A high-resolution numerical model of hydrodynamics to simulate salinity conditions in the lowermost Mississippi River was utilized to analyze the salt wedge propagation. Extensive upriver propagation occurred during 2022-2024 with discharge conditions between 5,000 and 8,500 cms, which are below long-term seasonal averages but above historically defined severe drought thresholds. Our analysis reveals that while sea level rise and deepening of the navigation channel contribute to upstream wedge movement excessive water loss through a series of lateral crevasses was a primary cause of the upriver wedge propagation distance. When the lateral crevasses (during drought events) are closed in the simulation using native sand material, it results in significant reduction of the salt wedge propagation upriver. The model also demonstrated that an underwater sand sill presently utilized in low events to limit propagation of the wedge upriver movement, if moved further downstream enhances its function and effectiveness. Overall, this model may serve as a vital tool for public risk communication and co-production, fostering informed decision-making for water management in the Lower Mississippi River. • River discharge at Head of Passes (RK0) is the primary control on salt wedge migration. • Sea level rise and channel deepening increase salt intrusion by 6.5 and 3.5 km. • Thalweg earthen sills are most effective near the river–ocean interface (e.g., RK72). • Existing earthen sills are ineffective when river discharge falls below 3.54k cms. Our study investigated how saltwater denser saltwater from the Gulf moves upstream beneath the freshwater layer in the Mississippi River, especially during droughts, using a computer model to understand causes and solutions. Among the modeled mitigation scenarios, artificial closure of eastern distributary outlets reduced wedge intrusion by up to 120 km relative to the benchmark case, exceeding the effect of sill relocation (10 km reduction) and sea level rise impacts (6.5 km increase). Earthen sills, acting as underwater speed bumps, halt the upriver movement of salt and help by mixing saltwater with freshwater. Our model not only predicts saltwater movement and evaluates solutions but also helps communicate these complex issues to the public, encouraging informed decision-making for river management.

• Soil physicochemical traits and microbes characterized along a salinity gradient • Salinity, sulfur, and iron shape microbial structure across wetlands • Sulfur-reducing bacteria dominate highly saline soils • Salinization lowers CH 4 but increases CO 2 emissions Coastal wetlands play a critical role in carbon sequestration, biogeochemical cycling, and ecosystem stability. These habitats support diverse microbial communities that regulate organic matter decomposition and greenhouse gas fluxes, influencing climate-related feedback mechanisms. However, rising sea levels and saltwater intrusion may disrupt microbial processes, particularly those associated with the sulfur cycle and methane dynamics. Here, we characterize soil physicochemical properties and microbial communities along a salinity gradient in three temperate coastal wetlands to assess the impact of salinity on organic matter decomposition and greenhouse gas emissions. Using full-length Oxford Nanopore MinION 16S rRNA amplicon sequencing, we analyzed microbial communities across freshwater, brackish, and saline wetland soils. Our results indicate that sulfur-reducing bacteria dominate salinized sites, while brackish environments are characterized by obligate anaerobic taxa involved in sulfate reduction, fatty acid degradation, and denitrification. These microbial assemblages contribute to lower CH 4 emissions but increased CO 2 fluxes in the brackish areas, highlighting key microbial-mediated trade-offs in wetland carbon cycling. By integrating microbial diversity, and metabolic functions with soil geochemistry, this site-specific but ecologically meaningful case study improves our understanding of microbe-soil interactions in temperate wetland ecosystems facing increased salinization due to climate change.

