Earths Future最新文献

{"title":"Democratizing Hydroclimate Science for Just and Resilient Futures","authors":"K. M. Whitney,&nbsp;J. Cranko Page,&nbsp;A. Dengri,&nbsp;S. Hina,&nbsp;H. Okachi,&nbsp;V. Rabanal,&nbsp;J. Sirisena,&nbsp;Y. A. Yılmaz,&nbsp;P. N. Afego,&nbsp;A. Arshad,&nbsp;L. Baratgin,&nbsp;L. M. Cappelletti,&nbsp;C. N. Gulizia,&nbsp;S. M. A. Habib,&nbsp;Q. He,&nbsp;J. Hsu,&nbsp;M. R. Islam,&nbsp;S. Kulkarni,&nbsp;L. Lebedeva,&nbsp;S. K. Mandal,&nbsp;A. V. Matus,&nbsp;U. Mondal,&nbsp;P. L. Nguyen,&nbsp;U. K. Okoro,&nbsp;D. Pradhananga,&nbsp;M. Sabot,&nbsp;P. Saha,&nbsp;A. Suzuki,&nbsp;A. Tejada","doi":"10.1029/2026EF008172","DOIUrl":"https://doi.org/10.1029/2026EF008172","url":null,"abstract":"<p>Hydroclimatic extremes are intensifying, escalating risks to ecosystems, infrastructure, and vulnerable communities. Rapid technological innovation and scientific discovery offer powerful tools to address these challenges, yet a gap remains between hydroclimate knowledge production and its use in decision-making. Bridging this divide requires democratizing hydroclimate science through expanded participation in research design and implementation, as well as in the distribution of recognition, resources, and decision power. Democratizing science can foster outcomes that are (a) more credible, through transparency and integration of decision-maker perspectives; (b) more just, through fair distribution of research opportunities, resources, recognition, and decision power; and (c) more resilient, by strengthening the capacity of communities and institutions to adapt, learn, and recover from climate pressures. Drawing on insights from the 2024 Global Energy and Water EXchanges (GEWEX) Early Career Researcher Workshop, which gathered participants from 19 countries across disciplines, we outline pathways toward more democratic hydroclimate science grounded in diverse participation and shared leadership. We highlight three priorities: building trust through co-production, improving the usability of hydroclimate information, and promoting responsible research and innovation in emerging technologies. Case studies illustrate how early- and mid-career researchers and practitioners are advancing these priorities and modeling practices that connect innovation with equity. Achieving lasting and effective change requires research and funding institutions to recognize and support collaborative leadership, and to value relevance and accountability alongside technical excellence. Strengthening such democratic frameworks can help ensure that hydroclimate science advances more just research practices and supports the resilience of the communities it serves.</p>","PeriodicalId":48748,"journal":{"name":"Earths Future","volume":"14 8","pages":""},"PeriodicalIF":8.5,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EF008172","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increasing Frequency of Coastal Erosion Indicated by a Hindcast Model of Storm-Driven Forcing Calibrated With Beach Stratigraphy","authors":"W. John Schmelz,&nbsp;Kenneth G. Miller,&nbsp;Jonathan Liu,&nbsp;J. N. Stanley,&nbsp;James V. Browning","doi":"10.1029/2025EF007482","DOIUrl":"https://doi.org/10.1029/2025EF007482","url":null,"abstract":"<p>Beach stratigraphy at North Beach, Sandy Hook, New Jersey is used to calibrate a model of coastal erosion, establish a model-based erosion threshold, and evaluate how often threshold conditions have been exceeded since 1979 through hindcast analysis. Ground penetrating radar (GPR) was used to identify 20 stratigraphic surfaces generated in response to storm-driven erosion, and centimeter-accurate GNSS data were used to constrain their formation between 2009 and 2019 CE. To quantify the forcing conditions generating the preserved erosion surfaces, we ran more than 1000 48-hr XBeach simulations using tide-gauge and offshore wave buoy data. We then statistically emulated the XBeach output and calibrated it with observed beach-profile change using a semi-empirical model that we used to identify the storms most likely to have produced the preserved erosion surfaces. The modeling results suggest storms exceeding a water-level threshold of 1.3 m above MSL and significant wave heights of 3.8 m resulted in significant coastal erosion. Analysis of hindcast wave conditions and water-level data suggests an approximately two-fold increase in the exceedance frequency of this storm threshold between 1979 and 2023 CE. The inferred erosion threshold is tested using pre-, during-, and post-event observations from a recent 10 January 2024 storm that exceeded threshold conditions. We assess that beach stratigraphy is underutilized for the study of impacts and frequency of coastal storms that cause significant erosion, and our results demonstrate how model-data integration can be used to broaden inferences made from stratigraphic data.