ALBERT

Description: CO2 injection has been deemed a promising method for CH4 production from gas hydrate-bearing sediments for its potential in stabilizing the host sediments and balancing carbon emission. However, the process is yet to be fully understood, as it involves interactions of multi-physical and chemical processes including the generation of water-immiscible CH4–CO2 fluid mixtures, the evolution of chemical reaction kinetics for both CH4 and CO2 hydrates, heat emission and absorption during hydrate formation and dissociation, and stress redistribution caused by spatially evolving responses of CH4–CO2 hydrate-bearing sediments. This paper develops a coupled thermo-hydro-chemo-mechanical formulation that captures the complexity of these processes and applies it to investigate the behavior of CH4 hydrate-bearing sediments subjected to CO2 injection. The capabilities of this coupled formulation are validated through numerical simulations of laboratory experiments of CO2 injection into CH4 hydrate-bearing soil. Moreover, the application of this formulation in a field-scale scenario reveals insights into the efficiencies of CH4 production and CO2 storage and the geomechanical implications. Notably, the study finds that compared to the depressurization-only method, the combined hot CO2 injection and depressurization method could increase CH4 production by approximately 400%. In addition, this method could sequester about 70% of injected CO2 into solid hydrates, while exhibiting smaller maximum slope of differential displacement. These outcomes highlight the viability and benefits of CH4 hydrate production through CO2 injection, increasing the prospects of this approach.

Description: Suspended particulate matter (SPM) carries a major fraction of metals in turbid coastal waters, markedly influencing metal bioaccumulation and posing risks to marine life. However, its effects are often overlooked in current water quality criteria for metals, primarily due to challenges in quantifying SPM’s contribution. This contribution depends on the SPM concentration, metal distribution coefficients (Kd), and the bioavailability of SPM-bound metals (assimilation efficiency, AE), which can collectively be integrated as a modifying factor (MF). Accordingly, we developed a new stable isotope method to measure metal AE by individual organisms from SPM, employing the widely distributed filter-feeding clam Ruditapes philippinarum as a representative species. Assessing SPM from 23 coastal sites in China, we found average AEs of 42% for Zn, 26% for Cd, 20% for Cu, 8% for Ni, and 6% for Pb. Moreover, using stable isotope methods, we determined metal Kd of SPM from these sites, which can be well predicted by the total organic carbon and iron content (R2 = 0.977). We calculated MFs using a Monte Carlo method. The calculated MFs are in the range 9.9-43 for Pb, 8.5-37 for Zn, 2.9-9.7 for Cu, 1.4-2.7 for Ni, and 1.1-1.6 for Cd, suggesting that dissolved-metal-based criteria values should be divided by MFs to provide adequate protection to aquatic life. This study provides foundational guidelines to refine water quality criteria in turbid waters and protect coastal ecosystems.

Description: There is only sparse empirical data on the settling velocity of small, nonbuoyant microplastics thus far, although it is an important parameter governing their vertical transport within aquatic environments. This study reports the settling velocities of 4031 exemplary microplastic particles. Focusing on the environmentally most prevalent particle shapes, irregular microplastic fragments of four different polymer types (9-289 mu m) and five discrete length fractions (50-600 mu m) of common nylon and polyester fibers are investigated, respectively. All settling experiments are carried out in quiescent water by using a specialized optical imaging setup. The method has been previously validated in order to minimize disruptive factors, e.g., thermal convection or particle interactions, and thus enable the precise measurements of the velocities of individual microplastic particles (0.003-9.094 mm/s). Based on the obtained data, ten existing models for predicting a particle's terminal settling velocity are assessed. It is concluded that models, which were specifically deduced from empirical data on larger microplastics, fail to provide accurate predictions for small microplastics. Instead, a different approach is highlighted as a viable option for computing settling velocities across the microplastics continuum in terms of size, density, and shape

Description: Im Rahmen des Projektes „Aufbau und Betrieb eines erweiterten umweltsensitiven Verkehrsmanagementsystems in Berlin (eUVM)“ wird die mögliche Aufhebung der Tempo-30-Zone in der Leipziger Straße und die Rückkehr zu Tempo 50 untersucht. In diesem Zwischenbericht werden die ersten Ergebnisse einer Messkampagne rund um die Leipziger Straße vorgestellt, insbesondere die Erfassung von Rad- und Fußverkehr und die Befragungen beider Gruppen bezüglich deren geschätzter Sicherheit.

Description: L’alimentation est à la fois un levier central pour engager la transition socio-écologique et un theme quotidien tangible pour chaque citoyen.ne. En Allemagne comme en France, quelques collectivités territoriales engagent des mesures innovantes pour promouvoir une alimentation locale et durable. Le Forum pour l’avenir franco-allemand s’est penché sur les expériences de certaines de ces collectivités et a facilité le dialogue entre elles durant plusieurs mois afin de comprendre quelles politiques nationales peuvent soutenir de telles initiatives locales. En associant des expert.e.s issus de la sphère scientifique, de l’administration et de la société civile, il a recommandé de « Donner la priorité au développement de systèmes alimentaires locaux et durables » avec cinq propositions d’action concrètes aux gouvernements français et allemand. Cette étude présente les initiatives françaises et allemandes ayant nourri les propositions d’action du Forum pour l’avenir.

Description: Food and food policy is central to social-ecological transformation. It is also an everyday issue that is easy to communicate to citizens. Municipalities in Germany and France have recognized the potential of innovative local food policies and have developed and tested innovative approaches to transforming local food systems. However, they are encountering structural barriers that cannot be overcome at the municipal level. The Franco-German Forum for the Future has researched the opportunities and obstacles of local nutritional change and brought engaged municipalities from both countries into exchange with each other. Together with experts from academia, public administrations and civil society, it has developed the seven recommendations for the national governments, one of which concerns "Prioritizing the development of local and sustainable food systems" with five proposals for action. This study is intended as a background paper to the Recommendation. With recourse to the concrete example of Mouans-Sartoux and other municipalities in France and Germany, it describes the potentials of a sustainable municipal food policy and provides – from concrete local practice – the background knowledge for each of the five proposals for action.

Description: Technologien für CO₂-Abscheidung und -Speicherung machen Hoffnung, werden aber gleichzeitig als Rechtfertigung für die geringe Reduktion von Emissionen aus fossilen Energiequellen genutzt. Das ist nicht vereinbar mit dem Ziel, die Erderwärmung auf 1,5 oder 2 °C zu begrenzen.

Description: Sea spray aerosols (SSA) greatly affect the climate system by scattering solar radiation and acting as seeds for cloud droplet formation. The ecosystems in the Arctic Ocean are rapidly changing due to global warming, and the effects these changes have on the generation of SSA, and thereby clouds and fog formation in this region, are unknown. During the ship-based Arctic Century Expedition, we examined the dependency of forced SSA production on the biogeochemical characteristics of seawater using an on-board temperature-controlled aerosol generation chamber with a plunging jet system. Our results indicate that mainly seawater salinity and organic content influence the production and size distribution of SSA. However, we observed a 2-fold higher SSA production from waters with similar salinity collected north of 81°N compared to samples collected south of this latitude. This variability was not explained by phytoplankton and bacterial abundances or Chlorophyll-a concentration but by the presence of glucose in seawater. The synergic action of sea salt (essential component) and glucose or glucose-rich saccharides (enhancer) accounts for 〉80% of SSA predictability throughout the cruise. Our results suggest that besides wind speed and salinity, SSA production in Arctic waters is also affected by specific organics released by the microbiota.

Description: In this paper, the authors discuss the role of China in the emerging geopolitics of hydrogen. It begins with a review of China's external energy policy and its evolution over the past decades, highlighting China's transition to a net-energy importer as an important inflection point in that process. It then goes on to describe the main pillars of China's national hydrogen policy. Building on this the paper provides and overview of China's external hydrogen policy and how this aligns with both its broader energy foreign policy and its hydrogen policy objectives. The paper finds that China’s hydrogen strategy – both internal and external – are still at an emergent stage. National targets remain modest, and policy remains ambiguous regarding the preferred production pathway. China’s long-term vision clearly emphasizes the role of renewable hydrogen to help balance an energy system dominated by wind and solar energy. However, current policy provides ample space for the promotion of other forms of hydrogen production. Rather, than a strong, centralized policy approach, local and provincial governments along with SOEs have been driving investment and policy experimentation in the sector, which includes efforts to boost fossil-based hydrogen production.

Description: This chapter reviews Japan’s hydrogen strategy with a particular focus on its international elements. It begins by outlining Japan’s international commitment to reduce economy-wide greenhouse gas emissions. The chapter then reviews Japan's domestic policy settings designed to support the deployment of hydrogen in power generation, transport, and industrial uses. The chapter then reviews the strategy that the government is using to enable the development of international supply chains to enable the required imports to satisfy projected hydrogen use in the country. It outlines bilateral technology partnerships and international activities within multilateral forums. It concludes with a short discussion of the geopolitical implications of Japan's hydrogen strategy. Japan has been at the forefront of global efforts to increase the role of hydrogen and ammonia as an option for supporting decarbonization. Japan’s government is positioning hydrogen to play a large role in its overall decarbonisation strategy in support of its mid-century, net zero emissions reduction goal. In this context, the Japanese government is supporting the development of technologies on both the supply and demand side, informed by its understanding of feasible decarbonization pathways domestically and the industrial policy opportunities it has identified to promote Japan's technological leadership. Key features of Japan’s strategy are the central focus on the need to import hydrogen and ammonia and the emphasis domestically on the use of hydrogen and ammonia co-combustion in existing thermal power generation as a transition technology, which is not emphasised in other countries’ national hydrogen strategies. In addition, the Japanese government is championing hydrogen and ammonia internationally through forums such as AZEC, which includes proposing ammonia as a technology option for reducing emissions from the power sector in the Asia-Pacific. A key near-term focus on the supply-side is testing the feasibility of different technology options for hydrogen transport, based on the strong emphasis on hydrogen and ammonia imports within Japan’s hydrogen strategy. Coupled with the potential for exporting technologies for hydrogen use, this suggests that new patterns of trade and investment may emerge, although there remain crucial questions about commercial feasibility in addition to technical challenges. Indeed, Japan’s hydrogen strategy is predicated on the ability to build international supply chains at scale. These are currently being enabled by public investment in early-stage projects. These testing different technology options to enable the export of hydrogen to Japan to support domestic decarbonization. Another challenge lies in unlocking hydrogen demand given that processes using hydrogen and ammonia remain more expensive than alternatives in most cases. A case in point is FCVs, in which consumer demand remains far lower than envisioned. In response, the Japanese government is developing a series of policies to reduce the gap between hydrogen and ammonia and best available technologies. The revised 2023 NHS also signalled a shift towards emphasising Japan’s technology leadership in fuel cells and taking a more neutral approach towards end-use sectors. We can expect Japan’s national hydrogen strategy to continue to develop in response to the effectiveness of policies implemented domestically and internationally to increase the demand for, and supply of hydrogen and associated vectors.

Description: Petroleum substances, as archetypical UVCBs (substances of unknown or variable composition, complex reaction products, or biological substances), pose a challenge for chemical risk assessment as they contain hundreds to thousands of individual constituents. It is particularly challenging to determine the biodegradability of petroleum substances since each constituent behaves differently. Testing the whole substance provides an average biodegradation, but it would be effectively impossible to obtain all constituents and test them individually. To overcome this challenge, comprehensive two-dimensional gas chromatography (GC × GC) in combination with advanced data-handling algorithms was applied to track and calculate degradation half-times (DT50s) of individual constituents in two dispersed middle distillate gas oils in seawater. By tracking 〉1000 peaks (representing ∼53–54% of the total mass across the entire chromatographic area), known biodegradation patterns of oil constituents were confirmed and extended to include many hundreds not currently investigated by traditional one-dimensional GC methods. Approximately 95% of the total tracked peak mass biodegraded after 64 days. By tracking the microbial community evolution, a correlation between the presence of functional microbial communities and the observed progression of DT50s between chemical classes was demonstrated. This approach could be used to screen the persistence of GC × GC-amenable constituents of petroleum substance UVCBs.

Description: In 2021, the United Nations Environment Programme (UNEP) recognized chemical pollution as a planetary crisis tantamount to climate change and biodiversity decline. (1) In an important next step, the international community agreed in March 2022 on establishing an independent, intergovernmental science–policy panel on chemicals, waste, and pollution prevention (hereafter termed “the Panel”). (2) This Panel will take its place among two other intergovernmental bodies, the Intergovernmental Panel on Climate Change (IPCC) (3) and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). (4) Now is a crucial time for establishing the Panel, following a process facilitated by UNEP to negotiate the Panel’s scope, functions, and institutional design, with the ambition to formally establish the Panel in 2024. As a group of international scientists working on chemical pollution, we applaud this milestone of progress to initiate the establishment of a panel for chemicals, waste, and pollution prevention. At the beginning of the negotiating process, we would like to highlight the following 10 critical aspects for consideration in determining the settings of the Panel.

