Explore the vast range of titles available.

Carbon capture and storage (CCS) is a developed technology to minimize CO2 emissions and reduce global climate change. Currently, shale gas formations are considered as a suitable target for CO2 sequestration projects predominantly due to their wide availability. Compared to conventional geological formations including saline aquifers and coal seams, depleted shale formations provide larger storage potential due to the high adsorption capacity of CO2 compared to methane in the shale formation. However, the injected CO2 causes possible geochemical interactions with the shale formation during storage applications and CO2 enhanced shale gas recovery (ESGR) processes. The CO2/shale interaction is a key factor for the efficiency of CO2 storage in shale formations, as it can significantly alter the shale properties. The formation of carbonic acid from CO2 dissolution is the main cause for the alterations in the physical, chemical and mechanical properties of the shale, which in return affects the storage capacity, pore properties, and fluid transport. Therefore, in this paper, the effect of CO2 exposure on shale properties is comprehensively reviewed, to gain an in-depth understanding of the impact of CO2/shale interaction on shale properties. This paper reviews the current knowledge of the CO2/shale interactions and describes the results achieved to date. The pore structure is one of the most affected properties by CO2/shale interactions; several scholars indicated that the differences in mineral composition for shales would result in wide variations in pore structure system. A noticeable reduction in specific surface area of shales was observed after CO2 treatment, which in the long-term could decrease CO2 adsorption capacity, affecting the CO2 storage efficiency. Other factors including shale sedimentary, pressure and temperature can also alter the pore system and decrease the shale “caprock” seal efficiency. Similarly, the alteration in shales’ surface chemistry and functional species after CO2 treatment may increase the adsorption capacity of CO2, impacting the overall storage potential in shales. Furthermore, the injection of CO2 into shales may also influence the wetting behavior. Surface wettability is mainly affected by the presented minerals in shale, and less affected by brine salinity, temperature, organic content, and thermal maturity. Mainly, shales have strong water-wetting behavior in the presence of hydrocarbons, however, the alteration in shale’s wettability towards CO2-wet will significantly minimize CO2 storage capacities, and affect the sealing efficiency of caprock. The CO2/shale interactions were also found to cause noticeable degradation in shales’ mechanical properties. CO2 injection can weaken shale, decrease its brittleness and increases its plasticity and toughness. Various reductions in tri-axial compressive strength, tensile strength, and the elastic modulus of shales were observed after CO2 injection, due to the dissolution effect and adsorption strain within the pores. Based on this review, we conclude that CO2/shale interaction is a significant factor for the efficiency of CCS. However, due to the heterogeneity of shales, further studies are needed to include various shale formations and identify how different shales’ mineralogy could affect the CO2 storage capacity in the long-term.

In nearly all reservoirs, storage capacity is steadily lost due to trapping and accumulation of sediment. Despite critical importance to freshwater supplies, reservoir sedimentation rates are poorly understood due to sparse bathymetry survey data and challenges in modeling sedimentation sequestration. Here, we proposed a novel approach to estimate reservoir sedimentation rates and storage capacity losses using high‐resolution Sentinel‐2 satellites and daily in situ water levels. Validated on eight reservoirs across the central and western United States, the estimated reservoir bathymetry and sedimentation rates have a mean error of 4.08% and 0.05% yr−1, respectively. Estimated storage capacity losses to sediment vary among reservoirs, which overall agrees with the pattern from survey data. We also demonstrated the potential applications of the proposed approach to ungauged reservoirs by combining Sentinel‐2 with sub‐monthly water levels from recent satellite altimeters. Plain Language Summary Reservoir storage capacity is steadily lost due to sediment filling, which threatens freshwater supplies both now and in the future. Yet, lost reservoir storage capacities to sediment are largely unknown. Here, we develop a generic method to estimate capacity losses and reservoir sedimentation rates by leveraging remote sensing techniques. We tested on eight reservoirs across the central and western United States and found capacity losses and sedimentation rates vary across reservoirs. The proposed method offers a promising alternative to evaluate and predict capacity losses in reservoirs nationwide and globally, and thus supports effective water managements and planning for sustainable freshwater supplies in the future. Key Points High‐resolution Sentinel‐2 images and daily in situ water levels were used to estimate reservoir sedimentation rates and capacity losses Estimated reservoir sedimentation rates and storage capacity losses have a mean error of 0.05% yr−1 of full storage capacity Potential applications of this method to ungauged reservoirs are feasible with sub‐monthly level data from recent satellite altimeters

