Found 10463 publications. Showing page 397 of 419:
2025
2025
Towards an integrated data-driven infrastructure (InfraNor)
The Arctic is warming almost four times faster compared to the rest of the world (Rantanen et al. 2022). Svalbard and its surroundings have warmed faster than most of the Arctic (Cai et al. 2021; Isaksen et al. 2022). The Svalbard archipelago also shows large temperature variations from south to north and east to west (Østby et al. 2017). Svalbard has good infrastructure, logistics and communications (airport, port, laboratories), and excellent possibilities for data transfer. This makes Svalbard and its surroundings an attractive living natural laboratory for long-term and campaign-based Arctic studies.
2025
VKM has assessed the positive and negative effects on biodiversity were sterile salmon to be used in Norwegian aquaculture. Triploidisation is assessed as the most effective method for sterilising fish, but it can affect the welfare and health of the fish.
Several other techniques for producing sterile salmon are being tested, but it is too early to determine whether they can be used in large-scale farming.
This is the key message in a knowledge summary VKM has prepared for the Norwegian Environment Agency.
Background
Escaped farmed salmon poses a major threat to wild salmon in Norway. hey can interbreed with wild salmon, genetically alter them, and make the populations less adaptable and more vulnerable to disease and environmental changes. A possible solution to the problem may be to use sterile salmon in farming.
To date, only triploidisation has been tested. Newly fertilised eggs are given a hydrostatic pressure shock, thereby retaining an extra set of chromosomes which render the fish sterile. This method is currently the only one tested on a large scale. Triploidisation is effective but can also pose health and welfare challenges to fish.
Methods
VKM has reviewed available scientific literature regarding methods that can be used to produce sterile salmon. VKM has assessed whether these methods work as well, or better, than triploidy and whether they are likely to have fewer negative effects on fish welfare. Assessments have also been made of whether farmed fish treated with other sterilisation methods pose a greater or lesser threat to wild salmon than traditional farmed salmon.
VKM has looked at the possibilities for further development of the triploidisation technique and has also assessed various methods currently being tested for producing sterile fish. Some of these are still at the laboratory-testing stage, while others are approaching trials with release into sea-pens. VKM has grouped the different methods based on whether they cause permanent changes in the genome (so-called "knock-out" of important genes) or whether the changes only result in temporary blocking or downregulation of gene expression (so-called "knock-down").
Results
VKM concludes that triploidisation remains the most effective method and that there are possibilities to further develop this methodology through targeted breeding and adjustments in how the fish are kept. These measures can potentially solve the challenges for fish health and welfare. Using pure triploid female lines can also reduce some of the other challenges by preventing spawning interactions in rivers and reducing disease transmission to wild salmon.
Alternative sterilisation methods, such as gene editing, vaccination, and temporary downregulation of proteins for gonad development using antisense oligomers and egg immersion, are promising but still under development.
VKM assesses that methods causing permanent changes in the genome of diploid fish have a higher inherent risk than methods that only affect gene expression.
Hope in egg-bathing
Perhaps the most promising technique for safe production of sterile salmon is to add synthetic oligonucleotides to the eggs at an early stage, thereby preventing germ cell development without causing any inheritable changes. Such oligonucleotides can be injected into the eggs or absorbed by the eggs through bathing (immersion) in a special solution.
"Especially the method involving targeted 'tools,' such as oligonucleotides that prevent germ cell development and can be added to the eggs in a water bath, seems promising," says Johanna Bodin, member of the Panel for Genetically Modified organisms and spokesperson for the report.
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2025
From streets to seas: New greener ways to analyse urban snow pollution
Arctic cities experience long winters with heavy snowfalls. Every year, tonnes of urban snow contaminated with microplastics from tire wear and other traffic-related environmental pollutants are dumped into the sea.
2025
Australia has significant sources of atmospheric methane (CH₄), driven by extensive coal and natural gas production, livestock, and large-scale fires. Accurate quantification and characterization of CH₄ emissions are critical for effective climate mitigation strategies in Australia. In this study, we employed an inverse analysis of atmospheric CH₄ observations from the GOSAT satellite and surface measurements from 2016 to 2021 to assess CH₄ emissions in Australia. The inversion process integrates anthropogenic and natural emissions as prior estimates, optimizing them with the NIES-TM-FLEXPART-variational model (NTFVAR) at a resolution of up to 0.1° × 0.1°. We validated the performance of our inverse model using data obtained from the United Nations Environment Program Methane Science (UNEP), Airborne Research Australia 2018 aircraft-based atmospheric CH₄ measurement campaigns. Compared to prior emission estimates, optimized emissions dramatically enhanced the accuracy of modeled concentrations, aligning them much better with observations. Our results indicate that the estimated inland CH4 emissions in Australia amount to 6.84 ± 0.51 Tg CH4 yr−1 and anthropogenic emissions amount to 4.20 ± 0.08 Tg CH4 yr−1, both slightly lower than the values reported in existing inventories. Moreover, our results unveil noteworthy spatiotemporal characteristics, such as upward corrections during the warm season, particularly in Southeastern Australia. During the three most severe months of the 2019–2020 bushfire season, emissions from biomass burning surged by 0.68 Tg, constituting over 71% of the total emission increase. These results highlight the importance of continuous observation and analysis of sectoral emissions, particularly near major sources, to guide targeted emission reduction strategies. The spatiotemporal characteristics identified in this study underscore the need for adaptive and region-specific approaches to CH₄ emission management in Australia.
