CICERO Research Archive (CICERO Senter for klimaforskning)
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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
Full text linkEarth'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
Befolkningen er mer bekymret for klimaendringene etter Hans - En undersøkelse av befolkningens syn på klimautfordringene før/etter ekstremværet Hans
Full text linkSiden 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
Omstilling til et utslippsfritt energisystem: EUs energiregelverk og implikasjoner for Norge
Full text linkEU 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
Veien til lavutslippssamfunnet i Hamar
Full text linkHamar 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
Biomass burning emission analysis based on MODIS
Full text linkWe 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
Reducing the cost of capital to finance the energy transition in developing countries
Full text linkClimate stabilization requires the mobilization of substantial investments in low- and zero-carbon technologies, especially in emerging and developing economies. However, access to stable and affordable finance varies dramatically across countries. Models used to evaluate the energy transition do not differentiate regional financing costs and therefore cannot study risk-sharing mechanisms for renewable electricity generation. In this study, we incorporated the empirically estimated cost of capital differentiated by country and technology into an ensemble of five climate–energy–economy models. We quantified the additional financing cost of decarbonization borne by developing regions and explored policies of risk premium convergence across countries. We found that alleviating financial constraints benefits both climate and equity as a result of more renewable and affordable energy in the developing world. This highlights the importance of fair finance for energy availability, affordability and sustainability, as well as the need to include financial considerations in model-based assessments.publishedVersio
Dynamic determinants of optimal global climate policy
Full text linkWe explore the impact of dynamic characteristics of greenhouse-gas emitting systems, such as inertia, induced innovation, and path-dependency, on optimal responses to climate change. Our compact and analytically tractable model, applied with stylized damage assumptions to derive optimal pathways, highlights how simple dynamic parameters affect responses including the optimal current effort and the cost of delay. The conventional cost-benefit result (i.e., an optimal policy with rising marginal costs that reflects discounted climate damages) arises only as a special case in which the dynamic characteristics of emitting systems are assumed to be insignificant. Our analysis highlights and distinguishes from the (often implicit) assumption in many cost-benefit models, which neglect inertia and assume exogenous technology progress. This tends to defer action. More generally, our model yields useful policy insights for the transition to deep decarbonization, showing that enhanced early action may greatly reduce both damages and abatement costs in the long run.publishedVersio
Strong increase in mortality attributable to ozone pollution under a climate change and demographic scenario
Full text linkLong-term exposure to ambient ozone (O3) is associated with excess respiratory mortality. Pollution emissions, demographic, and climate changes are expected to drive future ozone-related mortality. Here, we assess global mortality attributable to ozone according to an Intergovernmental Panel on Climate Change (IPCC) Shared Socioeconomic Pathway (SSP) scenario applied in Coupled Model Intercomparison Project Phase 6 (CMIP6) models, projecting a temperature increase of about 3.6 °C by the end of the century. We estimated ozone-related mortality on a global scale up to 2090 following the Global Burden of Disease (GBD) 2019 approach, using bias-corrected simulations from three CMIP6 Earth System Models (ESMs) under the SSP3-7.0 emissions scenario. Based on the three ESMs simulations, global ozone-related mortality by 2090 will amount to 2.79 M [95% CI 0.97 M–5.23 M] to 3.12 M [95% CI 1.11 M–5.75 M] per year, approximately ninefold that of the 327 K [95% CI 103 K–652 K] deaths per year in 2000. Climate change alone may lead to an increase of ozone-related mortality in 2090 between 42 K [95% CI −37 K–122 K] and 217 K [95% CI 68 K–367 K] per year. Population growth and ageing are associated with an increase in global ozone-related mortality by a factor of 5.34, while the increase by ozone trends alone ranges between factors of 1.48 and 1.7. Ambient ozone pollution under the high-emissions SSP3-7.0 scenario is projected to become a significant human health risk factor. Yet, optimizing living conditions and healthcare standards worldwide to the optimal ones today (application of minimum baseline mortality rates) will help mitigate the adverse consequences associated with population growth and ageing, and ozone increases caused by pollution emissions and climate change.publishedVersio
Integrating climate model projections into environmental risk assessment: A probabilistic modeling approach
Full text linkThe Society of Environmental Toxicology and Chemistry (SETAC) convened a Pellston workshop in 2022 to examine how information on climate change could be better incorporated into the ecological risk assessment (ERA) process for chemicals as well as other environmental stressors. A major impetus for this workshop is that climate change can affect components of ecological risks in multiple direct and indirect ways, including the use patterns and environmental exposure pathways of chemical stressors such as pesticides, the toxicity of chemicals in receiving environments, and the vulnerability of species of concern related to habitat quality and use. This article explores a modeling approach for integrating climate model projections into the assessment of near- and long-term ecological risks, developed in collaboration with climate scientists. State-of-the-art global climate modeling and downscaling techniques may enable climate projections at scales appropriate for the study area. It is, however, also important to realize the limitations of individual global climate models and make use of climate model ensembles represented by statistical properties. Here, we present a probabilistic modeling approach aiming to combine projected climatic variables as well as the associated uncertainties from climate model ensembles in conjunction with ERA pathways. We draw upon three examples of ERA that utilized Bayesian networks for this purpose and that also represent methodological advancements for better prediction of future risks to ecosystems. We envision that the modeling approach developed from this international collaboration will contribute to better assessment and management of risks from chemical stressors in a changing climate. Integr Environ Assess Manag 2024;20:367–383. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).publishedVersio