CICERO Research Archive (CICERO Senter for klimaforskning)
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Global CO2 uptake by cement from 1930 to 2019
Get PDFBecause of the alkaline nature and high calcium content of cements in general, they serve as a CO2- absorbing agent through carbonation processes, resembling silicate weathering in nature. This carbon uptake capacity of cements could abate some of the CO2 emitted during their production. Given the scale of cement production worldwide (4.10 Gt in 2019), a life-cycle assessment is necessary to determine the actual net carbon impacts of this industry. We adopted a comprehensive analytical model to estimate the amount of CO2 that had been absorbed from 1930 to 2019 in four types of cement materials, including concrete, mortar, construction waste, and cement kiln dust (CKD). In addition, the process CO2 emission during the same period based on the same datasets was also estimated. The results show that 21.02 Gt CO2 (95 % confidence interval, CI: 18.01– 24.41 Gt CO2) had been absorbed in the cements produced from 1930 to 2019, with the 2019 annual figure mounting up to 0.89 Gt CO2 yr−1 (95 % CI: 0.76–1.06 Gt CO2). The cumulative uptake is equivalent to approximately 55 % of the process emission based on our estimation. In particular, China’s dominant position in cement production or consumption in recent decades also gives rise to its uptake being the greatest, with a cumulative sink of 6.21 Gt CO2 (95 % CI: 4.59–8.32 Gt CO2) since 1930. Among the four types of cement materials, mortar is estimated to be the greatest contributor (approximately 59 %) to the total uptake. Potentially, our cement emission and uptake estimation system can be updated annually and modified when necessary for future low-carbon transitions in the cement industry. All the data described in this study, including the Monte Carlo uncertainty analysis results, are accessible at https://doi.org/10.5281/zenodo.4459729 (Wang et al., 2021).publishedVersio
Ethical choices behind quantifications of fair contributions under the Paris Agreement
Get PDFThe Parties to the UNFCCC and Paris Agreement agreed to act on the basis of equity to protect the climate system. Equitable effort sharing is an irreducibly normative matter, yet some influential studies have sought to create quantitative indicators of equitable effort that claim to be value-neutral (despite evident biases). Many of these studies fail to clarify the ethical principles underlying their indicators, some mislabel approaches that favour wealthy nations as ‘equity approaches’ and some combine contradictory indicators into composites we call derivative benchmarks. This Perspective reviews influential climate effort-sharing assessments and presents guidelines for developing and adjudicating policy-relevant (but not ethically neutral) equity research.acceptedVersio
National specialization policy versus farmers’ priorities: Balancing subsistence farming and cash cropping in Nepal
Get PDFThe Nepali Government is currently implementing policies for a radical agricultural transformation into large-scale, mechanized, specialized and commercial farming. However, the peasants prioritize diversified subsistence production of resilient and versatile food crops and regard cash crops only as a supplement. Cash cropping represents a potentially profitable income source but involves risk. Complete agricultural commercialization would jeopardize household and community food security, weaken trust- and reciprocity-based social mechanisms for exchanging food and labour, and break with traditions. Peasants’ motivations for balancing subsistence and market production are multiple and interrelated because their economic pursuits are deeply embedded in social and cultural structures.publishedVersio
Public support for air travel restrictions to address COVID-19 or climate change
Get PDFAn improved understanding of public support is essential to design effective and feasible climate policies for aviation. Our motivation is the contrast between high support for air travel restrictions responding to the COVID-19 pandemic and low support for restrictions to combat climate change. Can the same factors explain individuals’ support for restrictive measures across two different problems? Using a survey, we find that largely the same factors explain support. Support increases with expected effectiveness, perceived threat and imminence of the problem, shorter expected duration of the measure, knowledge, and trust, while support decreases with expected negative consequences for self and the poor. When controlling for all perceptions, there is no significant residual difference in support depending on whether the measures address climate change or COVID-19. The level of support differs because COVID-19 is perceived as a more imminent threat, and because measures are expected to be shorter-lasting and more effective.publishedVersio
