Search Results (1,875)

Under the continuous impact of global warming, the water cycle has undergone significant changes, causing a series of problems such as water shortage, frequent climate disasters and ecological environment deterioration. Therefore, understanding the evolution of regional historical and future drought and wet conditions is crucial for adapting and mitigating disasters. This paper discusses the evolution of drought and pluvial events in the Henan section of the Yellow River from 1970 to 2014, projects the future evolution of drought and wet conditions, and assesses the performance of various climate models from Coupled Model Intercomparison Project Phase 6 in simulating precipitation and temperature. Subsequently, future drought and wet conditions in the Henan section were projected for the 2015–2100 period across four SSP-RCP scenarios using Standardized Precipitation and Evapotranspiration Index (SPEI) and run theory. The results indicate that the Henan section of the Yellow River exhibited a significant drying trend during the historical period, with a rate of 0.15 per decade. Looking ahead, a wetting tendency is projected under the SSP1-2.6 scenario, with an increasing rate of 0.02 per decade, whereas the other three scenarios consistently show drying trends, with rates of −0.11, −0.15, and −0.23 per decade, respectively. Across all scenarios, drought and wetness variations exhibit pronounced periodicity, particularly at timescales of approximately 20–30 years, suggesting the persistence of multi-decadal hydroclimatic oscillations. Furthermore, drought and wetness events are projected to become more persistent and severe during the mid-to-late 21st century. Compared with the historical baseline, increasing radiative forcing is associated with an expansion in drought-affected areas, accompanied by reduced event frequency but longer duration and greater severity. In terms of risk, the SSP3-7.0 scenario presents the highest overall drought and wetness risk with the widest spatial extent, whereas the SSP2-4.5 scenario shows relatively lower risk levels and a more balanced spatial distribution. Full article

Stratospheric Aerosol Injection (SAI) has been investigated as a climate intervention strategy to offset global warming, and regional impacts studies rely on simulations from the Geoengineering Large Ensemble (GLENS). The probabilistic behavior of the GLENS ensemble has not been systematically characterized for Southeast Asia. Because GLENS is a counterfactual experiment combining the Representative Concentration Pathway 8.5 (RCP8.5) forcing with active SAI, comparison with observations cannot validate the SAI response itself. In the early protocol years, the SAI forcing is small, so the early window provides a diagnostic of statistical consistency between the ensemble and the observed climate and of ensemble spread reliability. We compare the 21-member GLENS ensemble for 2020–2025 with ERA5 for daily precipitation and mean and maximum temperature using empirical coverage of the 95% prediction interval, rank histograms with the Jolliffe–Primo decomposition, the Continuous Ranked Probability Score, and the Brier Score for rainfall occurrence. Coverage is well below nominal for all variables, and rank histograms show pronounced U-shapes dominated by the dispersion error component, indicating systematic underdispersion. Because the underlying mechanisms are properties of the ensemble system rather than of the SAI forcing, this underdispersion is expected to persist in the future record, motivating statistical post-processing of GLENS before its use in SAI impact assessments. Full article

Background: Traumatic brain injury (TBI) affects millions of individuals annually and remains a major global cause of neurological disability and death. Tau protein hyperphosphorylation, particularly in its cis conformation, is a major pathological hallmark contributing to neurodegeneration following TBI. Single-chain variable fragments (scFvs), despite their diagnostic potential, suffer from rapid renal clearance and short circulation half-lives, which limit their in vivo performance. PEGylation is therefore employed to prolong systemic circulation and improve the pharmacokinetic behavior of scFvs, enabling more effective brain retention and target engagement. Methods: In this study, we utilized a previously validated anti-cis p-tau scFv antibody fragment, radiolabeled with technetium-99m tricarbonyl (^99mTc(CO)₃), as a diagnostic tracer to detect tau pathology in TBI rat models. The antibody was conjugated with polyethylene glycol (PEG, 20 kDa); PEGylation efficiency was determined by quantifying the products on SDS-PAGE, and the products were subsequently radiolabeled. Results: Radiochemical purity (RCP) was ~95.4% for the non-PEGylated tracer (^99mTc-AININ20) and ~92.7% for the PEGylated form (^99mTc-AININ20-PEG), with both showing >90% radiochemical purity consistently. Upon systemic administration, PEGylated scFv was able to cross the blood–brain barrier (BBB) and selectively accumulated in injured regions, as confirmed by single-photon emission computed tomography (SPECT) imaging. Both PEGylated and non-PEGylated scFv tracers showed significantly higher brain uptake in TBI rats compared to healthy controls (p < 0.0001). At 24 h, the PEGylated form exhibited a significantly higher brain signal than the non-PEGylated version (p < 0.0001), indicating improved tracer retention. Biodistribution analysis at 2 h post-injection showed significantly reduced renal clearance for the PEGylated tracer and increased hepatic uptake compared to the non-PEGylated form. At 24 h, in vivo imaging confirmed sustained brain retention, highlighting improved pharmacokinetics and imaging potential. Conclusions: These results support PEGylated scFv as a promising SPECT imaging agent for early detection of tauopathy in TBI, offering enhanced brain retention and improved pharmacokinetics. Full article

