Economic methods for the selection of renewable energy sources: a case study

Governments need to evaluate technologies generating electricity from different sources; levelised cost of energy (LCOE) is a widely used metric. However, LCOE is weak at comparing disparate technologies, especially where they have different operational lifespans. The discrepancy is demonstrated using UK government data to examine a range of technologies, namely combined cycle generation (natural gas and hydrogen), sustainable renewable technologies along with independent data describing nuclear power and tidal range schemes. Three methods of analysis were used: LCOE, the internal rate of return (IRR), and a novel analysis. A new metric, the sustained cost of energy (SCOE), negates some of the LCOE shortcomings such as the application of discounting. SCOE examines a fixed period of continuous generation, using the lowest common length of operating life of the technologies analysed. It appears to be a useful metric, especially when interpreted with IRR. The analyses produce broadly similar ordering of technologies, but the longer-lasting systems with high initial costings perform better in SCOE. Subsidies, carbon tax, or credit schemes are essential government incentives if net zero emissions targets are to be met without overly burdening consumers with rapidly growing electricity rates

Radiosonde Measurements and Polar WRF Simulations of Low-Level Wind Jets in the Amundsen Sea Embayment, West Antarctica

We show that low-level jets (LLJs) occurred in 11 out of 22 radiosonde profiles in late austral summer over the coastal region of the Amundsen Sea Embayment, with ten of the LLJs directed offshore. The LLJs had core speeds from 9 to 32 m s −1 , jet core heights from 80 to 800 m, and were associated with strong, low-level temperature inversions. Seven of the observed offshore LLJs were reasonably simulated by the polar-optimized Weather Research and Forecasting (Polar WRF) model, with output from the model subsequently used to elucidate their generation mechanisms. This study shows that one of the offshore LLJs simulated by the Polar WRF was caused by katabatic winds, while the remaining six were caused by the enhancement of katabatic winds by synoptic forcing in response to a low-pressure system over the Bellingshausen Sea, i.e., the offshore wind component associated with this system plays a crucial role in the enhancement of the katabatic LLJ. Examination of the Polar WRF output further shows that the LLJs extended over large areas of the Amundsen Sea Embayment, resulting in substantially enhanced near-surface wind speeds over both the Thwaites and Pine Island ice shelves, as well as the open ocean over the continental shelf. The wind-driven forcing associated with the LLJs could perhaps have important impacts on the redistribution of snow over the ice shelves significantly, as well as to affecting sea-ice and ocean circulation variability, including the transport of relatively warm water over the continental shelf to the ice shelf cavities and extension basal melting

Density‐dependent effects on the reproductive ecology of trees in a temperate woodland

The reproductive success of plants often depends on their local conspecific densities. The degree of isolation from conspecific plants can mediate an individual's interactions with other organisms. For example, a high density of flowers can attract pollinators and improve seed set, and a high density of seeds can attract enemies such as seed predators. It is the joint outcome of positive and negative density‐dependent effects that will determine the spatial distribution of a population, yet they are rarely studied simultaneously. We related two indicators of reproductive success (fruit set and fruit drop) to tree size and the density of neighbouring conspecifics for 32 Crataegus monogyna (Rosaceae) individuals in a temperate woodland. Overall, 26% of flowers set seed, but seed set was not density dependent. We found that 25% of fruits were dropped before reaching maturity, and 24% of mature fruits were dropped before the typical dispersal period. The drop of both immature and mature fruits increased with the density of reproductive conspecifics in this system, with potential implications for spatial patterns of seedling recruitment

​​Skin, but not gut, microbial communities vary with social density in Antarctic fur seals

Comparative studies of microbial communities occupying different body sites in wild vertebrates are scarce, but they are crucial for advancing our understanding of the ecological and evolutionary factors shaping animal microbiomes. We therefore used a "natural experiment" comprising motheroffspring pairs from two adjacent Antarctic fur seal breeding colonies that differ in social density to investigate differences between skin and gut microbial communities in relation to host-specific and environmental factors. Using 16S rRNA amplicon sequencing, we uncovered a strong influence of colony on the diversity and composition of skin but not gut microbial communities. Specifically, we observed a suppressive effect of high social density on skin microbial alpha diversity as well as an overabundance of phyla associated with diseases and bite wounds in the high-density colony. Our findings suggest that skin microbial communities may be more sensitive to external factors, whereas gut communities are more tightly regulated by the host. Overall, this study highlights the importance of considering multiple body sites and their distinct microbial communities to develop a more comprehensive understanding of the factors shaping microbial diversity and composition in marine mammals

