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The practice of using climate metrics to estimate carbon dioxide equivalent emissions has long been subject to scientific discussion. One strand of this literature has analysed whether the choice of metric affects the relative cost-effectiveness of options for climate change abatement, but there has been little discussion on the effect of metric choices on cost-effective abatement of near-term climate forcers (NTCFs). These NTCFs are air pollutants primarily regulated by policies outside the climate policy arena and their estimated carbon dioxide equivalent emissions are not typically considered in the evaluation of cost-effective abatement. However, the attention to NTCFs as climate forcers has increased during the last decade. The objective of this paper is to identify whether the relative cost-effectiveness of different NTCF abatement options is robust to climate metric choices. We assess nine plausible NTCF abatement options available in Sweden (with negligible effect on long-lived GHG emissions) and evaluate the robustness of the ranking of these, according to their estimated cost-effectiveness. Different metric designs are considered as well as climate impact uncertainty of NTCFs, with corresponding uncertainty in metric values. The results indicate that the choice of metric has little effect on the ranking of the options according to their cost-effectiveness, with options affecting NOx indicated as an exception. This suggests that the choice of metric utilised when calculating cost-effectiveness of NTCF abatement options is likely to have minor effect on which NTCF abatement options should be targeted for policy interventions (if NOx emissions are not significantly affected). [ABSTRACT FROM AUTHOR]

This paper investigates the greenhouse gas emissions from a Swedish wetland, constructed to decrease nutrient content in sewage treatment water. To evaluate the effect of the construction in terms of greenhouse gas emissions we carried out ecosystem-atmosphere flux measurements of CO2, CH4 and N2O using a closed chamber technique. To evaluate the importance of vascular plant species composition to gas emissions we distributed the measurement plots over the three dominating plant species at the field site, i. E. , Typha latifolia, Phragmites australis and Juncus effusus. The fluxes of CO2 (total respiration), CH4 and N2O from vegetated plots ranged from 1. 39 to 77. 5 (g m−2 day−1), −377 to 1387 and −13. 9 to 31. 5 (mg m−2 day−1) for CO2, CH4 and N2O, respectively. Presence of vascular plants lead as expected to significantly higher total respiration rates compared with un-vegetated control plots. Furthermore, we found that the emission rates of N2O and CH4 was affected by presence of vascular plants and tended to be species-specific. We assessed the integrated greenhouse warming effect of the emissions using a Global Warming Potential over a 100-year horizon (GWP100) and it corresponded to 431 kg CO2 equivalents m−2 day−1. Assuming a 7-month season with conditions similar to the study period this is equal to 90 tonnes of CO2 equivalents annually. N2O emissions were responsible for one third of the estimated total greenhouse forcing. Furthermore, we estimated that the emission from the forested bog that was the precursor land to Magle constructed wetland amounted to 18. 6 tonnes of CO2 equivalents annually. Hence, the constructed wetland has increased annual greenhouse gas emissions by 71. 4 tonnes of CO2 equivalents for the whole area. Our findings indicate that management processes in relation to wetland construction projects must consider the primary function of the wetland in decreasing eutrophication, in relation to other positive aspects on for instance plant and animal life and recreation as well as possible negative climatic aspects of increased emissions of CH4 and N2O. [ABSTRACT FROM AUTHOR]

This article examines the hypothesis of deterministic emissions convergence for a panel of the BRICS and Indonesia to advanced countries' emissions levels as well as to Sweden (which is a country that has clearly gone through decoupling) using a novel dataset with ten series of annual estimates of anthropogenic emissions comprising aerosols, aerosol precursor and reactive compounds, and carbon dioxide from 1820 to 2018. For that purpose, we employ four novel panel unit root tests allowing for several forms of time-dependent and state-dependent nonlinearity. The evidence supports deterministic convergence following a linear process for carbon dioxide, whereas the adjustment is asymmetric and nonlinear for carbon monoxide. Methane and nitrogen oxides exhibit logistic smooth transition converging dynamics. In contrast, black carbon, ammonia, nitrous oxide, non-methane volatile organic compounds, organic carbon, and sulfur dioxide emissions diverge. These results have implications for the abatement of greenhouse gases emissions at the global level, given the high share of emissions of the BRICS. [ABSTRACT FROM AUTHOR]

