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Historical exploitation of the Mediterranean Sea and the absence of rigorous baselines makes it difficult to evaluate the current health of the marine ecosystems and the efficacy of conservation actions at the ecosystem level. Here we establish the first current baseline and gradient of ecosystem structure of nearshore rocky reefs at the Mediterranean scale. We conducted underwater surveys in 14 marine protected areas and 18 open access sites across the Mediterranean, and across a 31-fold range of fish biomass (from 3.8 to 118 g m(-2)). Our data showed remarkable variation in the structure of rocky reef ecosystems. Multivariate analysis showed three alternative community states: (1) large fish biomass and reefs dominated by non-canopy algae, (2) lower fish biomass but abundant native algal canopies and suspension feeders, and (3) low fish biomass and extensive barrens, with areas covered by turf algae. Our results suggest that the healthiest shallow rocky reef ecosystems in the Mediterranean have both large fish and algal biomass. Protection level and primary production were the only variables significantly correlated to community biomass structure. Fish biomass was significantly larger in well-enforced no-take marine reserves, but there were no significant differences between multi-use marine protected areas (which allow some fishing) and open access areas at the regional scale. The gradients reported here represent a trajectory of degradation that can be used to assess the health of any similar habitat in the Mediterranean, and to evaluate the efficacy of marine protected areas.

Plug-in hybrid electric vehicles (PHEVs) have a larger battery and can replace a certain amount of conventional fossil fuels with grid electricity, which differs from the traditional hybrid electric vehicles (HEVs). The application of the onboard electrical energy significantly influences the energy utilization efficiency and thus impacts the fuel economy. In this paper, the basic PHEV operation modes are defined as pure electric driving (PED), hybrid driving charge depleting (HDCD) and hybrid driving charge sustaining (HDCS) based on the battery state of charge (SoC) profile. For a plug-in hybrid electric bus (PHEB), three different energy management strategies, which are combined with two or three of the basic operation modes, are put forward and comparatively examined based on simulation models. If some trip information can be approximately known in advance such as the trip distance and the mean power demand, the PED + HDCD + HDCS strategy comprised optimally of the PED mode, the HDCD mode and the HDCS mode would be the best energy management strategy.

AbstractThe planetary boundary framework constitutes an opportunity for decision makers to define climate policy through the lens of adaptive governance. Here, we use the DICE model to analyze the set of adaptive climate policies that comply with the two planetary boundaries related to climate change: (1) staying below a CO2 concentration of 550 ppm until 2100 and (2) returning to 350 ppm in 2100. Our results enable decision makers to assess the following milestones: (1) a minimum of 33% reduction of CO2 emissions by 2055 in order to stay below 550 ppm by 2100 (this milestone goes up to 46% in the case of delayed policies); and (2) carbon neutrality and the effective implementation of innovative geoengineering technologies (10% negative emissions) before 2060 in order to return to 350 ppm in 2100, under the assumption of getting out of the baseline scenario without delay. Finally, we emphasize the need to use adaptive path-based approach instead of single point target for climate policy design.

Abstract Background The aim of this paper is to reconsider the necessity for the green transition and the key preconditions for the implementation of a circular economy in Western Balkan countries. With the objective of the research in mind, the method of analysis and synthesis was applied to determine (1) regulatory and institutional prerequisites for the green transition; (2) the need for the Western Balkan countries to redefine the model of sustainable economic growth towards the green transition; (3) the development opportunities for recovery defined in the Green Agenda for the Western Balkans; and (4) the possibility of implementing the circular economy in the Western Balkans. Main text The main findings of the research indicate that: (1) the countries of the Western Balkan region, following the example of the EU, should define a national strategic approach to the green transition with an accompanying action plan and regulatory framework; (2) the biggest challenge of the green transition is the reform of the energy sector and the restructuring of the energy-intensive economy; (3) the countries have untapped potential in renewable energy sources and report the improvement of energy efficiency; (4) the circular economy can boost the green transition, because the countries of the region have a five-time lower value of resource productivity than the average of the EU, while the generation of waste (excluding major mineral wastes) per GDP unit is lower compared to the EU; (5) cross-sectoral governance should be more coordinated. Conclusions The green transition might be a development opportunity for the Western Balkans, which should enable sustainable economic growth as well as energy security and environmental protection. However, the implementation of the Green Agenda is not easy, because the region faces the problem of underdeveloped regulatory and institutional capacities that might provide not only the base for long-term planning but also financial resources for the efficient implementation of projects. In addition, it is essential to understand the principles of the Green Agenda and the interaction of all activities that should enable the achievement of defined goals.

Abstract Improvement of the quantitative performance characterization of photovoltaic (PV) strings was investigated, based on their monitoring data during maximum power point tracking (MPPT) operation. The maximum power voltage Vmp and current Imp of the PV strings under MPPT were continuously monitored, and corrected to standard temperature of 25 °C by using the temperature correction formulas, which were recently developed for PV modules. The irradiance G was measured by using a PV module irradiance sensor. It was verified that the formulas are applicable to PV strings, enabling reproducible temperature correction of Vmp and Imp with relative standard deviation (σ) of about 0.4–0.9% under various weather conditions. Comparison of the outdoor results with indoor current–voltage curve measurements of the constituent modules in the strings showed that the maximum output power Pmax under the standard test conditions STC, i.e. 25 °C and 1 kWm−2, estimated from the temperature-corrected Vmp and Imp, agreed with the indoor result typically within ±1.5%. The experimental results also showed that other information of the string such as partial shading and activation of bypass diodes can be also sensitively detected by analyzing the temperature-corrected Vmp and Imp. The outdoor measurements and data analysis of this study can be carried out without stopping the MPPT operation of the string. The analysis is performed by using the real-time data. The present method is expected to be applicable to most kinds of crystalline silicon PV strings without modification.