa (Institute of Biosciences, CLP-UNESP) (20/03171-4).  

About São Paulo Research Foundation (FAPESP)

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

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JOURNAL

Biota Neotropica

DOI

10.1590/1676-0611-BN-2022-1385 

METHOD OF RESEARCH

Systematic review

ARTICLE TITLE

Marine and coastal biodiversity studies, 60 years of research funding from FAPESP, what we have learned and future challenges

Map of ancient ocean ‘dead zones’ could predict future locations, impacts

Peer-Reviewed Publication

NORTH CAROLINA STATE UNIVERSITY

 

IMAGE: GLOBORATALOIDES HEXAGONUS SHELL RECOVERED FROM A DEEP-SEA SEDIMENT CORE IN THE TROPICAL PACIFIC OCEAN. view more 

CREDIT: CATHERINE DAVIS

Researchers have created a map of oceanic “dead zones” that existed during the Pliocene epoch, when the Earth’s climate was two to three degrees warmer than it is now. The work could provide a glimpse into the locations and potential impacts of future low oxygen zones in a warmer Earth’s oceans.

Oxygen minimum zones, or OMZs, are areas in the ocean where oxygen levels in the mid-waters (from 100 to 1000 meters below the surface) are too low to support most marine life. These dead zones play an important role in the ocean’s overall health.

“OMZs are very important for geochemical cycling in the ocean,” says Catherine Davis, assistant professor of marine, earth and atmospheric sciences at North Carolina State University and corresponding author of the research. “They occur in areas where sunlight and atmospheric oxygen don’t reach. Their locations dictate where carbon and nitrogen (an essential nutrient for all life on Earth) are available in the ocean – so they’re important drivers of nutrient cycles.”

Being able to predict the location of OMZs is important not only for understanding nutrient cycling, but also because of their effects on marine life. Oceanic dead zones restrict the range of animals to the shallow surface ocean where oxygen is more plentiful.

Davis and her colleagues wanted to figure out how a warmer climate might impact future OMZs. So they looked to the Pliocene epoch, (5.3 to 2.6 million years ago) when the Earth’s atmospheric CO2 levels were close to what they are now.

“The Pliocene is the last time that we had a stable, warm climate globally, and the average global temperature was 2 C to 3 C warmer than it is now – which is what scientists predict could be the case in about 100 years,” Davis says.

To determine where Pliocene OMZs were located, the researchers used tiny fossilized plankton called foraminifera. Foraminifera are single-celled organisms about the size of a large grain of sand. They form hard, calcium carbonate shells, which can stay in marine sediments.

One species in particular – Globorotaloides hexagonus – is found only in low oxygen zones. By combing through databases of Pliocene sediments to locate that species, the team was able to map Pliocene OMZs. They overlaid their map onto a computer model of Pliocene oxygen levels, and found that the two agreed with each other.

The OMZ map showed that during the Pliocene, low-oxygen waters were much more widespread in the Atlantic Ocean – particularly in the North Atlantic. The North Pacific, on the other hand, had fewer low-oxygen areas.

“This is the first global spatial reconstruction of oxygen minimum zones in the past,” Davis says. “And it’s in line with what we’re already seeing in the Atlantic in terms of lower oxygen levels. Warmer water holds less oxygen. This dead zone map from the Pliocene could give us a glimpse into what the Atlantic might look like 100 years from now on a warmer Earth.”

What would a future with much less oxygen in the Atlantic mean? According to Davis, it could have a big impact on everything from carbon storage and nutrient cycling in the ocean to how fisheries and marine species are managed.

“OMZs act as a ‘floor’ for marine animals – they get squished to the surface,” Davis says. “So fishermen may suddenly see a lot of fish, but it doesn’t mean that there are actually more than normal – they’re just being forced into a smaller space. Fisheries will need to take the effects of OMZs into account when managing populations.

“We may also see subtle but far-reaching changes concerning the amounts of nutrients available for life in those surface waters, as well as where CO2 taken up by the ocean is stored.”

