Search Results (2,058)

Passive cooling strategies are essential to curbing the growing air-conditioning demand of dwellings in warm–humid regions. This work presents a Computational Fluid Dynamics (CFD) study, carried out with the open-source code OpenFOAM, of a passive system that couples an earth–air heat exchanger (EAHE) with a solar chimney (SC) serving a room-representative cavity, i.e., the coupled EAHE–SC device is analyzed together with the room it conditions. The methodology was built progressively: (i) a transient conduction sub-model (laplacianFoam) characterized the thermal inertia of the soil around the buried duct; (ii) a parametric study of eight coupling geometries identified the best relative position of the EAHE and the SC; (iii) three configurations—the complete system, the EAHE + cavity system, and the bare cavity—were solved under identical numerical conditions with the buoyancy-driven solvers of OpenFOAM and the k–$\epsilon$ turbulence model with the Boussinesq approximation; and (iv) the complete system was evaluated for a representative hot and a representative cold design day through a section-based post-processing of the ventilation and thermal-energy indicators. Over the four-day period simulated, the soil behaved as a stable thermal reservoir with no depletion. At the design condition, the complete system reached a mean cavity temperature of 33.2 °C, 8.32 air changes per hour (ACH) and 67.0 W of thermal power removed from the cavity, against 34.4 °C, 2.01 ACH and 4.56 W for the bare cavity; coupling the chimney raised ventilation by 94.8% and 313.9% relative to the EAHE-only and bare-cavity cases, respectively. The design-day comparison showed a marked climate-dependent response: on the hot day the EAHE dominated (air cooled by 5.75 °C, 2.51 ACH), whereas on the cold day the exchanger remained nearly neutral ($+0.19$ °C) and ventilation dropped to 0.69 ACH, lowering the cavity temperature to 24.1 °C. The results indicate a complementary, mutually reinforcing behavior—the coupled system removes more heat and renews more air than either device does on its own—for the design conditions analyzed. Full article

Sustainable mobility requires reducing energy use and emissions while considering accessibility and pressure on low-carbon resources. This study assesses passenger transport in Spain to 2050 with a system-dynamics model linking demand, modal and powertrain choice, fleet turnover, charging and fuel origins. Choice equations are estimated on pre-COVID data, with specification selection using 2001–2014 and evaluation with 2015–2019, followed by estimation with 2001–2019. Post-2019 observations provide diagnostic comparisons. Stylized Avoid–Shift–Improve packages share a common policy-reference approximation. In 2050, REF reaches 797.1 Gpkm, 754.9 PJ and 22.46 Mt of attributed operational CO₂. Avoid, Shift, medium Improve and high Improve reduce this emissions indicator by 9.87%, 0.39%, 2.07% and 3.94%, respectively. Both integrated packages are subadditive at the endpoint, while medium ASI is superadditive cumulatively. Parameter, policy-intensity, regulatory, resource-cap and fleet-allocation sensitivities qualify these comparisons. Uncapped high ASI with Fossil-Free fuels approaches zero attributed operational CO₂, but high resource caps raise its 2050 value to 29.49 Mt. Physical combustion remains positive. These conditional experiments identify energy, climate and resource trade-offs; they do not establish life-cycle neutrality, equitable accessibility or probabilistic forecasts. Full article

