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This study focuses on formulating the most sustainable concrete by incorporating recycled concrete aggregates and other products retrieved from construction and demolition (C&D) activities. Both recycled coarse aggregates (RCA) and recycled fine aggregates (RFA) are firstly used to fully replace the natural coarse and fine aggregates in the concrete mix design. Later, the cement rich ultrafine particles, recycled glass powder and mineral fibres recovered from construction and demolition wastes (CDW) are further incorporated at a smaller rate either as cement substituent or as supplementary additives. Remarkable properties are noticed when the RCA (4–12 mm) and RFA (0.25–4 mm) are fully used to replace the natural aggregates in a new concrete mix. The addition of recycled cement rich ultrafines (RCU), Recycled glass ultrafines (RGU) and recycled mineral fibres (RMF) into recycled concrete improves the modulus of elasticity. The final concrete, which comprises more than 75% (wt.) of recycled components/materials, is believed to be the most sustainable and green concrete mix. Mechanical properties and durability of this concrete have been studied and found to be within acceptable limits, indicating the potential of recycled aggregates and other CDW components in shaping sustainable and circular construction practices. The authors wish to acknowledge the financial support from EU Horizon 2020 Project VEEP ‘‘Cost-Effective Recycling of C&DW in High Added Value Energy Efficient Prefabricated Concrete Compo-nents for Massive Retrofitting of our Built Environment” (No.723582).

Bioenergy villages can be defined as villages, municipalities, settlements or communities, which produce and use most of their energy from local bioenergy and other renewable energy sources. A bioenergy village approach has not been applied in Macedonia yet, and it is at a nascent stage of implementation in other South-Eastern European countries. This work aims to integrate a techno-economic, social and environmental assessment and an implementation strategy into a bioenergy village concept, which is not often seen in works dedicated to bioenergy villages and biomass based heating systems. The assessment was conducted by means of energy audit and project-related tools, whilst the strategy was composed by bioenergy working group meetings. Results show that a biomass based district heating system is a more attractive solution for heating several public buildings instead of a fossil fuelled system, with numerous associated benefits. Such concepts can be replicated with variety of renewables, thus contributing to sustainable development pathways of small communities.

This paper analyses the impact of postponing global mitigation action on abatement costs and energy systems changes in China and India. It compares energy-system changes and mitigation costs from a global and two national energy-system models under two global emission pathways with medium likelihood of meeting the 2 °C target: a least-cost pathway and a pathway that postpones ambitious mitigation action, starting from the Copenhagen Accord pledges. Both pathways have similar 2010–2050 cumulative greenhouse gas emissions. The analysis shows that postponing mitigation action increases the lock-in in less energy efficient technologies and results in much higher cumulative mitigation costs. The models agree that carbon capture and storage (CCS) and nuclear energy are important mitigation technologies, while the shares of biofuels and other renewables vary largely over the models. Differences between India and China with respect to the timing of emission reductions and the choice of mitigation measures relate to differences in projections of rapid economic change, capital stock turnover and technological development. Furthermore, depending on the way it is implemented, climate policy could increase indoor air pollution, but it is likely to provide synergies for energy security. These relations should be taken into account when designing national climate policies.

Biomass pre-treatment is a key step in achieving the economic competitiveness of biomass conversion. In the present work, an imidazole pre-treatment process was performed and evaluated using wheat straw and eucalyptus residues as model feedstocks for agriculture and forest-origin biomasses, respectively. Results showed that imidazole is an efficient pre-treatment agent; however, better results were obtained for wheat straw due to the recalcitrant behavior of eucalyptus residues. The temperature had a stronger effect than time on wheat straw pre-treatment but at 160 °C and 4 h, similar results were obtained for cellulose and hemicellulose content from both biomasses (ca. 54% and 24%, respectively). Lignin content in the pre-treated solid was higher for eucalyptus residues (16% vs. 4%), as expected. Enzymatic hydrolysis, applied to both biomasses after different pre-treatments, revealed that results improved with increasing temperature/time for wheat straw. However, these conditions had no influence on the results for eucalyptus residues, with very low glucan to glucose enzymatic hydrolysis yield (93% for wheat straw vs. 40% for eucalyptus residues). Imidazole can therefore be considered as a suitable solvent for herbaceous biomass pre-treatment.

Abstract An increasing number of studies show that efficiency improvements alone will not be sufficient to attain the substantial emission reductions needed to mitigate global warming to a target of 2 °C. Consumption side changes are likely to be needed to achieve sufficient emission reductions. The United Nations emphasize the importance of developed countries taking the lead in lowering emissions to achieve the sustainable development goals. This paper assess to what extent Norwegian households can lower their carbon footprint consistent with territorial emission reductions towards the 2 °C target of global warming through implementing a set of behavioral actions. We evaluate the efficacy of the set of actions both initially and after considering rebound effects. A multiregional environmentally extended input-output database is linked with the Norwegian consumer expenditure survey to analyze both average and marginal expenditure per unit of increased income. Further, linear programming is applied to examine the changes needed by households to reach different emission reduction targets. We find that households implementing the full set of actions without re-spending can obtain a 58% decrease in their carbon footprint. When accounting for the effect of re-spending, this reduction drops to 24–35%, which is not within the requirements of the 2 °C target. The optimization analysis suggests households can achieve reductions up to 45% by restricting re-spending to specific goods and services. This indicates that curbing the rebound effect is key to achieving real reductions in household carbon footprints. We show that changing consumption patterns can significantly contribute to lowering anthropogenic greenhouse gas emissions without compromising the level of economic activity.

This paper illustrates the main results of an expert elicitation survey on advanced (second and third generation) biofuel technologies. The survey focuses on eliciting probabilistic information on the future costs of advanced biofuels and on the potential role of Research, Development and Demonstration (RD&D) efforts in reducing these costs and in supporting the deployment of biofuels in Organisation for Economic Co-operation and Development (OECD) and non-OECD countries. Fifteen leading experts from different EU member states provide insights on the future potential of advanced biofuel technologies both in terms of costs and diffusion. This information results in a number of policy recommendations with respect to public RD&D strategies and is an important contribution to the integrated assessment modelling community.

Degrowth and environmental justice movements share overarching aims of sustainability and justice and pursue them through radical social change and resistances. Both movements are diverse and comprised of groups that originate and operate in different contexts. The ever-growing metabolism of the world economy presents an obstacle to both movements' aims, while a socio-metabolic perspective unveils very different characteristics and contexts of the specific struggles. The strategies of many environmental justice movements located at the frontiers of resource extraction are employed to resist coerced socio-ecological transition towards industrialization and to protect more customary ways of life. Movements for the degrowth of industrial metabolism tend to push for socio-ecological transformation, pursuing new ways of life and reimagined social relations in alternative societies. The overarching aims and obstacles of these movements may be shared, but their struggles, strategies and required actions are not the same. Alliances should seek advantages from this plurality of perspectives and positions within their struggles, while acknowledging potential tensions arising from these different contexts.