Observed increases in wildfire activity across the contiguous United States (U.S.), together with continued warming and expanding development in fire-prone landscapes, highlight the need to anticipate near-term changes in fire regimes. We apply a Bayesian statistical model that integrates projected population density (SSP2) and downscaled climate simulations under a moderate emissions scenario (RCP 4.5) to estimate future wildfire occurrence, maximum fire size (using the 90th percentile of fire size distribution), and total area burned for large fires (>1000 acres) across all EPA Level III ecoregions for 2020–2060. Relative to 1984–2019, we project nationwide increases of 56% in fire occurrence and 59% in area burned, with larger increases in maximum fire size (63%) in 2020–2060. Spatial patterns vary substantially: fire occurrence increases most strongly in the eastern U.S., including regions where large fires have historically been rare, while western ecoregions experience the largest absolute increases in burned area and extreme fire size. The disproportionate growth in maximum fire size suggests that changes in fire weather will amplify extreme events beyond increases in ignition frequency alone. These projections indicate expanding wildfire risk across diverse U.S. landscapes and underscore the need for regionally tailored fire management and preparedness strategies. Full article

This study aimed to identify the main environmental drivers of the potential ranges of the rare species Hedysarum grandiflorum and Hedysarum argyrophyllum, to compare their ecological responses, and to assess changes in habitat suitability under current and projected climate conditions. The modeling program MaxEnt was used, with predictors including climate variables from CHELSA Bioclim, a digital elevation model, and variables from the SoilGrids global digital soil mapping system. The results indicate that climatic and orographic variables play a key role in determining the potential ranges of both species. The distribution of H. grandiflorum is more strongly influenced by soil properties, notably cation exchange capacity, whereas H. argyrophyllum is associated with nutrient-poor substrates. Model projections under the RCP4.5 and RCP8.5 climate scenarios suggest a potential local increase in modeled habitat suitability during 2040–2060, followed by a decline in highly suitable areas during 2060–2080, particularly for H. argyrophyllum. Although the models do not project complete extinction or a uniform large-scale reduction in the total potential range for either species, they indicate substantial regional declines in habitat suitability and marked reductions in the number of highly suitable habitats under the future climate scenarios considered. Model outputs can help identify areas of high and stable suitability that may serve as priorities for the monitoring or reintroduction of these species. Full article

Cairo’s Islamic architectural heritage represents one of the world’s most significant concentrations of pre-industrial environmental ingenuity. For over a millennium, an integrated suite of passive climate-control systems—the Mašrabiya latticework screen, the open courtyard (Ṣaḥn), the wind-scoop (Malqaf), and stalactite vaulting (Muqarnas)—has moderated temperature, humidity, and airflow with remarkable effectiveness. Today, these inherited solutions are under unprecedented stress from urban densification, chronic particulate pollution, climate-driven temperature rise, and growing visitor footfall. This study investigates indoor environmental quality (IEQ) in six Fatimid- and Mamlūk-era buildings in Historic Cairo through the integrated IQAD-IAH framework, combining IoT field monitoring (January–December 2023) of temperature, relative humidity, CO₂, and PM2.5 with CNN-based deterioration image analysis and Random Forest predictive modeling. Results document critical summer thermal buffering failures reaching 28% of occupied hours above the ASHRAE 55 adaptive comfort limit; hygrothermal stress cycles exceeding the EN 15757 ±10% RH safe threshold for up to 38% of annual hours; and PM2.5 courtyard concentrations of 40–61 µg/m³ under normal conditions, surging to 180–320 µg/m³ during Ḫamāsῑn-seasonal wind events. Machine-learning projections indicate all three principal passive elements will cross the critical deterioration threshold of 70/100 under RCP 8.5 before 2050. A precautionary intervention window is identified between 2025 and 2032. Evidence-based management recommendations compatible with UNESCO World Heritage obligations are presented. Full article