Cities face increasing pressure to accelerate climate action while operating within governance systems often characterised by institutional rigidity and slow regulatory adaptation. In this context, urban regulatory sandboxes have emerged as experimental instruments that enable municipalities to test innovative solutions while adapting institutional practices under conditions of uncertainty. Despite their growing implementation, limited evidence exists regarding their capacity to transform municipal governance itself. This research examines the conditions under which urban regulatory sandboxes can foster the governance capacities required for municipalities to lead the climate transition. A sequential mixed-methods design was applied, combining semi-structured interviews with municipal practitioners and a Likert-scale self-assessment instrument completed by the same practitioners. Four Spanish cities with active urban sandboxes—Barcelona, Madrid, Valencia, and Valladolid—were analysed across three governance dimensions: learning vs. isolation, flexibility vs. rigidity, and climate mission alignment. The findings suggest that, in the perception of the practitioners interviewed, urban sandboxes foster adaptive governance logics, though institutionalising these capacities exposes real tensions around intra- and inter-organisational collaboration, and the depth of transformation differs by each city context. These results carry practical implications for municipal policymakers seeking to integrate sandboxes as tools for climate-responsive urban governance and as enablers of local entrepreneurship and innovation ecosystems. This study contributes to the literature on adaptive governance and urban experimentation by positioning urban regulatory sandboxes as emerging instruments for leading climate transitions under conditions of uncertainty. Ultimately, urban sandboxes can serve as catalysts for embedding climate adaptability within municipal governance but only when accompanied by the deliberate institutional work needed to sustain them. Full article

This paper examines the multifractal organization of hourly wind-speed dynamics at nine automatic stations of the Brazilian National Institute of Meteorology in Paraíba, Northeast Brazil, over the common interval from 3 November 2017 to 17 November 2019. Missing records and values outside the inclusive 1.0–18.0 m/s analytical range are removed before station-level standardization, and multifractal detrended fluctuation analysis is applied to compacted retained-observation sequences. The stability-potential index (SPI) is defined as |α₀ − 0.5|, where α₀ is the singularity-spectrum peak and 0.5 is the uncorrelated benchmark. SPI therefore measures departure from random-like scaling and is interpreted as a temporal-organization indicator, not as a stand-alone measure of wind-power resource. Rolling windows of 720 retained observations, advanced by 168 observations, are assigned to seasons, El Niño, La Niña, neutral conditions, and tropical Atlantic-gradient regimes. The empirical design combines full-sample rankings, rolling spectra, two-way clustered ordinary least squares, Frisch–Newton bootstrap quantile regression, non-overlapping and coverage-threshold sensitivities, clock-span diagnostics, analytical-range and moment-order checks, 200 shuffled surrogates per station, and station-anchored inverse-distance-weighted maps. All full-sample α₀ estimates exceed 0.5, with SPI ranging from 0.1108 in Cabaceiras to 0.3937 in Areia. El Niño is associated with lower rolling SPI in both baseline and controlled mean regressions and in the lower and median quantiles; this sign persists after excluding low-coverage Camaratuba. La Niña is not significant at the mean but is negative at the 0.90 quantile. No north-warm Atlantic-gradient windows occur in the common sample, while the south-warm gradient is positive only near the median quantile. Four of nine stations have original raw spectrum widths above the shuffled 97.5% bound. Across stations, exact two-sided Spearman tests show no supported monotonic association between coverage, wind-distribution descriptors, or altitude and α₀, SPI, or W (n = 9; all p ≥ 0.194). The results document sample-specific spatial heterogeneity and climate-regime associations while showing that compacted-window duration, calm-wind screening, and the modest nine-station network require explicit sensitivity analysis and cautious generalization. Full article

Coal-fired power plants account for about half of China’s energy-related CO₂ emissions, making their decarbonization critical for climate change mitigation. However, small-scale facilities have received limited attention in carbon capture and storage (CCS) deployment due to their limited economies of scale. CCS clusters provide a cost-effective pathway to mitigate emissions from these plants. Four CCS deployment scenarios are developed to examine the mitigation potential and economic implications of including small-scale facilities. Point-to-point and clustered source-sink matching are applied to 3983 facilities and national storage site data for oilfields and saline aquifers. Results show that small-scale facilities account for 3.2 Gt CO₂ of cumulative abatement over 2030–2060, reducing the contribution required from large facilities. CCS clusters further reduce average transport distances for small-scale facilities by 71.5% and limit system cost increases to 0.4%, compared with a 3.8% increase under point-to-point layouts. Compared with the large facility point-to-point scenario (36.1 $/t), the average levelized cost of CCS is 12.7% lower when small-scale facilities are included and 15.5% lower under clustered deployment. These findings can support the sustainable transformation of China’s coal power sector by informing CCS deployment and shared infrastructure planning. Full article