Description: Pathologic hyperreactive inflammatory responses occur when there is excessive activation of a proinflammatory NF-kappa B pathway and a reduced cytoprotective NRF2 cascade. The noncytotoxic, highly selective COX-2 inhibitory flavonol-enriched butanol fraction (UaB) from Uvaria alba (U. alba) was investigated for its inflammatory modulating potential by targeting NF-kappa B activation and NRF2 activity. Enzyme-linked immunosorbent assay was initially performed to measure levels of proinflammatory mediators [nitric oxide (NO), prostaglandin E2, and reactive oxygen species (ROS)] and cytokines [tumor necrosis factor-alpha (TNF-alpha), IL-1 beta, and IL-6], followed by reverse transcription-polymerase chain reaction and western blotting to determine mRNA and protein expression, respectively. Using immunofluorescence staining combined with western blot analysis, the activation of NF-kappa B was further investigated. NRF2 activity was also measured using a luciferase reporter assay. UaB abrogated protein and mRNA expressions of inducible nitric oxide synthase (iNOS), COX-2, TNF-alpha, IL-1 beta, and IL-6 in RAW 264.7 macrophages, thereby suppressing the production of proinflammatory mediators and cytokines. This was further validated when a concentration-dependent decrease in NO and ROS production was observed in zebrafish (Danio rerio) larvae. UaB also increased NRF2 activity in HaCaT/ARE cell line and attenuated NF-kappa B activation by inhibiting the nuclear translocation of transcription factor p65 in RAW 264.7 macrophages. Nontargeted LC- MS analysis of UaB revealed the presence of the flavonols quercitrin (1), quercetin (2), rutin (3), kaempferol (4), and kaempferol 3O-rutinoside (5). Molecular docking indicates that major flavonol aglycones have high affinity toward COX-2 NSAID-binding sites, TNF-alpha, and TNF-alpha converting enzyme, while the glycosylated flavonoids showed strong binding toward iNOS and IKK-all possessing dynamic stability when performing molecular dynamics simulations at 140 ns. This is the first report to have elucidated the mechanistic anti-inflammatory potential of the Philippine endemic plant U. alba.

Description: Microplastics (MP) including tire wear particles (TWP) are ubiquitous. However, their mass loads, transport, and vertical behavior in water bodies and overlying air are never studied simultaneously before. Particularly, the sea surface microlayer (SML), a ubiquitous, predominantly organic, and gelatinous film (〈1 mm), is interesting since it may favor MP enrichment. In this study, a remote-controlled research catamaran simultaneously sampled air, SML, and underlying water (ULW) in Swedish fjords of variable anthropogenic impacts (urban, industrial, and rural) to fill these knowledge gaps in the marine-atmospheric MP cycle. Polymer clusters and TWP were identified and quantified with pyrolysis-gas chromatography–mass spectrometry. Air samples contained clusters of polyethylene terephthalate, polycarbonate, and polystyrene (max 50 ng MP m–3). In water samples (max. 10.8 μg MP L–1), mainly TWP and clusters of poly(methyl methacrylate) and polyethylene terephthalate occurred. Here, TWP prevailed in the SML, while the poly(methyl methacrylate) cluster dominated the ULW. However, no general MP enrichment was observed in the SML. Elevated anthropogenic influences in urban and industrial compared to the rural fjord areas were reflected by enhanced MP levels in these areas. Vertical MP movement behavior and distribution were not only linked to polymer characteristics but also to polymer sources and environmental conditions.

Description: Marine dissolved organic matter (DOM) presents key thermodynamic properties that are not yet fully constrained. Here, we report the distribution of binding sites occupied by protons (i.e., proton affinity spectra) and parametrize the median intrinsic proton binding affinities (log K̅H) and heterogeneities (m), for DOM samples extracted from the North Atlantic. We estimate that 11.4 ± 0.6% of C atoms in the extracted marine DOM have a functional group with a binding site for ionic species. The log K̅H of the most acidic groups was larger (4.01–4.02 ± 0.02) than that observed in DOM from coastal waters (3.82 ± 0.02), while the chemical binding heterogeneity parameter increased with depth to values (m1= 0.666 ± 0.009) ca. 10% higher than those observed in surface open ocean or coastal samples. On the contrary, the log K̅H for the less acidic groups shows a difference between the surface (10.01 ± 0.08) and deep (9.22 ± 0.35) samples. The latter chemical groups were more heterogeneous for marine than for terrestrial DOM, and m2 decreased with depth to values of 0.28 ± 0.03. Binding heterogeneity reflects aromatic carbon compounds’ persistence and accumulation in diverse, low-abundance chemical forms, while easily degradable low-affinity groups accumulate more uniformly in the deep ocean.

Description: Nitric oxide (NO) is an atmospheric pollutant and climate forcer as well as a key intermediary in the marine nitrogen cycle, but the ocean’s NO contribution and production mechanisms remain unclear. Here, high-resolution NO observations were conducted simultaneously in the surface ocean and the lower atmosphere of the Yellow Sea and the East China Sea; moreover, NO production from photolysis and microbial processes was analyzed. The NO sea–air exchange showed uneven distributions (RSD = 349.1%) with an average flux of 5.3 ± 18.5 × 10–17 mol cm–2 s–1. In coastal waters where nitrite photolysis was the predominant source (89.0%), NO concentrations were remarkably higher (84.7%) than the overall average of the study area. The NO from archaeal nitrification accounted for 52.8% of all microbial production (11.0%). We also examined the relationship between gaseous NO and ozone which helped identify sources of atmospheric NO. The sea-to-air flux of NO in coastal waters was narrowed by contaminated air with elevated NO concentrations. These findings indicate that the emissions of NO from coastal waters, mainly controlled by reactive nitrogen inputs, will increase with the reduced terrestrial NO discharge.

Description: Plastic is a widespread marine pollutant, with most studies focusing on the distribution of floating plastic debris at the sea surface. Recent evidence, however, indicates a significant presence of such low density plastic in the water column and at the seafloor, but information on its origin and dispersion is lacking. Here, we studied the pathways and fate of sinking plastic debris in the Mediterranean Sea, one of the most polluted world seas. We used a recent Lagrangian plastic-tracking model, forced with realistic parameters, including a maximum estimated sinking speed of 7.8 m/d. Our simulations showed that the locations where particles left the surface differed significantly from those where they reached the seafloor, with lateral transport distances between 119 and 282 km. Furthermore, 60% of particles deposited on the bottom coastal strip (20 km wide) were released from vessels, 20% from the facing country, and 20% from other countries. Theoretical considerations furthermore suggested that biological activities potentially responsible for the sinking of low density plastic occur throughout the water column. Our findings indicate that the responsibility for seafloor plastic pollution is shared among Mediterranean countries, with potential impact on pelagic and benthic biota.

Description: Total alkalinity (TA) is an essential variable for the study of physical and biogeochemical processes in coastal and oceanic systems, and TA data obtained at high spatiotemporal resolutions are highly desired. The performance of the current in situ TA analyzers/sensors, including precision, accuracy, and deployment duration, cannot fully meet most research requirements. Here, we report on a novel high-precision in situ analyzer for surface seawater TA (ISA-TA), based on an automated single-point titration with spectrophotometric pH detection, and capable of long-term field observations. The titration was carried out in a circulating loop, where the titrant (a mixture of HCl and bromocresol green) and seawater sample were mixed in a constant volume ratio. The effect of ambient temperature on the TA measurement was corrected with an empirical formula. The weight, height, diameter, and power consumption of ISA-TA were 8.6 kg (in air), 33 cm, 20 cm, and 7.3 W, respectively. A single measurement required ∼7 min of running time, ∼32 mL of seawater, and ∼0.6 mL of titrant. ISA-TA was able to operate continuously in the field for up to 30 days, and its accuracies in the laboratory and field were 0.5 ± 1.7 μmol kg–1 (n = 13) and 10.3 ± 2.8 μmol kg–1 (n = 29) with precisions of 0.6–0.8 μmol kg–1 (n = 51) and 0.2–0.7 μmol kg–1 (n = 8), respectively. This study provides the research community with a new tool to obtain seawater TA data of high temporal resolution.

Description: Onychomycosis caused by, e.g., Trichophyton rubrum or Candida albicans is the most common human nail disease with a worldwide prevalence of more than 10%. The therapeutic efficacy of topical antimycotics for the treatment of onychomycosis proved to be inadequate in numerous studies on patients. The main reasons are, above all, the poor bioavailability of the active ingredients in the nail compartment, causing the requirement for extremely long application periods and correspondingly high demands on adherence by the patient. In the present study, we aimed to develop a more effective and prompt photodynamic approach for the treatment of onychomycosis. The principle of photodynamic therapy (PDT) for onychomycosis has already been investigated. However, these studies used photosensitizers such as methylene blue, which were neither optimized for their keratinophilic features nor for their bioavailability in the nail. Hence, we initiated a screening campaign using T. rubrum and C. albicans cell-based assays, infected bovine keratin models, and keratin-penetrating irradiation to identify suitable hit compounds for a PDT approach toward onychomycosis. Here, we report on the discovery of Henna/Lawson-derived keratinophilic naphthazarines that act as highly potent PDT antimycotic photosensitizers with photoresponsiveness when irradiated by light at a keratin-permeable wavelength (〉500 nm, e.g., compounds 10 and 11 with PDT-IC50 = 1 and 3 nM, respectively, against T. rubrum), hence with superior efficacy than the positive controls nystatin and clotrimazole. Notably, our photodynamic approach not only affected the actual pathogens but also prevented reinfection of keratin models within 10 days, suggesting an additional efficacy against fungal spores. Compared to established concepts, our proposed PDT approach using the novel naphthazarine photosensitizers could enable an effective, precise, and sustainable therapy option for the future treatment of onychomycosis.

Description: Coastal waters are contaminated globally with millions of metric tons of munitions from the two world wars which constitute a potential threat to ecosystems and humans. Laboratory-based chemical methods for the detection of munition compounds (MCs) in seawater typically take weeks to months between sample collection and analysis. The current work details a novel, field-deployable system for rapid (under 10 min) analysis of four common MCs (1,3-dinitrobenzene (DNB), amino-4,6-dinitrotoluene (ADNT), 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)). The system uses a fluidic preconcentration unit with high-performance liquid chromatography (HPLC) and detection by electrospray-ionization mass spectrometry and UV–vis spectroscopy. The fluidic unit comprises two solid-phase extraction (SPE) columns for preconcentration of target MCs from the seawater matrix and allows loading and analysis of two samples simultaneously. Seven SPE resins were tested for extraction efficiency and robustness, with Porapak RDX showing best performance. Chromatographic separation of target MCs was performed using a C8 reversed-phase HPLC column. Limits of detection (LODs) were 3.7, 1.8, 3.6, and 10.7 ng L–1 for DNB, ADNT, TNT, and RDX, respectively. The system’s analytical performance and automated data processing procedure were demonstrated in the Baltic Sea.

Description: The air-blood partition coefficient (Kab) is extensively employed in human health risk assessment for chemical exposure. However, current Kab estimation approaches either require an extensive number of parameters or lack precision. In this study, we present two novel and parsimonious models to accurately estimate Kab values for individual neutral organic compounds, as well as their complex mixtures. The first model, termed the GC×GC model, was developed based on the retention times of nonpolar chemical analytes on comprehensive two-dimensional gas chromatography (GC×GC). This model is unique in its ability to estimate the Kab values for complex mixtures of nonpolar organic chemicals. The GC×GC model successfully accounted for the Kab variance (R2 = 0.97) and demonstrated strong prediction power (RMSE = 0.31 log unit) for an independent set of nonpolar chemical analytes. Overall, the GC×GC model can be used to estimate Kab values for complex mixtures of neutral organic compounds. The second model, termed the partition model (PM), is based on two types of partition coefficients: octanol to water (Kow) and air to water (Kaw). The PM was able to effectively account for the variability in Kab data (n = 344), yielding an R2 value of 0.93 and root-mean-square error (RMSE) of 0.34 log unit. The predictive power and explanatory performance of the PM were found to be comparable to those of the parameter-intensive Abraham solvation models (ASMs). Additionally, the PM can be integrated into the software EPI Suite, which is widely used in chemical risk assessment for initial screening. The PM provides quick and reliable estimation of Kab compared to ASMs, while the GC×GC model is uniquely suited for estimating Kab values for complex mixtures of neutral organic compounds. In summary, our study introduces two novel and parsimonious models for the accurate estimation of Kab values for both individual compounds and complex mixtures.

Description: Groundwater discharge into the sea occurs along many coastlines around the world in different geological settings and constitutes an important component of global water and matter budget. Estimates of how much water flows into the sea worldwide vary widely and are largely based on onshore studies and hydrological or hydrogeological modeling. In this study, we propose an approach to quantify a deep submarine groundwater outflow from the seafloor by using autonomously measured ocean surface data, i.e., 222Rn as groundwater tracer, in combination with numerical modeling of plume transport. The model and field data suggest that groundwater outflows from a water depth of ∼100 m can reach the sea surface implying that several cubic meters per second of freshwater are discharged into the sea. We postulate an extreme rainfall event 6 months earlier as the likely trigger for the groundwater discharge. This study shows that measurements at the sea surface, which are much easier to conduct than discharge measurements at the seafloor, can be used not only to localize submarine groundwater discharges but, in combination with plume modeling, also to estimate the magnitude of the release flow rate.

