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This study compares the biogas potential of solid common reed residues after undergoing vapothermal and hydrothermal pre-treatment, accompanied by a compositional and structural biomass characterization. In a pre-test series, a design of experiments approach was used to determine the influence of the initial biomass water content during vapothermal pre-treatment on the biogas yield. In the main test series, common reed was pre-treated hydrothermally (i.e., in liquid water) and vapothermally (i.e., in saturated steam) while varying temperature and residence time. The initial biomass water content significantly impacted the biogas potential, with an optimum at a value of 32 to 46 wt-%FM. In the main test series, unlike the residence time, temperature significantly impacted the subsequent anaerobic digestion. Vapothermal pre-treatment had a narrow temperature optimum while hydrothermal pre-treatment led to a biogas increase in a broader temperature range. The optimum temperature of both methods was 170 °C, where methane potentials increased by 28 % (vapothermal) and 36 % (hydrothermal) compared to the untreated sample. Considering the mass loss occurring during the pre-treatment, this increase was still 18 % for vapothermal pre-treatment, while it diminished the increase to 6 % for hydrothermal pre-treatment. Overall, vapothermal pre-treatment produced a similar amount of biogas under comparable conditions, but was less susceptible to carbon loss, and, according to an estimation of the required process energy, may offer energy savings compared to hydrothermal pre-treatment.

Abstract This research presents a straightforward and economically efficient design for a microbial fuel cell (MFC) that can be conveniently integrated into a borehole to monitor natural attenuation in groundwater. The design employs conventional, transparent, and reusable PVC bailers with graphite tape and granular activated carbon to create high surface area electrodes. These electrodes are connected across redox environments in nested boreholes through a wire and variable resistor setup. The amended electrodes were installed in pre-existing boreholes surrounding a groundwater plume near a former gasworks facility. Among all the MFC locations tested, the MFC at the plume fringe exhibited the highest electrical response and displayed significant variations in the differential abundance of key bacterial and archaeal taxa between the anode and cathode electrodes. The other MFC configurations in the plume center and uncontaminated groundwater showed little to no electrical response, suggesting minimal microbial activity. This straightforward approach enables informed decision-making regarding effectively monitoring, enhancing, or designing degradation strategies for groundwater plumes. It offers a valuable tool for understanding and managing contaminant degradation in such environments.

The decarbonization of industrial processes requires efficient and scalable renewable energy solutions. Concentrated Solar Power (CSP) technology stands out by providing both electricity and high-temperature heat, yet its optimal deployment remains a challenge. This study presents an innovative framework for selecting and optimizing CSP technologies tailored for potential industrial practical applications. In this study, a multi-phase approach is deployed integrating a decision matrix, performance simulations using SOLARPILOT and SAM, and techno-economic evaluation to identify the best CSP solution. The study addresses the feasibility of four candidate CSP technologies, the characteristics of deployment areas, operation parameters such as energy storage time, and characteristics of energy storage material (comparing commercially available materials and an innovative molten salt named FERT-1). The results highlight solar towers as the most suitable technology, while the characteristics of the deployment can lead to over 3.2% difference in annual energy generation (when comparing between two areas, A1 and A2). Regarding energy storage, an optimal storage time of 11 h was identified, achieving a Levelized Cost of Electricity (LCOE) of 24–25 cents/kWh and a 31–32% energy capacity factor. Moreover, regarding energy storage material, the innovative molten salt highlighted improved thermal efficiency.

Abstract Blooms of dark pigmented microalgae accelerate glacier and ice sheet melting by reducing the surface albedo. However, the role of nutrient availability in regulating algal growth on the ice remains poorly understood. Here, we investigate glacier ice algae on the Greenland Ice Sheet, providing single-cell measurements of carbon:nitrogen:phosphorus (C:N:P) ratios and assimilation rates of dissolved inorganic carbon (DIC), ammonium and nitrate following nutrient amendments. The single-cell analyses reveal high C:N and C:P atomic ratios in algal biomass as well as intracellular P storage. DIC assimilation rates are not enhanced by ammonium, nitrate, or phosphate addition. Our combined results demonstrate that glacier ice algae can optimise nutrient uptake, facilitating the potential colonization of newly exposed bare ice surfaces without the need for additional nutrient inputs. This adaptive strategy is particularly important given accelerated climate warming and the expansion of melt areas on the Greenland Ice Sheet.