Caribbean Small Island Developing States (SIDS) are on the frontline of climate-induced coastal risks, where rising sea levels and intensifying storm surges converge with concentrated socioeconomic exposure. The inherent spatial constraints, economic dependency on tourism, and infrastructure clustering in coastal zones exacerbate systemic vulnerability. This study establishes an integrated high-resolution compound coastal risk framework by coupling hydrodynamic storm surge simulations with sea level projections and socioeconomic exposure data. The framework evaluates systemic risks across diverse return periods and Shared Socioeconomic Pathways including SSP1-1.9, SSP2-4.5, and SSP5-8.5, utilizing a modified static inundation model to integrate sea level rise and surge extremes for generating spatially explicit vulnerability assessments. Results revealed spatial heterogeneity and a distinctive ‘high-exposure–high-density–high-sensitivity’ configuration across several SIDS. Under SSP5–8.5, annual economic losses exceed USD 300 million in Jamaica and Cuba, and over 30,000 people may be affected in Dominica. Mitigation pathways consistent with a 1.5 °C warming limit (SSP1–1.9) reduce potential losses by 30–50%, while adaptation strategies, such as coastal ecosystem restoration and early-warning systems, deliver up to 40% carbon co-benefits. Beyond risk quantification, this framework supports climate-resilient infrastructure planning. By correlating spatial risks with adaptation finance, this research supports the Paris Agreement and Sustainable Development Goals (SDGs).

Enhancing the accuracy of seawater intrusion vulnerability assessment using a hybrid GALDIT framework in tropical low-lying coastal settings.

Since the Last Glacial Maximum (LGM) ~21.5 kya, global sea-level rise has reshaped coastal areas by contracting subaerial regions, severing mainland connections and driving the progressive fragmentation of pre-existing islands. These changes led to supersaturation of island communities, triggering community relaxation through local extinctions. However, it remains unclear which ecological processes are responsible for patterns of species extinction. Here, we integrate a paleo-coastline model with well-characterized squamate community data from 163 Mediterranean islands to assess how past geographical changes influenced community structure. We evaluate phylogenetic and functional community structure and test links to paleogeographic variables. Our findings suggest phylogenetic overdispersion (co-occurring species being more distantly related than expected by chance) dominates and is higher on older islands, implying ongoing community relaxation and that extinctions are driven more by interspecific competition than environmental filtering. Island time-since-isolation emerges as the strongest predictor of phylogenetic structuring, indicating that longer isolation drives phylogenetic overdispersion via selective extinction of close relatives. These results underline the significance of relaxation dynamics in shaping insular communities.

In this study, we develop a surrogate model for the efficient estimation of the seawater extent in leaky offshore aquifers, in which the dispersive mixing zone is represented approximately. The model is trained using factorial sampling of a five-parameter non-dimensional parameter space. The samples are modelled with a numerical code (SEAWAT), and the results are used to correct the parameters of a two-parameter semi-analytical sharp-interface model to take into account the mixing zone, which is represented by the 5 % and 50 % seawater concentration contours (isochlors). These corrections allow both the tip and the toe (where a specified isochlor meets the top and bottom, respectively, of the aquifer) to be approximated. The method applies corrections to the freshwater-seawater density difference, the rate of freshwater inflow, and the head drop across the offshore aquitard, allowing the semi-analytical approach to match the dispersive, numerical solution. This approach builds on previous dispersive correction formulae developed for onshore coastal aquifers. This surrogate model requires that the tip is located offshore and provides a rapid method for estimating the offshore freshwater extent and volume, and any seawater intrusion (represented by a shift from one steady-state condition to another) arising from changes to the stresses of the system, e.g., due to sea-level rise or modified submarine groundwater discharge. A macro-enabled Excel workbook implementing the correction is provided to disseminate the methodology. This is available at https://github.com/ZAsiri/Surrogate-Model-.git . • A surrogate model for the dispersive mixing zone in leaky offshore aquifers. • Trained using factorial sampling of a five-parameter space. • The model is validated using independently generated testing data. • Model corrects a two-parameter semi-analytical sharp-interface model. • The model provides a rapid method for estimating the offshore freshwater extent and volume.

