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In order to make adequate projections on the consequences of climate change stressors on marine organisms, it is important to know how impacts of these stressors are affected by the presence of other species. Here we assessed the direct effects of ocean warming (OW) and acidification (OA) along with non-consumptive effects (NCEs) of a predatory crab and/or a predatory snail on the habitat-forming mussel Perumytilus purpuratus. Mussels were exposed for 10-14 weeks to contrasting pCO2 (500 and 1400 μatm) and temperature (15 and 20 °C) levels, in the presence/absence of cues from one or two predator species. We compared mussel traits at sub-organismal (nutritional status, metabolic capacity-ATP production-, cell stress condition via HSP70 expression) and organismal (survival, oxygen consumption, growth, byssus biogenesis, clearance rates, aggregation) levels. OA increased the mussels' oxygen consumption; and OA combined with OW increased ATP demand and the use of carbohydrate reserves. Mussels at present-day pCO2 levels had the highest protein content. Under OW the predatory snail cues induced the highest cell stress condition on the mussels. Temperature, predator cues and the interaction between them affected mussel growth. Mussels grew larger at the control temperature (15 °C) when crab and snail cues were present. Mussel wet mass and calcification were affected by predator cues; with highest values recorded in crab cue presence (isolated or combined with snail cues). In the absence of predator cues in the trails, byssus biogenesis was affected by OA, OW and the OA × OW and OA × predator cues interactions. At present-day pCO2 levels, more byssus was recorded with snail than with crab cues. Clearance rates were affected by temperature, pCO2 and the interaction between them. The investigated stressors had no effects on mussel aggregation. We conclude that OA, OW and the NCEs may lead to neutral, positive or negative consequences for mussels.

Low emission and green hydrogen as a carbon-free energy carrier has attracted worldwide attention in decarbonizing the energy system and meeting the Paris agreement target of limiting warming to 2 °C or below. This study investigates the contribution of different hydrogen pathways to the energy transition and sheds light on adopting different decarbonization scenarios for Quebec, Canada, while including biogenic emissions from forest-based biomass consumption. We assess various alternative policy scenarios using a TIMES model for North America (NATEM), a bottom-up techno-economic approach. This study examines the role of various hydrogen pathways in Quebec's energy transition by considering different net-zero policy scenarios and an additional set of “green” scenarios, which prohibit the use of fossil fuel-based hydrogen. The results show that varying the penetration of hydrogen provides a key trade-off between reliance on direct air capture, reliance on carbon storage, reliance on wind and solar buildout, the inter-sector allocation of residual emissions, and the overall cost of achieving emission targets. In particular, the use of hydrogen in the industrial sector, a sector known to be difficult to decarbonize, reduces industrial emissions and reliance on direct air capture (DAC). Clustering industrial plants to use captured CO2 as a feedstock for synthetic fuel production may not reduce industrial GHG emissions by 2050, but it offers the opportunity to use captured CO2 instead of sequestering it in deep saline aquifers. Even though increasing industrial green hydrogen penetration increases marginal GHG abatement costs in the green net-zero scenario by 2050, it further minimizes industrial GHG emissions and the need for DAC among all net-zero scenarios by 2050. Hydrogen plays a significant role in achieving ambitious net-zero emission target, especially where electrification is not feasible, or electricitystorage is required.

Isolated microgrids are promoted as solutions for rural electrification in the Global South but they often encounter difficulties during their lifespan. Despite this, long-term research on microgrid viability and sustain- ability is scarce. Building on existing works, we develop a multidimensional approach to sustainability based on four dimensions: technical, financial, institutional and socio-cultural. This framework is applied to an isolated microgrid in a Senegalese village over a seven-year timeframe, looking at both local and external factors. The unusually long-term approach uncovers the deep roots of entangled and evolving sustainability issues. Our re- sults are three-fold. First, intertwined sustainability factors intensify challenges. Technical challenges exacerbate financial and institutional ones, while the design of the microgrid impacts socio-cultural aspects. This leads to a vicious cycle between the four sustainability dimensions. Secondly, sustainability is mostly affected in the in- terval between technical breakdown and repairs as maintenance delays have repercussions on users' practices and their trust in the MG, as well as the operator's business models. Lastly, MGs are never a completely local system, even if they are designed to be (partially) autonomous. The study thus makes recommendations for researchers, practitioners and decision-makers. A long-term vision is necessary from the MG design stage. External support and funding are essential to ensure the sustainability of microgrids in poor and remote settings, moving away from the image of microgrids as autonomous systems. Future research agendas would benefit from additional case studies with a longitudinal and multiple-scale approach. 111;