Prospective use of perovskite hydride materials in H storage a crucial element of clean energy systems has drawn a lot of attention. The structural, electrical, mechanical, thermodynamic, and H storage qualities of Na 2 CaCdH 6 hydride alloys were examined in this work using DFT. According to the structural properties, Na 2 CaCdH 6 has space group 225 (Fm3m), and optimized lattice parameters and volume of Na 2 CaCdH 6 are 3.3485 Å and 593.764 Å 3 . The measured gravimetric H storage capacity of Na 2 CaCdH 6 hydrides is 2.956 wt%. The hydrides under research are semiconductors, as indicated by the computed electronic characteristics. Elastic constants, Pugh’s ratio, modulus, Poisson’s ratio, anisotropic, and microhardness of Na 2 CaCdH 6 are calculated under mechanical properties. The hydrides are dynamically stable, as indicated by the phonon dispersion curves, but mechanically stable according to the Born criterion for elastic constant (C ij ). The Cauchy’s pressure (C″ = 7.836) revealed the ductile behavior. The electronic and mechanical characteristics imply that Na 2 CaCdH 6 hydride can conduct electricity and is also mechanically stable. Our findings shed light on the possibilities of Na 2 CaCdH 6 perovskite hydride material for H storage utilization.

Water storage capacity in the layers of canopy, litter, and soil of forest ecosystems has not yet been thoroughly investigated on a global scale. We estimated the global pattern of water storage capacity of forest ecosystems related to water regulation services (WSCFE) in the above three layers based on 1,288 observations and analyzed their 22 controlling environmental factors. The results show that the global mean WSCFE per unit area is 456.7 mm, and the total volume of WSCFE is 22,662.5 km3. Climatic variables are the leading factors contributing to the variations of WSCFE, followed by forest attributes, terrain factors, soil properties, and litter characteristics. This study advances the understanding of the large‐scale variation mechanisms of WSCFE in different forest types and climate zones and provides scientific evidence for ecological protection according to local conditions. Plain Language Summary Forest ecosystem plays a vital role in the earth's hydrological process, and water storage capacity of forest ecosystems related to water regulation service (WSCFE) is of vital importance for human well‐being. Water can be intercepted by forest canopy, be held by litter, and be stored in soils, which accounts for more than a quarter of the water volumes in the terrestrial hydrologic cycle. The WSCFE is affected by many factors and its global pattern has not been well understood. In this study, based on the observed data from literature, we provided a robust global pattern of the WSCFE in canopy layer, litter layer, and soil layer. The results show that the WSCFE in the canopy and soil layer decrease gradually from tropical climate zone to polar climate zone, while the maximum WSCFE in the litter layer appears in polar and cold climate zone. The main controlling factors have different impacts on the WSCFE in the three layers. These should be considered in the developing protection policies for important ecological functional areas. Key Points Forest water storage capacity related to water regulation decreases from equator to pole, from coast to inland, and from mountains to plains Among the controlling factors, climatic factors have the largest and most positive influence on water storage capacity The quantification of three important water storages provides a basis to delineate global water regulation zones

Shape-memory polymers (SMPs) show great potential in various emerging applications, such as artificial muscles, soft actuators, and biomedical devices, owing to their unique shape recovery-induced contraction force. However, the factors influencing this force remain unclear. Herein, we designed a simple polymer blending system using a series of tetra-branched poly(ε-caprolactone)-based SMPs with long and short branch-chain lengths that demonstrate decreased crystallinity and increased crosslinking density gradients. The resultant polymer blends possessed mechanical properties manipulable across a wide range in accordance with the crystallinity gradient, such as stretchability (50.5–1419.5%) and toughness (0.62–130.4 MJ m−3), while maintaining excellent shape-memory properties. The experimental results show that crosslinking density affected the shape recovery force, which correlates to the SMPs’ energy storage capacity. Such a polymer blending system could provide new insights on how crystallinity and crosslinking density affect macroscopic thermal and mechanical properties as well as the shape recovery force of SMP networks, improving design capability for future applications.

