Biomass burning emission analysis based on MODIS

We assessed the biomass burning (BB) smoke aerosol optical depth (AOD) simulations of 11 global models that participated in the AeroCom phase III BB emission experiment. By comparing multi-model simulations and satellite observations in the vicinity of fires over 13 regions globally, we (1) assess model-simulated BB AOD performance as an indication of smoke source–strength, (2) identify regions where the common emission dataset used by the models might underestimate or overestimate smoke sources, and (3) assess model diversity and identify underlying causes as much as possible. Using satellite-derived AOD snapshots to constrain source strength works best where BB smoke from active sources dominates background non-BB aerosol, such as in boreal forest regions and over South America and southern hemispheric Africa. The comparison is inconclusive where the total AOD is low, as in many agricultural burning areas, and where the background is high, such as parts of India and China. Many inter-model BB AOD differences can be traced to differences in values for the mass ratio of organic aerosol to organic carbon, the BB aerosol mass extinction efficiency, and the aerosol loss rate from each model. The results point to a need for increased numbers of available BB cases for study in some regions and especially to a need for more extensive regional-to-global-scale measurements of aerosol loss rates and of detailed particle microphysical and optical properties; this would both better constrain models and help distinguish BB from other aerosol types in satellite retrievals. More generally, there is the need for additional efforts at constraining aerosol source strength and other model attributes with multi-platform observations.Biomass burning emission analysis based on MODI

Befolkningen er mer bekymret for klimaendringene etter Hans - En undersøkelse av befolkningens syn på klimautfordringene før/etter ekstremværet Hans

Siden 2018 har CICERO årlig undersøkt nordmenns oppfatninger, normer, handlinger og holdninger knyttet til klimaomstilling. Høsten 2023 gjennomførte vi en ekstra datainnsamling etter kommunestyre- og fylkestingsvalget samme år, med mål om å undersøke om sommerens ekstremvær og økt klimafokus i media påvirket folks oppfatninger. Denne rapporten presenterer resultater fra dataene som ble samlet inn høsten 2023. Den omhandler nivået av klimabekymring, oppfatninger om hvorvidt klimaendringer har negative konsekvenser, folks støtte til fortsatt oljeproduksjon, og klima og miljø som sak i lokalvalget. Sammenlignet med tall fra CICEROs klimaundersøkelse våren 2023 finner vi at bekymringen for klimaendringer er noe høyere, på tvers av både demografiske grupper og velgergrupper. Støtten til å redusere oljeproduksjonen har også økt. Et stort flertall er enige i at klimaendringer har negative konsekvenser. Vi ser videre stort sett de samme forskjellene mellom velgergrupper og grupper med ulike demografisk kjennetegn som i tidligere datasamlinger, og en antydning til noe mindre forskjeller mellom grupper enn tidligere. Klima og miljø ser ut til å ha vært en mindre viktig sak for velgerne i dette valget enn ved de siste lokalvalgene. Hvorvidt tendensene vi oppsummerer i denne rapporten representerer en varig endring, må vurderes i lys av fremtidige datainnsamlinger.publishedVersio

Veien til lavutslippssamfunnet i Hamar

Hamar kommune skal revidere kommuneplanens samfunnsdel. Som en del av underlaget for revisjonen, har kommunen bestilt en utredning av hvilke grep det er viktig at kommunen tar i denne kommuneplanrevisjonen for å kunne bli et lavutslippssamfunn i 2050. Det er lovfestet at Norge skal bli et lavutslippssamfunn i 2050. Klimaloven inneholder også et mål om at utslippene i 2050 skal reduseres i størrelsesorden 90-95 prosent fra utslippsnivået i 1990. Klimautvalget 2050 utredet hvilke veivalg Norge står overfor for å nå målet om å bli et lavutslippssamfunn. Denne rapporten tar utgangspunkt i vurderingene til Klimautvalget og hvilke problemstillinger som er særlig relevante i Hamar.publishedVersio