Monitoring the Greenland Ice Sheet (GrIS) melt is critical for understanding cryospheric change and global sea-level rise. Existing passive microwave methods are limited by coarse resolution and detection biases. This study develops a novel multi-index decision-tree method for GrIS melt detection. Applied to enhanced-resolution brightness temperature data (up to 3.125 km), this method integrates dynamic thresholding of diurnal amplitude variation (DAV) from 37 GHz vertical polarization and Gaussian Mixture Model (GMM) classification from 19 GHz horizontal polarization, enabling precise identification of diverse melt types, including sporadic/intermittent melt, persistent melt, and supraglacial lake formation. Compared to traditional methods (245 K and MEMLS), our method significantly improves accuracy, achieving a 95.81% overall accuracy. For high-melt sites, 76.82% of AWS-recorded melt days are correctly classified. Long-term analysis (1988–2023) reveals a significant lengthening of the GrIS melt period: melt onset advanced by 0.31 d/yr, melt end delayed by 0.50 d/yr, and annual melt days increased by 0.35 d/yr (p < 0.01). These trends correlate with the negative summer North Atlantic Oscillation (r = −0.62) and increased Greenland blocking (r = 0.71, p < 0.01). This melt detection framework provides an observational basis for investigating ice sheet surface processes and supports more reliable assessments of melt-related impacts under climate change.

Climate change driven by anthropogenic greenhouse gas (GHG) emissions represents an immediate and grave threat to human health and survival. Sea level rise, altered weather patterns and increasingly frequent and severe extreme weather events can damage health directly (eg, injury, heat stress, altered aeroallergen and particulate exposure). They also bring indirect health impacts through altered patterns of zoonotic and vectorborne diseases, disruption of food systems and downstream social consequences (economic collapse, mass migration and conflict).Healthcare providers and healthcare workers all need to take immediate action to drive and deliver reductions in GHG emissions, and to help patients in better managing the health impacts brought about by climate change. Here, we propose the '4Ps framework' (Personal, Professional, Pathway-specific and Policy) to empower and facilitate such action.

Predicting future coral reef responses and climate-driven sea-level rise requires robust historical records of reef vertical accretion rates and their ecological drivers. However, comparable empirical data on past reef growth and framework bioconstruction are often spatiotemporally limited, precluding detection of regional patterns and long-term trends. Here, we compile and evaluate standardized Holocene vertical accretion rates and coral community structure data from 288 Indo-Pacific paleo-reef records across 92 sites to examine intrinsic and extrinsic drivers of accretion. Our findings reveal that reef formation and long-term accretion are determined by a complex interplay between sea-level change and eco-geomorphological factors. Maximum vertical accretion rates indicate that many Indo-Pacific reefs do not have the capacity to keep pace with projected rates of sea-level rise, particularly under high-emissions scenario (76% of reef sites). Critical thresholds suggest that reef accretion is very unlikely (>90% probability) to be maintained when relative sea-level rise rate exceeds 5.3 mm yr-1, a scenario likely to be surpassed within ~35 years. Without substantial reductions in global emissions, many coral reefs face increasing risk of submergence, structural collapse and loss of critical ecosystem services, especially where modern coral communities differ from predominantly competitive Holocene assemblages and are increasingly dominated by weedy taxa.

With growing consensus on the scale of climate change and its direct impacts on societies and economies, the debate on how direct climate damages cascade through interconnected economic systems eventually leading to profound indirect effects remains open amid limited quantitative evidence. The localised nature of climate risk means that regional economies may face stark differences in how they are impacted by the direct and indirect physical risks. In Europe, the world's fastest warming continent, concentrated local damages spill over asymmetrically into tightly-interconnected regional markets, potentially leading to increased inter-regional inequalities despite the continent's prioritisation of economic unity through its regional cohesion policy. Solid regionalized economy-wide analysis could identify if physical climate risks serve as structural drivers of future regional inequality, offering timely insights for policy interventions to curb exacerbating socio-economic adversities. Here, using an empirical dynamic computable general equilibrium model disaggregated to NUTS2 European regions, we explore a range of regional economic projections from two particularly costly climate-driven hazards: river flooding and sea-level rise. Our methodology captures complex economic feedbacks across granular regions and sectors to estimate both direct and indirect economic repercussions of combined sea-level rise and river flood events by 2100. We find that these climate-induced hazards represent an economically divergent force for the European regions. In contrast to aggregated studies, the resulting regional economic projections reveal wide heterogeneity in combined (direct and indirect) physical risks, with the most affected regions experiencing devastating declines in GDP up to 51% by 2100. Our disaggregated projections capture the effects of two climate-induced hazards with distinct geographical hotspots - coastal and inland - which occur simultaneously though unfold at different rates, enabling a detailed assessment of regional economic inequalities. Low income regions experience by far the highest proportional losses, leading to increases in both between and within-country regional inequality.