Quantification of long-term partitioning of precipitation into evaporation and runoff is a fundamental pursuit in catchment hydrology. The Budyko framework provides a theoretical basis for this and estimates the evaporative fraction based on the aridity index. However, deviations from the global-average Budyko curve point to additional controls on precipitation partitioning beyond the aridity index. We hypothesized that root zone storage capacity ( S r, max ), defined as maximum subsurface water volume accessible to vegetation roots, is a key driver of these deviations. The relationship between S r, max and precipitation partitioning in the Budyko space was investigated globally across >5000 catchments. S r, max was calculated using the memory method based on runoff observations and the water balance. The ω -parameter from Fu’s equation, which was used here to construct parametric Budyko curves, reflects deviations from the global-average Budyko curve and hence precipitation partitioning. Results revealed a globally stronger correlation (Spearman’s ρ = 0.68) of ω with S r, max , than with other potential controls, indicating S r, max as a dominant driver of precipitation partitioning. Further analysis based on Köppen–Geiger climatic zone classification revealed variations in the S r, max – ω relationship, with the strongest correlations observed in cold ( ρ = 0.87) and Mediterranean ( ρ = 0.83) climates, followed by temperate ( ρ = 0.76), tropical ( ρ = 0.64) and arid climates ( ρ = 0.61). Regional differences in S r, max indicate that, at a given aridity, E A / P largely reflects vegetation adaptation to the seasonal interplay between water supply and atmospheric water demand. This study provides strong empirical evidence on a global scale for S r, max as a governing factor in modulating catchment precipitation partitioning, as evident in the Budyko space. As a major implication our results provide a theoretical basis for the maximum values of S r, max found in nature, as constrained by the water and energy limits of the Budyko framework.

Black carbon has been shown to suppress microbial methane production by promoting anaerobic oxidation of organic carbon, diverting electrons from methanogenesis. This finding represents a new process through which black carbon, such as wildfire char and biochar, can impact the climate. However, the mechanism and capacity of black carbon to support metabolism remained unclear. We hypothesized black carbon could support microbial growth exclusively through its electron storage capacity (ESC). The electron contents of a wood biochar was quantified through redox titration with titanium(III) citrate before and after Geobacter metallireducens growth, with acetate as an electron donor and air-oxidized biochar as an electron acceptor. Cell number increased 42-fold, from 2.8(± 0.6) × 10 8 to 1.17(± 0.14) × 10 10 , in 8 days based on fluorescent cell counting and the result was confirmed by qPCR. The qPCR results also showed that most cells existed in suspension, whereas cell attachment to biochar was minimal. Graphite, which conducts but does not store electrons, did not support growth. Through electron balance and use of singly 13 C-labeled acetate ( 13 CH 3 COO – ), we showed (1) G. metallireducens could use 0.86 mmol/g, or ~ 19%, of the biochar's ESC for growth, (2) 84% and 16% of the acetate was consumed for energy and biosynthesis, respectively, during biochar respiration and (3) ca . 80 billion electrons were deposited into biochar for each cell produced. This is the first study to establish electron balance for microbial respiration of black carbon and to quantitatively determine the mechanism and capacity of biochar-supported growth. Graphical Abstract