The research appears in Nature Communications and was supported by the National Science Foundation (grant OCE-1851589). Davis began the research while a postdoctoral researcher at Yale. Postdoctoral researcher Elizabeth Sibert, Associate Professor of Geology and Geophysics Pincelli Hull, former Ph.D. student Peter Jacobs and Associate Professor of Atmospheric, Oceanic and Earth Sciences Natalie Burls, also contributed to the work. Sibert and Hull are at Yale, Burls is at George Mason University, and Jacobs, formerly at George Mason, is at NASA.

-peake-

Note to editors: An abstract follows.

“Intermediate water circulation drives distribution of Pliocene Oxygen Minimum Zones”

DOI: 10.1038/s41467-022-35083-x

Authors: Catherine Davis, Elizabeth Sibert, Pincelli Hull, Yale University; Peter Jacobs, Natalie Burls, George Mason University
Published: Jan. 4, 2023 in Nature Communications

Abstract:
Oxygen minimum zones (OMZs) play a critical role in global biogeochemical cycling and act as barriers to dispersal for marine organisms. OMZs are currently expanding and intensifying with climate change, however past distributions of OMZs are relatively unknown. Here we present evidence for widespread pelagic OMZs during the Pliocene (5.3-2.6 Mya), the most recent epoch with atmospheric CO2 analogous to modern (~ 400-450 ppm). The global distribution of OMZ-affiliated planktic foraminifer, Globorotaloides hexagonus, and Earth System and Species Distribution Models show that the Indian Ocean, Eastern Equatorial Pacific, eastern South Pacific, and eastern North Atlantic all supported OMZs in the Pliocene, as today. By contrast, low-oxygen waters were reduced in the North Pacific and expanded in the North Atlantic in the Pliocene. This spatially explicit perspective reveals that a warmer world can support both regionally expanded and contracted OMZs, with intermediate water circulation as a key driver.

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JOURNAL

Nature Communications

DOI

10.1038/s41467-022-35083-x 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

ntermediate water circulation drives distribution of Pliocene Oxygen Minimum Zones

ARTICLE PUBLICATION DATE

4-Jan-2023

New method helps understand the global organic carbon cycle

Peer-Reviewed Publication

MARUM - CENTER FOR MARINE ENVIRONMENTAL SCIENCES, UNIVERSITY OF BREMEN

Oceans serve as a sink for carbon. This means that carbon from the atmosphere is stored in the oceans. However, a distinction is made between organic and inorganic carbon. The organic carbon bound in marine sediments is also a source of oxygen. Until now, it has been common practice to determine the mass balance between inorganic and organic carbon – but this method is considered inaccurate. A team from the USA, Great Britain and Germany has now developed a different approach. Their goal was to be able to better determine the rate of carbon over a longer period of time.

To do this, they used data from deep-sea drilling at 81 global sites to determine the history of organic carbon burial during the Neogene (about 23 to 3 million years ago). This approach makes it possible to better determine the variability over such a long period of time.

”Our results support the assumption that rates were high in the early Miocene and Pliocene and low in the middle Miocene,” explains first author Dr. Ziye Li from MARUM – Center for Marine Environmental Sciences at the University of Bremen. “We calculated the mass accumulation rate of organic carbon directly from the organic carbon content of marine sediments. This is possible thanks to standardized measurements combined with well validated age models from sites from the international drilling program IODP and its predecessors DSDP and ODP. Traditionally, estimates have been based on the isotopic composition of carbon, which requires, among other things, a number of assumptions about carbon sources and key fluxes within the carbon cycle,” says Li, who works at MARUM in the Low Latitude Climate Variability group.

“Our new results are very different – they are the opposite of what the isotope calculations are suggesting,” says co-author Benjamin Mills from the University of Leeds, an expert on the established isotope methods. “I was really surprised how wrong our current ideas might be.”

Li and her colleagues assume that carbon sequestration, or rather its absence, is related to temperature-dependent bacterial decomposition of organic matter during the warm period of the middle Miocene. Thus, this feedback mechanism would be expected to play out during other warming intervals in Earth's history, as well as in any future warming of the global ocean.

