Circular economy (CE) practices pave the way for the construction sector to become less material- and carbonintensive. However, for CE quantification by climate mitigation models, one must first identify the CE practices along a product (or material) value chain. In this review, CE practices are mapped for the value chain of 6 construction materials to understand how these practices influence and can be considered in climate mitigation modelling. The main sub-categories of steel, cement, glass, clay-brick, insulation materials, and wood were used to identify which Rs are currently addressed at the lab and industrial scales: refuse, reduce, rethink, repair, reuse, remanufacture, refurbish, repurpose, recycle, and recover. The CE practices were reviewed using scientific repositories and grey literature, validated by European-wide stakeholders, and mapped across the life-cycle stages of the six materials - extraction, manufacturing, use, and end-of-life (EoL). The mapping was limited to the manufacturing and EoL stages because materials could be identified at these stages (the extraction phase pertains to resources, and the use phase to a product, for example, buildings). All reviewed CE practices identified at the industrial scale were quantified at the European level. For example, EoL reinforcement steel is 1-11 % reused and 70-95 % recycled; manufacturing CEM I is up to 60 % reduced; remanufacturing flat glass is 26 % remanufactured while less than 5 % EoL flat glass is recycled. A major barrier to closed-loop recycling is the need for sorting and separation technologies. Open-loop recycling synergies are found at the industrial scale between, for example, flat glass and glass wool value chains. Climate mitigation models are proposed to be augmented to include these practices requiring an explicit link between building use and the other construction materials' value chain stages.

The carbon-neutrality target set by the European Union for 2050 drives the increasing relevance of green hydrogen as key player in the energy transition. This work uses the JRC-EU-TIMES energy system model to assess opportunities and challenges for green hydrogen trade from North Africa to Europe, analysing to what extent it can support its decarbonization. An important novelty is addressing uncertainty regarding hydrogen economy development. Alternative scenarios are built considering volumes available for import, production costs and transport options, affecting hydrogen cost-effectiveness. Both pipelines and ships are modelled assuming favourable market conditions and pessimistic ones. From 2040 on, all available North African hydrogen is imported regardless of its costs. In Europe this imported hydrogen is mainly converted into synfuels and heat. The study aims to support policymakers to implement effective strategies, focusing on the crucial role of green hydrogen in the decarbonization process, if new competitive cooperations are developed.

While European regions face a range of different climate hazards, little is known about how these differences affect local climate adaptation planning. We present an analytical framework for evaluating local climate adaptation plans (LCAPs) and apply it to 327 cities in 28 countries across different European regions. To do this, we use statistical methods to identify regional clusters based on overall plan quality, impacts, vulnerable population groups, and sectors addressed by LCAPs. By comparing both geographic and statistical clusters, we found (1) significant spatial heterogeneity across European cities but (2) higher average plan quality scores and more consistent strategies across cities in Central and Eastern Europe. Notably, we found no regional differences regarding (a) the climate impacts and vulnerable communities identified in plans: (b) the most commonly addressed impacts, which were urban temperature and changing precipitation patterns; and (c) the residents that cities identified as most vulnerable, namely older people, women, infants, and the sick. Our study provides a spatial analysis of European LCAPs to uncover regional policy perspectives on local climate adaptation issues. Such approaches can effectively inform broader EU, national and regional strategies that aim to support local adaptation planning in a context of multi-level governance.

Energy system models are important tools to guide our understanding of current and future carbon dioxide emissions as well as to inform strategies for emissions reduction. These models offer a vital evidence base that increasingly underpins energy and climate policies in many countries. In light of this important role in policy formation, there is growing interest in, and demands for, energy modellers to integrate more diverse perspectives on possible and preferred futures into the modelling process. The main purpose of this is to ensure that the resultant policy decisions are both fairer and better reflect people's concerns and preferences. However, while there has been a focus in the literature on efforts to bring societal dimensions into modelling tools, there remains a limited number of examples of well-structured participatory energy systems modelling processes and no available how-to guidance. This paper addresses this gap by providing good practice guidance for integrating stakeholder and public involvement in energy systems modelling based on the reflections of a diverse range of experts from this emergent field. The framework outlined in this paper offers multiple entry points for modellers to incorporate participatory elements either throughout the process or in individual stages. Recognising the messiness of both fields (energy systems modelling and participatory research), the good practice principles are not comprehensive or set in stone, but rather pose important questions to steer this process. Finally, the reflections on key issues provide a summary of the crucial challenges and important areas for future research in this critical field.