This study systematically investigates the spatiotemporal evolution of sea level rise under climate change, employing a tri-scale quantitative framework (global, China’s coastal waters, and Shanghai municipality) to elucidate its underlying drivers and regional disparities. By synthesizing IPCC AR6 datasets and NASA sea level projection models, we integrate the Theil-Sen Median Method with Mann-Kendall Test to analyze trajectory patterns from 2030 to 2100. Spatial clustering effects are further identified through hotspot analysis (Getis-Ord Gi*) implemented in ArcGIS Pro. The findings reveal a statistically significant upward trend in global sea levels, primarily attributed to thermal expansion and cryospheric melt (glaciers and polar ice sheets), with localized subsidence observed in certain high-latitude regions. China’s coastal waters exhibit accelerated sea level rise, particularly in the South China Sea and East China Sea, where rates surpass the global mean—a phenomenon driven by coupled effects of monsoon circulation, Kuroshio Current dynamics, and freshwater discharge from major rivers (e.g., Yangtze and Yellow Rivers). At the urban scale, Shanghai’s coastal zone demonstrates exacerbated relative sea level rise due to superimposed land subsidence and localized hydrodynamic processes, manifesting distinct spatiotemporal clustering patterns. By integrating global-scale thermodynamic baselines, regional oceanic drivers, and local land subsidence patterns, this study provides a quantitative foundation for place-based adaptation strategies in delta cities. The findings enable evidence-based risk assessment and inform anticipatory governance measures—such as targeted infrastructure reinforcement and land-use planning adjustments—to address the compound sea level risks identified at each scale.

Glacial terminations stand out for their high rates of sea-level rise, particularly during meltwater pulses. Termination IV (T-IV; ~340,000 years before present) is a prominent example, with sea level rising at up to ~5 m per century. Due to sparse absolute age constraints on marine records, the causes for the high rates of sea-level rise at T-IV remain elusive. In this work, we provide a speleothem chronology from northern Italy, which we transpose to North Atlantic marine records. We infer that the high T-IV sea-level rise rate likely relates to a feedback whereby protracted meltwater release caused enhanced ocean heat storage, followed by heat release upon circulation recovery, driving additional ice-sheet collapse. This analysis highlights the critical role of oceanic feedbacks in driving exceptional rates of sea-level rise during terminations.

Tracing developments in 2025 on the issue of sea-level rise and maritime zones, this article offers new perspectives on emerging questions about the implementation of stable maritime zones, focusing especially on the question of how stable maritime zones can be achieved for the different baseline types, especially the normal baseline. Illustrated through an analysis of Australia’s legal framework, the article offers lessons from Australia’s maritime jurisdiction which provide a practical pathway towards the preservation of baselines and maritime zones amid sea-level rise, and which are supported by state practice and consistent with a contemporary interpretation of international law.

