CICERO Research Archive (CICERO Senter for klimaforskning)
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1083 research outputs found
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Cost reduction in low-carbon hydrogen: effective but insufficient to mitigate carbon emissions
Get PDFMany countries have announced hydrogen promotion strategies to achieve net zero CO2 emissions around 2050. The cost of producing low-carbon (green and blue) hydrogen has been projected to fall considerably as production is scaled up, although more so for green hydrogen than for blue hydrogen. This article uses a global computable general equilibrium (CGE) model to explore whether the cost reduction of green and blue hydrogen production can mitigate the use of fossil fuels and related carbon emissions. The results show that cost reduction can raise low-carbon hydrogen consumption markedly in relative terms but marginally in absolute terms, resulting in a modest decrease in fossil fuel use and related carbon emissions. The cost reduction of low-carbon hydrogen slightly lowers the use of coal and gas but marginally increases the use of oil. If regional CO2 taxes are introduced the increase in green hydrogen production is considerably larger than in the case of low-carbon hydrogen cost reduction alone. However, if cost reduction in low-carbon hydrogen is introduced in addition to the CO2 tax the emissions from fossil fuels are only marginally reduced. Hence, synergy effects between the two measures on emissions are practically absent. A low-carbon hydrogen cost reduction alone is effective but insufficient to have a substantial climate impact. This study also calls for modeling development to capture special user preferences for low-carbon hydrogen related to climate mitigation when phasing in new energy carriers like hydrogen.Cost reduction in low-carbon hydrogen: effective but insufficient to mitigate carbon emissionspublishedVersio
Does a change in the 'global net zero' language matter?
Get PDFChanges in language used in long term climate policy can undermine their credibility and discourage climate action. Previous IPCC reports have promoted an idea of reaching ‘global net zero’ (GNZ) emissions by 2050 in order to limit global warming to 1.5 °C. In the latest IPCC Report, this language has been changed. To understand the impact of this change, we survey COP 26 participants to test their willingness to accept a shift in long term policy goals. We find a low tolerance for a change and, indeed, there is substantial finance, business and political effort behind the idea of reaching GNZ by 2050. This suggests that GNZ by 2050 will remain central to climate action.publishedVersio
African biomass burning affects aerosol cycling over the Amazon
Get PDFSmoke from vegetation fires affects air quality, atmospheric cycling, and the climate in the Amazon rain forest. A major unknown has remained the quantity of long-range transported smoke from Africa in relation to local and regional fire emissions. Here we quantify the abundance, seasonality, and properties of African smoke in central Amazonia. We show that it accounts for ~ 60% of the black carbon concentrations during the wet season and ~ 30% during the dry season. The African smoke influences aerosol-radiation interactions across the entire Amazon, with the strongest impact on the vulnerable eastern basin, a hot spot of climate and land use change. Our findings further suggest that the direct influence of African smoke has been historically relevant for soil fertilization, the carbon and water cycles, and, thus, the development of the Amazon forest ecosystem, even in the pre-industrial era.publishedVersio
Spatial and sector-specific contributions of emissions to ambient air pollution and mortality in European cities: a health impact assessment
Get PDFAmbient air pollution is a major risk to health and wellbeing in European cities. We aimed to estimate spatial and sector-specific contributions of emissions to ambient air pollution and evaluate the effects of source-specific reductions in pollutants on mortality in European cities to support targeted source-specific actions to address air pollution and promote population health.publishedVersio
The deployment length of solar radiation modification: an interplay of mitigation, net-negative emissions and climate uncertainty
Get PDFA growing body of literature investigates the effects of solar radiation modification (SRM) on global and regional climates. Previous studies have focused on the potentials and the side effects of SRM, with little attention being given to possible deployment timescales and the levels of carbon dioxide removal required for a phase out. Here, we investigate the deployment timescales of SRM and how they are affected by different levels of mitigation, net-negative emissions (NNEs) and climate uncertainty. We generate a large dataset of 355 emission scenarios in which SRM is deployed to keep warming levels at 1.5 C global mean temperature. Probabilistic climate projections from this ensemble result in a large range of plausible future warming and cooling rates that lead to various SRM deployment timescales. In all pathways consistent with extrapolated current ambition, SRM deployment would exceed 100 years even under the most optimistic assumptions regarding climate response. As soon as the temperature threshold is exceeded, neither mitigation nor NNEs or climate sensitivity alone can guarantee short deployment timescales. Since the evolution of mitigation under SRM, the availability of carbon removal technologies and the effects of climate reversibility will be mostly unknown at its initialisation time, it is impossible to predict how temporary SRM deployment would be. Any deployment of SRM therefore comes with the risk of multi-century legacies of deployment, implying multi-generational commitments of costs, risks and negative side effects of SRM and NNEs combined.publishedVersio
Does polycentrism deliver? A case study of energy community governance in Europe
