Publikasjoner

Klimaendringene

Evolution of atmospheric methane under the global methane pledge: insights from an Earth system model

Citizen-operated low-cost sensors for estimating outdoor particulate matter infiltration

Fine particulates observed indoors exhibit high variability, influenced by both indoor emission sources and the infiltration of outdoor particles through open spaces and the incomplete building insulation. This study examines the relationship between indoor and outdoor PM2.5 levels in Legionowo, Poland, using data from low-cost air quality sensors operated by citizens. The indoor PM2.5 was lower than outdoor levels (median PM2.5: 1.9–17.3 μg m–3 indoors and 6.7–27.9 μg m–3 outdoors), with occasional peaks attributed to potential indoor emission sources. Statistical analysis identified emission events—particularly during cooking and household-heating periods—occurring more frequently from October to April. During this period, nearly 17% of indoor PM2.5 measurements were attributed to indoor emission sources after 18:00 LT, representing a 7% increase compared to the May–September period. In the absence of indoor sources, outdoor particles accounted for 29% to 75% of indoor concentrations, highlighting the significance of infiltration. This research emphasizes how citizen-generated data using low-cost sensors, after post-processing, can provide decision-ready information as for example outdoor particles’ infiltration factors for each building. The knowledge of the infiltration factor enables the determination of the contribution of indoor and outdoor sources to each resident’s exposure to airborne PM. This information can help decision-makers in devising interventions such as prioritizing indoor ventilation, reducing indoor activities resulting in increased exposure, and addressing outdoor pollution sources.

Towards a remote-sensing-driven model of isoprene emissions from Alpine tundra

Abstract This study investigates isoprene emissions in a high-latitude Alpine tundra ecosystem, focusing on using near-field remote sensing of surface temperatures, the photochemical reflectance index (PRI) and normalized difference vegetation index (NDVI), and meteorological measurements to model these emissions. Isoprene is a key biogenic volatile organic compound (BVOC) emitted by select plants, which can impact atmospheric chemistry and climate. Increased temperatures, particularly in high latitudes, may enhance isoprene emissions due to extended growing seasons and heightened plant stress. The research was conducted in Finse, Norway, where isoprene and CO 2 fluxes were measured with eddy covariance alongside spectral and meteorological data, and surface temperature. A random forest (RF) model was developed to predict isoprene fluxes, considering the variable importance of different environmental factors. The results showed that surface temperature and CO 2 flux were consistently important predictors, across three differential temporal data aggregations (hourly, daily, weekly), while the PRI demonstrated low predictive power, possibly due to the heterogeneous vegetation and variable light conditions. The NDVI was more effective than anticipated, likely linked to phenological changes in vegetation. Model performance varied with temporal resolution, with weekly data achieving the highest predictive accuracy ( R 2 up to 0.76). The RF model accurately reflected seasonal emission patterns but underestimated short-term peaks, suggesting the potential to combine machine learning with process-based modelling. This research highlights the promise of proxy data from remote sensing for scaling BVOC emission models to regional levels, essential for understanding climate impacts in Arctic ecosystems.

IRISCC: Advancing Environmental Science through Integrated Services for Climate Change Risks

Kan vi bruke havet til å fange karbon?

Muri, Helene (journalist)

Havet kan spille en rolle i arbeidet med å fjerne CO2 fra atmosfæren for å begrense farlig global oppvarming.

DIGG-MIN-SKOLE: prosjektgjennomgang for Standard Norge

Physics-Informed Deep Learning for Wind Downscaling over Oslo

Running a numerical weather model such as WRF at kilometre or sub-kilometre grid spacing over a regional domain is computationally expensive. We present physics-informed deeplearning models that ingest a single 9km WRF wind field and simultaneously predict two finer-scale wind fields at 3 km and 1 km resolution via dual decoder heads. Four representative architectures are benchmarked-Deep Residual U-Net (DeepRU), DEVINE, a bespoke 3-D Transformer, and a Fourier Neural Operator (FNO)-each trained with divergence-free, vorticity, and Navier-Stokes residual constraints plus Charbonnier and gradient perceptual losses. We train and validate our models on the city of Oslo for the year 2018. DeepRU achieves R2=0.94 (RMSE =0.050) at 3km and R2=0.89(RMSE=0.065) at 1 km. DEVINE, Transformer 3-D, and FNO yield 3 km scores of 0.91−0.93, with 1km scores lower by 0.02−0.08, illustrating the increased difficulty of finer-scale reconstruction. Physicsinformed losses improve all models compared to MSE-only baselines, and the residual architecture (DeepRU) remains most effective for this dual-scale task.

Overview of methods for production of sterile salmonids, their applicability in aquaculture and possible implications to wild salmon populations and biodiversity in Norway

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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Microplastic pellets in Arctic marine sediments: a common source or a common process?

Plastic consumption is increasing, and millions of tonnes of plastic are released into the oceans every year. Plastic materials are accumulating in the marine environment, especially on the seafloor. The Arctic is contaminated with plastics, including microplastics (MPs, <5 mm) but occurrences, concentrations and fate are largely unknown. This study aimed at assessing whether MPs accumulate at greater water depths in the Barents Sea, and close to the Longyearbyen settlement, and at understanding the ubiquity and source of a specific type of collected pellets. Surface sediments were collected at seven stations around Svalbard with a box-corer, and three replicates were taken at each station. MPs were extracted through density separation with saturated saltwater. Many pellets were found, and their composition was assessed by pyrolysis-GC/MS. Procedural blanks were performed using field blanks as samples to assess the overall contamination. The composition of all extracted particles was then analysed by μRaman spectroscopy. On average, 3.61 ± 1.45 MPs/100 g (dw) were found. The sea ice station, after blank correction, was more contaminated and displaying a different profile than the other stations, and the deepest station did not show the highest MP concentrations but rather the opposite. Sediments close to Longyearbyen were not more contaminated than the other stations either. Dark pellets of similar aspect were found at all stations, raising the question about a possible common source or process. These pellets were made of several plastic polymers which varied in proportion for each pellet, suggesting a common process was at the origin of those pellets, potentially marine snow formation.

Min AI-karriere: Til Aurskog fra Amazon

Mapping human-nature archetypes to guide global biodiversity, food security and land use policy

Reconciling biodiversity conservation, food security, and sustainable agriculture at global scale requires a clear understanding of regional social-ecological opportunities and challenges. This understanding helps untap regional contributions to better achieve global policy targets, such as those framed in the Kunming-Montreal Global Biodiversity Framework (GBF). Yet previous global syntheses of social-ecological interlinkages remain limited in thematic and spatial detail, restricting the discussion of regional contributions and targeted policy implementation. Here, we present 25 human-nature archetypes derived from clustering of global social-ecological data revealing regional opportunities and challenges for meeting global policy targets. Our results differentiate regions with large conservation opportunities from those well suited for ecological restoration or ecological intensification. They highlight the widespread need for improving governance to enhance food security and re-design agricultural systems. Overall, our analysis supports international and national decision makers in tailoring GBF targets to regional specificities in order to more effectively achieve global sustainability goals.

Statusrapport 2025. Nasjonalt referanselaboratorium for luftkvalitetsmålinger

Denne rapporten oppsummerer oppgavene til Nasjonalt referanselaboratorium for luftkvalitetsmålinger (NRL), delkontrakt 1b, for første halvår 2025.

NILU