Climate change is intensifying environmental stressors—rising temperatures, erratic precipitation, sea-level rise, and more frequent extreme events—with profound consequences for livelihoods and human mobility. In India, where large rural populations depend on climate-sensitive sectors such as agriculture, fisheries, and forestry, recurring droughts, floods, cyclones, heatwaves, and irregular monsoons increasingly erode livelihood security and contribute to displacement and rural-to-urban migration, notably in the Sundarbans, coastal Odisha, flood-prone Bihar, and Uttarakhand. This study aims to elucidate the link between climate change and rural–urban migration in India by examining livelihood disruptions, associated socio-economic vulnerabilities, challenges encountered by migrants in urban destinations, and policy options to strengthen resilience and protect vulnerable groups. Using a qualitative, descriptive design based primarily on secondary sources (including government and international agency reports, census and policy documents, and peer-reviewed literature), the study synthesizes evidence through thematic analysis guided by the Sustainable Livelihood Framework, complemented by Political Ecology, Environmental Migration Theory, and Climate Justice Theory. Findings indicate that climate hazards undermine natural, physical, financial, human, and social capital, reducing agricultural productivity, damaging infrastructure, degrading ecosystems, and deepening debt, food insecurity, and poverty; migration thus emerges as a seasonal, circular, temporary, or permanent coping and adaptation strategy, shaped by ecological pressures interacting with inequality, limited livelihood diversification, and governance constraints. Vulnerability is uneven, disproportionately affecting small and marginal farmers, landless workers, women, indigenous communities, and lower caste groups; gendered impacts include feminization of agriculture and heightened risks for women migrants in informal urban labor markets. Urban destinations often reproduce or intensify vulnerability through insecure employment, inadequate housing, barriers to welfare and services, exposure to heat and flooding, and social marginalization, as starkly revealed during the COVID-19 lockdowns. The study concludes that climate-induced migration should be recognized as both adaptation and a symptom of structural vulnerability, requiring integrated policies that build climate-resilient rural livelihoods, mainstream migration in adaptation planning, ensure portability of social protection, strengthen labor and housing, develop climate-resilient cities, and advance climate justice through inclusive governance and targeted support for vulnerable populations

The rate and impacts of sea level rise vary considerably around the world, but the contribution of human-caused climate change to increases in local and regional flood risks has not yet been systematically explored. Because such information is critical to local decision making, legal proceedings, and loss and damage determinations, we quantify human-caused climate change’s contributions to sea level rise at worldwide locations using budget-based and semiempirical model methods. Results show that human-caused sea level rise is quantifiable at 97% of 519 tide gauge sites and is responsible for 58% (44 to 65%) of the observed daily extreme water level exceedances over 2000–2018. On average, human-caused sea level rise has caused a near-tripling in the number of days with attributable exceedances since the 1970s.

Climate justice is not a monolithic concept but one shaped by geography, biophysical risks and structural inequalities. Rather than a singular struggle, it encompasses multiple, intersecting forms of injustice – both group-based (rooted in class, nation, gender, race and intergenerational inequality) and threat-based (arising from phenomena such as sea-level rise, glacial retreat, droughts and floods). This research note proposes a three-layered analytical framework to organise these diverse climate injustices. It argues that climate injustices emerge at the intersection of three dimensions: (1) biophysical threats such as sea-level rise, glacial retreat, heatwaves, droughts and flooding; (2) local political economies and patterns of social vulnerability; and (3) historical and institutional contexts. To illustrate how similar hazards generate distinct moral and political claims, the research note introduces a non-exclusive taxonomy informed by various cases from the Majority World.

Environmental change can affect social contracts, which are the relationships between societal groups and between such groups and the state. Droughts, river pollution and rising sea levels often change the distribution of resources within countries or harm some societal groups more than others, raising questions about compensation. Social contracts can also trigger environmental change, mainly because the environment and future generations cannot themselves participate in social contract negotiations. Many social contracts allow influential elites to overuse or pollute natural resources, harming the environment, other societal groups and future generations. Drawing on existing social contract and environmental governance research, this introductory article develops a conceptual approach for analyzing the bidirectional effects between the environment and the relations between different parts of society and the state. It presents different types of interaction using multiple examples. This approach helps to identify starting points for the negotiation of more sustainable and inclusive social contracts.