Description: The EU’s Carbon Border Adjustment Mechanism (CBAM) is expected to launch in October 2023, with reporting obligations only. The scheme aims to ensure that European efforts to reduce greenhouse gas emissions do not induce so-called ‘carbon leakage’, which could occur if companies based in the EU relocate carbon-intensive production to countries with less ambitious climate standards or increase imports of carbon-intensive products to the EU. The mechanism will require companies importing certain products to the EU to offset embedded GHG emissions by purchasing CBAM certificates, thus ensuring that the carbon price of imported products is equivalent to that of products made by European producers under the EU Emissions Trading Scheme (ETS). CBAM’s effectiveness and impact will be evaluated by the EU towards the end of its phase-in period. This evaluation will likely lead to adjustments in the mechanism’s design and will be followed closely by third countries considering the introduction of similar instruments. Economies and sectors dependent on exports to the EU will be both more exposed and vulnerable to the mechanism. In this policy brief we explore the views of stakeholders in South Africa, the EU’s largest trading partner in Africa, and consider measures necessary to ensure that CBAM addresses issues of justice and sustainability. In particular we identify three key recommendations for European policymakers.

Description: In mid-2021, the Republic of Nauru invoked a treaty provision at the International Seabed Authority known as the “two-year rule”. This effectively imposed a deadline on the Council of the International Seabed Authority to complete the elaboration and adoption of regulations for the exploitation of seabed minerals in the international seabed Area by 9 July 2023. Come 10 July 2023, the Authority would be presented with a new legal situation, whereby applications for mining activities may be submitted despite the absence of applicable regulations. There remain many outstanding matters in the negotiations and, considering that the regulations for exploitation must be adopted by consensus at the Council, it would appear that there is still a long and winding road ahead before an agreement is reached among member states – if this is at all possible. In light of this, the Council clearly needs to discuss what would occur if an application for the approval of a plan of work for exploitation activities happens to be submitted in the absence of applicable regulations. While the open legal questions that arise from the invocation of the two-year rule and upon the expiration of the deadline have been analysed elsewhere, this discussion paper examines the new political reality that the Authority finds itself in following the expiry of the deadline on 9 July 2023. Building on previous work by the author, this discussion paper attempts to underscore what is at stake at the Authority and explores how member states should approach this situation.

Description: This paper examines the challenges and prospects for Norway’s internal and external hydrogen strategy from around 2019, when Norway’s low-carbon hydrogen policies and activities began to gain traction. Norway has taken a technology-neutral approach to ‘green’ and ‘blue’ hydrogen technologies linked to reducing emissions. Two end-use sectors have been prioritised: maritime transport and energy-intensive industries. This strategy is based on Norway’s energy mix, industry structure/interest and research competence. While climate concerns appear as the predominant motivation underlying the Norwegian government’s low-carbon hydrogen strategy, industrial value creation is an additional key goal. Political priorities roughly align with actual funding priorities – there has been a massive increase in direct state aid to low-carbon hydrogen projects. Externally, Norway’s hydrogen strategy has potential significance for Europe, particularly for countries with maritime interests and high hydrogen import needs. However, Norway’s technology-neutral approach deviates from most other European countries. What Norway’s hydrogen strategy will mean for Europe remains to be seen – but its main interests concern the export of ‘blue’ hydrogen, with ‘green’ hydrogen primarily suited to meet domestic needs.

Description: The COVID-19 pandemic has led to a surge in online communication, offering a unique burning glass perspective on the advantages of transferring formerly face-to-face conversations online as well as uncovering limitations of using technical applications to this end. These experiences are of great importance for the development of new e-participation instruments. So far, digital participation has failed to match the quality of real-world procedures. This paper discusses various emerging formats for online participation and their prerequisites. Blended participation models, in particular, appear to offer the most promise, enhancing negotiation processes between heterogenous social groups and facilitating responsive policy making.

Description: Die Corona-Pandemie hat die Nutzung der Online-Kommunikation stark befördert. Diese einzigartige experimentelle Situation machte die Möglichkeiten und Grenzen eines Wechsels der Kommunikationsmedien von Face-to-Face- in Online-Formate sichtbar. Die gesammelten Erfahrungen sind von erheblicher Bedeutung für die Entwicklung neuer Instrumente und Tools der Online-Beteiligung. Bislang allerdings sind Online-Beteiligungsformate den klassischen Offline-Beteiligungsformaten qualitativ nicht ebenbürtig. Daher werden in diesem Beitrag Ansatzpunkte für neue Formate und deren Grundvoraussetzungen diskutiert. Insbesondere Konzepte, welche sowohl Online- als auch Offline-Elemente verbinden (Blended Participation), erscheinen vielversprechend, da sie Austauschprozesse zwischen heterogenen sozialen Gruppen verbessern und die Responsivität des politischen Entscheidungsfindungsprozesses erhöhen können.

Description: The invocation of a treaty provision known as the "two-year rule" at the International Seabed Authority effectively placed a deadline on the Authority to complete the adoption of regulations for exploitation activities within two years, i.e. by 9 July 2023. However, it is not a hard "deadline" and it is likely that the Authority might miss this deadline. In recent months, the member states of the Authority have commenced discussions on what would happen if the deadline is missed (or the "what if scenario"). It follows that missing the deadline will give rise to a host of open legal questions. Building on previous work, this discussion paper attempts to provide some insights and possible interpretations to answer some of those questions.

Description: Stakeholder engagement has become increasingly important in energy research and is now even required by many funding agencies. Recent energy modelling projects also claim to involve stakeholders in the research process, although this is usually a process of one-way communication. This raises the question of the extent to which stakeholder involvement can have an impact on the modelling work, or whether it is often a case of mere ‘stakeholder-washing’ to meet funding requirements. In this discussion paper, I reflect on the experiences of stakeholder engagement in the EU Horizon 2020 project Sustainable Energy Transition Laboratory (SENTINEL), discuss the impacts of stakeholder participation on the energy modelling and unfold key challenges of involving stakeholders in energy modelling. I discuss that it worked well to engage stakeholders in defining user needs and discussing modelling results, while only a few stakeholders could be continuously involved through the project period. I also show that although the project successfully identified research questions and needs, the ability of models to answer questions was limited, and making models understandable to users remains a key challenge. Stakeholder engagement in SENTINEL was more than ‘stakeholder-washing’: it led to the identification of user needs and research questions, impacted scenario design, modelling improvements and the development of new modelling tools, and enabled critical reflection on modelling approaches and results. Finally, I make nine recommendations for future stakeholder engagement in energy (modelling) research that can enable mutual learning and enhance the legitimacy, relevance and impact of modelling. The further development of multi-stakeholder communities of practice around innovative energy modelling approaches can facilitate the transition to climate neutrality.

Description: This chapter provides a review of Germany’s ambitious import-oriented hydrogen strategy. It places the German policy approach in the context of its broader Energiewende (energy transition) strategy, aimed not only at a transition of Germany’s energy and industrial system to carbon neutrality by 2045 but also at the promotion of the German Energiewende approach abroad. The chapter begins by providing a short review of the German Energiewende policy legacy, relating it to it emerging hydrogen policy. On this basis, it provides a comprehensive review of Germany’s National Hydrogen Strategy (NHS) with a particular focus on its outward-oriented elements. It discusses Germany’s external hydrogen policy along the following five dimensions: political dialogue and diplomacy (both bilateral and multilateral); interventions aimed at building international supply chains; cooperation in research and innovation; capacity building and skill development; and activities aimed at addressing questions of sustainability. The chapter closes with discussion of key strengths and weaknesses of the strategy and highlights areas for its further development. While Germany's outward-oriented approach is identified as an important strength of the strategy, it could place greater emphasis on cooperation with partners in the EU. Moreover, collaboration with partner countries, both in- and outside the EU, should go beyond the relatively narrow focus on the promotion of hydrogen production and trade. Rather, it should take a broader perspective, aimed at promoting competitive and resilient industrial value chains centered on the EU and its policy and regulatory model. In particular, countries in the European Neighborhood represent important partners in such a strategy. Broadening the scope of cooperation with these countries will also increase the incentives for these countries to engage in partnership development. Finally, the chapter points out that Germany has taken an ambiguous stance on the role that blue hydrogen should play in a future hydrogen economy. While its strategy comes out strongly in favor of green hydrogen, it is also pursuing partnerships for the import of blue hydrogen. This has resulted in a mismatch. While analytical capacities and standardization-related activities are being advanced for green hydrogen production, the government also needs to clearly define its stance on blue hydrogen imports and develop the needed analytical tools and policy instruments for this purpose.

Description: The UK aims to become a leader in green industries by developing a competitive hydrogen industry, bringing new jobs, and revitalizing peripheral areas of the country. Hydrogen is also seen as an opportunity for the country to improve its energy security, as extracting fossil fuels is increasingly costly and unfeasible given the UK’s decarbonization goals. Its hydrogen strategy takes a “twin track” approach, that is, simultaneously promoting hydrogen from gas with carbon capture and hydrogen from low-carbon electricity. The UK strategy focuses on the importance of applying hydrogen to industry including chemicals, steel, and glass. However, its funding and research initiatives rather place an emphasis on developing local hydrogen markets by using hydrogen for heating and transportation. In the short term, the UK aims to develop “blue” hydrogen, which is perceived as cheaper, to replace household gas use. Funding for hydrogen innovation comes from the government, but revenue support is likely to be funded by levies on energy consumption. This approach seems unlikely to result in the green industrial leadership the government hopes to achieve. The unwillingness of the government to take strategic decisions on hydrogen types and uses means that its funding is stretched across different cases. And, while the UK participates in international standard-setting initiatives to better participate in global markets, it is not officially coordinating with or investing in hydrogen infrastructure that could connect it with Europe and thereby enable regional hydrogen trade. Given the rise in industrial policy measures including for hydrogen in the US and EU, the UK’s goal of becoming a major hydrogen player seems unlikely without a significant change in policy clarity and ambition.

Description: Der Strukturwandel in den ehemaligen Braunkohlerevieren wird mit erheb- lichen Bundes- und Landesmitteln gefördert. Sie fließen zum einen als Kompensation für einen vorzeitigen Kohleausstieg. Damit verbunden ist zum anderen der Anspruch, dass Transformationen Erfolg haben können, indem neue Arbeitsplätze sowie lebenswerte und zukunftsfähige Regionen entstehen. Es geht um Nachhaltigkeit im Strukturwandel und nicht nur um den Kohleausstieg. Da es bisher kein Nachhaltigkeitsmonitoring für die Lausitz gibt, lassen sich aufgrund der vorliegen- den Projekte und Projektanträge sowie zahlreicher Gespräche vor Ort nur erste vorsichtige Schlüsse zie- hen. Diese beziehen sich auf die verabschiedeten und vorgeschlagenen Projekte, bei denen das Land Bran- denburg die Verantwortung hat (sog. Arm 1-Projekte): Antragsstellende müssen erläutern, wie ihre Projek- te einen positiven Beitrag zu einem ökologischen und einem weiteren der 17 nachhaltigen Entwick- lungsziele der Vereinten Nationen leisten. Diese Auflage führte bislang kaum dazu, dass die Projek- te einen hohen Nachhaltigkeitsanspruch verfolgen. Hohe Förderquoten würden es bereits jetzt ermög- lichen ambitioniertere Nachhaltigkeitsinvestitionen zu vertretbaren Kosten umzusetzen. Eher günstige geographische und makroökonomi- sche Bedingungen führen dazu, dass viele Projekte auf eine Reduktion von Treibhausgasemissionen bzw. zur Erforschung entsprechender Technologi- en ausgerichtet sind. Mit seinem bisherigen Verfahren verfolgt Branden- burg einen anderen Ansatz als Sachsen, das Nachhal- tigkeit in einem Scoring-Verfahren berücksichtigt. Sowohl die Nachhaltigkeitserklärungen als auch die Scoring-Verfahren setzen geringe Nachhaltigkeitsan- reize im Vergleich etwa zu EU-Vorgaben. In diesem Policy Brief liefern wir drei umsetzbare und kostengünstige Vorschläge, wie sich die Nach- haltigkeit des Strukturwandels in der brandenburgischen Lausitz verbessern ließe.

Description: This RIFS discussion paper presents preliminary insights from transdisciplinary research on the Co-Creative Reflection and Dialogue Space (CCRDS) implemented at the 25th, 26th and 27th United Nations Framework Convention on Climate Change (UNFCCC) Conference of the Parties (COP). The transformative research design and findings from over six years of dedicated experimentation with different participatory formats and design principles at the CCRDS are emphasised. The aim was to better understand the communication culture at the COP and to orientate the experimental formats towards reflecting the rich and diverse perspectives, knowledge, and potential of COP participants. A key objective was thereby to better understand whether participatory and reflective formats can support individual and collective climate action. Building on this, CCRDS research and practice design at COP 28 is presented, which aims to understand more relational communication practices as a way to more effective and supportive communication pathways and to work with other organisations and individuals to scale these efforts.