</p>","PeriodicalId":48748,"journal":{"name":"Earths Future","volume":"14 8","pages":""},"PeriodicalIF":8.5,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025EF007482","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial Heterogeneity and Nonlinear Influencing Mechanisms of Vegetation Carbon Sequestration Capacity in the Southwest China Karst Region","authors":"Xiangwen Gong,&nbsp;Lei Fan,&nbsp;Bo Yao,&nbsp;Xuyang Wang,&nbsp;Chunlin Wang,&nbsp;Jun Liu,&nbsp;Hongling Yang,&nbsp;Aixia Yang,&nbsp;Zhixuan Lu,&nbsp;Yuqiang Li","doi":"10.1029/2025EF007737","DOIUrl":"https://doi.org/10.1029/2025EF007737","url":null,"abstract":"<p>Understanding of the spatiotemporal dynamics of vegetation carbon sequestration capacity (VCSC) in Southwest China's contiguous karst region is critical for regional carbon cycling. Using MOD17A3 data from 2001 to 2023, we analyzed spatial heterogeneity in vegetation net primary productivity (NPP) and applied Geodetector to evaluate nonlinear influencing mechanisms across 32 factors. The results showed that the multi-year average NPP in the southwest karst was 725 g C m⁻² yr⁻¹, exhibiting a southward-increasing gradient. Recovery areas expanded at a rate of 3.21 g C m⁻² yr⁻¹, covering 79.3% of the region. Comparative analysis revealed that Engineering Governance Areas (EGA) significantly outperformed Natural Recovery Areas (NRA) in enhancing VCSC. In EGA, the mean recovery rate (3.67 g C m⁻² yr⁻¹), significantly improved areas (51.3%), extremely stable area (71.7%), and future sustainable recovery (72.0%) were 1.38, 1.23, 1.22, and 1.18 times higher than those in NRA, respectively. However, natural factors played a greater role than anthropogenic activities in explaining the spatial heterogeneity of NPP. Environmental interactions exhibited both nonlinear and bivariate enhancement, with combined effects exceeding those of individual factors. The dominant interactions were AET ∩ ELE (77.7%) for the whole region, AET ∩ PRS (61.8%) in EGA, and AET ∩ ELE (87.3%) in NRA. The optimal environmental thresholds for vegetation growth were AET of 1,244–1,397 mm, precipitation of 2,025–2,259 mm, temperature of 18.5–20.8°C, and elevation of 1,094–1,438 m. Integrating restoration strategies with these environmental thresholds helps identify priority zones, providing a scientific basis for the precision management of karst desertification and supporting China's “dual carbon” goals.</p>","PeriodicalId":48748,"journal":{"name":"Earths Future","volume":"14 8","pages":""},"PeriodicalIF":8.5,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025EF007737","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Grain Expansion in China's Drylands Secures Food but Intensifies Environmental Trade-Offs","authors":"Fengyu Fu,&nbsp;Shuai Wang,&nbsp;Xutong Wu,&nbsp;Lu Yu,&nbsp;Shuangshuang Zi,&nbsp;Jiafen Li,&nbsp;José M. Grünzweig,&nbsp;Lixin Wang,&nbsp;Bojie Fu","doi":"10.1029/2026EF009127","DOIUrl":"https://doi.org/10.1029/2026EF009127","url":null,"abstract":"<p>Drylands are increasingly crucial for global food supply, and grain cultivation there continues to expand. Newly cultivated croplands in these regions are often assumed to be biophysically marginal and low yielding. However, the food-security benefits, environmental costs, and associated trade-offs of this expansion remain insufficiently quantified. Here, we assessed maize, wheat, and rice expansion across China's drylands (2000–2019) by harmonizing 1-km crop maps, estimating grid-scale expected yields (under typical local production conditions) with machine-learning models, and coupling these estimates with a process-based crop water-demand model and gridded fertilizer and pesticide data sets. Results show that drylands accounted for a significantly increasing national share of all three crops, driven primarily by maize and rice expansion. Crop expansion areas exhibited competitive expected yields, with ∼60% exceeding stable-area benchmarks. However, this competitive performance was accompanied by higher input burdens. Relative to stable croplands, median fertilizer inputs increased by 11.1%–18.1%, pesticide inputs by 3.2%–15.5%, and blue-water demand by 3.2%–11.7%, while their use efficiencies declined for most crops. Overall, 89.4% of crop expansion areas exhibited at least one high-input indicator, with 58.1% facing double or triple burdens. These findings highlight spatially heterogeneous yield-input trade-offs, suggesting that yields in these expansion areas are maintained largely through elevated inputs. Such input-dependent yields can trigger a self-reinforcing “high-yield trap,” where competitive yields incentivize further expansion and intensification in water-limited regions. Future dryland agriculture must therefore move beyond aggregate production growth toward differentiated zoning centered on yield benefits, input efficiency, and resource sustainability.