The Brazilian Amazon coast is characterized by pronounced seasonal hydroclimatic variability and may also reflect remote Pacific and Atlantic climate signals. This study investigated associations between large-scale climate variability and atmospheric and oceanographic conditions using monthly data from 1995 to 2024. Pacific variability was classified as El Niño, La Niña, or neutral, whereas Atlantic variability was evaluated using drought-related and neutral conditions. Climatic associations were assessed using seasonally adjusted multivariate and univariate analyses, restricted-permutation tests, Spearman correlations, lagged correlations, and multiple regression. El Niño–Southern Oscillation (ENSO) phase showed a significant but modest multivariate association with environmental conditions, supported by restricted-permutation analysis (R² = 0.036, p = 0.0015). Wind speed and mean wave period showed the clearest ENSO-related differences, with higher winds and shorter wave periods during El Niño. Atlantic drought-related conditions showed an event-consistent increase in salinity, whereas the monthly wind-speed difference was more event-dependent. FDR-adjusted Spearman correlations revealed persistent wind–wave covariation, particularly during the dry season. ONI–SST correlations showed a broad positive pattern at lags of 4–9 months, with the largest observed coefficient at lag 6 (r = 0.348, nominal p = 0.012); however, no individual lag remained significant after false-discovery-rate correction (lag 6: q = 0.066), and the lagged pattern was therefore interpreted as exploratory. Overall, regional seasonality predominated, with climate signals acting as secondary, variable-specific modulators. Full article

The European Union’s climate-neutrality objective is reshaping coal-dependent regions, but transition pathways differ according to historical coal dependence, institutional capacity, national energy systems, and regional economic structures. Coal phase-outs represent not merely a sector-specific energy shift, but a systemic socio-spatial transformation that reconfigures regional planning and territorial dynamics. This study examines how governance coordination, phase-out clarity, labour-market instruments, innovation strategies, and post-mining land reuse operate across three major Central European coal regions: the Ruhr Area (Germany), Upper Silesia (Poland), and the Moravian–Silesian Region (Czechia). It applies a qualitative, structured comparative review based on academic literature, policy and strategic documents, official statistics, and three flagship redevelopment cases within the framework of the EU RFCS-funded RAISING project. The comparison shows that the Ruhr Area’s long-term, corporatist coordination has facilitated structural diversification and land reuse over several decades, though challenges regarding job quality and socio-spatial inequalities persist. In Upper Silesia, negotiated agreements foster regional consensus, while the multi-decade transition timeline reflects national energy-security priorities, supply-security constraints, and institutional complexity. In the Moravian–Silesian Region, early reactive restructuring in the 1990s contrasts with a more coordinated contemporary phase leveraging EU transition funding and strategic investment. Across all three cases, transition outcomes are mediated by place-specific conditions rather than formal closure speed alone. The study demonstrates that while core principles of early planning, multi-level coordination, and integrated asset reuse offer valuable insights, their application remains context-dependent, highlighting the necessity for place-sensitive European and national transition policies. Full article