This exploratory study aimed to compare the determination of metabolic thresholds using muscle oxygen saturation (SmO₂) and gas exchange data during graded exercise testing in individuals with spinal cord injury. Nine participants (six males, three females) performed a graded exercise test on an arm-crank ergometer, with continuous measurements of breath-by-breath pulmonary gas exchange and SmO₂ from the biceps brachii and triceps brachii. Thresholds were identified as gas exchange threshold (GET) and respiratory compensation point (RCP), and their SmO₂ counterparts as MOT1 and MOT2. The results showed no differences between GET and MOT1 in either muscle (biceps: p = 0.14; triceps: p = 1.00), and similar results were observed between RCP and MOT2 for triceps brachii (p = 0.39) and biceps brachii (p = 0.12). Reliability analysis revealed good but non-significant agreement for the triceps brachii (ICC = 0.44–0.60), while the biceps brachii demonstrated very good agreement at GET (ICC = 0.78, p < 0.01) and excellent agreement at RCP (ICC = 0.81, p < 0.01), and Bland–Altman analyses confirmed no systematic bias between muscle sites. In conclusion, SmO₂ may be a valid and promising variable for detection in individuals with spinal cord injury during ramp exercise testing. Both muscles showed agreement with pulmonary gas exchange, but the biceps brachii provided more consistent and reliable estimates, particularly for the second threshold. These preliminary findings suggest the use of near-infrared spectroscopy as a non-invasive technology for metabolic threshold detection in spinal cord injury populations. Full article

Renewable energy deployment has accelerated globally in recent years, with renewables accounting for 29% of global electricity generation by 2024. In this context, Ecuador has significantly expanded its renewable capacity, relying predominantly on hydropower, which represented 70% of total electricity generation in 2024. Installed capacity increased from 1707 MW in 2000 to 5371 MW in 2024. This study addresses a research gap by integrating climate scenario analysis with long-term energy system modeling, evaluating the viability of Ecuador’s hydropower sector under four Representative Concentration Pathway scenarios through 2060 using the TIMES platform. The results project reductions in hydropower generation of 22%, 19%, and 15% under RCP 8.5, RCP 6.0, and RCP 4.5, respectively, with a modest increase of 1.4% under RCP 2.6, driven by changes in water availability. Overall, an average decline of approximately 14% is projected by 2060. These findings indicate that reductions in hydropower generation may compromise system reliability in hydro-dependent systems such as Ecuador. While the quantified impacts are specific to the national context, the relationship between climate variability, capacity factors, and electricity generation provides insights relevant for other regions with similar hydropower dependence. The study highlights the need to integrate climate projections into future energy planning. Full article

Sustainable groundwater management in regions subjected to intensive agricultural pressure requires reliable simulation tools capable of anticipating the impacts of climate change. However, in overexploited multilayer aquifers such as Tierra del Vino, locally calibrated predictive tools capable of quantifying climate-driven piezometric decline remain scarce. This study develops a numerical groundwater flow model using MODFLOW for the Tierra del Vino aquifer (Spain), a multilayer detrital system currently characterized by a critical quantitative status. Agricultural irrigation accounts for approximately 94% of total groundwater withdrawals, making it the dominant anthropogenic pressure on the system. The model was manually calibrated through more than 500 iterations, achieving a consistent representation of groundwater dynamics. Statistical evaluation based on groundwater level data from 34 piezometric monitoring points distributed across the aquifer yielded a good fit (NSE = 0.816; R = 0.928), supporting the suitability of the model for scenario analysis. Under the RCP 8.5 climate scenario, aquifer recharge could decrease by 31.75%, resulting in a significant piezometric decline within the system. At the representative well selected for the farm-scale agricultural impact analysis, this decline reaches 3.33 m and is used to evaluate its effect on pumping energy costs. The implementation of management measures proposed by the water authority reduces this decline to 1.84 m, although overexploitation conditions persist. These results indicate that current administrative restrictions are insufficient on their own and that future management should adjust abstraction rights to projected recharge conditions, maintaining the exploitation index below 0.8 to reduce the risk of long-term overexploitation. In this context, aquifer resilience is interpreted as the capacity of the groundwater system to respond to the combined pressures of climate change and agricultural abstraction while maintaining its hydrological functioning. Full article