2025
Stochastic and deterministic processes in Asymmetric Tsetlin Machine
This paper introduces a new approach to enhance the decision-making capabilities of the Tsetlin Machine (TM) through the Stochastic Point Location (SPL) algorithm and the Asymmetric Steps technique. We incorporate stochasticity and asymmetry into the TM's process, along with a decaying normal distribution function that improves adaptability as it converges toward zero over time. We present two methods: the Asymmetric Probabilistic Tsetlin (APT) Machine, influenced by random events, and the Asymmetric Tsetlin (AT) Machine, which transitions from probabilistic to deterministic states. We evaluate these methods against traditional machine learning algorithms and classical Tsetlin (CT) machines across various benchmark datasets. Both AT and APT demonstrate competitive performance, with the AT model notably excelling, especially in complex datasets.
2025
Ensuring a healthy and comfortable indoor environment in schools is essential for student well-being and academic performance. The purpose of this study is to investigate the factors influencing students’ satisfaction with indoor air quality (IAQ) and thermal comfort in classrooms. To address this, one year-long measurements were conducted across multiple classrooms in a Norwegian secondary school, collecting data on indoor climate (CO₂, VOC levels, temperature, relative humidity, and air pressure) along with outdoor climate variables (temperature, humidity, and solar radiation). Additional room-specific data, including orientation, floor level, and ventilation system specifications, were also considered. An online feedback system was used to gather 1,473 real-time student responses on satisfaction levels. Supervised machine learning (ML) models were developed to assess the importance of these parameters in predicting perceived indoor comfort: IAQ perceptions and thermal environmental perceptions. Results showed ML models effectively predicted student dissatisfaction, achieving accuracy greater than 80% when environmental and building parameters were considered simultaneously. The findings emphasized that dissatisfaction with indoor conditions is driven by multiple interacting factors of measured variables and building parameters single independent variables. SHAP analysis provided valuable interpretability, revealing how variations in environmental conditions collectively impact students' perceived comfort. This comprehensive approach demonstrates the practical potential of ML-based IEQ monitoring systems, suggesting that schools can proactively improve indoor conditions through targeted interventions informed by real-time predictions.
2025
Ikke-spesifikk screening av støv fra norske husholdninger
Denne rapporten presenterer resultater fra en ikke-spesifikk screening av husstøv fra norske hjem. Totalt ble 203 kjemiske forbindelser identifisert, med ftalater som den mest dominerende stoffgruppen. Flere av de påviste stoffene er kjent som hormonforstyrrende, nevrotoksiske eller klassifisert som persistente, mobile og toksiske (PMT). Resultatene viser et endret stoffmønster sammenlignet med tidligere studier og understreker behovet for videre overvåkning av innemiljø, forskning på cocktail-effekter og bedre regulering av forbrukerprodukter.
NILU
2025
Construction of an enterprise-level global supply chain database
Data tracing global supply chains, commonly captured in input–output models, is a foundational resource across economic, regulatory, investment, defense, and environmental applications. Such models provide insight into interdependency and environmental burden-shifting, forming part of the empirical basis for policies such as Scope 3 embodied emissions targets, supply chain transparency, life cycle assessments, and product declarations. Current approaches, based on national statistics, remain constrained by sector-level resolution, limiting their precision and utility in certain applications. Here, we document the construction of an enterprise-level multi-regional input–output (EMRIO) table. This database merges official national input–output tables with publicly available firm-level production and transaction data, creating a globally consistent account of purchases and sales across 9,466 companies, 86,305 subsegments, and 121 countries. The finer resolution allows supply chain transactions to be represented in greater detail, providing an additional resource for analyses and policy tools requiring more disaggregated supply chain information.