“As we warm up the ocean, it will make it harder for organic carbon to find its way to be buried in the marine sediment system, and that is what we have found in our study – the lowest rates of carbon sequestration happen when the planet was warm”, said co-author Yige Zhang of Texas A&M University. “So that’s not helping from this perspective, in terms of the issues that we’re facing in the present day.”

However, the team's research suggests that this respiration-like process prevents organic carbon sequestration from reducing carbon dioxide emissions to the atmosphere. When bacteria process the organic carbon, it is returned to its original form as CO2.

First author Ziye Li calls the team's work the beginning of a potentially significant new method for data analysis that can help understand climate change and mitigate its effects.

Original publication:
Ziye Li, Yi Ge Zhang, Mark Torres and Benjamin J. W. Mills: Neogene burial of organic carbon in the global ocean. Nature 2023. DOI: 10.1038/s41586-022-05413-6

MARUM produces fundamental scientific knowledge about the role of the ocean and the ocean floor in the total Earth system. The dynamics of the ocean and the ocean floor significantly impact the entire Earth system through the interaction of geological, physical, biological and chemical processes. These influence both the climate and the global carbon cycle, and create unique biological systems. MARUM is committed to fundamental and unbiased research in the interests of society and the marine environment, and in accordance with the Sustainable Development Goals of the United Nations. It publishes its quality-assured scientific data and makes it publicly available. MARUM informs the public about new discoveries in the marine environment and provides practical knowledge through its dialogue with society. MARUM cooperates with commercial and industrial partners in accordance with its goal of protecting the marine environment.

 

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JOURNAL

Nature

DOI

10.1038/s41586-022-05413-6 

DRI leading $5 million regional climate adaptation project

DRI is partnering with Scripps Institution of Oceanography to build climate resiliency through the California Nevada Adaptation Program (CNAP)

Business Announcement

DESERT RESEARCH INSTITUTE

Reno, Nev. (January 4, 2023) - The impacts of climate change have been acute in California and Nevada, with most of the last two decades spent in extended drought conditions and 2021 wildfires producing Reno’s worst recorded air quality in the 21st century. Adapting to these challenges will require not only focused research to better predict climatic events, but will also depend on empowering local communities to use this knowledge to make informed decisions in the face of adversity. With $5 million in funding from NOAA’s Climate Adaptation Partners initiative, the California Nevada Adaptation Program (CNAP) will spend the next five years bringing together researchers, community members, and practitioners to cooperatively conduct research and identify solutions.

For the first time, CNAP will be hosted in Nevada under the leadership of DRI’s Tamara Wall, Ph.D., research professor of atmospheric science and deputy director of the Western Regional Climate Center (WRCC). DRI’s long-standing partnership with Scripps Institution of Oceanography at the University of California San Diego will continue, with Dan Cayan, Ph.D., regional climate researcher and CNAP lead since its founding in 1999, and Julie Kalansky, Ph.D., who has served as CNAP program manager for six years, joining Wall to lead the project.

“The goal of CNAP has always been to expand more fully across the California and Nevada region,” Wall says. “This is the first time that DRI is leading CNAP, and it’s also the first time that CNAP is a system-wide effort. Bringing on partners from UNLV and UNR is important for meeting that goal and will help us address climate change impacts across the state.”

California and Nevada have partnered for the CNAP program since 2011, producing research and results that include: the first Nevada Climate Assessment; California’s Fourth Climate Change Assessment; recommendations for updating red flag warnings and the fire weather watch system; and analyses of water use and supply in California’s agricultural communities.

The next five years will focus on adaptation, with an intentional transition from statewide climate research toward preparing communities for local-level action to address regional climate hazards. Six projects will support adaptation needs to address four of the most pressing climate issues in the region: extreme heat, wildfire smoke, coastal flooding, and water scarcity.

As part of the project’s commitment to equity and diversity, it will include a mentorship program within community colleges to prepare the future’s workforce to address climate impacts. In addition, a small grants program, Building Capacity through Reciprocity with Tribal Communities, will work to enact community-identified solutions for tribal communities by supporting a Leaders Indigenous Climate Fellowship Program.