Natural farming (NF) has emerged as a promising agro-ecological tactic to enhance resource use and reduce dependence on synthetic agricultural inputs. However, comprehensive field-based evidence across diverse agro-climatic regions remains limited. This study assessed the effects of NF on water use, water and crop productivity, economic returns, energy consumption, and soil fertility across four agro-climatic zones of Andhra Pradesh, India, using a paired-field approach during 2023–2025. Compared with conventional farming (CF), NF reduced total water utilization by 16.1–39.0%, resulting in a 15.0–55.5% improvement in water productivity. Although rice yield declined marginally by 4.40–8.40% in the Southern, Krishna, and High-Altitude zones during some seasons, yields remained comparable in the Godavari zone. The cost of cultivation decreased substantially by 20.6–35.1%, while gross returns remained largely comparable between production systems, varying from −7.0% to +5.05%. Consequently, NF increased net returns by 8.8–29.0% and improved the benefit-cost ratio by 23.7–47.8% relative to CF. Irrigation-related energy consumption was reduced by 21.8–57.7%, indicating greater resource-use efficiency under NF. The sustainable yield index values remained high (0.68–0.91), demonstrating stable crop productivity despite reduced external inputs. Natural farming practices also improved soil health by buffering soil pH towards neutrality; soil organic carbon (SOC) enhanced from 0.38–0.73% under CF to 0.57–1.01% under NF. Similarly, available nitrogen, phosphorus, and potassium increased under NF. Overall, these findings demonstrate that natural farming improves water and energy productivity, reduces production costs, and increases farm profitability while maintaining stable rice productivity across diverse agro-climatic conditions. The results highlight the potential of natural farming as a climate-resilient and resource-efficient strategy for sustainable rice production in India. Full article

Soil organic carbon (SOC) in permafrost regions is a critical component of terrestrial carbon reservoirs, and spatially explicit multi-depth mapping is essential for identifying subsurface carbon emission hotspots and supporting carbon neutrality accounting. The Kamalan River Basin in the Greater Khingan Mountains, situated in a discontinuous permafrost zone with relatively high SOC stocks and strong sensitivity to climate warming, was selected as the study area. A total of 90 field sampling points were collected and integrated with Sentinel-1 Synthetic Aperture Radar (SAR) imagery, Sentinel-2 multispectral imagery, and topographic data, yielding 238 environmental features. Three predictive models, Random Forest (RF), Geographically Weighted Random Forest (GWRF), and One-Dimensional Convolutional Neural Network (1D-CNN), were combined with three feature selection methods (Boruta, RF importance, and Shapley) to construct 27 model–feature–depth combinations across three soil layers (0–10 cm, 10–20 cm, and 20–30 cm). RF feature selection combined with RF model achieved the highest prediction accuracy at 0–10 cm (R² = 0.93, RMSE = 16.58 g/kg), with its bootstrap aggregation strategy effectively suppressing overfitting under small-sample and high-dimensional conditions. 1D-CNN showed relatively unstable performance, which may be associated with feature selection strategy, feature ordering sensitivity, a potential mismatch between its inductive bias and tabular environmental data. Feature importance analysis suggested that bulk density (BD) and soil moisture content (SMC) were among the most influential predictors across all depth layers, with elevation, radar backscatter coefficients, and Sentinel-1 texture features demonstrating relatively high cross-method and cross-depth stability. Boruta excluded BD and SMC at 0–10 cm, which may be partly attributable to inter-predictor redundancy, a strict independent-contribution threshold, and insufficient statistical power under small-sample conditions. For spatial mapping, the best-performing combination for each model was applied: RF feature selection with RF model, RF feature selection with GWRF model, and RF feature selection with 1D-CNN model. SOC maps revealed considerable spatial heterogeneity, with relatively high values concentrated in valley lowlands and lower values in high-altitude forest zones; mean SOC declined from 93.08 g/kg at 0–10 cm to 69.88 g/kg at 20–30 cm. Despite the limited number of sampling points (n = 90), these findings provide practical guidance for model and feature selection in SOC mapping of permafrost forests and a scientific basis for carbon sink assessment under climate warming scenarios. Conservation efforts should prioritize riparian zones and high-elevation areas with elevated SOC concentrations, while vegetation protection and reduced soil disturbance are recommended in low-SOC regions to help limit further carbon loss. Full article