Get PDFThe European Union's Clean Energy Package (CEP) plans to transform ‘passive consumers’ into ‘active citizens’ to support the transition to a carbon-neutral energy system by 2050. By stimulating the growth of renewable energy communities, the CEP works towards the redefinition of renewable energy as an economic commodity to a common good. In this paper, we approach the implementation of the CEP through the notion of polycentricity. Building on previous literature, we identified seven variables for effective polycentric energy governance: equity and co-benefits; inclusivity and local involvement; information, demonstration and innovation; ownership and accountability; organizational multiplicity; experimentation and flexibility; and clear goals set and enforced by a higher-level authority. To compare a variety of polycentric institutional configurations, we analyze Norway, the Netherlands, and Germany. Our findings indicate that, in general, some degree of polycentricity appears to be beneficial for the energy transition. This is the foundation for building local ownership and inclusivity and thus the emphasis is rightly placed there and could be expanded. Secondly, issues of ownership and accountability stand out as key enablers of renewable energy communities and the additional common goods that they bring to the energy system. These communities need to be enabled in financial terms to deploy a sufficient amount of projects, e.g., by giving them access to risk capital in the early development stages. In turn, this requires clear regulations and accountability mechanisms being installed on what precisely falls under the definition of a renewable energy community. Finally, we found that even as polycentricity is a promising approach, it does need to be anchored with a significant role for higher level government in order to function effectively.publishedVersio
Developing countries’ responsibilities for CO<inf>2</inf> emissions in value chains are larger and growing faster than those of developed countries
Get PDFCarbon emissions associated with international trade are significant. The emergence of complex global value chains (GVCs) in recent decades, in which a country can operate as both a consumer and producer simultaneously, has led to a further rise in emissions. The complexity of these GVCs makes it increasingly difficult to determine what country is responsible for the emissions embodied within them. Here, we propose a new method based on input-output analysis to identify and distinguish self- and shared responsibility for CO2 emissions along GVCs, where self-responsibility describes emissions embodied in purely domestic value chains. Our results show that developing countries’ self-responsibility for CO2 emissions has been the largest driver in the growth of total GVC embodied emissions since 2001. Even considering the shared responsibility for emission transfers via GVCs, developing countries’ total responsibility has exceeded that of developed countries since 2012. We argue that climate negotiations should seriously consider GVC-based responsibility sharing to enable more effective climate policies.Developing countries’ responsibilities for CO2 emissions in value chains are larger and growing faster than those of developed countriespublishedVersio
Hvor langt har norske kommuner kommet i klimatilpasningsarbeidet? Spørreundersøkelse om klimatilpasning våren 2023
Get PDFCICERO Senter for klimaforskning har for tredje gang gjennomført en spørreundersøkelse for å kartlegge i hvor stor grad kommunene er rustet til å håndtere følgene av klimaendringer. Undersøkelsen om klimatilpasning i norske kommuner ble gjennomført i samarbeid med IVL Svenska Miljöinstitutet og på oppdrag fra forsikringsselskapet If våren 2023. Målet med undersøkelsen er å synliggjøre utfordringer og behov i kommunene og vise frem gode eksempler fra kommuner som har kommet langt i sitt klimatilpasningsarbeid. Vi håper dette kan inspirere til økt søkelys på arbeid med klimatilpasning og gi beslutningstakere informasjon om hvilke barrierer kommunene står overforpublishedVersio
Implications of differences between recent anthropogenic aerosol emission inventories for diagnosed AOD and radiative forcing from 1990 to 2019
Get PDFThis study focuses on implications of differences between recent global emissions inventories for simulated trends in anthropogenic aerosol abundances and radiative forcing (RF) over the 1990–2019 period. We use the ECLIPSE version 6 (ECLv6) and CEDS year 2021 release (CEDS21) as input to the chemical transport model OsloCTM3 and compare the resulting aerosol evolution to corresponding results derived with the first CEDS release, as well as to observed trends in regional and global aerosol optical depth (AOD). Using CEDS21 and ECLv6 results in a 3 % and 6 % lower global mean AOD compared to CEDS in 2014, primarily driven by differences over China and India, where the area average AOD is up to 30 % lower. These differences are considerably larger than the satellite-derived interannual variability in AOD. A negative linear trend over 2005–2017 in global AOD following changes in anthropogenic emissions is found with all three inventories but is markedly stronger with CEDS21 and ECLv6. Furthermore, we confirm that the model better captures the sign and strength of the observed AOD trend over China with CEDS21 and ECLv6 compared to using CEDS, while the opposite is the case for South Asia. We estimate a net global mean aerosol-induced RF in 2014 relative to 1990 of 0.08 W m−2 for CEDS21 and 0.12 W m−2 for ECLv6, compared to 0.03 W m−2 with CEDS. Using CEDS21, we also estimate the RF in 2019 relative to 1990 to be 0.10 W m−2, reflecting the continuing decreasing trend in aerosol loads post-2014. Our results facilitate more rigorous comparison between existing and upcoming studies of climate and health effects of aerosols using different emission inventories.publishedVersio
What If Country Commitments for CO<inf>2</inf> Removal Were Based on Responsibility for Historical Emissions?
No full textThis study explored the consequences of allocating commitments to remove CO2 to countries according to their responsibility for human-made climate change based on historical (cumulative) CO2 emissions from fossil fuel use and industry. The ‘carbon debt’ to be restored through CO2 removal was calculated as the remaining carbon budget for warming by 2 °C minus emissions until 2100. The study included the remaining carbon budget from the recent literature and scenarios for greenhouse gas emissions. This experiment showed that industrialized countries would need to take on the biggest share of CO2 removal if the calculation of historical emissions starts with the industrial era. If accounting instead starts with the global negotiations on climate policy in 1990, however, developing countries would have to take on the largest commitment for CO2 removal. Given this scheme and with the aim of settling the carbon debt over two decades with equal annual efforts, the eight countries with the largest shares of historical emissions would have to take on annual CO2 removal efforts from 1 to 12 Gt CO2. These CO2 removal commitments would imply substantial efforts for many countries but nevertheless depend on the choice of a fairness principle and calculation method to render this operational.publishedVersio