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•A methodology was proposed to evaluate circularity alternatives for CDW products.•Key CE alternatives for concrete waste were identified.•CE and linear economy alternatives were ...compared using multicriteria analysis.•An environmental (LCA) and economic assessment of alternatives was performed.•CE options showed environmental and economic advantages over conventional options.
Construction and demolition waste (CDW) is identified by multiple circular economy (CE) policies as a key sector for implementing circularity strategies due to the high volume of waste produced and the large consumption of raw materials. However, CE is not widely applied in the sector because of the lack of solid estimations on its environmental and economic viability. The main aim of this study was to propose a set of methodological steps to identify the optimal circularity alternatives for CDW products based on a multicriteria analysis of their environmental and economic performance. This methodology is applied to evaluate concrete waste. In specific, high-grade applications of concrete waste were analyzed comprising the processing into recycled coarse aggregates (RCA) for their use in structural and non-structural concrete. Multiple scenarios with different RCA replacements (20%, 30% and 100%) and different types of sorting and recycling (on-site and off-site) were evaluated in accordance with the specific site conditions of the region of Catalonia, Spain. The Life Cycle Analysis methodology (LCA) was used to perform the environmental analysis, while a detailed cost analysis was conducted for the economic aspect. The multicriteria method VIKOR was used for the selection of alternatives considering three different criteria. The results of this study showed environmental and economic advantages of CE scenarios based on the use of RCA over conventional concrete, mainly due to the influence of landfilling and transport distances. RCA produced on-site showed a better performance than RCA from fixed plants.
A global mass market adoption of electric vehicles (EVs) is still hindered by the high costs of lithium-ion batteries (LIBs). Repurposing degraded EV batteries in second use applications holds the ...potential to reduce first-cost impediments of EVs. New business models are emerging rapidly within the EV and battery second use (B2U) industries but they focus on economic aspects without integrating social and environmental dimensions. Simultaneously, the emerging research topic around sustainable business models (SBMs) seem to be able to bridge the environmental management concerns in conjunction with economic and social changes. This paper addresses this paucity in the literature by offering an interdisciplinary approach by drawing upon key perspectives from the emerging sustainable technology of EVs and its underlying B2U market in relation to SBMs. Findings reveal major contributions to theorists and practitioners. B2U holds the potential to facilitate current unsustainable practices in the EV industry. This in turn, will lead towards a faster EV market uptake and improvements of overall sustainability performance through SBM perspectives. Accordingly, a B2U business model framework is conceptualised that embodies the cross-sector multi-stakeholder impact and the shared value creation mechanism for the EV industry and emerging B2U market. We finally conclude that as such B2U holds the potential to prove itself to be a viable and efficient case for sustainability. This can be implemented by taking a multi-stakeholder network centric business model design compared to traditionally firm-centric models, which ultimately refreshes the traditional business models on sustainability.
•SBMs for EV B2U will solve current unsustainable practices in the EV industry.•B2U leads to innovative multi-stakeholder cross-sector relationships as part of SBMs.•B2U is a shared sustainable value creation mechanism for the EV industry.•B2U slows resource loops as part innovative business models for sustainability.
Aerosol‐cloud interaction is the most uncertain mechanism of anthropogenic radiative forcing of Earth's climate, and aerosol‐induced cloud water changes are particularly poorly constrained in climate ...models. By combining satellite retrievals of volcano and ship tracks in stratocumulus clouds, we compile a unique observational data set and confirm that liquid water path (LWP) responses to aerosols are bidirectional, and on average the increases in LWP are closely compensated by the decreases. Moreover, the meteorological parameters controlling the LWP responses are strikingly similar between the volcano and ship tracks. In stark contrast to observations, there are substantial unidirectional increases in LWP in the Hadley Centre climate model, because the model accounts only for the decreased precipitation efficiency and not for the enhanced entrainment drying. If the LWP increases in the model were compensated by the decreases as the observations suggest, its indirect aerosol radiative forcing in stratocumulus regions would decrease by 45%.