Challenges in the harmonisation of global integrated assessment models: A comprehensive methodology to reduce model response heterogeneity
Get PDFHarmonisation sets the ground to a solid inter-comparison of integrated assessment models. A clear and transparent harmonisation process promotes a consistent interpretation of the modelling outcomes divergences and, reducing the model variance, is instrumental to the use of integrated assessment models to support policy decision-making. Despite its crucial role for climate economic policies, the definition of a comprehensive harmonisation methodology for integrated assessment modelling remains an open challenge for the scientific community. This paper proposes a framework for a harmonisation methodology with the definition of indispensable steps and recommendations to overcome stumbling blocks in order to reduce the variance of the outcomes which depends on controllable modelling assumptions. The harmonisation approach of the PARIS REINFORCE project is presented here to layout such a framework. A decomposition analysis of the harmonisation process is shown through 6 integrated assessment models (GCAM, ICES-XPS, MUSE, E3ME, GEMINI-E3, and TIAM). Results prove the potentials of the proposed framework to reduce the model variance and presenpublishedVersio
Fossilfri anleggsvirksomhet, Innlandet fylkeskommune
Get PDFDette notatet tar for seg direkte utslipp fra anleggsmaskiner på anleggsplass, og er utarbeidet av CICERO Senter for klimaforskning på oppdrag fra Innlandet fylkeskommune, avdeling Samferdsel, Trafikk og miljø. Tema som omtales er bærekraftsutfordringer for biodrivstoff og kostnader og barrierer for biodrivstoff og for utslippsfrie løsninger. Vi har også utarbeidet et grovt anslag for direkte utslipp, forbruk av drivstoff i anleggsmaskiner og merkostnader ved bruk av biodrivstoff i anleggsprosjekter. Notatet oppsummerer til sist status for kravstilling ved offentlige innkjøp til bygg og anlegg, og aktuelle tiltak for kutt i direkte utslipp innen anleggsvirksomhet
Climate assessments of six key Norwegian sectors
Get PDFThe Sustainable Edge sector briefs summarize material climate-related risks and impacts to investors and lenders. The briefs cover key risks, emission sources, risk management and climate-related regulation relevant for each sector. They also provide key analyst questions that are important to consider in order to understand the climate risk of companies in the sector. The sector briefs are developed to support capacity building on climate risk in financial institutions.
The six sectors covered are agriculture, aluminium, aquaculture, land transport, real estate, and shipping. The next section summarizes some key messages from each brief.publishedVersio
Forest-based bioenergy in Norway’s green transition: Balancing production and other societal interests
Get PDFThis report explores the potential of bioenergy from forests to contribute to the green transition of society. Forest biomass is the largest potential bioenergy source in Norway, in the form of firewood, chips for heating, and biofuels. Firewood and chips for firing can be produced locally and small-scale, whereas biofuels must be produced at industrial and large scale - also implying more industrial logging practices. Bioenergy must compete with other societal needs, especially timber for buildings and fiber for industry, which have higher value. In addition, forests provide eco-services like nature protection for biodiversity, carbon storage as a climate measure, as well as an arena for outdoor activities. In this report I first examine available forest resources for bioenergy in Norway, then assess how bioenergy production can be balanced with nature protection and outdoor activities in Oslo and Viken county. This assessment is based on interviews with stakeholders from forest owners, industry, environmental organizations, and authorities. There are unused forest resources for bioenergy in Norway based on biomass with lowest quality. Increased biofuel production requires large investments in production facilities and depends on higher prices and more taxing of fossil fuels. Local logging and firewood production is easier to combine with nature protection and outdoor activities than industrial logging for biofuels, timber, or fiber production. Conflicts with other societal interests is reduced if more forest areas are protected, especially in the vicinity of cities, whereas other areas are open for logging.publishedVersio
Emerging reporting and verification needs under the Paris Agreement: How can the research community effectively contribute?