Solid oxide fuel cell (SOFC) is a mature opportunity for producing power energy in remote areas like islands, where access to the electrical grid is not favoured, and gas distribution is the only viable approach. In this context, generally, biogas represents the most convenient fuel resources in these areas. However, the direct use of biogas in SOFCs is still an issue to be solved due to its negative effect on the conventional Ni-YSZ anode. In this study, to overcome this issue, we suggested using a protective layer coated on the anode of a commercial SOFC. A nickel manganite showing mixed ionic and electronic conductivity tailored specifically for this approach was investigated. The preliminary characterisations showed that the formation of a Ruddlesden-Popper (RP) n ¼ 1 structure supporting fine encapsulated particles based on Ni was formed around 800 C in consequence of the reducing environment. The electrochemical experiments carried out for 270 h demonstrated for the coated cell significant stability in the presence of dry biogas, albeit an ageing effect was noticed in the electrical percolation of both cell electrodes. The post mortem analyses revealed an attractive redox property for the nickel manganite, which partially returned to the RP n ¼ 2 phase. Moreover, the absence of carbon deposits on the anode suggests possible applications for this approach.

Distributed maximum power point tracking photovoltaic (PV) systems based on series-connected dc/dc converters are one of the most promising PV configurations for an enhanced security and efficiency in distributed generation systems. Most of the works reported so far in the literature for control and stability analysis of these configurations are based on small-signal ac models. This could be a significant limitation, as this kind of linearization produces a good approximation of the nonlinear model of series-connected dc/dc converters only at the operating point. However, PV systems must be controlled for a large set of operating points with a satisfactory performance and robustness. Moreover, stability analysis of series-connected dc/dc converters has not yet been widely discussed in previous research. Therefore, this article presents a nonlinear model of series-connected boost dc/dc converters and develops control and stability analysis to fill the gap in this emerging topic. A systematic experimental and numerical investigation is performed in order to validate the effectiveness of the proposed control approach in this study.

Abstract Reducing energy consumption and emissions from freight transport plays an important role in climate change mitigation. However, there remains a need for enhanced policy making and research to explore decarbonization of freight transport. This research establishes a freight transport model to simulate transport demand, energy consumption and emissions, and applies the model to Ireland with scenarios running out to 2050. This model provides advanced technological details in freight transport modelling, responses of transport demand to economic changes, and behavioural responses in the representation of competition between transport technologies. The results show a strong growth of land freight transport demand in Ireland resulting from economic growth (GDP) despite increasing carbon taxes. The new EU CO 2 emission performance standards on light and heavy-duty vehicles have the potential to effectively slow down the growth of energy consumption from 2015 to 2050 but possible technical barriers need to be evaluated to ensure full compliance. In the short term, carbon taxation (or higher fuel prices) may have a greater impact but the effect of emission performance standards will be realised in the longer term as the vehicle stock is replaced with new technology vehicles. Notably, adoption of biofuel and alternative freight vehicles are expected to bring additional reductions in future energy consumption and emissions. For a low carbon future for freight transport, integrated efforts are needed to develop a comprehensive policy agenda (technology specific standards and pricing mechanisms) and promote low or zero emission vehicles technologies, especially for heavy goods vehicles.

Climate change could seriously threaten global lake ecosystems by warming lake surface water and increasing the occurrence of lake heatwaves. Yet, there are great uncertainties in quantifying lake temperature changes globally due to a lack of accurate large-scale model simulations. Here, we integrated satellite observations and a numerical model to improve lake temperature modeling and explore the multifaceted characteristics of trends in surface temperatures and lake heatwave occurrence in Chinese lakes from 1980 to 2100. Our model-data integration approach revealed that the lake surface waters have warmed at a rate of 0.11 °C 10a-1 during the period 1980–2021, being only half of the pure model-based estimate. Moreover, our analysis suggested that an asymmetric seasonal warming rate has led to a reduced temperature seasonality in eastern plain lakes but an amplified one in alpine lakes. The durations of lake heatwaves have also increased at a rate of 7.7 d 10a-1. Under the high-greenhouse-gas-emission scenario, lake surface temperature and lake heatwave duration were projected to increase by 2.2 °C and 197 d at the end of the 21st century, respectively. Such drastic changes would worsen the environmental conditions of lakes subjected to high and increasing anthropogenic pressures, posing great threats to aquatic biodiversity and human health.