The European Union's low carbon power plants installed capacity needs to increase by 90% by 2030. Using a spreadsheet model, we calculate the total amounts of construction materials (henceforth materials) and natural resources (henceforth resources) used for the new renewable and nuclear power plants. Considering concrete, glass, and steel as materials and sand and water as resources, future CO2e impacts are estimated using 2010–2020 as a reference. To test if circular economy measures reduce the effects of materials and resource consumption, we derive three near-future scenarios for the decade 2020–2030: business as usual (BAU), EU manufacture (EUM), and circular (CIRC). Independent of the scenario, CO2e emissions double from increasing low-carbon power plants. Circular economy substantially lowers resource consumption but not carbon emissions. With 90% recycling (CIRC), we spare 90% sand and 5% water compared to a BAU scenario. Resource-efficient power plant design and major technological advancement in recycling processes are needed to fulfill a CIRC scenario.

Extreme weather events (EWE) can affect energy supply, particularly when energy systems are significantly reliant on renewable energy sources, highly vulnerable to climate and weather conditions. We combine observational energy data from EUROSTAT with records of EWE, between 1990 and 2019, to evaluate European power plants capacity factors (CF) responses to those events. Using a statistical compositing analysis, we show that years with floods and storms increased annual European hydropower CF by 7 and 5.8%, respectively, compared to non-EWE years, while CF of fossil power plants decreased (−2.8%). Similar behaviours are found for Central and Mediterranean countries. From 1993 to 2004 to 2005–2016 European hydropower tripled during floods and quintupled during storms suggesting that the events are becoming more severe or there is more efficient water use. On the contrary, from 1993 to 2016, in every year with droughts/heatwaves the European hydropower decreased (−6.5%), with a subsequent increase of fossil CF (2.3%). Such behaviour is also observed across Central and Eastern Europe. Cold waves negatively affected solar photovoltaic output at the European level and Central Europe (−5%). Vulnerability of wind power plants to floods is increasing: from 1993 to 2004 to 2005–2016 there is 3-fold decrease in the European wind CF; from one flood year to the following, wind CF decreases in Central (−1.9%yr−1) and Eastern Europe (−3.7%yr−1). During droughts/heatwaves, wind CF increases in Central Europe (2%yr−1), but decreases in Mediterranean (−3%yr−1). Shifting to renewable energy sources is key to decarbonization. It's crucial understanding the historical impacts of EWE in the power system towards its resilience and stability.

Urbanization and the concentration of energy-consuming economic activities make cities responsible for more than 70% of global greenhouse gas emissions. At the same time, cities are becoming increasingly vulnerable to climate change impacts. The European Cities Mission launched a call in September 2021 to set out on a path towards "100 climate-neutral and smart cities by 2030". A very large and diverse sample of 344 candidate cities in 35 countries (a subset of the 362 considered eligible to participate in the Cities Mission) was used to conduct this timely research aimed at identifying the main dimensions on which cities are working to achieve a smart and sustainable transition. The research focused on five main dimensions: local climate planning, climate emergency declarations, participation in networks, international projects and competitions. Results show that only 20 (5.8%) cities have no experience in any of them, while there are 18 (5.2%) cities that have in their background activities that fall under all dimensions. Moreover, networking is the most important dimension, among the five analysed, for cities applying for this Mission, involving 309 cities (approximately 90% of the sample). This is followed by local climate planning, involving 275 cities (80%) and city participation in international projects, involving 152 cities (44%). Cities that have declared a climate emergency are less than a fifth of the sample and are very unevenly distributed in only 37.1% of the countries represented (interestingly, all the UK cities in the sample). Similarly, only 49 cities (14.2%) have received international awards. The results provide insights into the main efforts currently being made by cities to engage in the transition to climate neutrality and may be useful to practitioners, scholars and policy-makers at all levels to improve their knowledge of the steps they need to take to support this process and amplify its scope.