Ecotechnologies have the potential to reduce the use of finite resources while providing a variety of co-benefits to society, though they often lack in market competitiveness. In this study, we investigate the sustainability of ecotechnologies for recovering carbon and nutrients, and demonstrate how a so-called "bottom-up" approach can serve as a decision-making instrument. Based on three case study catchments with a focus on domestic wastewater in Sweden and Poland, and on manure, grass and blackwater substrates in Finland, we apply a cost–benefit analysis (CBA) on system alternatives derived from a participatory process. After drawing on an initial systematic mapping of relevant ecotechnologies, the scope of the CBA is determined by stakeholder suggestions, namely in terms of the considered assessment criteria, the physical impacts and the utilised data. Thus, this CBA is rooted in a localised consideration of ecotechnologies rather than a centralised governmental approach to systems boundaries. The key advantage of applying such a bottom-up approach is that it has gone through a robust participatory selection process by local stakeholders, which provides more legitimacy to the decisions reached compared with traditional feasibility studies. Despite considering the revenues of the recovered products as well as the provision of the non-market goods CO2 mitigation and reduced eutrophication, findings from this study indicate that the benefits of the considered ecotechnologies are often outweighed by their costs. Only anaerobic digestion of agricultural wastes appears to be economically feasible under the current conditions, highlighting that further efforts and incentives may be required to mainstream ecotechnologies. [ABSTRACT FROM AUTHOR]

This study undertakes a decomposition analysis to identify the drivers of carbon dioxide emissions change in the Swedish business and industry sectors 1993–2006. On aggregate, energy intensity decreased, but this does not seem to have been very important for reducing emissions. Rather, fuel substitution seems to have been more important, which is in line with findings from the decomposition literature on Sweden. However, at the sectoral level, we find no clear pattern of the effect of fuel substitution and energy intensity on emissions. We also draw some methodological conclusions: decomposition analysis should be undertaken at the most disaggregate level possible; assessing decomposition results by summing results over several time periods leads to biased results; and decomposition analysis should not be based only on some initial and final years of a long time period. Furthermore, we address the problem of double counting energy flows in decomposition analysis of aggregate effects when the energy sector is included, and point out potential problems related to output measured in monetary terms. [ABSTRACT FROM AUTHOR]

Ponds are active components of the global carbon cycle processing and emitting carbon dioxide and methane to the atmosphere. These common habitats frequently experience seasonal water table variations resulting in periodically air-exposed sediments. However, the influence of these events on both the system scale carbon balance and in-pond environmental conditions remains poorly studied. We took advantage of an extraordinarily warm and dry summer to quantify the CO2 efflux from air-exposed sediments and water surfaces in desiccating ponds on Öland, Sweden. Simultaneously, we modelled metabolism and measured environmental variables within the ponds. We found that air-exposed sediments had high CO2 effluxes greatly exceeding that from the water surfaces. Sediment water content influenced the temperature and strongly regulated the CO2 efflux gradually approaching zero as water evaporated. Within the desiccating ponds, respiration was generally higher than gross primary production, but was lower compared to the same ponds with higher water table. These findings highlight the role of periodically air-exposed pond sediments as sites of highly active carbon processes. Not only is this important for the system-scale carbon in ponds, but it may also influence the destiny of buried carbon in lakes subject to climate changes. The environmental conditions within desiccating ponds, most notably high water temperatures and poor oxygen conditions, further iterate the dynamics and extreme nature of ponds. [ABSTRACT FROM AUTHOR]

This study investigates the effect of a CO2 tax on profitability by using firm-level data on output and inputs from Swedish industry between 1990 and 2004. The purpose of this exercise is to investigate the validity of the so-called Porter hypothesis. By utilizing a factor-demand modeling approach, and specifying a profit function that has a technology component dependent upon firm-specific effective tax on CO2, we are able to separate out the effect of regulatory pressure on technological progress. The results indicate that there is evidence of a “reversed” Porter effect in most industrial sectors, especially in energy-intensive industries; that is, after controlling for the fuel price effect, technological progress and consequently profits are further negatively affected by the CO2 tax. [ABSTRACT FROM AUTHOR]

The main objective of this study is to improve the modelling of household demand for transport services in a Computable General Equilibrium (CGE) model. The new extended model is then used for numerical calculations to test how the Swedish economy reacts to a carbon target. Special attention will be given to distributional effects and the connection between labour supply and work journeys in a sparsely populated country like Sweden. A differentiation between trip purposes and trip length, a complementary relationship between work journeys and labour supply, and a subdivision of households by density of population and income influence the numerical results. Our main conclusions from the analysis of a carbon target are that if the carbon tax revenue is recycled by decreasing the employers’ social contribution fee, welfare costs are lower than with lump-sum replacements of tax revenue to households. The welfare cost may be reduced even further if work journeys are not additionally taxed as compared to the base year. However, the lower total welfare cost is obtained at the expense of making society more unequal, since both labour tax recycling (cuts in employers’ social contributions) and exempting tax on work journeys will make low income groups carry a higher burden. An increased carbon dioxide tax is also shown to increase welfare differences between sparsely populated areas and city regions in Sweden. [ABSTRACT FROM AUTHOR]