Nordmenns oppfatninger om klimaendringer, politikk og virkemidler Oppsummering av datakilder over utvikling og sammenligning med andre befolkninger

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Assessing the robustness and implications of econometric estimates of climate sensitivity

Earth's transient climate response (TCR) quantifies the global mean surface air temperature change due to a doubling of atmospheric CO2 concentration after 70 years of a compounding 1% per year increase. TCR is highly correlated with near-term climate projections, and thus of relevance for climate policy, but remains poorly constrained in part due to uncertainties in the representation of key physical processes in Earth System Models (ESMs). Within state-of-the-art ESMs participating in the Coupled Model Intercomparison Project (CMIP6), the TCR range (1.1 ºC–2.9 ºC) is too wide to offer useful guidance to policymakers. Similarly, the sixth report of the Intergovernmental Panel on Climate Change, while not solely reliant on ESMs for its TCR assessment, produced a very likely range of 1.2 ºC–2.4 ºC. To complement earlier, ESM-based, estimates, we here present a new TCR estimate of 2.17 (1.72–2.77) ºC (95% confidence interval), derived based on a statistical relationship between surface air temperature and observational proxies for its main drivers, i.e. changes in atmospheric greenhouse gases and aerosols. We show that, within uncertainty, this method correctly diagnoses TCR from 20 CMIP6 ESMs if the same input variables are taken from the ESMs that are available from observations. This increases confidence in the new observation-based central estimate and range, which is respectively higher and narrower than the mean and spread of the estimates from the entire ensemble of CMIP6. Many ESM-based estimates tend to produce TCRs lower than the observational range reported here. Our findings suggest that a misrepresentation of the aerosol cooling effect could be the cause of this discrepancy. Further, the revised TCR estimate suggests a downward revision of the remaining carbon budgets aligned with the overarching goal of the Paris agreement.Assessing the robustness and implications of econometric estimates of climate sensitivitypublishedVersio

Omstilling til et utslippsfritt energisystem: EUs energiregelverk og implikasjoner for Norge

EU har et stort energiregelverk som har implikasjoner for Norge. EU har lenge hatt et ambisiøst klimalovverk, og klima er fremdeles pekt ut som en hovedutfordring for EU å løse. I EUs ren industri-pakke fortsetter vektleggingen av klima, selv om klimapolitikken utfordres fra ulike kanter. Klimapolitikken er tett sammenvevd med energisektoren. Vi beskriver utviklingen i relevant energipolitikk på EU-nivå som gjelder avkarbonisering, hydrogen og satsing på grønn industri. For å få til omstillingen har EU blant annet vedtatt raskere saksbehandling, utpeking av områder for utbygging av fornybar energi, vektlegging av grønt framfor blått hydrogen, åpnet for nye tiltak som skal sikre stabil og sikker kraftforsyning og har innført støtteordninger for klimaomstillingen. Selv om regelverket er vedtatt, pågår det diskusjoner i EU om blant annet energipriser og industriens konkurransekraft. Det er også usikkert hvordan kraftmarkedet og markedet for gass og hydrogen vil utvikle seg fremover, noe som er avhengig av om medlemslandene klarer å bygge ut så mye fornybar kraft som de har mål om. Når det gjelder hydrogen er det en usikkerhet blant aktører i næringslivet om hydrogen faktisk vil spille en sentral rolle i energiomstillingen, og om den ambisiøse klimapolitikken vil opprettholdes. Selv om EU er tydelig på at de ambisiøse målene står ved lag, går utviklingen av hydrogenindustrien likevel saktere enn det EU forventet få år tilbake.publishedVersio

Strong regional trends in extreme weather over the next two decades under high- and low-emissions pathways