Cities across Mediterranean Europe face common climatic threats. They are highly vulnerable and very likely to suffer losses and damages due to heat waves, droughts, wildfires, landslides, and extreme coastal events. To this date, however, there is no systematic understanding of how cities in Mediterranean Europe are preparing to adapt to these impacts. To address this question, we analyse local adaptation plans in 73 cities located in 51 regions across 9 European countries along the Mediterranean Sea (France, Italy, Spain, Greece, Portugal, Croatia, Slovenia, Cyprus and Malta). We also investigate upper levels of planning to understand the influence of policy environments. Across the sample, 67 % of regions have adopted a plan, but only 30 % of the cities. The most common climate-related hazards these cities prepare for are extreme temperatures and rainfall, followed by drought and water scarcity, as well as floods and landslides. Without legal obligations, neither regional nor national adaptation policy frameworks seem to influence the development of urban plans. In some cases, cities are ahead of national policy. This paper sheds light on the progress of local adaptation planning in Mediterranean Europe and paves the way for further research in this climate-threatened geographical area.

Linear climate mitigation models look into aggregated economic sectors and model greenhouse gas (GHG) emissions disregarding downstream value chains, making particular sectors accountable for downstream (or upstream) GHG emissions. Hence, the present climate mitigation models inconsistently account for indirect GHG emissions; underrepresent upstream and downstream value chains; do not address Circular Economy (CE) practices; do not cover resource consumption, thus not considering materials’ circularity. To provide curated policy support for decision-making for carbon neutrality and other Sustainable Development Goals (SDGs), models need to shift from linear to circular. To achieve this, a link between energy-climate mitigation modelling and cradle-to-cradle assessment CE analytical tools must be established. This is the core issue covered in the CO 2 NSTRUCT Horizon project (2022-2026). CO 2 NSTRUCT proposes a framework to supplement the well-established JRC-EU-TIMES model, using a highly comprehensive technological representation with CE measures. The framework will apply CE measures to the value chain of six carbon-intensive construction materials (i.e., cement, steel, brick, glass, wood, and insulation materials) and will provide new components to the JRC-EU-TIMES model, including citizen behaviour; societal impacts; rebound effects; supply and value chains. The results will be used for policy approaches integrating CE into climate change mitigation actions.

Defining and measuring progress in adaptation are important questions for climate adaptation science, policy, and practice. Here, we assess the progress of urban adaptation planning in 327 European cities between 2005 and 2020 using three ‘ADAptation plan Quality Assessment’ indices, called ADAQA-1/ 2/ 3, that combine six plan quality principles. Half of the cities have an adaptation plan and its quality significantly increased over time. However, generally, plan quality is still low in many cities. Participation and monitoring and evaluation are particularly weak aspects in urban adaptation policy, together with plan ‘consistency’. Consistency connects impacts and vulnerabilities with adaptation goals, planned measures, actions, monitoring and evaluation, and participation processes. Consistency is a key factor in the overall quality of plans. To help evaluate the quality of plans and policies and promote learning, we suggest incorporating our ADAptation plan Quality Assessment indices into the portfolio of adaptation progress assessments and tracking methodologies.

With fast-growing technology, schools have to adapt and use technology constantly as a tool to grow. This study aims to understand the influence of computer factors on students' academic achievement. We propose a model on the influence of computer attitudes, computer learning environments, computer learning motivations, computer confidence, computer use, computer self-efficacy, loneliness, mothers' education, parents' marital status and family size on academic achievement (AA). To validate the conceptual model, 286 students aged 16-18 years old answered an online questionnaire. The most important drivers that positively affect AA are computer use, employment motivations, and mothers' education. While enjoyment attitudes, school environment, interest motivations, and loneliness influence AA negatively. Also, family size and computer self-efficacy work as moderators, and computer use works as a mediator between computer learning environments and academic achievement.