The timing and significance of mid-crustal shearing and exhumation of amphibolite-facies rocks along the Great Glen Fault Zone, Scotland

The Rosemarkie Inlier lies on the NW side of the Great Glen Fault Zone (GGFZ) and is composed of foliated and lineated Archean orthogneisses and Moine metasedimentary rocks. The mylonitic foliation strikes NE–SW (parallel to the GGFZ), dips steeply SE and contains a gently to moderately plunging mineral lineation. Microstructural and quartz c -axis fabric analyses indicate that oblique sinistral shearing occurred under amphibolite-facies conditions. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses on monazite rims in the gneisses yielded 206 Pb/ 238 U ages of 401.8 ± 4.8 Ma (including 2 σ uncertainty and a propagated additional 1% external uncertainty). Similar deformation and recrystallization temperatures indicated by quartz fabrics (610°C) and monazite–xenotime thermometry (616 ± 25°C), respectively, in the gneisses suggest that ductile sinistral shearing was ongoing at c . 402 Ma. The c . 402 Ma rim age is the youngest monazite age recorded in the Northern Highland Terrane (NHT) and indicates that sinistral shearing at mid-crustal levels was ongoing along the GGFZ in Lower Devonian (Emsian, 407–393 Ma) times when the thrust sheets of the NHT to the NW had already been exhumed. The Rosemarkie basement rocks are unconformably overlain by Middle Devonian (Eifelian, 393–387 Ma) sedimentary rocks, indicating time-averaged exhumation rates of c . 1.75 mm a −1 between 402 and c . 390 Ma, assuming a geothermal gradient of 30°C km −1

Biogeochemical‐Argo floats reveal seasonality of the biological carbon pump influenced by the Lofoten Basin Eddy

The Lofoten Basin Eddy (LBE) is a persistent topographically constrained anticyclonic eddy in the Norwegian Sea. Considering its local, dynamically distinct state, we test the hypothesis that the LBE has unique biogeochemical signatures. Using satellite observations and a 12-year Biogeochemical-Argo float record, we constructed a climatological view of the annual biogeochemical cycle within and surrounding the LBE. The biological carbon pump influenced by the LBE was less effective than surrounding waters, particularly during late spring. Particulate organic carbon export out of the productive zone was hindered during summer and likely associated with enhanced respiration and slower particle sinking speeds. Enhanced export into the twilight zone was also observed and consistent with shoaling of deep mixed layers in early spring, production of large particles in late summer, and subduction in late autumn; however, these mechanisms appear to be accompanied by enhanced remineralization within the LBE influence zone, highlighting the biogeochemical complexity of eddies

Atmospheric forcing as a driver for ocean forecasting

The connection of the ocean component with the Earth system is subject to the way the atmosphere interacts with it. The paper illustrates the state of the art in the way atmospheric fields are used in ocean models as boundary conditions for the provisioning of the exchanges of heat, freshwater, and momentum fluxes. Such fluxes are typically based on numerical weather prediction (NWP) systems which ingest observations from remote sensing and in situ instruments. This study also discusses how the ocean–atmosphere fluxes are numerically ingested in ocean models from global to regional to coastal scales. Today's research frontiers on this topic are opening challenging opportunities for developing more sophisticated coupled ocean–atmosphere systems and improved ocean–atmosphere flux datasets

Catalyzing change: a literature review on the implementation of the Nature Futures Framework

The Nature Futures Framework (NFF), developed under the Intergovernmental Science–Policy Platform on Biodiversity and Ecosystem Services (IPBES), serves as a catalyst for advancing new scenarios and models focused on biodiversity and ecosystem services within the broader research community. In particular, the framework facilitates the development of scenarios and models that can help guide change processes toward desirable futures for nature and people. This paper assesses 31 studies that have engaged with the NFF since its introduction in 2020, aiming to identify which research areas have been addressed, and where development needs remain. The applications exhibit a large diversity in terms of locations, spatial scales, methods, outputs, and stakeholder involvement. The most common use of the framework has been in developing visions and scenarios. Nearly all studies engaged with diverse values of nature through the framework’s fundamental value perspectives: ‘ Nature for Society ’, ‘ Nature for Natur e’, and ‘ Nature as Culture / One with Nature ’. While the framework is generally perceived as useful, challenges remain in integrating the NFF across multiple scales and fully incorporating plural values, particularly in measuring relational aspects and avoiding Western-centric biases. Future research priorities include developing integrated, quantitative studies and exploring transformative pathways to enhance the framework's effectiveness in driving sustainable outcomes. Overall, the growing body of work using the NFF provides a strong foundation for distilling best practices, facilitating large-scale applications, and achieving the framework's objectives