Wetlands are valuable ecosystems because they are highly productive, support a wide range of wildlife, and serve as hotspots for biogeochemical cycling. Historically, vast areas of wetlands in the United States (US) were drained and converted to agriculture. Efforts are currently underway to restore wetland and floodplain functioning across the US and elsewhere. Re-wetting historically drained and farmed soils can potentially liberate legacy phosphorus (P) to surface waters as soluble reactive P (SRP), offsetting P retained by sedimentation during floods. A better understanding of the controls on SRP release is needed to estimate net P retention in these settings. Soil P saturation ratio (PSR) and soil P storage capacity (SPSC) are two proxies for SRP runoff risk that have shown promise for characterizing restored wetlands but require further testing. In this study, we examined soils at 42 riparian sites ranging from active farms to mature wetlands in the Vermont portion of the Lake Champlain Basin (USA), where phosphorus load reduction is a critical goal to achieve in-lake water quality targets. We additionally quantified potential SRP release to overlying water using intact soil cores from 20 plots spanning 14 sites. Final SRP concentrations in intact cores spanned two orders of magnitude and were predicted well by SPSC and PSR. SRP release was greatest at more recently and frequently farmed sites. Several soil properties, including PSR and SPSC, were correlated with farming frequency and time since farming, indicating that SRP release could be mapped using existing geodata for soils, hydrology and land use. Our findings confirm that soil SRP release during flooding needs to be considered in estimates of net P balance for restored riparian wetlands in agricultural landscapes.

1. Optimal resource partitioning theory predicts that plants should increase the ratio between water absorbing and transpiring surfaces under short water supply. An increase in fine root mass and surface area relative to leaf area has frequently been found in herbaceous plants, but supporting evidence from mature trees is scarce and several results are contradictory. 2. In 12 mature Fagus sylvatica forests across a precipitation gradient (820-540 mm yr⁻¹), we tested several predictions of the theory by analysing the dependence of standing fine root biomass, fine root production and fine root morphology on mean annual precipitation (MAP), the precipitation of the study year, and stand structural and edaphic variables. The water storage capacity of the soil (WSC) was included as a covariable by comparing pairs of stands on sandy (lower WSC) and loam-richer soils (higher WSC). 3. Fine root biomass, total fine root surface area, fine root production and the fine root : leaf biomass production ratio markedly increased with reduced MAP and precipitation in the study year, while WSC was only a secondary factor and stand structure had no effect. 4. The precipitation effect on fine root biomass and production was more pronounced in stands on sandy soil with lower WSC, which had, at equal precipitation, a higher fine root biomass and productivity than stands on loam-richer soil. 5. The high degree of allocational plasticity in mature F. sylvatica trees contrasts with a low morphological plasticity of the fine roots. On the more extreme sandy soils, a significant decrease in mean fine root diameter and increase in specific root area with decreasing precipitation were found; a similar effect was absent on the loam-richer soils. 6. Synthesis. In support of optimal partitioning theory, mature Fagus sylvatica trees showed a remarkable allocational plasticity as a long-term response to significant precipitation reduction with a large increase in the size and productivity of the fine root system, while only minor adaptive modifications occurred in root morphology. More severe summer droughts in a future warmer climate may substantially alter the above-/below-ground C partitioning of this tree species with major implications for the forest C cycle.

Tree growth sensitivity to precipitation varies dramatically across Mediterranean climate regions, but the mechanisms controlling this variation remain poorly understood. We investigated how subsurface water storage capacity mediates the relationship between winter wet season precipitation and annual tree ring width across seasonally dry ecosystems of the western United States. We analyzed tree ring chronologies from the International Tree-Ring Data Bank combined with climate databases and a root zone water storage capacity dataset encompassing both soil and bedrock storage. We categorized seasonal water storage at tree-ring sites into precipitation-limited, intermediate, and storage-capacity-limited groups based on the ratio of net winter precipitation to root zone storage capacity. Our central hypothesis was that sites where winter precipitation consistently exceeds storage capacity would show weaker precipitation-growth coupling than sites where precipitation inconsistently fills available storage. Using Spearman rank correlations between ring width and winter precipitation, we found that storage-capacity-limited sites indeed showed significantly weaker precipitation-growth coupling compared to precipitation-limited sites. This pattern suggests that when subsurface storage is consistently filled, trees have access to similar amounts of water each year regardless of precipitation variability, buffering growth against climate fluctuations. Conversely, where storage is inconsistently filled, tree growth remains sensitive to precipitation variation. These findings have important implications for understanding drought resilience in Mediterranean ecosystems and for paleoclimate reconstruction using tree rings. In storage-capacity-limited environments, tree rings may not reliably record precipitation variability, potentially limiting their utility for drought reconstruction. Our results emphasize the critical role of subsurface storage dynamics in mediating plant responses to climate variability.