Climate change will impact renewable resources and electricity demand, usually not jointly considered when designing future decarbonized power systems. This paper assesses how sensitive the Portuguese carbon-neutral power sector is to climate change by 2050 and what are the implications for the formally approved Portuguese Carbon Neutrality Roadmap. The future capacity factors for wind, solar and hydropower and electricity demand response to temperature are estimated for 22 climate projections along the Representative Concentration Pathway 4.5 and 8.5. The eTIMES_PT optimization model is used to assess its combined impact on the cost-optimal configuration of the power sector by 2050. Results show that climate change lowers hydropower generation by 20% (in median terms). Improving spatial and temporal resolution and including future climate patterns, results also in lower cost-effectiveness of solar photovoltaic vis-a-vis the Carbon Neutrality Roadmap. While future climate does not impact onshore wind production, offshore wind power generation is positively affected, being a climate-resilient carbon-neutral option for Portugal. Annual electricity unitary costs at final users (excluding taxes and levies) only increase up to 4% with climate change, but seasonal costs have higher variability. This analysis highlights that climate change affects the cost-optimal annual carbon-neutral power sector and needs to be included in energy planning. (C) 2021 Elsevier Ltd. All rights reserved.

Climate change may increase water needs for irrigation in southern Europe competing with other water uses, such as hydropower, which may likely be impacted by lower precipitation. Climate change will also potentially affect the variability and availability of other renewable energy resources (solar and wind) and electricity consumption patterns. This work quantifies the effect of competition for water use between irrigation and hydropower in the future 2050 Portuguese carbon-neutral power sector and under Representative Concentration Pathway 8.5 climate change projections. It uses the power system eTIMES_PT model to assess the combined effects of climate change on the cost-optimal configuration of the power sectorconsidering changes in irrigation, hydropower, wind and solar PV availability. eTIMES_PT is a linear optimisation model that satisfies electricity demand at minimal total power system cost. Results show that, by 2050, climate change can lead to an increase in annual irrigation water needs up to 12% in Tagus and 19% in Douro watersheds (from 2005 values), with substantially higher values for spring (up to 84%). Combining these increased water needs with the expected reduction in river runoff can lead to a decline in summer and spring hydropower capacity factors from half to three times below current values. By 2050, concurrent water uses under climate change can reduce hydropower generation by 26–56% less than historically observed, mainly in summer and spring. Higher solar PV, complemented with batteries' electricity storage, can offset the lower hydropower availability, but this will lead to higher electricity prices. Adequate transboundary water management agreements and reducing water losses in irrigation systems will play a key role in mitigating climate impacts in both agriculture and power sector.

Climate conditions have a significant impact on energy demand and production. The project CLIM2POWER, completed in 2021, aimed to develop a climate service at European scale for the planning of the power infrastructures operations using seasonal forecasts and long-term climate projections. This work presents part of the project and focus on assessing the climate change impacts on hydropower production of Torrao Dam. Torrao reservoir is located on the Tamega river, a tributary of the Douro River in northern Portugal. The long-term (2016-2100) climate data used is obtained from the EURO-CORDEX simulations, on a daily time scale. Two different combinations of regional and global climate models for scenarios RCP 4.5 and 8.5 (four combinations) were used: ICHEC-EC-EARTH-CLMcom-CCLM4 (CCLM4) and ICHEC-EC-EARTH-DMI-HIRHAM5 (HIRMAM5). Long-term precipitation data was bias-corrected using the multiplicative shift method, and for rainfall-runoff simulation, HEC-HMS model was used. The results showed that 30-years total annual precipitation for future periods (i.e, 2016-2040, 2041-2070 and 2071-2100) was 3.4%-28.1% lower than the historical one. 30-years annual total discharges of all future periods decreased for both models and RCPs (1.2%-30.2% less than the historical ones). Regarding future 30-year annual average capacity factors, there was reduction (1.8%-24.8%) with respect to historical one, except in two future periods for CCLM4 model of RCP 4.5 scenario i.e., 1.2% increase in the period 2016-2040 and 1.5% increase in the period 1971-2100. This suggest that hydropower production is not only dependent on future precipitation trends but also on the hydropower production procedures.