</p>","PeriodicalId":48748,"journal":{"name":"Earths Future","volume":"14 8","pages":""},"PeriodicalIF":8.5,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EF009127","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing the Rainwater Harvesting and Roof Sprinkling System to Adapt to Urban Extreme Heat","authors":"Junjie Yu,&nbsp;Keith W. Oleson,&nbsp;Yue Qin,&nbsp;Lei Zhao,&nbsp;David O. Topping,&nbsp;Zhonghua Zheng","doi":"10.1029/2026EF008876","DOIUrl":"https://doi.org/10.1029/2026EF008876","url":null,"abstract":"<p>Roof watering is a novel strategy for reducing air conditioning energy consumption and mitigating excess urban heat, yet its application is often constrained by water availability. To address this challenge, we propose an adaptation strategy that integrates rainwater harvesting tank with roof sprinkling to strengthen urban heat resilience. We develop a new module implemented in the Community Land Model Urban (CLMU) to evaluate the efficacy of the proposed strategy, whose parameters were further determined by a framework using multi-objective optimization combined with a transformer-based tabular foundation model. This integrated modeling framework enables the optimization of the proposed strategy and provides insights into its impacts on air conditioning energy consumption and its co-benefits on the urban thermal environment. Results show that the temperature threshold for triggering sprinkling is a more important parameter than rainwater tank size or sprinkling intensity. The optimal strategies effectively reduce cooling energy demand, lower extreme temperatures, and decrease heatwave days. However, a trade-off exists between rainwater tank size and the reduction in cooling energy consumption and heatwave days. Additionally, the energy saving is more pronounced under higher atmospheric temperatures. The implementation of the rainwater harvesting and roof sprinkling system in CLMU provides valuable insights for improving urban resilience and can be further coupled into Earth system model for large-scale studies.</p>","PeriodicalId":48748,"journal":{"name":"Earths Future","volume":"14 8","pages":""},"PeriodicalIF":8.5,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EF008876","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate Change Shows Inverse Effects on Grain Yield and Protein Concentration in West Africa","authors":"David Abigaba,&nbsp;Bernhard Schauberger,&nbsp;Abel Chemura,&nbsp;Christoph Gornott","doi":"10.1029/2026EF008409","DOIUrl":"https://doi.org/10.1029/2026EF008409","url":null,"abstract":"<p>Climate change driven shifts in temperature, precipitation patterns, and atmospheric CO₂ concentrations threaten both productivity and nutritional quality of maize, a staple crop that underpins daily energy and protein intake for millions of households in Africa and beyond. While several studies focus on yield, impacts on maize grain nutrient composition remain less assessed. Here, we use the Agricultural Production Systems simulator (APSIM) crop model to estimate climate impacts on maize yield and grain protein levels across 16 West African countries under two contrasting shared socioeconomic pathways (SSP1-RCP2.6 and SSP3-RCP7.0). Our model results show spatially heterogeneous climate impacts across the region, with a mean reduction of −5.7% (range: −43.7%–49.7%) for yield and −4.8% (range: −42.6%–54.3%) for protein content under the high-emission scenario by mid-century. Spatially, protein concentration shows an inverse trend with yield: areas that experience yield and protein content gains show reductions in protein concentration, and vice versa. Across the region, protein concentration shows a mean increase of 4.6% (range: −4.9%–19.3%). Northern regions exhibit larger percentage yield increases, driven by higher projected precipitation and comparatively low baseline yields. By jointly evaluating productivity and nutritional quality at subcontinental scale, we demonstrate that yield-only assessments may underestimate future food system vulnerability and thus a potential trade-off between yield and protein concentration. Since adaptation measures that aim to stabilize or increase maize grain yield may jeopardize improvements in grain quality, further research on region-specific measures that optimize grain yield and quality are warranted and discussed in this study.