Description: This deliverable provides a summary of a two-day expert workshop conducted in hybrid format. The workshop’s primary objective was aimed towards identifying future opportunities within the global ocean governance regime to strengthen governance of ocean-based NETs in a comprehensive manner. The workshop was organised by the Research Institute for Sustainability – Helmholtz Centre Potsdam (RIFS) as part of the work of Task 2.2 of the OceanNETs project. This deliverable follows a first online workshop (see Deliverable 2.3) that identified challenges within the current governance framework for ocean-based NETs. The second workshop consisted of breakout groups and plenary discussions designed to explore scenarios that reflect on identified governance challenges within the current and potential future global ocean governance regimes. Participants were asked to reflect on the concept of „good governance” and develop responses to the scenarios presented through specific prompts. They were encouraged to actively contribute to discussions that aimed to advance our understanding of the future governance of ocean-based NETs.

Description: Europe's growing interest in securing green hydrogen from North Africa is part of a strategic effort to enhance its energy security. The promise of green hydrogen projects in Morocco, Algeria, and Mauritania is substantial, offering economic growth and job opportunities. However, numerous factors limit these countries’ ability to develop robust local green hydrogen sectors, while political disputes—particularly around Western Sahara—complicate regional collaboration. European actors can play an important role in advancing green hydrogen’s development in the region, but must tread carefully to secure local buy-in and avoid exacerbating tensions within or between these countries.

Description: À la suite de la fermeture de ses mines dans les années 1980, Loos-en-Gohelle, ancien haut lieu minier du nord de la France, est devenu un modèle de commune écologique. L’action culturelle et son importance singulière dans la transformation dite « du noir au vert » demeurent encore peu connues. À l’échelle du Bassin minier des Hauts-de-France, la sortie du charbon a été accompagnée par une politique d’équipement et d’investissement culturel visant à faire évoluer l’image extérieure de ce territoire. Cette étude met en évidence la singularité de l’approche loossoise, dont l’ambition est d’abord d’impliquer ses propres habitant.e.s à la transition écologique et sociale du territoire. Ce travail culturel participatif est ainsi devenu un outil d’émancipation. Toutefois, au cours des dernières années, les possibilités de mobilisation de la population semblent être à un tournant. Loos-en-Gohelle fait face au défi de construire de nouvelles formes de participation culturelle afin d’éviter l’essoufflement de son dynamisme.

Description: Following the end of coal production in 1986, the small town of Loos-en-Gohelle in northern France transformed itself from a former mining stronghold into a model municipality for sustainability. This article highlights the importance of cultural policy measures in this structural change: while in other municipalities in the northern French coalfield, cultural policy was used to change the image of the region, Loos-en-Gohelle aimed to involve the local population in the socio-ecological transformation process. Participatory cultural work thus became an instrument of emancipation. However, the possibilities for mobilising the population appear to have reached a turning point in recent years. Loos-en-Gohelle is faced with the challenge of developing new forms of cultural participation in order to prevent the momentum from slowing down.

Description: Städte stehen vor der Herausforderung, ihr Verwaltungshandeln auf komplexe sozial-ökologische Transformationsprozesse auszurichten. Die Landeshauptstadt München hat mit dem Modell der Handlungsräume einen Ansatz entwickelt, um dieser Herausforderung zu begegnen. Durch eine strategische Priorisierung von Teilgebieten, und agilen, fachübergreifenden Kooperationsstrukturen ermöglicht der Handlungsraumansatz eine konstruktive Moderation von komplexen Interessenslagen, die Akquise von innovativen Entwicklungs- und Forschungsprojekten und schafft Synergieeffekte zwischen Verwaltung und Zivilgesellschaft. Die vorliegende Analyse untersucht die Potenziale des Ansatzes und legt Empfehlungen zu seiner Weiterentwicklung in München vor. Gleichzeitig bietet die Analyse empirische Evidenz zu Debatten über die Rolle von strategischen Planungsräumen und ‚soft spaces‘ in der nachhaltigen Stadtentwicklung.

Description: Cities are faced with the challenge of aligning their administrative actions with complex socio-ecological transformation processes. The City of Munich has developed an approach to meet this challenge with strategic action spaces or opportunity areas (Handlungsraumansatz). Through a strategic prioritisation of geographic areas in the city and agile, interdisciplinary cooperation structures, the action space approach enables a constructive moderation of complex interests, the acquisition of innovative development and research projects and creates synergy effects between administration and civil society. The present analysis examines the potentials of the approach and presents recommendations for its further development in Munich. At the same time, the analysis provides empirical evidence for debates on the role of strategic planning spaces and 'soft spaces' in sustainable urban development.

Description: The Dutch government believes hydrogen will play an important role in decarbonizing the energy system. Industry, NGOs and the government work together in the Netherlands to setup low-carbon hydrogen supply chains. The Netherlands is in a good position to make a significant contribution to Europe's low-carbon hydrogen market, thanks to its current role as a European energy hub, large chemical industry, geographic location at the North Sea, offshore wind potential and existing gas and oil infrastructure. The Dutch national hydrogen strategy predominantly focuses on hydrogen produced via electrolysis from renewable electricity. However, there is also room for hydrogen produced from natural gas or waste gases with CCS, given that this effectively contributes to the development of the broader Dutch hydrogen system, without hampering the growth of hydrogen produced via electrolysis from renewable electricity. In the initial market phase, the Dutch government will prioritize hydrogen supply for the hard-to-abate sectors such as heavy industry and heavy-duty transportation. In later market phases more sectors could be using hydrogen as an energy carrier. The Dutch government has chosen for a combination of obligations and a variety of subsidies schemes, to increase investment security and scale up the low-carbon hydrogen market by 2030. Internationally the Netherlands aims to position itself as the low-carbon hydrogen hub of Northwest Europe, connecting international exporters and Dutch domestic production at the North Sea with industrial demand centres in Northwest Europe. Acknowledging the scale of the task at hand, the Dutch government is open for partnerships along the whole value chain to work towards an international low-carbon hydrogen market.

Description: This paper examines the recent evolution of the domestic and external dimension of hydrogen in Spain. When published in 2020, the Spanish Hydrogen Strategy was focused on the creation of hydrogen clusters that could concentrate production and consumption, attracting economic activity associated with the molecule. For this reason, the external dimension of Spain's hydrogen strategy was relatively modest in its nascent state. The Russian invasion of Ukraine and the EU Commission's call in the REPowerEU to increase the level of ambition for renewable hydrogen has led to a change in Spain's hydrogen policy, reinforcing its external and energy security dimensions and contributing to a more geopolitically resilient Europe. This new approach to hydrogen development creates a complex tension between the promises of industrial development and the potential for integrating Spain in the European energy system.

Description: Southeast Asia is one of the fastest growing regions worldwide by both gross domestic product and electricity demand. Solar photovoltaics (PV) will play an increasingly important role as the region strives to decarbonize and meet rising energy demand. High solar resource potential, a significant cost drop for installed PV in the region (about 45 percent between 2012 and 2016), and favourable policies have allowed Southeast Asia to surpass other regions in solar capacity growth, from approximately 23 GW in 2020 a projected 241 GW by 2030. The International Renewable Energy Agency (IRENA) deems solar “the flagship resource for ASEAN’s decarbonization”. Two countries in particular–Vietnam and Malaysia–have led the way in solar offtake in recent years and installed more new PV capacity than others in the region in 2020. They are the world’s second and third largest manufacturers of solar PV modules and have significantly lowered barriers to utility-scale and residential solar adoption. However, their diverging approaches to electricity markets, renewables integration, and distributed energy resources have resulted in very different outcomes for solar growth. In many respects, Malaysia’s holistic approach to solar pricing, grid modernization, and regional interconnectivity provides lessons for both Vietnam’s solar market and the broader ASEAN region.

Description: Hydrogen is a much-discussed facet of Hungary’s energy transition that has seen little progress, but offers an important tool to extend the government’s foreign and energy policy. Policy-making in Hungary is highly centralised and government ambitions have prioritised the continued role of nuclear power, natural gas, and a solar PV boom. These closely trace foreign policy priorities as well, given that the former two entrench relations with Russia, while the latter enhances self-reliance while allowing the country to meet EU renewable energy targets. A hydrogen economy supports such ambitions, while the government has also welcomed EU funds and foreign investment into novel (green) technologies that increase the value added in the economy. Domestic demand offers a secondary, but nonetheless important, push for the uptake of hydrogen in industry and transportation. Hungary’s case shows how pre-existing political economic confines shape the uptake of hydrogen, as governments and other key actors take action while disrupting pre-existing practices to the least extent possible.

Description: This paper investigates the main elements, drivers and challenges of the hydrogen sector in Sweden. A particular focus is placed on the approach of the Swedish government to hydrogen development and its internal and external dimensions. The Swedish government has intensified its support for the decarbonization of the economy in recent years in a bid to meet its goals of reaching climate neutrality by 2045 and reducing transport emissions (excluding aviation) by 70% until 2030, relative to 2010. Climate Leap, introduced in 2015, and Industrial Leap, launched in 2018, are the two main government funding schemes for private and public investments in low-carbon technologies in Sweden. While the government has set ambitious long-term climate goals and put in place the corresponding funding programs, investment and technology decisions have been mainly left to the business actors. Although such a market-based and private sector-driven approach may have worked well in the past, the Swedish government will need to embrace a more coherent steering role in ensuring smooth decarbonization and successful integration of hydrogen in the energy system of the future. The domestic interest in hydrogen in Sweden has in the past been primarily focused on the decarbonization of hard-to-abate industrial sectors, in particular the steel industry. Given the current surplus of low-carbon electricity supply, which relies on hydropower, nuclear and increasingly wind power, the attention was solely directed towards domestic production and use of low-carbon hydrogen for the industry. With the growing importance of hydrogen at the EU level, accompanied by the introduction of an EU hydrogen strategy, investment funds and common standards, there has been a rapid increase in interest by business actors in various hydrogen sectors (e-fuels, green hydrogen, ammonia) in Sweden. Individual regions in Sweden have also taken the initiative and made use of EU funds to try position themselves in and benefit economically from the emerging hydrogen sectors. As most private investors aim to use green hydrogen produced by renewable energy sources, the demand for green electricity, particularly in onshore and offshore wind, is expected to skyrocket. The government, however, has so far failed to enact credible plans and policies detailing where and how new wind power projects will be built and which sectors may gain priority access to renewable electricity. There has also been a lack of effort in facilitating the realization of infrastructure for the potential transport of hydrogen through pipelines or Swedish ports. The draft of the national hydrogen strategy by the Swedish Energy Agency laid out the ambitious target of 5 GW of electrolyser capacity by 2030. Such a target has been formulated largely based on the expressed intentions of business actors and without a direct link to EU strategic hydrogen targets. In light of the growing interest in low-carbon hydrogen, the considerable industry know-how and the vast renewable energy potential in Sweden, there is a pressing need for a more comprehensive approach by the government and a stronger alignment with the efforts of the EU and other Member States.

Description: In this report, the authors reflect on three key lessons they learned for the community from the two- day event that led to follow-up questions and elaborations: ▪ Transformative research critically advances from collaborative questioning: Is it really a mat- ter of combining efforts to formulate the right questions instead of generating fast knowledge and solutions? ▪ Transformative research benefits from a shared identity: Who are we and what does trans- formative research change for us in our role and every-day scientific practice? ▪ Embodying participatory practices is key for transformative research: What kind of attitudes and formats do we use to come together in meaningful ways?

Description: The U.S. is a leading actor in today’s hydrogen economy and possesses significant geo-economic potential to lead in the global clean hydrogen economy. The U.S. hydrogen strategy has been shaped by the strive to balance a) energy independence b) the fight against climate change, and c) expanding technology leadership. The recent landmark legislative packages of the Bipartisan Infrastructure Law and the Inflation Reduction Act reflect these priorities and include large-scale investments and financial incentives to promote the supply of clean hydrogen at lower costs, to strengthen innovation, and domestic value chains. The U.S. has been pioneering policy instruments for scaling up domestic clean hydrogen production and use cases across multiple sectors, which raised significant interest among policymakers and industrial actors worldwide. The international dimension of the U.S. hydrogen strategy has received much less attention in the U.S. policy debate and is less defined. This is apparent in comparison with other actors, such as a much more outward-oriented European Union, which reached out to numerous countries as potential trading partners for much-needed hydrogen imports. In contrast, the United States currently focuses much more on building up domestic hydrogen value chains, enabled by a favorable resource endowment. Nevertheless, the U.S. has fostered bilateral partnerships on hydrogen and strengthened its hydrogen-related engagement in international organizations and multilateral initiatives in the past five years. Emerging priorities for the United States' international collaboration on hydrogen include international demand creation and management, upscaling investments, international research collaborations, and joint efforts on regulation, standards, and certification. These efforts can be seen as the first steps towards the U.S. long-term goal to export hydrogen and related technologies to regional and global partners from the 2030s onwards.