Coastal low-voltage isolated or impedance-earthed-neutral (IT) systems are capable of continuous power supply following the first earth fault. However, environmental erosion and converter-related system unbalance render the neutral-to-earth characteristics of such systems highly dependent on insulation performance and protective-earthing-path conditions. This paper proposes an environmental-state-driven and traceable configuration method for fixed series resistance–inductance neutral-to-earth branches. The method represents environment-dependent variations in system insulation and protective-earthing paths through temperature, humidity, salt contamination, and component aging and establishes four coupled environmental states accordingly. For each candidate neutral branch configuration, three critical indicators, i.e., neutral-point displacement voltage, first-earth-fault current, and touch voltage, are comprehensively evaluated. A common robust feasible region satisfying all prescribed environmental states is extracted through full-state constraint screening. Infeasible configuration candidates are traced to their dominant environmental states and restrictive constraints. Furthermore, a Pareto max–min selection criterion is adopted to determine the optimal configuration, which maximizes the minimum normalized safety margin without requiring additional empirical trade-off weights or online parameter retuning. A 400 V primary case study, complemented by cross-site climatic and electrical-system transferability assessments, demonstrates the applicability of the proposed framework over the investigated conditions. Full article

Climate-Neutral Districts (CNDs) and Positive Energy Districts (PEDs) have become central concepts in European strategies for climate-neutral cities. Existing research, however, has predominantly interpreted these models from technological and energy-system perspectives, while their governance implications and effects on real-estate investment remain comparatively underexplored. This paper develops a conceptual and interpretative framework that also considers CNDs and PEDs as governance and investment environments shaped by different stakeholder configurations. Methodologically, the study combines an evidence-informed stakeholder and governance framework developed within CapaCITIES 2.0 with an interdisciplinary conceptual interpretation. The framework derives from comparative analysis of Countries’ Self-Assessments and National Action Plans involving 33 consortium participants representing 14 Member States, complemented by interviews, focus-group exchanges, collegial reconciliation, and participant validation. The unit of analysis is the stakeholder configuration associated with a dominant district-transition logic. The analysis positions PEDs as an energy-system-led, rather than energy-system-exclusive, configuration characterised by high infrastructural integration and comparatively strong dependence on specialised technical and regulatory actors. This perspective also highlights the structurally central, yet often under-leveraged, role of real estate actors. The paper concludes that recognising the plurality of district-transition logics provides a more differentiated basis for examining governance arrangements and the conditions under which real-estate stakeholders may move from reactive implementation roles towards greater strategic agency in urban climate transitions. Full article

Rural courtyard dwellings in cold regions are commonly characterized by low winter indoor temperatures, intermittent heating, solar heat gain, pronounced thermal fluctuations, and strong occupant adaptation. This study aimed to compare short-term winter indoor thermal conditions among three rural courtyard dwelling cases in Qingcheng Ancient Town, Gansu Province, Northwest China, and to examine the associations between operative temperature and multidimensional subjective thermal responses under the monitored conditions. Synchronized indoor–outdoor environmental measurements and 216 paired questionnaire records were collected during two winter survey days. To account for shared environmental exposure, the questionnaire records were organized into 66 dwelling–time clusters. The results showed that: (1) outdoor air temperature ranged from −13.34 °C to 13.24 °C, with a mean of −3.91 °C, while the mean operative temperature during the questionnaire periods was 11.31 °C and the mean thermal sensation vote (TSV) was −0.97, indicating an overall sensation close to slightly cool; (2) the dwelling with an added sunspace had the highest mean operative temperature, the ordinary brick–concrete dwelling exhibited the greatest temperature fluctuation, and the earth–wood dwelling remained cooler but relatively stable; (3) each 1 °C increase in operative temperature was associated with 75% higher odds of reporting a warmer TSV category (OR = 1.75, 95% CI: 1.53–2.00), while the two-way fixed-effects model estimated a 0.176-unit increase in mean TSV; and (4) higher operative temperature was associated with greater broad and clear thermal acceptability and a lower likelihood of preferring warmer conditions, with the study-specific neutral operative temperature estimated at 16.75 °C and a block-bootstrap 95% confidence interval of 15.66–18.40 °C. These findings provide field-based evidence of the associations between operative temperature and multidimensional winter thermal responses and offer an empirical basis for climate-responsive and heritage-sensitive thermal improvement strategies for rural courtyard dwellings. Full article