Plain Language Summary
It remains unclear how much of the global warming induced by greenhouse gases is offset by aerosols because the effect of aerosol particles on clouds is the most uncertain mechanism of forcing of Earth's climate by human activities. Cloud water responses to aerosols are especially uncertain. Here we compare the properties of low marine clouds impacted by volcanic and ship emissions with the properties of the nearby unpolluted clouds in order to increase the understanding of aerosol impacts on clouds. Clouds impacted by emissions from volcanoes and ships lose or gain water depending on meteorological conditions, but on average the amount of water does not change much in the polluted clouds. These observations disagree with the systematic increases in cloud water in response to aerosols simulated by the Hadley Centre climate model. This model, like other contemporary climate models, only accounts for cloud water increases that result from decreased precipitation efficiency and does not account for the enhanced drying in polluted clouds. Our results suggest that the ability of aerosols to offset global warming might be overestimated. The observational constraints derived here on aerosol‐induced cloud water changes would ultimately translate into reduced uncertainties in projections of the future climate.
Key Points
Volcano and ship tracks reveal bidirectional changes in cloud water in response to aerosols, dependent on meteorological conditions
In contrast to common behavior of climate models, observations suggest that increases in cloud water are closely compensated by decreases
Accounting for the aerosol enhanced entrainment would offset cloud water increases and result in weaker indirect effects in climate models
Recent technological advances have demonstrated the feasibility of deploying spaceborne optical detectors with full polarimetric capabilities. The measurement of all four Stokes coefficients opens ...significant new opportunities for atmospheric aerosol studies and applications. While considerable amounts of attention have been dedicated to sensors with sensitivity to the total intensity and linear polarization (represented by Stokes coefficients I, U, Q), there has been less attention to the additional information brought by measuring circular polarization (coefficient V). This report fills this gap in knowledge by providing an overview of aerosol sources of circular polarization in the atmosphere and discusses possible remote sensing signatures.
In this manuscript, circularly polarized radiation that results from the interaction of incident unpolarized radiation are considered in three physical settings: optical activity originating in biogenic aerosols, alignment of non-spherical particles in the presence of electrical fields (such as dust, smoke, and volcanic ash) and aerosol multiple scattering effects. Observational and theoretical evidence of, and the settings and conditions for non-zero aerosol circular polarization generated from incident unpolarized radiation are here gathered and discussed. In addition, novel radiative transfer simulations are shown to illustrate notable spectral and other features where circular polarization may provide additional information that is possibly independent from total intensity and linear polarization only observations.
Current techniques for detection of aerosol composition (also referred as aerosol type) from space provide limited information. Remote identification of aerosols such as smoke, volcanic ash, and dust particles can only be accomplished with some degree of confidence for moderate to high concentrations. When the same aerosols are found at lower concentrations (but still high enough to be of importance for air quality and cloud formation), these methods often produce ambiguous results. The circular polarization of aerosols is rarely utilized, and we explore its value for improved determination aerosol composition. This study is presented as an overview with a goal to provide a new perspective on an overlooked optical property and to trigger interest in further exploration of this subject.
High Latitude Dust in the Earth System Bullard, Joanna E.; Baddock, Matthew; Bradwell, Tom ...
Reviews of geophysics (1985),
June 2016, Letnik:
54, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Natural dust is often associated with hot, subtropical deserts, but significant dust events have been reported from cold, high latitudes. This review synthesizes current understanding of ...high-latitude (> or = 50degN and > or = 40degS) dust source geography and dynamics and provides a prospectus for future research on the topic. Although the fundamental processes controlling aeolian dust emissions in high latitudes are essentially the same as in temperate regions, there are additional processes specific to or enhanced in cold regions. These include low temperatures, humidity, strong winds, permafrost and niveo-aeolian processes all of which can affect the efficiency of dust emission and distribution of sediments. Dust deposition at high latitudes can provide nutrients to the marine system, specifically by contributing iron to high-nutrient, low-chlorophyll oceans; it also affects ice albedo and melt rates. There have been no attempts to quantify systematically the expanse, characteristics, or dynamics of high-latitude dust sources. To address this, we identify and compare the main sources and drivers of dust emissions in the Northern (Alaska, Canada, Greenland, and Iceland) and Southern (Antarctica, New Zealand, and Patagonia) Hemispheres. The scarcity of year-round observations and limitations of satellite remote sensing data at high latitudes are discussed. It is estimated that under contemporary conditions high-latitude sources cover >500,000 sq km and contribute at least 80-100 Tg/yr1 of dust to the Earth system (approx. 5% of the global dust budget); both are projected to increase under future climate change scenarios.