</p>","PeriodicalId":48748,"journal":{"name":"Earths Future","volume":"14 8","pages":""},"PeriodicalIF":8.5,"publicationDate":"2026-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EF008409","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deforestation Triggers State-Dependent Cloud Regimes in the Amazon","authors":"Tom Dror,&nbsp;Graham Feingold","doi":"10.1029/2026EF008515","DOIUrl":"https://doi.org/10.1029/2026EF008515","url":null,"abstract":"<p>The Amazon's arc of deforestation is a hotspot of rapid land-cover change. Using 20 years of MODIS imagery combined with cloud property retrievals, CERES radiative fluxes, and ERA5 data, we show that deforestation consistently enhances low-level cloudiness over non-forest relative to nearby forest during the Amazon dry season. Non-forest-preference cloud scenes overwhelm those of forest- or no-preference, with MODIS imagery often revealing clouds strikingly echoing the underlying land cover pattern. While the sign of this cloud response is robust, its magnitude is state-dependent, varies with the background atmospheric state. Within the non-forest-preference cloud scenes, two distinct cloud regimes emerge: a warmer and drier regime, where higher sensible heat and lower latent heat produce sparse, shallow clouds with low cloud fraction (CF), liquid water path (LWP), and optical thickness (COT); and a cooler and moister “deepening” regime, where enhanced latent heat supports clustered, deeper clouds with higher CF, LWP, COT, greater precipitation, and stronger net cooling at the top-of-atmosphere (TOA). Our findings reveal that while deforestation triggers an enhancement in cloudiness, the nature of this response is tightly coupled to the background climate conditions, with implications for both the radiative energy budget and the hydrological cycle. As the Amazon trends toward a warmer and drier climate, a shift in cloud regime prevalence could diminish the TOA cooling and precipitation currently provided by the deepening cloud regime.</p>","PeriodicalId":48748,"journal":{"name":"Earths Future","volume":"14 8","pages":""},"PeriodicalIF":8.5,"publicationDate":"2026-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EF008515","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reassessing Alpine Permafrost Thermal State by Accounting for Ground Ice","authors":"Hailong Ji,&nbsp;Zhuotong Nan,&nbsp;Yuhong Chen,&nbsp;Lihua Chen,&nbsp;Shuping Zhao","doi":"10.1029/2025EF007931","DOIUrl":"https://doi.org/10.1029/2025EF007931","url":null,"abstract":"<p>Permafrost thermal state, representing the stored “cold energy” in the ground, is crucial for assessing permafrost changes. However, the conventional metric, mean annual ground temperature (MAGT), has inherent limitations because it overlooks the thermodynamic contribution of ground ice. To address this, we developed an alternative metric based on enthalpy change (Δ<i>H</i>′), which integrates ground temperature and ice content. Using a process-based model, we designed controlled warming experiments to evaluate the performance of the two metrics. The results show that permafrost traditionally classified as “unstable” (MAGT between −0.5 and 0°C) can persist for 30–100 years under an air warming rate of 0.4°C per decade, largely due to variations in ground ice content. Compared with MAGT, Δ<i>H</i>′ provides a more uniform scale and higher discernibility in indicating potential permafrost duration, and is therefore more suitable for representing permafrost thermal state. Furthermore, using high-resolution gridded data sets, we mapped permafrost thermal state across the Qinghai-Tibet Plateau (QTP) and quantified the spatial discrepancy between the two metrics. The results indicate that permafrost on the western QTP is less stable than suggested by MAGT, whereas permafrost in the southeast and around lakes in the endorheic basins is more stable than MAGT estimates. Explainable machine-learning analyses reveal that precipitation, soil coarse fraction, and solar radiation are the primary factors controlling the spatial heterogeneity of this discrepancy. This study highlights the dominant role of ground ice in regulating permafrost thermal state and calls for greater attention to ground ice in future permafrost projections.