“Centering CNAP’s research on adaptation allows us to focus on producing community-centered solutions,” Wall says. “Impacts from climate change are expected to amplify in the coming decades, and disadvantaged communities are the least able to manage those impacts without additional support. Our research includes community partners so that we can adequately understand community needs and concerns and actually improve people’s lives.”

 

Research Focus Areas

Extreme Heat

Highlights for planned research include creating the Southern Nevada Heat Resilience Lab (SNHRL), a regionally focused program that will bring together public service providers, including emergency responders and social services workers, with scientific experts on extreme heat. Real-time air temperature sensors will be installed in at-risk neighborhoods within Las Vegas, targeting locations such as public transit stops and buses, cooling centers, places with outdoor laborers, and unhoused communities. Following a trial period in Las Vegas, the project aims to expand local heat sensor networks to rural and Indigenous communities, where heat impacts are less well studied and understood.

Water Resiliency

In order to help California prepare a more resilient workforce in the face of growing issues with water availability, CNAP will partner with community colleges in the San Joaquin Valley to create climate-related workforce training opportunities. The goal is to create a more climate-technical workforce to support community adaptation to changes in water availability and climate extremes. 

Coastal Erosion

Southern California is lined with some of the most heavily used beaches on the West coast, and this region is likely to experience increased flooding and erosion due to sea-level rise. CNAP will partner with collaborators to explore nature-based solutions and Indigenous stewardship as coastal adaptation strategies.

Public Health in the Face of Extreme Heat and Wildfire Smoke

California and Northern Nevada are increasingly experiencing extreme weather conditions with overlapping heat waves and intense wildfires. CNAP will explore the public health impacts of these events by directly assessing a sample of households in Washoe County, Nevada. Research will include installing air sensors to monitor heat exposure and air pollution, conducting interviews to understand decision-making under environmentally challenging conditions, and baseline health monitoring.

Understanding Burnout in Climate Change Professionals

Previous CNAP research has shown that climate change professionals are experiencing high rates of burnout, and institutional support isn’t yet providing adequate resources to this population. CNAP will continue this line of study by evaluating the traits and communities that lead to more psychological resiliency and developing training materials based on the results for the CNAP team and partner networks.

State Climate Assessments

Both California and Nevada will likely produce new statewide climate assessments within the next five years, and CNAP will continue to coordinate among state and local efforts. CNAP will also pilot a mentoring program focused on early career faculty at universities and colleges in California and Nevada.

“NOAA Climate Adaptation Partnerships (CAP, formerly Regional Integrated Sciences and Assessments, or ‘RISA’) advances equitable adaptation through sustained regional research and community engagement,” says Caitlin Simpson, program manager, NOAA Climate Adaptation Partnerships. “Climate affects every part of society, and this is most visible to us when we see long-term changes in social and environmental conditions, increased unpredictability, and extreme weather events. We seek to help people plan for and adjust to a changing climate by supporting long-lasting partnerships among scientists, decision makers, and communities. The result is a shared understanding about society’s needs and the co-generation of credible and actionable knowledge to support community solutions. We work within regions composed of multiple U.S. state/territory jurisdictions which share similar climates and cultures.” 

“CNAP’s long history in the CAP/RISA program dates from 1997, and features many accomplishments, including substantial scientific contributions to all five of California’s climate assessments in close partnership with the state government,” continued Simpson. “CNAP has achieved deep expertise on sea level rise, drought, water resources, and wildfire planning issues and has closely partnered with a number of federal and nonfederal partners to advance local, state, and regional planning around these issues. The NOAA Climate Program Office is thrilled to fund the California-Nevada Climate Applications Program (CNAP) team for another five years as a part of the CAP/RISA Network.”

 

More information:

For additional information about CNAP visit: https://www.dri.edu/cnap/

CNAP Principal Investigators include Tamara Wall (DRI), Julie Kalansky (Scripps), and Daniel Cayan (Scripps).

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About DRI

The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.

 

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METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People