Wetland degradation in soda saline–alkali ecosystems can profoundly alter belowground microbial communities, yet its effects on bacterial phylogenetic distribution and predicted ecological characteristics remain insufficiently understood. This study investigated soil physicochemical properties, enzyme activities, and bacterial communities across a wetland degradation gradient in the Halahai Provincial Nature Reserve, China, including reed wetland (RW), meadow steppe (MS), and degraded Suaeda saline patches (DS). Soil analyses were integrated with 16S rRNA gene amplicon sequencing, phylogenetic reconstruction, and FAPROTAX and BugBase prediction. DS showed significantly higher pH and electrical conductivity, but lower soil water content, organic carbon, nutrient availability, and urease activity than RW and MS. Alpha diversity analysis indicated that DS had lower bacterial richness and diversity, but higher dominance, whereas RW and MS did not differ significantly. Beta-diversity analysis revealed clear habitat-dependent separation, with DS harboring the most distinct community structure. Taxonomic and phylogenetic analyses indicated enrichment of Gemmatimonadota and the RCP2-54 lineage in DS, whereas RW and MS were more strongly associated with Pseudomonadota, Acidobacteriota, and related groups. Predicted functional and phenotypic analyses further suggested a shift toward stress-related and degradation-associated traits in DS. These findings demonstrate that wetland degradation reshaped the taxonomic composition, phylogenetic distribution, and predicted ecological characteristics of soil bacterial communities in this fragile ecosystem. Full article

Climate-related extremes such as floods and droughts have been the main causes of natural disasters in southern Africa in recent years, with noticeable trends in climate extremes being observed. The Limpopo Province in South Africa has been especially prone to these extremes. The extreme precipitation in Limpopo is mainly caused by a mix of intense tropical weather systems and La Niña conditions, both exacerbated by climate change. Climate change exacerbates current water challenges across the province by affecting precipitation patterns, distribution, timing and intensity, leading to extreme climate events such as floods and drought. The historical and future trends of precipitation and relevant extreme indices using observed data from the South African Weather Service and CORDEX ensemble model simulations under the RCP4.5 and RCP8.5 scenarios were examined. An analysis of all precipitation data suitable for the study of long-term variability and trends indicates that most areas underwent drying to various degrees over the last century, especially the central and western parts. Drier conditions over the eastern parts have become more prevalent over the last 50 years. Also, more extremes on a sub-seasonal basis were experienced. Regarding future scenarios, three projected time periods compared to the baseline period (1976–2005) were examined: Current climatology (2006–2035), near-future (2036–2065), and far-future (2066–2095). Most areas will experience a further decrease in precipitation under both emission scenarios, especially in the south-east, central and extreme northern parts. In addition, these areas are expected to experience a decrease in the frequency of heavy precipitation days for all periods under both RCP scenarios, mainly due to drying. Consecutive dry days are expected to increase significantly. Transitioning to renewable energy and enhancing natural carbon sinks can reduce emissions, while prioritizing resilience through renewable energy, water management, and climate-smart agriculture will help address climate change challenges in the province. Full article

Understanding how land-use dynamics and carbon balance respond to socio-economic development and future climate change is essential. It supports the refinement of ecological management strategies in environmentally fragile regions and the achievement of China’s dual-carbon goals. This study aims to (i) analyze historical land-use evolution in Xinjiang from 2000 to 2020 and simulate its future dynamics from 2021 to 2060 under multiple SSP-RCP scenarios; (ii) quantify land-use carbon emissions and carbon storage using the coupled SD-PLUS-InVEST model; and (iii) evaluate the carbon balance through the carbon emission to storage ratio (CESR). This study coupled the system dynamics (SD) model, Patch-generating Land Use Simulation (PLUS) model, and InVEST model by integrating socio-economic statistics, IPCC climate data, and land-use datasets. The integrated model was used to simulate land-use evolution in Xinjiang from 2000 to 2060 and to quantify the spatiotemporal variation in land-use carbon emissions, carbon storage, and the CESR. Results indicated that carbon emission increased continuously from 2000 to 2020. Carbon emission showed an inverted U-shaped pattern from 2020 to 2060, with the peak occurring in approximately 2030 under the SSP1–2.6 and SSP2–4.5 scenarios, while it continued to rise from 2020 to 2060 under SSP585. Carbon storage exhibited an “initial increase followed by decline” from 2000 to 2020 but increased consistently from 2020 to 2060 under all scenarios. Xinjiang is a carbon-contributing area with the CESR less than 1 from 2000 to 2060. The CESR increased first and then decreased from 2020 to 2060 under SSP126 and SSP245, while it increased significantly under SSP585. The carbon contribution capacity in Xinjiang decreased under SSP585. These findings indicated that Xinjiang is a carbon contribution area, but its contribution function may be weakened by the expansion of energy-related land use and reduction in forest areas. Hence, it is necessity to uphold Xinjiang’s role within the national carbon balance framework by enhancing spatially differentiated land management, promoting the low-carbon transformation of the energy structure, and strengthening ecological restoration efforts to improve regional carbon sink capacity. Full article