Because emissions from weak volcanic eruptions tend to remain in the low troposphere, they may have a significant radiative impact through the indirect effect on clouds. However, this type of ...volcanic activity is underreported and its global impact has been assessed only by model simulations constrained with very limited observations. First observations of the impact of high‐latitude active volcanoes on marine boundary layer clouds are reported here. These observations were made using a combination of standard derived products and visible images from the MODIS, AMSR‐E and GOES detectors. Two distinctive effects are identified. When there is an existing boundary layer cloud deck, an increase in cloud brightness and a decrease in both cloud effective radius and liquid water content were observed immediately downwind of the volcanoes. The visible appearance of these “volcano tracks” resembles the effect of man‐made ship tracks. When synoptic conditions favor low cloudiness, the volcano plume (or volcano cloud) increases significantly the cloud cover downwind. The volcano cloud can extend for hundreds of kilometers until mixing with background clouds. Unlike violent eruptions, the volcano clouds reported here (the Aleutian Islands in the North Pacific and the South Sandwich Islands in the South Atlantic) have retrieved microphysical properties similar to those observed in ship tracks. However, when comparing the volcano clouds from these two regions, liquid water content can decrease, increase or remain unchanged with respect to nearby unperturbed clouds. These differences suggest that composition at the source, type of eruption and meteorological conditions influence the evolution of the cloud.
Buildings and greenhouses consume vast amounts of energy and natural resources for heating and ventilation. It is still unclear how the synergetic effect of combining greenhouses and buildings' ...forced waste airflows could improve both systems' energy efficiency. This study quantified the energy recovery potential of exchanging airflows in a rooftop greenhouse (iRTG) integrated with an office building HVAC system in a Mediterranean climate. Using monitored and calibrated energy model data, the results showed that the iRTG can act as a solar collector and as a sink for a building's low-grade waste heat. The magnitude of harvested thermal energy that could be recirculated into the building by the integrated HVAC system was 205.2 kWh/m2y−1 and was limited by greenhouse low transmissivity (54%). The magnitude of building exhaust air was 198 kWh/m2y−1 at temperatures sufficient to heat and cool the iRTG. Compared to a passive ventilated configuration, the integration of active ventilation strategies doubled the energy benefits. Building ventilation requirements directly determined building and greenhouse waste flows and energy benefits, which increased by 63.1% when air changes per hour moved from 1.59 to 3.16. Overall, this demonstrates that greenhouse and building functionalities could be coupled to contribute to urban circularity and sustainability.
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•A greenhouse integrated within the building HVAC system was investigated.•Real and modelling data was combined to quantify energy co-benefits.•The iRTG recycled 143 kWh/m2·y of sensible heat from building waste heat.•The iRTG solar capacity conveyed 205 kWh/m2·y of sensible heat to the building.•Active strategies doubled the energy benefits compared to passive mechanisms.
This paper explores sustainable business models (SBMs) evolution for the rapidly developing battery second use (B2U) market within the emerging electric vehicle (EV) industry. Previous work ...identified that SBMs and EV B2U are emerging as major research streams but there is paucity among literature to deliver an overarching framework or a holistic view between these fields and highlight fresh areas for future research. We adopted an inductive multiple-case study approach to unearth new knowledge by comprehending how B2U stakeholders undertake their sustainability-related business activities. These are not only focused on economic profitability but more importantly address wider social and environmental stakeholder value as part of prospective SBMs. The SBM archetypes were adopted as the major lens for our data analysis to study multiple cases of B2U stakeholder roles and comprehend further the scope and ultimate purpose of their operations. Major results indicate that the SBM archetypes as major sustainable innovation strategies have the potential to create a new conception of business models for sustainability in the EV B2U market. In turn, this creates and drives shared sustainable value for multiple stakeholders through cross-sectoral collaborations as part of ntire new and more SBMs. Finally, this study proposes the conceptual sustainable innovation business model (SIBM) framework for the EV B2U industry that includes such shared sustainable value creations which in turn drives forward business performance and sustainability at the same time, eventually creating the business case for sustainability within the EV industry.