Global warming is rapidly shifting climate conditions away from what societies and ecosystems are adapted to. While the magnitude of changes in mean and extreme climate are broadly studied, regional rates of change, a key driver of climate risk, have received less attention. Here we show, using large ensembles of climate model simulations, that large parts of the tropics and subtropics, encompassing 70% of current global population, are expected to experience strong (>2 s.d.) joint rates of change in temperature and precipitation extremes combined over the next 20 years, under a high-emissions scenario, dropping to 20% under strong emissions mitigation. This is dominated by temperature extremes, with most of the world experiencing unusual (>1 s.d.) rates relative to the pre-industrial period, but unusual changes also occur for precipitation extremes in northern high latitudes, southern and eastern Asia and equatorial Africa. However, internal variability is high for 20 year trends, meaning that in the near term, trends of the opposite sign are still likely for precipitation extremes, and rare but not impossible for temperature extremes. We also find that rapid clean-up of aerosol emissions, mostly over Asia, leads to accelerated co-located increases in warm extremes and influences the Asian summer monsoons.acceptedVersio

Environmental impact of Norwegian food and beverages: compilation of a life cycle assessment food database

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The need for carbon-emissions-driven climate projections in CMIP7

Previous phases of the Coupled Model Intercomparison Project (CMIP) have primarily focused on simulations driven by atmospheric concentrations of greenhouse gases (GHGs), for both idealized model experiments and climate projections of different emissions scenarios. We argue that although this approach was practical to allow parallel development of Earth system model simulations and detailed socioeconomic futures, carbon cycle uncertainty as represented by diverse, process-resolving Earth system models (ESMs) is not manifested in the scenario outcomes, thus omitting a dominant source of uncertainty in meeting the Paris Agreement. Mitigation policy is defined in terms of human activity (including emissions), with strategies varying in their timing of net-zero emissions, the balance of mitigation effort between short-lived and long-lived climate forcers, their reliance on land use strategy, and the extent and timing of carbon removals. To explore the response to these drivers, ESMs need to explicitly represent complete cycles of major GHGs, including natural processes and anthropogenic influences. Carbon removal and sequestration strategies, which rely on proposed human management of natural systems, are currently calculated in integrated assessment models (IAMs) during scenario development with only the net carbon emissions passed to the ESM. However, proper accounting of the coupled system impacts of and feedback on such interventions requires explicit process representation in ESMs to build self-consistent physical representations of their potential effectiveness and risks under climate change. We propose that CMIP7 efforts prioritize simulations driven by CO2 emissions from fossil fuel use and projected deployment of carbon dioxide removal technologies, as well as land use and management, using the process resolution allowed by state-of-the-art ESMs to resolve carbon–climate feedbacks. Post-CMIP7 ambitions should aim to incorporate modeling of non-CO2 GHGs (in particular, sources and sinks of methane and nitrous oxide) and process-based representation of carbon removal options. These developments will allow three primary benefits: (1) resources to be allocated to policy-relevant climate projections and better real-time information related to the detectability and verification of emissions reductions and their relationship to expected near-term climate impacts, (2) scenario modeling of the range of possible future climate states including Earth system processes and feedbacks that are increasingly well-represented in ESMs, and (3) optimal utilization of the strengths of ESMs in the wider context of climate modeling infrastructure (which includes simple climate models, machine learning approaches and kilometer-scale climate models).publishedVersio

CICERO Simple Climate Model (CICERO-SCM v1.1.1) – an improved simple climate model with a parameter calibration tool

The CICERO Simple Climate Model (CICERO-SCM) is a lightweight, semi-empirical model of global climate. Here we present a new open-source Python port of the model for use in climate assessment and research. The new version of CICERO-SCM has the same scientific logic and functionality as the original Fortran version, but it is considerably more flexible and also open-source via GitHub. We describe the basic structure and improvements compared to the previous Fortran version, together with technical descriptions of the global thermal dynamics and carbon cycle components and the emission module, before presenting a range of standard figures demonstrating its application. A new parameter calibration tool is demonstrated to make an example calibrated parameter set to span and fit a simple target specification. CICERO-SCM is fully open-source and available through GitHubpublishedVersio