Study region: Temperate beech forest in central Germany’s low mountain range Study focus: Soil moisture is essential for ecosystem functioning, influencing hydrological, biological, and biogeochemical processes. It regulates water, energy, and carbon cycles, supporting ecosystem organization, biodiversity, and vegetation resilience. However, climate change and human activities increasingly disrupt soil moisture dynamics, altering spatio-temporal variability due to altered precipitation, rising temperatures, and droughts, making prediction attempts a challenge. This study examines a temperate beech forest in central Germany’s low mountain range, aiming to: (1) analyse spatio-temporal variations in soil moisture and temperature, (2) assess correlations with topographic indices across seasons, and (3) validate ERA5-Land retrievals. We employed 62 automatic sensors and manual measurements at 236 sites within a 900 × 600 m area. Field data were merged with ERA5-Land reanalysis and topographic indices, including depth-to-water and topographic position indices, to assess their performance in predicting soil water content spatial patterns. New hydrological insights for the region: Temporal variation exceeded spatial variation by 3.60–3.68 times. While soil moisture was associated with mesorelief (topographic position index), the correlation was weak. Flow accumulation-based indices were ineffective in capturing spatial soil moisture variation and failed to model spatio-temporal variability. This suggests that model results need to be reconsidered, and suitable indices developed. Insights from this study contribute to improving soil–vegetation–atmosphere models and support sustainable forest management in a changing climate.

<p>In the context of the global adoption of the Blue Economy agenda, new challenges and opportunities emerge for gender mainstreaming in traditional male-dominated maritime industries. This thematic issue mobilizes knowledge on barriers and structural hindrances faced by women in the Blue Economy, from exclusionary workplace norms and hierarchies to inadequate support for work-life balance. These hindrances discourage women’s entry and retention in industries like fisheries, aquaculture, maritime transportation, and marine research. Lessons from the Nordic countries, which have significantly advanced gender equality and adopted numerous policies to enhance gender inclusivity, show that in the absence of effective implementation and evaluation of policy impacts, policies alone are not effective. Using gender as an analytical perspective reveals the importance of language and discourses in advancing gender inclusion, highlights issues of intersectionality across national borders, and exposes the need for Blue Justice alongside Blue Economy agendas. The collection of papers underscores the need for both systemic change and localized, tailored interventions. The methodological contribution exemplifies how discourse analysis unpacks societal norms, while ethnography reveals on-the-ground experiences of exclusion and resistance. Furthermore, tracking career trajectories provides data-driven insights into workforce retention, while interviews analyze the nuanced motivations and challenges women face. It is concluded that the agendas of the Blue Economy and gender equality could be indeed compatible, however, it must be acknowledged that the way these two can be simultaneously pursued remains a challenge that needs action.</p>

Abstract Despite continuous investigation, reasons for both the abandonment of Roman Britain around 410 CE, and the separate collapse of the Western Roman Empire in 476 CE remain unclear. Here, we use tree ring-based climate reconstructions and written documentary sources to show that a sequence of severe summer droughts from 364 to 366 CE not only contributed to prolonged harvest failures and food shortages, but also played a role in the ‘Barbarian Conspiracy’, a catastrophic military defeat for Roman Britain in 367 CE. In line with contemporary reports from the historian Ammianus Marcellinus, this pivotal event in pre-modern history coincided with anomalous coin hoarding, and a gradual depopulation of Roman villas and towns. Expanding our climate-conflict analysis from Roman Britain as a case study to the entire Roman Empire and the period 350–476 CE reveals clear linkages between years in which battles occurred and preceding warm and dry summers. Based on these findings, we develop a mechanistic model to explain the vulnerability of agrarian societies to climate variability, whereby prolonged droughts cause harvest failures and food shortages (dependant on societal resilience) that lead to systematic pressure, societal instability, and eventually outright conflict.