•Multi-stakeholder cross sectoral innovative sustainable business model behaviours for EV B2U confirmed.•SBM Archetype(s) occurrence confirmed in the EV B2U industry leading to new conception of SBMs.•Evidence that B2U stakeholders have engaged in shared sustainable value creations.•Sound sustainable value propositions for EV B2U stakeholders unearthed.•Sustainable innovation business model framework for EV B2U market is conceptualised.
Urban and building systems are awash with materials. The incorporation of green infrastructure such as integrated rooftop greenhouses (iRTGs) has the potential to contribute to buildings’ and cities’ ...circularity. However, its greater sophistication than conventional agriculture (CA) could lead to a shift in environmental impacts. One of the key elements for greenhouse building-integrated agriculture (BIA) and CA to achieve high levels of environmental performance is their structural design, which largely impacts the economic and environmental life-cycle costs (by up to 63%). In this context, the study assessed iRTGs life-cycle material and energy flows and their environmental burdens at structural level (m-2y-1) within life cycle assessment (LCA), based on a case study in Barcelona. A structural assessment following European standards allowed the identification of key design factors to minimize the environmental impacts of RTGs’ structure within improvement scenarios. The assessment revealed that a steel structure in a business-as-usual (BAU) scenario contributed from 31.5 to 67.3% of the impact categories analyzed, followed by the polycarbonate covering material (from 21.8 to 45.9%). The key design factors responsible for these environmental impacts were ground height, ventilation design, building integration and urban location. The improvement scenarios compensated for additional steel inputs by up to 35.9% and decreased environmental impacts that might occur in the BIA context by 24.1% compared with the BAU scenario. The assessment also revealed that urban environments do not imply shifting environmental impacts per se, as greenhouse BIA structures can benefit from their advantageous characteristics or be compensated by optimized greenhouse structures.
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In order to improve aerosol representation in the NASA Goddard Earth Observing System (GEOS) model, we evaluated simulations of the aerosol properties and transport over the southern African biomass ...burning source and outflow region using observations made during the first deployment of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) field campaign in September 2016. An example case study of September 24 was analyzed in detail, during which aircraft-based in-situ and remote sensing observations showed the presence of a multi-layered smoke plume structure with significant vertical variation in single scattering albedo (SSA). Our baseline GEOS simulations were not able to represent the observed SSA variation, nor the observed organic aerosol-to-black carbon ratio (OA : BC). Analyzing the simulated smoke age suggests that the higher altitude, less absorbing smoke plume was younger (~4 days), while the lower altitude and more absorbing smoke plume was older (~7 days). We hypothesize a chemical or microphysical loss process exists to explain the change in aerosol absorption as the smoke plume ages, and we apply a simple 6-day e-folding loss rate to the model hydrophilic biomass burning OA to mimic this process. Adding this loss process required some adjustment to the model assumed scaling factors of aerosol emissions to conserve the regional aerosol loading and further improve the simulated OA : BC ratio. Accordingly, we have increased our biomass burning emissions of OA by 60 % and biomass burning BC by 15 %. We also utilized the ORACLES airborne observations to better constrain the simulation of aerosol optical properties, adjusting the assumed particle size, hygroscopic growth, and absorption. Our final GEOS model simulation with additional OA loss and updated optics showed a better performance in simulating AOD and SSA compared to independent ground and space-based retrievals for the entire month of September 2016, including the OMI Aerosol Index. In terms of radiative implications of our model adjustments, the final GEOS simulation suggested a decreased atmospheric warming of about 10 % (~2 W m-2) over the south-east Atlantic region and above the stratocumulus cloud decks compared to the model baseline simulations. These results improve the representation of the smoke age, transport, and optical properties in Earth system models.
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