Constraints from uranium and molybdenum isotope ratios on the origin of enriched mid-ocean ridge basalts

Most mid-ocean ridge basalts (MORB) are depleted in highly incompatible elements relative to the primitive mantle and are termed normal (N)-MORB. Some MORB, erupted at ridge segments distal from mantle hot-spots, are enriched in incompatible elements. The origin of these enriched (E)-MORB is debated, although many studies have proposed that recycled oceanic crust shapes their compositions. Uranium (U) and molybdenum (Mo) isotope ratios have been argued to trace the contribution of recycled oceanic crust in the source of N-MORB, which has high δ238U and low δ98/95Mo relative to the bulk silicate Earth (BSE). Here, we provide U and Mo isotopic data on E-MORB samples from the northern mid-Atlantic ridge (13° & 45° N). We analysed hand-picked, leached MORB glass, yielding 234U/238U near secular equilibrium, therefore reflecting samples unperturbed by surface processes. Samples have uniform δ238U and δ98/95Mo, with means of −0.307 ± 0.032 ‰, 2sd, and −0.14 ± 0.04 ‰, 2sd, respectively, both within uncertainty of BSE, and distinct from N-MORB. These data, as well as unremarkable Ce/Pb and radiogenic Pb isotopic compositions in E-MORB globally, are incompatible with their sources containing recycled oceanic crust or continental derived sediments. Instead, our data fit with a model of low degree partial melting of the uppermost mantle that metasomatises the sub-oceanic lithosphere. Given BSE-like U isotopic compositions of E-MORB, that are isotopically unfractionated during low degree partial melting, we suggest that the initial melting event must have occurred prior to the recycling of isotopically distinct in U oceanic crust into the upper mantle (i.e., prior to ca. 600 Ma, the estimated time of deep ocean oxygenation). Metasomatised portions of oceanic lithospheric mantle preserve these ≥600 Ma U isotopic compositions, which are subducted and stirred back into the convecting upper mantle, ultimately to be sampled at ridges as E-MORB. Molybdenum isotopic compositions of E-MORB are in line with such a model but also reflect isotopic fractionation to higher δ98/95Mo during low degree partial melting of ≥600 Ma upper mantle, that counter acts the lowering of δ98/95Mo in the upper mantle by an on-going process of plate recycling

Agricultural landscapes impede woodland ground-dwelling beetle colonisation and establishment in planted woodlands

Global insect declines have been partly attributed to habitat loss and agricultural intensification. Large-scale habitat restoration is crucial to address this biodiversity crisis, with woodlands representing a key habitat that supports diverse insect communities, particularly beetle assemblages. However, little is known about beetle colonisation and establishment processes as woodland is created. Using data from a long-term natural experiment (the WrEN project), we investigate the relative importance of local and landscape characteristics on ground-dwelling beetle colonisation and establishment across 60 UK secondary broadleaved woodlands. Our sites, planted 12 – 160 years ago, range in size between 0.5 – 32 ha and are embedded in landscapes ranging from 20 – 90 % agriculture. Using structural equation models, we show that woodland generalist and specialist beetles were more abundant in larger woodlands and more species-rich in woodlands with a lower proportion of surrounding agriculture. Woodland specialists were more abundant in woodlands with lower tree densities, a positive indirect effect of woodland age. Beetle community composition varied according to woodland age and structure, with younger and more homogenous woodlands having more non-woodland species. These findings suggest that the agricultural matrix may hinder woodland beetle colonisation into newly established woodlands in farmed landscapes. To enhance beetle biodiversity, woodland restoration initiatives should prioritise planting larger sites, and active management such as selective thinning that reduces tree density and increases structural heterogeneity. We highlight a potential paradox between the benefits of restoration that avoids landscapes with high agriculture to promote beetle colonisation vs. targeting these landscapes in efforts to enhance biodiversity