</p>","PeriodicalId":48748,"journal":{"name":"Earths Future","volume":"14 8","pages":""},"PeriodicalIF":8.5,"publicationDate":"2026-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025EF007931","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Role of Structural and Transient Compoundness in Advancing Compound Event Characterization","authors":"Elisa Ragno,&nbsp;Faidon Diakomopoulos,&nbsp;Srividya Hariharan Sudha,&nbsp;Carlo De Michele","doi":"10.1029/2025EF007691","DOIUrl":"https://doi.org/10.1029/2025EF007691","url":null,"abstract":"<p>Compound events, arising from the combinations of multiple interacting underlying physical drivers, have gained increasing attention over the past decade with a wide range of applications, including floods, droughts, and wildfires. This growing body of research has advanced both the conceptual understanding and statistical modeling of compound events, often emphasizing the role of dependence between underlying drivers. Building on this foundation, we recognize the need to further describe hydrological and climate phenomena not only through the overall tendency of contributing physical drivers to interact but also by considering the individual combinations of drivers leading to compound events, regardless of whether these drivers are statistically dependent. Here, we introduce the concepts of structural and transient compoundness as system properties of compound events. Structural compoundness quantifies the overall contribution of each driver to the generative mechanism of the compound variable, while transient compoundness captures the role of each driver in the individual realization of the compound variable. This will ultimately improve risk assessment and mitigation strategies. Indeed, by applying these concepts to two types of compound events, river discharge at confluences and hot and dry events, we show that structural and transient compoundness can inform modeling choices and enhance system understanding, with both the dependence and magnitude of the drivers playing critical roles in shaping compound events. Incorporating structural and transient compoundness enhances scientific modeling and, at the same time, improves risk assessment, guiding adaptation strategies for persistent (structural) and temporary (transient) risks.</p>","PeriodicalId":48748,"journal":{"name":"Earths Future","volume":"14 8","pages":""},"PeriodicalIF":8.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025EF007691","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148647776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen Memoryscapes: Typologies of Nitrogen Inputs and Riverine Loads Across the Continental United States","authors":"D. K. Byrnes,&nbsp;K. J. Van Meter,&nbsp;N. B. Basu","doi":"10.1029/2026EF008532","DOIUrl":"https://doi.org/10.1029/2026EF008532","url":null,"abstract":"<p>Nitrogen pollution has severely impacted inland and coastal waters, contributing to eutrophication, harmful algal blooms, and drinking water contamination. Reducing nitrogen inputs is widely expected to improve water quality, but watershed responses to changing nitrogen surplus are often nonlinear and delayed, complicating expectations of recovery. Here, we analyze long-term trends in nitrogen surplus and riverine nitrogen loads across 490 US watersheds from 1990 to 2017 to examine how changes in inputs translate into changes in load. By jointly classifying watersheds based on the direction of surplus and load trends, we identify four response regimes that capture the diversity of nitrogen dynamics across US landscapes. Using a multivariate classification framework, we show that watershed responses are shaped by interactions among nitrogen source type, hydrologic connectivity, climate constraints, and legacy nitrogen storage. Livestock density is associated with increasing nitrogen surplus, while declining atmospheric deposition is associated with decreasing surplus and loads. Groundwater-dominated watersheds exhibit increasing nitrogen loads despite declining surplus, reflecting the long memory of subsurface nitrogen storage. Connectivity modulates these responses: tile-drained watersheds exhibit tight coupling between surplus and load, whereas arid, low-connectivity systems show declining loads despite increasing surplus. These results show that spatial patterns in riverine loads cannot be used to infer recovery trajectories following reductions in nitrogen inputs, and effective nitrogen management requires accounting for watershed-specific response regimes.</p>","PeriodicalId":48748,"journal":{"name":"Earths Future","volume":"14 8","pages":""},"PeriodicalIF":8.5,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026EF008532","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148647777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}