Description: The Marine Regions Forum 2023 was held under the headline “Navigating Ocean Sustainability in the Western Indian Ocean and Beyond”, placing a focus on the Western Indian Ocean ( WIO) region and its challenges, and featuring many of the region’s ocean actors and experts. It provided an opportunity to reconnect in-person after the COVID -19 pandemic in a biodiversity-rich area that is particularly vulnerable to climate change, food insecurity and where a large proportion of the population is reliant on the coast for their livelihoods. But the WIO region is also pioneering a regional ocean governance strategy and is a hub of research, capacity development and science-to-policy engagement. This conference provided a platform to share best practices from the WIO region with other marine regions and learn from experiences from other parts of the world. Further, the conference offered a space for on-going processes to receive input from stakeholders and advance work, such as for the regional ocean governance strategy for the WIO that is being developed through an extensive collaborative process and under the auspices of the Nairobi Convention Secretariat. And, at a time where it can feel like international relationships are breaking down, and nations are looking inwards more than out, it was encouraging to gather over 180 people in Dar es Salaam and be hosted by both the United Republic of Tanzania and Republic of Seychelles to look at ways to work together towards a common goal of improved ocean governance at national, regional, and global levels. The conference programme of the Marine Regions Forum 2023 was developed together with partners from the WIO region and experts engaging in the region and built on a yearlong process of engagement and consultation. The coordinating team facilitated the overall co-design and co-delivery of the Marine Regions Forum conference. The shaping of the programme, fine-tuning of content, the selection of speakers and other contributors, and the moderation of sessions and discussions at the conference were a collaborative effort of the team, its partners, and the co-chairs of topical strands and sessions. This is reflected in the key messages of the Marine Regions Forum 2023 which have been compiled by the coordinating team from summary notes of plenaries and workshop sessions and developed jointly with the co-chairs. Although the four topical strands dealt with a broad range of issues, there were commonalities that spread across the discussions. These are summarised below as key messages that emerged and stood out from the three days of the conference.

Description: The Marine Regions Forum 2023 was held under the headline “Navigating Ocean Sustainability in the Western Indian Ocean and Beyond”, placing a focus on the Western Indian Ocean ( WIO) region and its challenges, and featuring many of the region’s ocean actors and experts. It provided an opportunity to reconnect in-person after the COVID -19 pandemic in a biodiversity-rich area that is particularly vulnerable to climate change, food insecurity and where a large proportion of the population is reliant on the coast for their livelihoods. But the WIO region is also pioneering a regional ocean governance strategy and is a hub of research, capacity development and science-to-policy engagement. This conference provided a platform to share best practices from the WIO region with other marine regions and learn from experiences from other parts of the world. Further, the conference offered a space for on-going processes to receive input from stakeholders and advance work, such as for the regional ocean governance strategy for the WIO that is being developed through an extensive collaborative process and under the auspices of the Nairobi Convention Secretariat. And, at a time where it can feel like international relationships are breaking down, and nations are looking inwards more than out, it was encouraging to gather over 180 people in Dar es Salaam and be hosted by both the United Republic of Tanzania and Republic of Seychelles to look at ways to work together towards a common goal of improved ocean governance at national, regional, and global levels. The conference programme of the Marine Regions Forum 2023 was developed together with partners from the WIO region and experts engaging in the region and built on a yearlong process of engagement and consultation. The coordinating team facilitated the overall co-design and co-delivery of the Marine Regions Forum conference. The shaping of the programme, fine-tuning of content, the selection of speakers and other contributors, and the moderation of sessions and discussions at the conference were a collaborative effort of the team, its partners, and the co-chairs of topical strands and sessions. This is reflected in the key messages of the Marine Regions Forum 2023 which have been compiled by the coordinating team from summary notes of plenaries and workshop sessions and developed jointly with the co-chairs. Although the four topical strands dealt with a broad range of issues, there were commonalities that spread across the discussions. These are summarised below as key messages that emerged and stood out from the three days of the conference.

Description: Welche Rolle spielen Akteure in Energiewende-Konflikten? Inwiefern müssen spezifische Akteurskonstellationen beachtet werden, um Konfliktlösungsstrategien zu finden? Welche Einstellungen, Interessenlagen und Gerechtigkeitsvorstellungen bei Stakeholdern und in der Bevölkerung spielen hierbei eine zu berücksichtigende Rolle. Die Studienergebnisse einer im Rahmen des DEMOKON-Forschungsprojektes durchgeführten deutschlandweiten vergleichenden Fallanalyse weisen darauf hin, dass Konfliktfälle in der Energiewende trotz vordergründiger Parallelen höchst unterschiedlich gelagert sind und die Präferenzen von Akteuren in jedem Einzelfall berücksichtigt und abgewogen werden müssen. Es hat sich gezeigt: Sowohl die Anerkennungs-, Prozess- als auch Verteilungsgerechtigkeit sind hierbei außerordentlich bedeutsam. Vertreter:innen betroffener Kommunen sollten aktiv mit Konflikten umgehen und Strategien entwickeln; eine passive Rolle ist nicht erfolgversprechend. Grundsätzlich gilt: Je mehr Beteiligung gewährt wird und Akteure sich in den Entscheidungsfindungsprozess einbringen können, desto besser ist es. Dies ist in vielen Anwendungsfällen der Energiewende jedoch schwer möglich, polarisierte Pro- und Contra-Lager sind eher die Regel als die Ausnahme. Wichtig ist daher die vermittelnde Rolle von neutralen Akteuren, die in polarisierten Konfliktfällen mediativ wirken können. Lokale Charakteristika sollten in den Diskursen angemessen widergespiegelt sein (z.B. ein von Windkraft betroffener Wald). Lokale Identitäten fußen häufig auf Ortsverbundenheiten und Heimatgefühle, auf deren Verletzung lokale Gemeinschaften empfindlich reagieren. Entsprechend sind (hoch)sensible Umgangsweisen mit den betroffenen Standorten und Schutzgütern erforderlich. Sie sollten bestenfalls neben Einbezug und Gehör sowie finanzieller Beteiligung (Bürgerenergie) auch Kompensation und andere Benefits für die Allgemeinheit bieten (z.B. Investitionen in öffentliche Einrichtungen und Infrastrukturen, lokale Stromtarife, Vergünstigungen), um möglichen Beeinträchtigungen, Benachteiligungen und Ungleichheiten entgegenzuwirken.

Description: What role do various actors play within conflicts relating to the energy transition? To what extent do specific constellations of actors need to be considered in order to identify adequate conflict resolution strategies? Which views, interests and notions of justice held by stakeholders and the wider public need to be taken into account? The findings of a nationwide comparative case analysis conducted as part of the DEMOKON research project indicate that, while some superficial similarities exist, the spectrum of conflicts relating to the German energy transition is highly diverse and actors’ preferences should be considered and carefully weighed in each individual case. This research shows that recognition, procedural, and distributive justice all play an important role here. Representatives of affected communities must actively engage with conflicts and develop strategies as passivity is unlikely to deliver positive outcomes. The more opportunities for participation that are available and the more that stakeholders are able to engage with the decision-making processes, the better the outcome. However, this is not easily achieved in many cases; the polarization of supporters and opponents is the rule rather than the exception. Neutral actors with the ability to mediate in polarized conflicts are an important asset. Local characteristics should be carefully considered in discourse (e.g., a forest affected by a wind power project). Local identities are often based on a sense of place and a sense of home. Local communities can respond sensitively when these values are disregarded. Highly sensitive approaches are needed to address conflicts arising in connection with affected sites and prized assets. At best, these should provide compensation and other benefits to the community (e.g. investment in public facilities and infrastructure, local electricity tariffs, concessions) along with opportunities for participation and consultation as well as financial participation (community energy / ownership) in order to mitigate possible adverse effects, disadvantages, and inequalities.

Description: Die geplante Verordnung der Europäischen Union (EU) über forstwirtschaftliche Risikowaren verlangt von Unternehmen, die in den oder aus dem EU-Markt verkaufen, die Bereitstellung von Geolokalisierungsdaten der Produktionsgebiete. Zur Umsetzung der obligatorischen Sorgfaltspflicht schreiben die Regulierungsbehörden die Nutzung von EU-Datenerfassungs- und Analyseinstrumenten wie dem Raumfahrtprogramm der Union (EGNOS/Galileo und Copernicus) und der EU-Beobachtungsstelle vor. Darüber hinaus empfiehlt der Gesetzentwurf, auf bestehenden öffentlich oder privat verfügbaren Datenquellen und Überwachungsinitiativen aufzubauen. In dieser Arbeit werden digitale Transparenzinitiativen in Brasilien untersucht, um den Beitrag der digitalen Technologien zur Rückverfolgung der sozio-ökologischen Herkunft von Produkten zu verstehen. Als Rohstoffproduzent und Heimat des größten Regenwaldes der Welt bietet der brasilianische Fall Lehren für die Umsetzung der EU-Abholzungsverordnung und bietet gleichzeitig die Möglichkeit, über das Potenzial des Technologie- und Wissenstransfers aus dem globalen Süden nachzudenken. Darüber hinaus können staatliche und nichtstaatliche Akteure durch die Nutzung vorhandener Datensätze und digitaler Artefakte wie in Brasilien digitale Innovationen fördern, den Wert für die Gesellschaft steigern und Wege für eine verstärkte transnationale Zusammenarbeit eröffnen. Die Fallstudie zeigt, dass es mehrere hochwertige offene Datenquellen und digitale Plattformen gibt. Das Haupthindernis für die Umgestaltung des brasilianischen agroindustriellen Komplexes liegt eher in der Verwirklichung institutioneller als technologischer Innovationen. Insbesondere müssen die brasilianische Regierung und die Agrarindustrie von rückwärtsgewandten Narrativen und Handlungen Abstand nehmen, einschließlich des Datenmissbrauchs und der Instrumentalisierung von Maßnahmen im Zusammenhang mit digitalen Technologien, die mit der aktuellen globalen Klimakrise unvereinbar sind. Während Unternehmen, Behörden und die Zivilgesellschaft sich darauf verlassen können sollten, dass die brasilianischen digitalen Initiativen die Einhaltung der Abholzungsvorschriften überprüfen, muss die EU einen kooperativeren Ansatz verfolgen, um Brasilien bei der Bewältigung seiner dringenden politisch-institutionellen Herausforderungen zu unterstützen.

Description: The upcoming European Union (EU) forest-risk commodities regulation requires companies selling to or from the EU market to provide the geolocation data of production areas. To implement the mandatory due diligence requirements, regulators prescribe using EU data collection and analysis tools such as the Union’s Space programme (EGNOS/Galileo and Copernicus) and the EU Observatory. Furthermore, the draft law recommends building on existing publicly or privately available data sources and monitoring initiatives. This paper examines digital transparency initiatives in Brazil to understand digital technologies’ contribution to tracing products’ socio-environmental origin. As a commodity powerhouse and home to the world’s largest rainforest, the Brazilian case offers lessons for implementing the EU Deforestation Regulation while presenting a chance to reflect on the potential of technology and knowledge transfer from the Global South. Moreover, by building on existing datasets and digital artifacts as those in Brazil, state and non-state actors may foster digital innovation, increase value to society, and open paths for enhanced transnational collaboration. The case study shows several high-quality open data sources and digital platforms exist. The major obstacle to transforming the Brazilian agro-industrial complex lies in realising institutional rather than technological innovations. Specifically, the Brazilian government and agribusiness must abandon retrograde narratives and actions, including data misuse and the instrumentalization of policies related to digital technologies, which are incompatible with the current global climate crisis. While operators, authorities, and civil society should rely on Brazilian digital initiatives to conduct non-deforestation compliance checks, the EU must adopt a more collaborative approach to help Brazil address its pressing political-institutional challenges.

Description: France was one of the European frontrunners in formulating policies to develop hydrogen for decarbonisation, publishing its first hydrogen plan in 2018, followed by a larger, €9-billion plan in 2020, hot on the heels of plans released by the European Commission and Germany. The French strategy for hydrogen deployment focuses in particular on applications where hydrogen is key for deep decarbonisation, including refineries and the chemical industry as well as steel production, and the mobility sector. The country aims to have a head start on European and world competitors thanks to large electricity resources from the existing nuclear fleet and by building new nuclear capacity. Additionally, it relies on several existing innovation hubs specialised in hydrogen, as well as the support of many local governments involved in hydrogen development and a relatively structured hydrogen industry. The French strategy for hydrogen does not include ambitions at the international level beyond scientific and technological cooperation within the European Union. The political priority is to develop a domestic industry sized to meet national demand, which is seen as a more secure sourcing strategy than relying on imports. This comes in contrast with the positions of France’s neighbours, notably Spain, Portugal and Germany, which are pushing to enable cross-border trade of hydrogen as early as possible. This situation has generated political tensions within the European Union and in particular in the Franco-German relationship.