Urban–climate interactions in a warming climate remain largely uncertain; therefore, it is crucial to realistically evaluate and project these feedbacks to establish effective adaptation strategies. This study investigates projected shifts in summertime urban–climate interactions over eastern North America by employing the GEM regional climate model coupled with the Town Energy Balance (TEB) scheme, driven by RCP4.5 and RCP8.5 scenarios for the 1981–2100 period. Evaluations for the current climate (1981–2010) demonstrate that the model simulates an urban-induced warming of 0.5–0.7 °C and a precipitation reduction of 0.2–0.4 mm/day with high fidelity. By the late 21st century (2071–2100), projections under the RCP8.5 scenario indicate a steady weakening of the summer mean Urban Heat Island (UHI) intensity by approximately 0.10 °C, with a more pronounced nighttime attenuation of 0.15 °C. Physically, this weakening is attributed to an enhanced urban-induced evaporative fraction, which limits solar radiation storage within the urban fabric during the day, thereby reducing the thermal energy available for post-sunset release. This UHI attenuation correlates strongly with localized increases in precipitation, particularly in coastal regions where urban-induced effects contribute 20–40% to the total precipitation rise. While this study intentionally utilizes static urban boundaries to isolate the specific sensitivities of current urban morphologies to global warming, these results emphasize that diverse climatological regions will undergo distinct urban–climate feedback changes, providing essential baseline data for resilient urban planning. Full article

Hurricane Florence (2018) proved to be a damaging tropical cyclone that formed off the coast of the Cabo Verde Islands. On 12 UTC 14 September 2018, Florence made landfall as a weakened category 1 Hurricane in Wrightsville Beach, NC. In the midst of landfall, Florence’s ground speed stalled considerably to near zero. Because of this stall, Florence continued to accumulate feet of rain along the coastline, and the inundation of seawater became extreme. Due to the impacts of Florence, the Weather Research and Forecasting Model (WRF-ARW) was used to simulate the tropical cyclone and provide insight into the thermodynamics and dynamics that played a significant role at the time of landfall. After the control case, several sensitivity experiments were conducted. The historical sensitivity experiments utilize the thermodynamic and moisture fields of ERA5 reanalysis data from 1968 and 1998, respectively, to modify the thermodynamic and moisture fields in the initial conditions of the WRF–ARW control case. In addition, to study the potential future climate impacts of Florence, the NCAR CESM Global Bias-Corrected CMIP5 Output to Support WRF/MPAS Research dataset was utilized. The same approach was taken as the historical versions of Florence for sensitivity experiments for future climate, i.e., thermodynamic and moisture fields for both 2038 and 2068 under the RCP6.0 and RCP8.5 climate scenarios, respectively. Results suggest a corresponding intensity shift with minor track deflections. Based on these modifications, synoptic and mesoscale dynamics will be studied to provide insight into how Florence-like hurricanes may change based on certain climate scenarios. Full article

Africa’s rainfed agricultural systems are highly exposed to climate change, making shifts in temperature and rainfall a major concern for staple-food crop production. Using a MaxENT ecological niche modelling approach with crop occurrence, elevation, soil and climatic predictors, this study assessed current and future suitability for rainfed maize, millet and sorghum under RCP 4.5 and RCP 8.5. The projections show a notable expansion of 11.1–22.0% in areas suitable for maize cultivation, and a decline of 1.6–7.3% in areas suitable for production of millet and sorghum, indicating likelihood for increased food-security risks in regions dependent on drought-tolerant cereals. These differing shifts highlight the need for targeted adaptation measures, including crop diversification and region-specific planning to help sustain crop production under a changing climate. Full article