Europe is committed to a new growth strategy with no net greenhouse gases emissions by 2050, where hydrogen has a clear role to play. Portugal's strategy for H2 sets public policies promoting an industry focused on the hydrogen value chain. Considering the production of green hydrogen from renewable sources is key, water electrolysis becomes a priority, and with it, the need to assess the suitability of water sources, which is determined by both quantitative and qualitative factors. This work presents a new approach to assess the suitability of water sources for hydrogen production via water electrolysis by applying a Sustainable Value Methodology for decision-making support, combining economic, environmental and social criteria. The approach is applied to two different sites in Portugal: a semi-urban location on the Atlantic coast (site A) and a rural area far from the coast (site B). For both sites, water sources are evaluated regarding water availability, quality, transport options, abstraction costs, treatment needs and regulation (including environmental constraints) and social acceptance. The resulting sustainable value indicator, aggregator of different levels of information, enables a relative quantitative comparison of the performance of different water sources for electrolysis and the involved costs. It is found that the public grid water is the most suited source of water for electrolysis due to lower risk of supply, lower costs and avoids complex permitting processes. Likewise, seawater and wastewater treatment plant effluent (only in site A) showed to be possible water sources where the factors most affecting suitability are transport costs for water and waste disposal from water treatment.

In Europe, regions in the Mediterranean area share common characteristics in terms of high sensitivity to climate change impacts. Does this translate into specificities regarding climate action that could arise from these Mediterranean characteristics? This paper sheds light on regional and local climate mitigation actions of the Mediterranean Europe, focusing on the plans to reduce greenhouse gases emissions in a representative sample of 51 regions and 73 cities across 9 Mediterranean countries (Croatia, Cyprus, France, Greece, Italy, Malta, Portugal, Slovenia, Spain). The study investigates: (i) the availability of local and regional mitigation plans, (ii) their goals in term of greenhouse gas emissions reduction targets on the short and medium-long term, and (iii) the impact of transnational climate networks on such local and regional climate mitigation planning. Results of this study indicate an uneven and fragmented planning, that shows a Mediterranean West-East divide, and a link with population size. However, overall, both regional and city action seem insufficiently ambitious with regards to meeting the Paris Agreement, at least at city level. While national frameworks are currently weak in influencing regional and local actions, transnational networks seem to be engaging factors for commitment (at city level) and ambitiousness (at regional level). The uneven and fragmented progress revealed by this study, does not align with the characteristics shared by investigated regions and cities in terms of environmental, socio-political, climatic and economic conditions. The results support the call of a common green deal at the Mediterranean level to further address specific Mediterranean challenges and related needs. This will allow to capitalise on available resources, generate local-specific knowledge, build capacities, and support Mediterranean regions and cities in preparing the next generation of more ambitious mitigation plans.

Climate and weather conditions influence energy demand. as well as electricity generation, especially due to the strong development of renewable energy. The changes of the European energy mix, together with ongoing climate change, raise a number of questions on impact on the electricity sector. In this paper we present results for the whole of the European power sector regarding on how considering current and future climate variability affects the results of a TIMES energy system model for the whole European power sector (eTIMES-EU) up to 2050. For each member-state we consider six climate projections to generate future capacity factors for wind, solar and hydro power generation. as well as temperature impact on electricity demand for heating and cooling. These are input into the eTIMES-EU model to assess how climate affects the optimal operation of the power system and if current EU-wide RES and emissions target deployment may be affected. Results show that although at EU-wide level there are no substantial changes, there are significant differences in countries RES deployment (especially wind and solar) and in electricity trade.

The World Energy Outlook reports produced by the International Energy Agency have long been considered the “gold standard” in terms of energy modeling and projecting future trends. It is thus extremely important to assess how well its projections are aligned with sustainable development goals as well as closely tracking observed, historical values. In this work we analyzed thirteen sets of World Energy Outlook projections from the last 25 years. Different scenarios were considered for the following regions and countries: world, OECD, OECD Europe, OECD North America, China, India, Russia, and Africa. The maximum variation between the projections for 2030 CO2 emissions from the energy sector, made between 2006 and 2018 for OECD, Europe and North America were found to be comparable with the gap between the Paris Agreement goals and the voluntary (unconditional) nationally determined contributions to remain below a 2 °C global temperature increase. For the same period, projections for the percentage of renewable electricity exhibited maximum variations between 51% and 96%, signaling a huge underestimation. We discuss the significance of overestimating energy demand and underestimating the rate of renewable energy implementation in the context of 2030 climate and energy policy targets, as well as desirable methodological changes to energy modeling under aggressive climate mitigation policies.