Description: Poland is the third largest producer of hydrogen in the EU, with around 1.3 million tonnes produced every year. This grey hydrogen is generated almost exclusively from steam methane reforming and utilised mainly by the chemical, petrochemical, steel and food sectors. The emergence of low-carbon hydrogen technologies has captured a significant interest by various Polish stakeholders, including both oil and gas sector incumbents, renewable energy promoters and local governments. In 2021, the Polish Hydrogen Strategy until 2030 with an outlook until 2040 was published as the first official government strategy affecting low-carbon hydrogen development. The document presents an optimistic and ambitious approach to hydrogen potential, with a focus on domestic production and use in multiple sectors. This is despite the fact that production of low-carbon hydrogen in Poland could face significant challenges, such as a relatively low availability of clean electricity, reliance on natural gas imports and limited experience with CCS. Issues regarding the global hydrogen market and international trade are largely omitted. This paper analyses the possible background of this fact, as well as the factors affecting the future Polish approach to the European and global hydrogen market. Although Poland would not be a frontrunner in these developments, we believe that it could become a pragmatic participant. In fact, we note that Polish companies, including state-owned enterprises, have already launched some relevant cooperative initiatives at European level.

Description: This report provides a comprehensive review of China’s emerging hydrogen economy with a particular focus on policy and regulation, both at the national and sub-national level. China’s promotion of the hydrogen sector is emblematic of its broader efforts to promote greenhouse gas reductions, while pursuing ambitious industrial development goals and promoting energy security. To date, industrial policy goals have clearly taken center stage, with a particular focus on fuel cell vehicles. For now, China is pursuing a diversified strategy in support of hydrogen supply, which includes all different types of hydrogen production, including coal-based hydrogen. Nevertheless, policy documents increasingly emphasize the potential of renewable hydrogen as a vehicle for stabilizing an electricity system based on variable renewable energy as well as broader decarbonization efforts. They also increasingly highlight the need to transition to an exclusively renewable hydrogen supply in the future. In a number of cases, local-level strategies have come out more strongly in support of renewable hydrogen than current central government policies. Local-level policy has also played a key role in the promotion of fuel cell vehicles. Policies for hydrogen-based decarbonization of industry are only at a nascent stage. Similarly, China’s ambitions to promote hydrogen storage and transport remain at a relatively early stage of development with an important emphasis on the promotion of innovation and acquisition of technological know-how. Finally, both China’s hydrogen strategy and the engagement of its energy SOEs do not appear to be strongly motivated by considerations of geopolitics at this stage. To be sure, Chinese officials are considering increasing opportunities for investment in hydrogen projects around the world. In this vein, the national hydrogen development plan considers the importance of the Belt and Road Initiative (BRI) for promoting hydrogen-related standards and investments. Beyond these geoeconomic considerations, the role of hydrogen as a future energy commodity and its geopolitical implications do not figure prominently in Chinese policy efforts. Indeed, due to China’s relative abundance of renewable energy resources, it is does not exhibit major vulnerabilities related to the future provision of hydrogen. Conversely, hydrogen could even offer an opportunity to reduce its energy dependence in the future. This and other efforts to shape global hydrogen trade do not seem to be a significant driver of its policy efforts, however.

Description: Die nordfranzösische Kleinstadt Loos-en-Gohelle mauserte sich nach dem Kohleausstieg 1986 von einer ehemaligen Bergbauhochburg zur Modellkommune für Nachhaltigkeit. Weniger bekannt ist die Bedeutung von kulturpolitischen Maßnahmen in diesem Strukturwandel: Während in anderen Kommunen des Nordfranzösischen Kohlereviers die Kulturpolitik eingesetzt wurde, um das Image der Region zu verändern, zielte Loos-en-Gohelle darauf ab, die lokale Bevölkerung in den sozial-ökologischen Transformationsprozess mit einzubinden. Partizipative Kulturarbeit wurde somit zum Instrument der Emanzipation. Jedoch scheinen die Möglichkeiten einer Mobilisierung der Bevölkerung in den letzten Jahren an einem Wendepunkt angelangt zu sein. Loos-en-Gohelle steht vor der Herausforderung, neue Formen der kulturellen Teilhabe aufzubauen, um zu verhindern, dass die Dynamik nachlässt.

Description: Following the end of coal production in 1986, the small town of Loos-en-Gohelle in northern France transformed itself from a former mining stronghold into a model municipality for sustainability. This article highlights the importance of cultural policy measures in this structural change: while in other municipalities in the northern French coalfield, cultural policy was used to change the image of the region, Loos-en-Gohelle aimed to involve the local population in the socio-ecological transformation process. Participatory cultural work thus became an instrument of emancipation. However, the possibilities for mobilising the population appear to have reached a turning point in recent years. Loos-en-Gohelle is faced with the challenge of developing new forms of cultural participation in order to prevent the momentum from slowing down.

Description: Italy presents, potentially, some important comparative advantages in the emerging clean hydrogen economy. However, unlike other large EU countries, Italy has not yet issued a comprehensive strategy on hydrogen nor has it developed a coherent hydrogen diplomacy. It was only with the National Recovery and Resilience Plan, launched in the wake of the COVID-19 crisis, that Italy upgraded its measures for promoting green hydrogen and related activities. The main players in the Italian hydrogen landscape are national industrial actors, especially state-owned energy companies. This leading role can be an important asset to overcome the problems related to an industrial system otherwise composed of small and medium companies, which can find it difficult to compete with hydrogen frontrunners. Externally, Italy has supported all the European and multilateral initiatives on hydrogen, although in the EU the country is a policy-taker rather than a policy-shaper. The main focus of the Italian international approach is linked to the hydrogen hub concept, which targets the MENA region and is also supported by its national energy companies. This concept has received a further push after the beginning of the war in Ukraine. However, its practical realization is very problematic because of domestic and external challenges.

Description: The European Union has identified clean hydrogen as essential to its climate targets, technology leadership and energy security in the decarbonizing world. The bloc is developing a comprehensive regulatory framework for a hydrogen economy, complete with supply-side policies and binding demand-side targets. In addition to boosting domestic production, the EU is planning to import large volumes of hydrogen and derivatives from third countries. Hydrogen is thus beginning to play a more prominent role in the EU’s bilateral partnerships. The EU is also actively participating in multilateral hydrogen governance with the goal of creating a functioning international hydrogen market featuring strong sustainability standards. At the same time, aligning the diverging interests of Member States and various hydrogen stakeholders has been a challenge. As the global hydrogen race accelerates, the bloc has struggled to keep up with powerful players like the United States, which are offering massive subsidies to the hydrogen industry. This discussion paper examines the domestic and external dimensions of the EU's hydrogen vision, situating it within the bloc's wider climate and energy policy and recent geopolitical developments. It discusses key policies, regulations, and funding schemes for hydrogen in the EU, highlighting existing points of contention and the interplay between the EU and Member State level. It then goes on to analyze the EU's evolving international engagement on hydrogen and the challenges of fostering mutually beneficial green industrial partnerships that go beyond securing hydrogen supplies. It remains to be seen whether the EU succeeds in drawing on its early mover advantage and potential synergies to remain an attractive investment destination and build resilient clean hydrogen supply chains.

Description: South Africa and Namibia are seeking to become leaders in green hydrogen production. Leveraging world-class renewable energy resources, both nations are working to scale their green hydrogen production capabilities. However, given their very different starting points, they also face different opportunities and challenges. In particular, South Africa hopes to develop its green hydrogen industry through green ammonia exports and applications in hard-to-abate industries, namely steel, chemicals, and aviation fuel. It also seeks to leverage its reserves of so-called platinum grade metals to position the country as a produce of protone-exchange membrane (PEM) electrolyzers, which rely on this rare metal. Namibia has mainly focused on the development of green ammonia exports, though policy documents have also identified potential opportunities for the production of green steel and aviation fuels. Given green hydrogen’s technological complexity and the countries' export-oriented ambitions, both countries must cooperate with foreign actors to facilitate technology sharing, financial flows, and technical assistance. To this end, international partnerships are playing a pivotal role in the development of both countries’ green hydrogen industries.

Description: Technologies for Carbon Capture, Usage and Storage (CCUS) and Carbon Dioxide Removal (CDR) only represent climate solutions in as much as they go hand in hand with deep emissions reductions. The (future) availability of CCUS and CDR technologies does not mean we can delay or avoid phasing out fossil fuels if we are to have a chance of limiting global warming to 1.5°C or even 2°C. Likewise, the expansion of renewable energy technologies will be nowhere near adequate for meeting agreed-upon climate targets unless fossil fuels are simultaneously ramped down. Up until now, renewables have been largely in addition to, rather than substituting for fossil fuels. Achieving our climate and broader sustainable development goals will require transformations that go beyond energy systems and reevaluate the structures and institutions behind our patterns of consumption, mobility, and food production, among others.

Description: Certain cyanobacteria of the secondary metabolite-rich order Nostocales can establish permanent symbioses with a large number of cycads, by accumulating in their coralloid roots and shifting their metabolism to dinitrogen fixation. Here, we report the discovery of two new lipoglycopeptides, desmamides A (1) and B (2), together with their aglycone desmamide C (3), from the nostocalean cyanobacterium Desmonostoc muscorum LEGE 12446 isolated from a cycad (Cycas revoluta) coralloid root. The chemical structures of the compounds were elucidated using a combination of 1D and 2D NMR spectroscopy and mass spectrometry. The desmamides are decapeptides featuring O-glycosylation of tyrosine (in 1 and 2) and an unusual 3,5-dihydroxy-2-methyldecanoic acid residue. The biosynthesis of the desmamides was studied by substrate incubation experiments and bioinformatics. We describe herein the dsm biosynthetic gene cluster and propose it to be associated with desmamide production. The discovery of this class of very abundant (〉1.5% d.w.) bacterial lipoglycopeptides paves the way for exploration of their potential role in root endosymbiosis.

Description: Insensitive munitions compounds (IMCs) are emerging nitroaromatic contaminants developed by the military as safer-to-handle alternatives to conventional explosives. Biotransformation of nitroaromatics via microbial respiration has only been reported for a limited number of substrates. Important soil microorganisms can respire natural organic matter (NOM) by reducing its quinone moieties to hydroquinones. Thus, we investigated the NOM respiration combined with the abiotic reduction of nitroaromatics by the hydroquinones formed. First, we established nitroaromatic concentration ranges that were nontoxic to the quinone respiration. Then, an enrichment culture dominated by Geobacter anodireducens could indirectly reduce a broad array of nitroaromatics by first respiring NOM components or the NOM surrogate anthraquinone-2,6-disulfonate (AQDS). Without quinones, no nitroaromatic tested was reduced except for the IMC 3-nitro-1,2,4-triazol-5-one (NTO). Thus, the quinone respiration expanded the spectrum of nitroaromatics susceptible to transformation. The system functioned with very low quinone concentrations because NOM was recycled by the nitroaromatic reduction. A metatranscriptomic analysis demonstrated that the microorganisms obtained energy from quinone or NTO reduction since respiratory genes were upregulated when AQDS or NTO was the electron acceptor. The results indicated microbial NOM respiration sustained by the nitroaromatic-dependent cycling of quinones. This process can be applied as a nitroaromatic remediation strategy, provided that a quinone pool is available for microorganisms.

Description: Vatairea guianenis Aubl. (Fabaceae) is an Amazonian medicinal plant species traditionally used for treating skin diseases. In an initial screening, a V. guianensis leaf extract and its subextracts showed antibacterial and antifungal activities. The EtOAc subextract was selected for chemical workup and afforded five known (1–4 and 8) and six undescribed isoflavones, vatairenones C–H (5–7 and 9–11). All isoflavones are prenylated in position C-8, displaying either chain-prenylated (1–7) or ring-closed forms (8–11). The most bioactive compound (3) exhibited in vitro activity against clinically relevant bacteria and fungi with IC50 values ranging from 6.8 to 26.9 μM. Due to its broad antimicrobial activity and low general toxicity, compound 3 is a potential lead compound for structural modifications. The results of the present study support the ethnomedicinal use of V. guianensis in the treatment of dermatological disorders. 1H NMR spectra of some of the isolated compounds showed intricate signal patterns, which might explain repeated errors in assigning the correct structure of the isoflavonoid B-ring in the literature and which we resolved by higher order spectra simulations.

Description: Understanding residence times of plastic in the ocean is a major knowledge gap in plastic pollution studies. Observations report a large mismatch between plastic load estimates from worldwide production and disposal and actual plastics floating at the sea surface. Surveys of the water column, from the surface to the deep sea, are rare. Most recent work, therefore, addressed the “missing plastic” question using modeling or laboratory approaches proposing biofouling and degradation as the main removal processes in the ocean. Through organic matrices, plastic can affect the biogeochemical and microbial cycling of carbon and nutrients. For the first time, we provide in situ measured vertical fluxes of microplastics deploying drifting sediment traps in the North Atlantic Gyre from 50 m down to 600 m depth, showing that through biogenic polymers plastic can be embedded into rapidly sinking particles also known as marine snow. We furthermore show that the carbon contained in plastic can represent up to 3.8% of the total downward flux of particulate organic carbon. Our results shed light on important pathways regulating the transport of microplastics in marine systems and on potential interactions with the marine carbon cycle, suggesting microplastic removal through the “biological plastic pump”.