No full textGreenhouse gas (GHG) emission inventories represent the link between national and international political actions on climate change, and climate and environmental sciences. Inventory agencies need to include, in national GHG inventories, emission and removal estimates based on scientific data following specific reporting guidance under the United Nation Framework Convention on Climate Change (UNFCCC) and the Paris Agreement, using the methodologies defined in the Intergovernmental Panel on Climate Change (IPCC) Guidelines. Often however, research communities and inventory agencies have approached the problem of climate change from different angles and by using terminologies, metrics, rules and approaches that do not always match. This is particularly true dealing with “Land Use, Land-Use Change and Forestry” (LULUCF), the most challenging among the inventory sectors to deal with, mainly because of high level of complexity of its carbon dynamics and the difficulties in disaggregating the fluxes between those caused by natural and anthropogenic processes. In this paper, we facilitate the understanding by research communities of the current (UNFCCC) and future (under the Paris Agreement) reporting requirements, and we identify the main issues and topics that should be considered when targeting improvement of the GHG inventory. In relation to these topics, we describe where and how the research community can contribute to producing useful inputs, data, methods and solutions for inventory agencies and policy makers, on the basis of available literature. However, a greater effort by both communities is desirable for closer cooperation and collaboration, for data sharing and the understanding of respective and common aims.publishedVersio
Aerosol absorption in global models from AeroCom phase III
Get PDFAerosol-induced absorption of shortwave radiation can modify the climate through local atmospheric heating, which affects lapse rates, precipitation, and cloud formation. Presently, the total amount of aerosol absorption is poorly constrained, and the main absorbing aerosol species (black carbon (BC), organic aerosols (OA), and mineral dust) are diversely quantified in global climate models. As part of the third phase of the Aerosol Comparisons between Observations and Models (AeroCom) intercomparison initiative (AeroCom phase III), we here document the distribution and magnitude of aerosol absorption in current global aerosol models and quantify the sources of intermodel spread, highlighting the difficulties of attributing absorption to different species. In total, 15 models have provided total present-day absorption at 550 nm (using year 2010 emissions), 11 of which have provided absorption per absorbing species. The multi-model global annual mean total absorption aerosol optical depth (AAOD) is 0.0054 (0.0020 to 0.0098; 550 nm), with the range given as the minimum and maximum model values. This is 28 % higher compared to the 0.0042 (0.0021 to 0.0076) multi-model mean in AeroCom phase II (using year 2000 emissions), but the difference is within 1 standard deviation, which, in this study, is 0.0023 (0.0019 in Phase II). Of the summed component AAOD, 60 % (range 36 %–84 %) is estimated to be due to BC, 31 % (12 %–49 %) is due to dust, and 11 % (0 %–24 %) is due to OA; however, the components are not independent in terms of their absorbing efficiency. In models with internal mixtures of absorbing aerosols, a major challenge is the lack of a common and simple method to attribute absorption to the different absorbing species. Therefore, when possible, the models with internally mixed aerosols in the present study have performed simulations using the same method for estimating absorption due to BC, OA, and dust, namely by removing it and comparing runs with and without the absorbing species. We discuss the challenges of attributing absorption to different species; we compare burden, refractive indices, and density; and we contrast models with internal mixing to models with external mixing. The model mean BC mass absorption coefficient (MAC) value is 10.1 (3.1 to 17.7) m2 g−1 (550 nm), and the model mean BC AAOD is 0.0030 (0.0007 to 0.0077). The difference in lifetime (and burden) in the models explains as much of the BC AAOD spread as the difference in BC MAC values. The difference in the spectral dependency between the models is striking. Several models have an absorption Ångstrøm exponent (AAE) close to 1, which likely is too low given current knowledge of spectral aerosol optical properties. Most models do not account for brown carbon and underestimate the spectral dependency for OA.publishedVersio