An accurate estimation of surface mass balance (SMB) is imperative for reliable quantification of the Greenland Ice Sheet (GrIS) mass changes and associated global sea level rise. Here, we present two new reconstructions of gridded annual SMB at the resolution of 0.1° × 0.1° across the GrIS from 1950 to 2020 by means of a CNN-Transformer model. This machine learning model is trained on the mostly recent compiled in-situ SMB observations, integrating with ERA5 Land reanalysis product, and outputs of the polar regional climate model MAR, respectively. When trained on the full dataset, the best-performing model predictions highly and significantly correlate with observations, with correlation coefficients of 0.96 and 0.93 for ERA5-Land-based and MAR-based reconstructions, respectively. Spatial cross-validation over unseen regions shows that reconstruction errors reduce by approximately 50% relative to the original datasets (ERA5-Land and MAR), with both reconstructions yielding statistically comparable RMSE (~53 mm w.e. yr-1) against in-situ observations. Independent validation against IceBridge airborne radar products further confirms their robustness, with 35% and 50% reduction in relative absolute error relative to ERA5-Land and MAR, respectively. The spatially and temporally complete annual SMB datasets can be used for the input of ice-sheet models and surface hydrological studies.

Abstract. The Ocean plays a central role in regulating climate, sustaining biodiversity, and supporting human societies, yet it is experiencing increasing environmental change driven by human activities. The Starfish Barometer provides an annual, science-based synthesis of global Ocean-related developments. It does not generate new data, but brings together already available siloed information. It is structured around five interconnected dimensions – the five arms of the Starfish: Ocean state, human pressures, societal harms, protection efforts, and opportunities for humanity. This article presents the second edition of the Barometer, released each year on World Ocean Day (8 June). In the 2026 Barometer, key highlights confirm the consequences and intensification of human pressures on the Ocean. Global sea-level rise and Ocean warming are accelerating; the number of identified threatened marine species continues to rise, and the level of threat they experience is intensifying. Over 84 % of global coral reefs are at risk, exposed to bleaching-level heat stress. Annual plastic waste generation reached 130 million t, with up to 10 % potentially reaching the Ocean. Global shipping emissions remain stable indicating limited decarbonization progress. Economic losses from tropical storms and floods were particularly high in 2024, illustrating how human pressures are translating into material costs for societies. Geopolitical instability has increased maritime insurance costs, and half of the social cost of climate change falls on the Ocean economy. Major in-situ ocean observing systems are shrinking reducing Ocean protection capacity. In parallel, protection efforts continue to expand. Stronger protection rules for rays and sharks have been adopted, reflecting gradual progress in conservation ambition. A treaty for the High Seas has been adopted, providing a legal framework to protect and govern the Ocean. More than 2000 Ocean startups worldwide are also contributing to innovation, with a growing will for sustainable Ocean development and Ocean-focused environmentally beneficial investments. Taken together, these signals show a growing gap between increasing human pressures on the Ocean and the efforts being made to protect it and drive change. While governance frameworks, financial commitments, and innovation ecosystems are advancing, current trajectories remain insufficient to meet global biodiversity, climate and Ocean sustainability objectives, as reflected for example in SDG 14, the link to other SDGs, and related international frameworks (von Schuckmann et al., 2020). By compiling robust, evidence-based information within a consistent annual framework guided by international and multidisciplinary expertise, the Starfish Barometer provides a transparent and evidence-based foundation to support accountability for a sustainable Ocean.

Despite large uncertainties associated with future mass loss from the Antarctic Ice Sheet, ice-sheet models show that the rate of sea-level rise from Antarctic ice loss in 2025 is strongly predictive of the rate for the next several decades, regardless of emission pathway or model complexity. This finding is robust across all models that were considered in the Intergovernmental Panel on Climate Change Sixth Assessment Report global mean sea-level projections, including the low-likelihood, high-impact scenarios of sea-level rise. Given this strong near-term decadal predictability, ice-sheet models that can accurately reproduce present-day ice-mass loss provide a reliable basis for near-term sea-level planning and adaptation through to mid-century. The predictability breaks down by the end of the twenty-first century as feedbacks, such as those related to marine ice-sheet retreat, begin to emerge, leading to accelerating ice loss. Drawing on these results, we identify key feedback mechanisms that can account for the transition between near-term decadal predictability and the longer-term, feedback-driven evolution, and suggest priorities for ice-sheet model development aimed at resolving long-term sea-level rise uncertainty.