2025
NILU har, på vegne av Telemarksforskning og Norsk Folkemuseum, analysert miljøgifter i støv, luft og materialprøver fra utvalgte antikvariske bygg. Målet var å kartlegge nivåer av miljøgifter brukt i tidligere konserveringsarbeid. Studien omfattet analyser av tungmetaller, PAH og pesticider i støv fra ni bygninger, screening av VOC i luft, samt materialprøver fra tre bygninger. Resultatene viste bekymringsverdige nivåer av tungmetaller, PAH og pesticider i støv, og svært høye nivåer av PCP i to av tre materialprøver, til tross for lav totalmengde VOC.
NILU
2025
Atmospheric ammonia (NH3) is a key transboundary air pollutant that contributes to the impacts of nitrogen and acidity on terrestrial ecosystems. Ammonia also contributes to the atmospheric aerosol that affects air quality. Emission inventories indicate that NH3 was predominantly emitted by agriculture over the 19th and 20th centuries but, up to now, these estimates have not been compared to long-term observations. To document past atmospheric NH3 pollution in south-eastern Europe, ammonium (NH) was analysed along an ice core extracted from Mount Elbrus in the Caucasus, Russia. The NH ice-core record indicates a 3.5-fold increase in concentrations between 1750 and 1990 CE. Remaining moderate prior to 1950 CE, the increase then accelerated to reach a maximum in 1989 CE. Comparison between ice-core trends and estimated past emissions using state-of-the-art atmospheric transport modelling of submicron-scale aerosols (FLEXPART (FLEXible PARTicle dispersion) model) indicates good agreement with the course of estimated NH3 emissions from south-eastern Europe since ∼ 1750 CE, with the main contributions from south European Russia, Türkiye, Georgia, and Ukraine. Examination of ice deposited prior to 1850 CE, when agricultural activities remained limited, suggests an NH ice concentration related to natural soil emissions representing ∼ 20 % of the 1980–2009 CE NH level, a level mainly related to current agricultural emissions that almost completely outweigh biogenic emissions from natural soil. These findings on historical NH3 emission trends represent a significant contribution to the understanding of ammonia emissions in Europe over the last 250 years.
2025
Metaller, PCB, PAH og dioksiner i mose i Sør-Varanger. Moseundersøkelser 2008, 2015 og 2020
I 2008 samlet Svanhovd Miljøsenter inn mose ved 11 lokaliteter i grenseområdene mot Russland som NILU analyserte for 11 metaller, PCB, PAH og dioksiner. Formålet var å undersøke om det var andre kilder til forurensning i grenseområdene enn gruvedrift og smelteverksindustri. Prøvetaking og analyse ble gjentatt av NILU i 2015 og 2020, men kun for 60 (2015) og 56 (2020) metaller. For spormetallene Ni, Cu, Co og As er det et klart mønster med forhøyede konsentrasjoner nedstrøms Nikel og Zapolyarnyj. Organiske miljøgifter viser lave konsentrasjoner.
NILU
2025
Climatic feedbacks and ecosystem impacts related to dust in the Arctic include direct radiative forcing (absorption and scattering), indirect radiative forcing (via clouds and cryosphere), semi-direct effects of dust on meteorological parameters, effects on atmospheric chemistry, as well as impacts on terrestrial, marine, freshwater, and cryospheric ecosystems. This review discusses our recent understanding on dust emissions and their long-range transport routes, deposition, and ecosystem effects in the Arctic. Furthermore, it demonstrates feedback mechanisms and interactions between climate change, atmospheric dust, and Arctic ecosystems.
2025
Satellite instruments for measuring atmospheric column mixing ratios have improved significantly over the past couple of decades, with increases in pixel resolution and accuracy. As a result, satellite observations are being increasingly used in atmospheric inversions to improve estimates of emissions of greenhouse gases (GHGs), particularly CO2 and CH4, and to constrain regional and national emission budgets. However, in order to make use of the increasing resolution in inversions, the atmospheric transport models used need to be able to represent the observations at these finer resolutions. Here, we present a new and computationally efficient methodology to model satellite column average mixing ratios with a Lagrangian particle dispersion model (LPDM) and calculate the Jacobian matrices describing the relationship between surface fluxes of GHGs and atmospheric column average mixing ratios, as needed in inversions. The development will enable a more accurate representation of satellite observations (especially high-resolution ones) via the use of LPDMs and, thus, help improve the accuracy of emission estimates obtained by atmospheric inversions. We present a case study using this methodology in the FLEXPART (FLEXible PARTicle dispersion model) LPDM and the FLEXINVERT inversion framework to estimate CH4 fluxes over Siberia using column average mixing ratios of CH4 (XCH4) from the TROPOMI (TROPOspheric Monitoring Instrument) instrument aboard the Sentinel-5P satellite. The results of the inversion using TROPOMI XCH4 are evaluated against results using ground-based observations.
2025