Description: Detailed geochemical and mineralogical insights into some of the richest rare earth elements and yttrium (REY)-containing bioapatites from ocean-floor sediments have been provided by combining laser ablation inductively coupled plasma diffraction analysis, and Ce L3-edge high energy-resolution X-ray absorption near edge structure (HR-XANES) spectroscopy. Bioapatites at 1.94 and 4.70 m below the seafloor (mbsf) of the Clarion-Clipperton Zone (CCZ) of the Pacific Ocean have 26,600 (RSD = 15.7%, n = 20) and 30,300 (RSD = 14.6%, n = 10) mg/kg (mg/kg) total REY, respectively, and bioapatites at 2.28 and 6.95 mbsf of the Peru Basin have 15,500 (RSD = 15.6%, n = 20) and 15,700 (RSD = 17.8%, n = 29) mg/kg total REY, respectively. All bioapatite specimens have a variety of isomorphic substitutions in all atomic positions of the crystallographic structure. The average crystallochemical formula of bioapatites at 6.95 mbsf of the Peru Basin is [(PO4)2.71(SiO4)0.04(CO3,SO4)0.25][Ca4.57Na0.29Y0.04][F0.87Cl0.21]. All other substituents are below 0.04 atoms per formula unit. HR-XANES provides the first direct evidence for trivalent Ce in sediment apatites. The strong negative geochemical anomaly of Ce in fossil bioapatites is well explained by the occurrence of four valent Ce-MnO2 and CeO2 within the sediment and in seafloor ferromanganese nodules.

Description: Iron (Fe) is the fourth most abundant element in the earth’s crust and plays important roles in both biological and chemical processes. The redox reactivity of various Fe(II) forms has gained increasing attention over recent decades in the areas of (bio) geochemistry, environmental chemistry and engineering, and material sciences. The goal of this paper is to review these recent advances and the current state of knowledge of Fe(II) redox chemistry in the environment. Specifically, this comprehensive review focuses on the redox reactivity of four types of Fe(II) species including aqueous Fe(II), Fe(II) complexed with ligands, minerals bearing structural Fe(II), and sorbed Fe(II) on mineral oxide surfaces. The formation pathways, factors governing the reactivity, insights into potential mechanisms, reactivity comparison, and characterization techniques are discussed with reference to the most recent breakthroughs in this field where possible. We also cover the roles of these Fe(II) species in environmental applications of zerovalent iron, microbial processes, biogeochemical cycling of carbon and nutrients, and their abiotic oxidation related processes in natural and engineered systems.

Description: We report a novel hybrid, molecular and elemental mass spectrometry (MS) setup for the absolute quantification of snake venom proteomes shown here for two desert black cobra species within the genus Walterinnesia, Walterinnesia aegyptia and Walterinnesia morgani. The experimental design includes the decomplexation of the venom samples by reverse-phase chromatography independently coupled to four mass spectrometry systems: the combined bottom-up and top-down molecular MS for protein identification and a parallel reverse-phase microbore high-performance liquid chromatograph (RP-μHPLC) on-line to inductively coupled plasma (ICP-MS/MS) elemental mass spectrometry and electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QToF MS). This allows to continuously record the absolute sulfur concentration throughout the chromatogram and assign it to the parent venom proteins separated in the RP-μHPLC-ESI-QToF parallel run via mass profiling. The results provide a locus-resolved and quantitative insight into the three desert black cobra venom proteome samples. They also validate the units of measure of our snake venomics strategy for the relative quantification of snake venom proteomes as % of total venom peptide bonds as a proxy for the % by weight of the venom toxins/toxin families. In a more general context, our work may pave the way for broader applications of hybrid elemental/molecular MS setups in diverse areas of proteomics.

Description: The world adds about 51 Gt of greenhouse gases to the atmosphere each year, which will yield dire global consequences without aggressive action in the form of carbon dioxide removal (CDR) and other technologies. A suggested guideline requires that proposed CDR technologies be capable of removing at least 1% of current annual emissions, about half a gigaton, from the atmosphere each year once fully implemented for them to be worthy of pursuit. Basalt carbonation coupled to direct air capture (DAC) can exceed this baseline, but it is likely that implementation at the gigaton-per-year scale will require increasing per-well CO2 injection rates to a point where CO2 forms a persistent, free-phase CO2 plume in the basaltic subsurface. Here, we use a series of thermodynamic calculations and basalt dissolution simulations to show that the development of a persistent plume will reduce carbonation efficiency (i.e., the amount of CO2 mineralized per kilogram of basalt dissolved) relative to existing field projects and experimental studies. We show that variations in carbonation efficiency are directly related to carbonate mineral solubility, which is a function of solution alkalinity and pH/CO2 fugacity. The simulations demonstrate the sensitivity of carbonation efficiency to solution alkalinity and caution against directly extrapolating carbonation efficiencies inferred from laboratory studies and small-injection-rate field studies conducted under elevated alkalinity and/or pH conditions to gigaton-per-year scale basalt carbonation. Nevertheless, all simulations demonstrate significant carbonate mineralization and thus imply that significant mineral carbonation can be expected even at the gigaton-per-year scale if basalts are given time to react.

Description: Inhibition of the major cyclic adenosine monophosphate- metabolizing enzyme PDE4 has shown potential for the discovery of drugs for cancer, inflammation, and neurodegenerative disorders such as Alzheimer's disease. As a springboard to explore new anti-cancer and anti-Alzheimer's chemical prototypes from rare Annonaceae species, the present study evaluated anti-PDE4B along with antiproliferative and anti-cholinesterase activities of the extracts of the Philippine endemic species Uvaria alba using in vitro assays and framed the resulting biological significance through computational binding and reactivity-based experiments. Thus, the PDE4 B2B-inhibiting dichloromethane sub-extract (UaD) of U. alba elicited antiproliferative activity against chronic myelogenous leukemia (K-562) and cytostatic effects against human cervical cancer (HeLa). The extract also profoundly inhibited acetylcholinesterase (AChE), an enzyme involved in the progression of neurodegenerative diseases. Chemical profiling analysis of the bioactive extract identified 18 putative secondary metabolites. Molecular docking and molecular dynamics simulations showed strong free energy binding mechanisms and dynamic stability at 50- ns simulations in the catalytic domains of PDE4 B2B, ubiquitin-specific peptidase 14, and Kelch-like ECH-associated protein 1 (KEAP-1 Kelch domain) for the benzylated dihydroflavone dichamanetin (16), and of an AChE and KEAP-1 BTB domain for 3- (3,4-dihydroxybenzyl)-3',4',6-trihydroxy-2,4-dimethoxychalcone (8) and grandifloracin (15), respectively. Density functional theory calculations to demonstrate Michael addition reaction of the most electrophilic metabolite and kinetically stable grandifloracin (15) with Cys151 of the KEAP-1 BTB domain illustrated favorable formation of a β-addition adduct. The top-ranked compounds also conferred favorable in silico pharmacokinetic properties.

Description: The physicochemical characteristics of dissolved organic matter (DOM) strongly influence its interactions with inorganic species such as protons and trace elements in natural waters. We collected water samples at Boknis Eck, a time series station in the Baltic Sea with a low exposure to freshwater inputs, to investigate how seasonal fluctuations impact the proton binding properties of the isolated DOM. We used potentiometric titrations to assess the binding properties of solid-phase extracted DOM (SPE–DOM) over a seasonal cycle. We report and critically analyze the first NICA parameters estimates of carboxylic-like and phenolic-like sites for brackish water SPE–DOM. The total amount of functional groups (QmaxH,tot) showed no seasonal fluctuations and an average value of 136 ± 5.2 mmol·mol C–1. The average proton affinity (logKH) and binding site heterogeneity (m) showed a relatively minor variability for samples obtained between April and September, when the water remained stratified. These results contribute to a better understanding of the ion binding characteristics of DOM in natural brackish waters.

Description: Microbial extracellular electron transfer plays an important role in diverse biogeochemical cycles, metal corrosion, bioelectrochemical technologies, and anaerobic digestion. Evaluation of electron uptake from pure Fe(0) and stainless steel indicated that, in contrast to previous speculation in the literature, Desulfovibrio ferrophilus and Desulfopila corrodens are not able to directly extract electrons from solid-phase electron-donating surfaces. D. ferrophilus grew with Fe(III) as the electron acceptor, but Dp. corrodens did not. D. ferrophilus reduced Fe(III) oxide occluded within porous alginate beads, suggesting that it released a soluble electron shuttle to promote Fe(III) oxide reduction. Conductive atomic force microscopy revealed that the D. ferrophilus pili are electrically conductive and the expression of a gene encoding an aromatics-rich putative pilin was upregulated during growth on Fe(III) oxide. The expression of genes for multi-heme c-type cytochromes was not upregulated during growth with Fe(III) as the electron acceptor, and genes for a porin-cytochrome conduit across the outer membrane were not apparent in the genome. The results suggest that D. ferrophilus has adopted a novel combination of strategies to enable extracellular electron transport, which may be of biogeochemical and technological significance.

Description: Nitric oxide (NO) is a short-lived intermediate of the oceanic nitrogen cycle, and it is produced by biological and photochemical processes in the ocean. Nitrogen dioxide (NO2) is a reactive atmospheric compound which has not been determined in the ocean so far. Here, we present the setup and validation of a novel continuous underway measurement system to measure dissolved NO and NO2 in the surface ocean. The system consists of a seawater/gas equilibration component coupled to a chemiluminescence detector. It was successfully deployed during a 12 day cruise to the East China Sea in May 2018. Dissolved NO and NO2 surface concentrations ranged from 〈limit of detection (LOD) to 98 × 10-12 mol L-1 and 〈LOD to 83 × 10-12 mol L-1, respectively. The ECS was supersaturated with NO but significantly undersaturated with NO2, indicating that the surface waters were a source for atmospheric NO but a sink for atmospheric NO2 at the time of our measurements.

Description: The "guest exchange"of methane (CH4) by carbon dioxide (CO2) in naturally occurring gas hydrates is seen as a possibility to concurrently produce CH4 and sequester CO2. Presently, process evaluation is based on CH4-CO2 exchange yields of small-or medium-scale laboratory experiments, mostly neglecting mass and heat transfer processes. This work investigates process efficiencies in two large-scale experiments (210 L sample volume) using fully water-saturated, natural reservoir conditions and a gas hydrate saturation of 50%. After injecting 50 kg of heated CO2 discontinuously (E1) and continuously (E2) and a subsequent soaking period, the reservoir was depressurized discontinuously. It was monitored using electrical resistivity, temperature and pressure sensors, and fluid flow and gas composition measurements. Phase and component inventories were analyzed based on mass and volume balances. The total CH4 production during CO2 injection was only 5% of the initial CH4 inventory. Prior to CO2 breakthrough, the produced CH4 roughly equaled dissolved CH4 in the produced pore water, which balanced the volume of the injected CO2. After CO2 breakthrough, CH4 ratios in the released CO2 quickly dropped to 2.0-0.5 vol %. The total CO2 retention was the highest just before the CO2 breakthrough and higher in E1 where discontinuous injection improved the distribution of injected CO2 and subsequent mixed hydrate formation. The processes were improved by the succession of CO2 injection by controlled degassing at stability limits below that of the pure CH4 hydrate, particularly in experiment E2. Here, a more heterogeneous distribution of liquid CO2 and larger availability of free water led to smaller initial degassing of liquid CO2. This allowed for quick re-formation of mixed gas hydrates and CH4 ratios of 50% in the produced gases. The experiments demonstrate the importance of fluid migration patterns, heat transport, sample inhomogeneity, and secondary gas hydrate formation in water-saturated sediments.

Description: The substance Tris (or THAM, 2-amino-2-hydroxymethyl-1,3-propanediol) is used in the preparation of pH buffer solutions for applications in natural water chemistry, including seawater. The development of a chemical speciation model of buffer solutions containing Tris, TrisH+, and the major ions of seawater is desirable, so that the effects of changes in the composition and concentration of the medium on pH can be calculated. The Pitzer activity coefficient equations, commonly used in such speciation models, describe the thermodynamic properties of solutions in terms of interactions between dissolved ions and uncharged solute species. To determine some of these interactions, we have measured solubilities of Tris(s) in water and aqueous solutions of NaCl, TrisHCl, and (TrisH)2SO4 and the solubility of NaCl(s) in aqueous Tris(aq), from 5 to 45 °C. We report measurements of the water activities of Tris solutions at 293.5 K to high supersaturation with respect to the solid. Using the Pitzer equations, we compare our results to literature data yielding stoichiometric dissociation constants of TrisH+ in aqueous NaCl, and to electromotive forces of cells containing dissolved Tris, TrisHCl, and NaCl. Values of parameters for the interactions of Tris with the ions TrisH+, Na+, and SO42– at 25 °C are determined.