Against the global carbon neutrality agenda, renewable energy subsidies have become a core policy tool for China’s energy transition, yet related policies have faced repeated anti-subsidy challenges in international trade for over a decade. This paper examines the compliance dilemma of China’s renewable energy subsidy policy under the WTO Agreement on Subsidies and Countervailing Measures (SCM Agreement), drawing on three landmark trade disputes: two WTO cases (DS419, US–China Wind Power; DS437, US–China Countervailing Duties) and one European Union anti-subsidy investigation into Chinese photovoltaic products. Different from existing single-dimensional studies, this paper constructs a coupled dual-dimensional analytical framework integrating domestic institutional compliance and international rule constraints. The results show that repeated challenges stem from the interaction of two sets of factors: domestic subsidy design fails to meet SCM Agreement requirements in terms of specificity, subsidy form and legislative positioning, while existing WTO rules lack special exemptions for climate-oriented renewable energy subsidies. The study further proposes targeted two-dimensional optimization paths, including domestic subsidy system compliance reform and proactive participation in WTO subsidy rule revision, to balance China’s dual carbon goals and international trade compliance. Full article

Explicit gender stereotypes are shifting toward neutrality, yet how widely a stereotype is endorsed and how consistently it appears across domains within those who endorse it are separable properties of a stereotype climate. The same Romanian adults, parents alongside teachers and school counsellors (N = 121), reported gender-stereotyped beliefs about children’s play and traits in the abstract, together with two applied judgements: gender-differentiated educational expectations and gender suitability of occupations. Stereotyped judgement covaried across all three domains, substantially among parents and moderately among teachers. This cross-domain covariation indexes consistency within respondents rather than a common latent construct, which the confirmatory models did not support. Stereotyping was voiced more strongly as abstract belief than in either applied domain. Explicitly gender-typing occupations was a minority position, yet those who did so held the strongest beliefs, a concentration that direction-cancelling coding rendered undetectable. Because gendered channelling is concentrated rather than diffuse, awareness work is better targeted than universal and better timed before high-stakes transitions such as allocation to high-school tracks. Teachers resembled parents, suggesting professional training does not by itself displace such judgement. Where access is no longer the binding constraint, monitoring that tracks only how prevalent gender bias is will miss what remains coherent in a shrinking minority. Full article

In the context of global climate change, the blue economy and coastal blue carbon are pivotal to sustainable ocean governance. However, integrating economic, social, and ecological dimensions into national accounting systems remains highly fragmented, particularly in China. China’s marine strategies currently prioritise Gross Value Added and industrial expansion, inadvertently excluding the immense non-market carbon sequestration value of mangroves, seagrass beds, and salt marshes from the System of National Accounts. Following the PRISMA guidelines, this paper systematically reviews international policy frameworks, scientific literature, and accounting instruments to assess current implementation of blue economy and blue carbon accounting. To bridge the identified structural gaps, this paper proposes an innovative integrated framework for blue carbon accounting and carbon asset optimisation, aimed at quantitatively tracking and mapping a concrete pathway to standardise blue carbon as a tradable asset and integrate it into the China Certified Emission Reduction market. Ultimately, this research systematically analyses the scientific basis of blue carbon ecosystems, the capital mobilisation mechanisms of blue finance, and the disclosure dilemmas of blue accounting to provide in-depth strategic insights for multilateral institutions, academia, and policymakers. It provides a robust, evidence-based foundation to reconcile marine economic development with ecological boundaries, thereby supporting China’s carbon neutrality targets and the Global Sustainable Development Goals. Full article