Description: The chemical speciation of iron (Fe) in oceans is influenced by ambient pH, dissolved oxygen, and the concentrations and strengths of the binding sites of dissolved organic matter (DOM). Here, we derived new nonideal competitive adsorption (NICA) constants for Fe(III) binding to marine DOM via pH-Fe titrations. We used the constants to calculate Fe(III) speciation and derive the apparent Fe(III) solubility (SFe(III)app) in the ambient water column across the Peruvian shelf and slope region. We define SFe(III)app as the sum of aqueous inorganic Fe(III) species and Fe(III) bound to DOM at a free Fe (Fe3+) concentration equal to the limiting solubility of Fe hydroxide (Fe(OH)3(s)). A ca. twofold increase in SFe(III)app in the oxygen minimum zone (OMZ) compared to surface waters is predicted. The increase results from a one order of magnitude decrease in H+ concentration which impacts both Fe(III) hydroxide solubility and organic complexation. A correlation matrix suggests that changes in pH have a larger impact on SFe(III)app and Fe(III) speciation than DOM in this region. Using Fe(II) measurements, we calculated ambient DFe(III) and compared the value with the predicted SFe(III)app. The underlying distribution of ambient DFe(III) largely reflected the predicted SFe(III)app, indicating that decreased pH as a result of OMZ intensification and ocean acidification may increase SFe(III)app with potential impacts on surface DFe inventories.

Description: Antimony (Sb) mobilization is widely explored with dissimilatory metal-reducing bacteria (DMRB) via microbial iron(III)-reduction. Here, our study found a previously unknown pathway whereby DMRB release adsorbed antimonite (SbIII-O) from goethite via elemental sulfur (S0) respiratory reduction under mild alkaline conditions. We incubated SbIII-O-loaded goethite with Shewanella oneidensis MR-1 in the presence of S0 at pH 8.5. The incubation results showed that MR-1 reduced S0 instead of goethite, and biogenic sulfide induced the formation of thioantimonite (SbIII-S). SbIII-S was then oxidized by S0 to mobile thioantimonate (SbV-S), resulting in over fourfold greater Sb release to water compared with the abiotic control. SbIV-S was identified as the intermediate during the oxidation process by Fourier transform ion cyclotron resonance mass spectrometry and electron spin resonance analysis. The existence of SbIV-S reveals that the oxidation of SbIII-S to SbV-S follows a two-step consecutive one-electron transfer from Sb to S atoms. SbV-S then links with SbIII-S by sharing S atoms and inhibits SbIII-S polymerization and SbIII2S3 precipitation like a “capping agent”. This study clarifies the thiolation and oxidation pathway of SbIII-O to SbV-S by S0 respiration and expands the role of DMRB in the fate of Sb.

Description: Explaining the dynamics of gas-saturated live petroleum in deep water remains a challenge. Recently, Pesch et al. (Environ. Eng. Sci. 2018, 35, 289−299) reported laboratory experiments on methane-saturated oil droplets under emulated deep-water conditions, providing an opportunity to elucidate the underlying dynamical processes. We explain these observations with the Texas A&M Oil spill/Outfall Calculator (TAMOC), which models the pressure-, temperature-, and composition-dependent interactions between: oil-gas phase transfer; aqueous dissolution; and densities and volumes of liquid oil droplets, gas bubbles, and two-phase droplet-bubble pairs. TAMOC reveals that aqueous dissolution removed 〉95% of the methane from ~3.5-mm live oil droplets within 14.5 min, prior to gas bubble formation, during the experiments of Pesch et al. Additional simulations indicate that aqueous dissolution, fluid density changes, and gas-oil phase transitions (ebullition, condensation) may all contribute to the fates of live oil and gas in deep water, depending on the release conditions. Illustrative model scenarios suggest that 5-mm diameter gas bubbles released at 〈470 m water depth can transport methane, ethane, and propane to the water surface. Ethane and propane can reach the water surface from much deeper releases of 5-mm diameter live oil droplets, during which ebullition occurs at water depths of 〈70 m.

Description: Chemical investigation of the marine bryozoan Flustra foliacea collected in Iceland resulted in isolation of 13 new bromotryptamine alkaloids, flustramines Q-W (1-7) and flustraminols C-H (8-13), and two new imidazole alkaloids, flustrimidazoles A and B (14 and 15), together with 12 previously described compounds (16-27). Their structures were established by detailed spectroscopic analysis using 1D and 2D NMR and HRESIMS. Structure 2 was verified by calculations of the 13C and 1H NMR chemical shifts using density functional theory. The relative and absolute configurations of the new compounds were elucidated on the basis of coupling constant analysis, NOESY, [α]D, and ECD spectroscopic data, in addition to chemical derivatization. The compounds were tested for in vitro anti-inflammatory activity using a dendritic cell model. Eight compounds (1, 3, 5, 13, 16, 18, 26, and 27) decreased dendritic cell secretion of the pro-inflammatory cytokine IL-12p40, and two compounds (4 and 14) increased secretion of the anti-inflammatory cytokine IL-10. Deformylflustrabromine B (27) showed the most potent anti-inflammatory effect (IC50 2.9 μM). These results demonstrate that F. foliacea from Iceland expresses a broad range of brominated alkaloids, many without structural precedents. The potent anti-inflammatory activity in vitro of metabolite 27 warrants further investigations into its potential as a lead for inflammation-related diseases.

Description: California hosts ∼124,000 abandoned and plugged (AP) oil and gas wells, ∼38,000 idle wells, and ∼63,000 active wells, whose methane (CH4) emissions remain largely unquantified at levels below ∼2 kg CH4 h–1. We sampled 121 wells using two methods: a rapid mobile plume integration method (detection ∼0.5 g CH4 h–1) and a more sensitive static flux chamber (detection ∼1 × 10–6 g CH4 h–1). We measured small but detectable methane emissions from 34 of 97 AP wells (mean emission: 0.286 g CH4 h–1). In contrast, we found emissions from 11 of 17 idle wells—which are not currently producing (mean: 35.4 g CH4 h–1)—4 of 6 active wells (mean: 189.7 g CH4 h–1), and one unplugged well—an open casing with no infrastructure present (10.9 g CH4 h–1). Our results support previous findings that emissions from plugged wells are low but are more substantial from idle wells. In addition, our smaller sample of active wells suggests that their reported emissions are consistent with previous studies and deserve further attention. Due to limited access, we could not measure wells in most major active oil and gas fields in California; therefore, we recommend additional data collection from all types of wells but especially active and idle wells.

Description: Iron is the most important micronutrient in the ocean, but the nature and magnitude of its sources and sinks to the ocean are poorly constrained. Here we assess our understanding of the sources and sinks of iron in margin environments by synthesizing observations from the U.S. GEOTRACES GP16 Eastern Tropical Pacific Zonal Transect (EPZT) cruise near the Peru margin. GP16 observations showed elevated dissolved iron (dFe) concentrations along the margin, but a larger westward plume of dFe at slope depths (1000–3000 m) in oxygenated waters, rather than at shelf depths (100–300 m) in oxygen deficient waters. We examine the potential explanations for this unexpected observation. Multiple tracers from GP16 suggest that sediment resuspension was important at slope depths, which would lead to enhanced benthic flux of dFe above what was previously measured. The difference in the apparent persistence and penetration of shelf versus slope plumes of dFe into the interior of the ocean likely results from faster removal rates of the shelf dFe compared to slope dFe. The dFe sourced from the shelf was almost entirely in the dFe(II) form, whereas dFe sourced from the slope was almost entirely in the dFe(III) form. Although benthic dFe(II) diffuses into oxygen deficient overlying waters, there is still oxidation of dFe(II), which precipitates to particulate Fe(III). In contrast, the slope plume appears to persist in a stabilized dFe(III) form. We hypothesize that sediment porewaters with moderate organic carbon delivery to sediments and shallow oxygen penetration are especially good sources of persistent dFe to the water column.

Description: Guided by LC-MS/MS molecular networking-based metabolomics and cytotoxic activity, two new discorhabdin-type alkaloids, tridiscorhabdin (1) and didiscorhabdin (2), were isolated from the sponge Latrunculia biformis, collected from the Weddell Sea (Antarctica) at -291 m depth. Their structures were established by HRESIMS, NMR, [α]D, and ECD data coupled with DFT calculations. Both compounds bear a novel C-N bridge (C-1/N-13) between discorhabdin monomers, and 1 represents the first trimeric discorhabdin molecule isolated from Nature. Tridiscorhabdin (1) exhibited strong cytotoxic activity against the human colon cancer cell line HCT-116 (IC50 value 0.31 μM).

Description: We report measurements of strontium concentrations and Sr/Ca ratios in the Indian and Southern Oceans, which show that subtle geochemical variations along the main thermocline are the product of calcium carbonate (CaCO3) and celestite (SrSO4) precipitation and dissolution. Our calculations suggest that celestite skeletons precipitated by Acantharia contribute up to 10 mol % of the combined amount of carbonate and celestite shells precipitated in the Indian Ocean. The data suggest that the distribution of the concentration of strontium in the global ocean is governed by the different modes of deep-water formation in the Southern Ocean and North Atlantic. The formation of Antarctic bottom waters from strontium-rich, upwelled deep waters forms a southern end member contrasted with the strontium depleted North Atlantic deep water. The difference in strontium concentrations and Sr/Ca ratios of the different water masses reported here is maintained by precipitation, export, and dissolution of CaCO3 and SrSO4. These preformed strontium concentrations correlate linearly with nitrate and phosphate concentrations in the Indian Ocean, but this correlation is weaker in low latitudes, where the mixotrophic lifestyle of Acantharia allows them to thrive in nutrient-depleted environments.

Description: Isovalerate is an important intermediate in anaerobic degradation of proteins/amino acids. Little is known about how this compound is degraded due to challenges in cultivation and characterization of isovalerate-degrading bacteria, which are thought to symbiotically depend on methanogenic archaea. In this study, we successfully enriched novel syntrophic isovalerate degraders (uncultivated Clostridiales and Syntrophaceae members) through operation of mesophilic and thermophilic isovalerate-fed anaerobic reactors. Metagenomics- and metatranscriptomics-based metabolic reconstruction of novel putative syntrophic isovalerate metabolizers uncovered the catabolic pathway and byproducts (i.e., acetate, H2, and formate) of isovalerate degradation, mechanisms for electron transduction from isovalerate degradation to H2 and formate generation (via electron transfer flavoprotein; ETF), and biosynthetic metabolism. The identified organisms tended to prefer formate-based interspecies electron transfer with methanogenic partners. The byproduct acetate was further converted to CH4 and CO2 by either Methanothrix (mesophilic) and Methanosarcina (thermophilic), which employed different approaches for acetate degradation. This study presents insights into novel mesophilic and thermophilic isovalerate degraders and their interactions with methanogens.

Description: The spatiotemporal dynamics of denitrification in groundwater are still not well-understood because of a lack of efficient methods to quantify this biogeochemical reaction pathway. Previous research used the ratio of N2 to argon (Ar) to quantify net production of N2 via denitrification by separating the biologically generated N2 component from the atmospheric-generated components. However, this method does not allow the quantification of the atmospheric components accurately because the differences in gas partitioning between N2 and Ar are being neglected. Moreover, conventional (noble) gas analysis in water is both expensive and labor-intensive. We overcome these limitations by using a portable mass spectrometer system, which enables a fast and efficient in situ analysis of dissolved (noble) gases in groundwater. By analyzing a larger set of (noble) gases (N2, He, Ar, and Kr) combined with a physically meaningful excess air model, we quantified N2 originating from denitrification. Consequently, we were able to study the spatiotemporal dynamics of N2 production due to denitrification in riparian groundwater over a six-month period. Our results show that denitrification is highly variable in space and time, emphasizing the need for spatially and temporally resolved data to accurately account for denitrification dynamics in groundwater.

Description: In 2013, the Pacific Northwest National Laboratory led a geologic carbon sequestration field demonstration where ∼1000 tonnes of CO2 was injected into several deep Columbia River Basalt zones near Wallula, Washington. Rock core samples extracted from the injection zone two years after CO2 injection revealed nascent carbonate mineralization that was qualitatively consistent with expectations from laboratory experiments and reactive transport modeling. Here, we report on a new detailed analysis of the 2012 pre-injection and 2015 post-injection hydrologic tests that capitalizes on the difference in fluid properties between scCO2 and water to assess changes in near-field, wellbore, and reservoir conditions that are apparent approximately two years following the end of injection. This comparative hydrologic test analysis method provides a new way to quantify the amount of injected CO2 that was mineralized in the field test. Modeling results indicate that approximately 60% of the injected CO2 was sequestered via mineralization within two years, with the resulting carbonates occupying ∼4% of the available reservoir pore space. The method presented here provides a new monitoring tool to assess the fate of CO2 injected into chemically reactive basalt formations but could also be adapted for long-term monitoring and verification within more traditional subsurface carbon storage reservoirs.