The El Niño–Southern Oscillation (ENSO) is a major driver of global climate variability, yet its long-term effect on life expectancy remains unclear. Here we quantify how ENSO persistently impedes mortality improvement, leading to considerable life expectancy and economic losses across high-income Pacific Rim countries. We estimate life expectancy losses of 0.5 years (monetary equivalent loss of US$2.6 trillion) for the 1982–1983 El Niño and 0.4 years (US$4.7 trillion) for the 1997–1998 event. Climate projections under moderate emissions pathways suggest a cumulative decline of 2.8 years in life expectancy by 2100, amounting to US$35 trillion losses, with most of the monetary burden falling on the middle-aged population. These findings reveal that intensifying ENSO variability poses an underrecognized and enduring threat to human health and socio-economic stability, underscoring the urgent need for targeted adaptation strategies to safeguard population well-being. The El Niño–Southern Oscillation threatens human health, and its impacts are likely to intensify under climate change. This research examines how historical El Niño–Southern Oscillation events have caused life expectancy and economic losses across the Pacific Rim and projects future impacts and vulnerable groups.

Holocene relative sea level (RSL) rise of the mid-Atlantic United States is dominated by two processes: ice-equivalent sea-level changes and Glacial Isostatic Adjustment (GIA) driven vertical land motion. Interpreting Holocene RSL processes in the Delaware Estuary is limited by the availability of RSL data: just 26% of 49 published sea-level index points (SLIPs) were older than 3000 years BP. Here, we extend the RSL history of the Delaware Estuary by combining new, unpublished, and published data. We produced four new SLIPs using foraminiferal data and radiocarbon dates from offshore cores in the Delaware Estuary. We used sea-level indicators and radiocarbon dates to create 14 SLIPs from unpublished data. The Delaware sea-level database now contains 67 SLIPs, with 24 older than 3000 years BP. We quantified the magnitude and rate of RSL rise over the Holocene using an Error-In-Variables Integrated Gaussian Process (EIV-IGP) model. We show a 15 m rise over the past 7000 years with variable rates of RSL rise. The rate of rise during the 20th century is the fastest rate for the last 4000 years. We compared RSL changes of Delaware with data from New Jersey and a suite of 1D and 3D GIA models. The 1D GIA models generally fit the mid- and late-Holocene RSL data, but misfit the oldest SLIPs. The 3D GIA model provides the best fit, predicting an RSL of -21.4 +/- 4.4 m at 7000 years BP, with the upper bound aligning with our oldest SLIPs. Comparisons with New Jersey EIV-IGP models reveal similar magnitudes and rates of change, but with a temporal offset of similar to 1000 years, likely due to local processes or artifacts of the models. The additional SLIPs for the Delaware Estuary extend and improve the RSL record and provide further data for refinement of GIA models in the mid-Atlantic region.

Abstract. Extreme sea levels pose significant risks to coastal communities and infrastructure. Joint probability methods are widely used to estimate return levels of extreme sea levels by combining tidal and non-tidal components, but most implementations assume independence between tide and surge. This assumption is not always valid, and neglecting correlation can affect the estimation of return levels and their associated uncertainties. Here, we introduce a Copula Joint Probability Method (CJPM) that explicitly accounts for non-linear correlation between peak tides and skew surges, generalising the Skew Surge Joint Probability Method (SSJPM). Using long tide gauge records (≥100 years) from 23 locations, we assess how incorporating correlation affects both central estimates and confidence intervals of estimated return levels. We find that accounting for this correlation can shift estimated return levels by up to approximately 10 cm at some locations. Importantly, uncertainty in the peak tide–skew surge correlation can be a statistically significant contributor to the width of confidence intervals, in some cases exceeding the contribution from uncertainty in the extreme skew surge distribution. At other locations, correlation has a negligible effect, and CJPM and SSJPM estimates are indistinguishable. These results demonstrate that explicitly representing correlation and its uncertainty provides a more complete quantification of return levels and their associated confidence intervals, and helps determine whether correlation materially affects return level estimation. The CJPM provides a flexible framework that can be applied across a wide range of settings without requiring assumptions about the strength or cause of any correlation.

The 2018 Palu-Donggala earthquake in Indonesia generated a devastating tsunami, despite originating from a strike-slip fault, which typically does not produce significant tsunamis. This tsunami was triggered by a combination of subaerial landslides, liquefaction, and submarine landslides. Here, we present the first application of sedimentary environmental DNA to characterize microbial community changes in deposits from a landslide-triggered tsunami. Sediment samples collected 2 months after the event provide a rare snapshot of the near-immediate microbial response to tsunami disturbance. Microbial assemblages derived from 16S rRNA gene sequencing clearly distinguished tsunami deposits from pre-tsunami samples across three sites in Palu Bay, even where conventional sedimentary evidence was inconclusive. The community composition varied among sites, suggesting site-specific environmental filters, which explain the absence of a universal tsunami microbial signature. Tsunami deposits were associated with microbial communities shaped by strong environmental disturbance linked to saline inundation and geochemical change. Microbial communities in the Palu tsunami deposits provide new insight into early microbial responses to extreme coastal flooding events.

Holocene relative sea-level (RSL) changes along the Atlantic coast of South America reflect a complex interplay between ice equivalent sea-level, glacio-isostatic adjustment (GIA), regional tectonics, and local sedimentary processes. However, the uneven spatial and temporal resolution of existing Holocene RSL data has hindered regional assessments. Here, we compile and standardize 1108 RSL data points from Brazil, Uruguay, Argentina, and Chilean Tierra del Fuego, creating the first comprehensive database for the southwestern Atlantic. The data reveals a widespread Mid-Holocene highstand between 7000 and 4000 years BP, with RSL rising 2 to 4 m above present-day sea level, followed by a gradual fall to present. This pattern is consistent with GIA model predictions across the region's > 50° latitudinal span. Peak rates of RSL change occurred during the Early to Mid-Holocene transition, reaching up to 17.2 mm/yr in Tierra del Fuego and decreasing to 1.6 mm/yr near the Amazon delta. After 5000 years BP, RSL started to fall at 0.5 mm/yr . This Atlantic coast of South America database fills a critical geographic gap and provides a robust framework for refining GIA models and understanding sea-level evolution during the Holocene in the Southern Hemisphere.

Mangrove sediments have served as valuable archives of Late-Holocene relative sea-level (RSL) change. However, challenges such as age uncertainties due to root penetration and bioturbation, as well as elevation uncertainties from surveying, indicative meaning, and sediment compaction remain. Here, we reconstructed Late-Holocene RSL from Singapore using a multi-proxy approach combining litho- (grain size and loss on ignition), bio- (pollen), and chrono-stratigraphical (Accelerator Mass Spectrometry radiocarbon dating) techniques to produce a series of sea-level index points (SLIPs). We surveyed the SLIPs to mean tide level, quantified the indicative meaning from the contemporary mangrove environment and minimised compaction by producing mostly basal SLIPs. We developed nine SLIPs and assessed RSL change using the Error-In-Variables Integrated Gaussian Process (EIV-IGP) model. We compared the RSL reconstructions with Glacial Isostatic Adjustment (GIA) models and a database of SLIPs from the East Coast of the Malay-Thai Peninsula. Our results show that RSL gradually decreased from 0.33 +/- 0.75 m to -0.07 +/- 0.17 m between similar to 4000 cal. yrs. BP and similar to 500 cal. yrs. BP. The EIV-IGP model suggests RSL likely (66% probability) went below present-day levels between similar to 900 cal. yrs. BP and similar to 500 cal. yrs. BP, aligning with regional RSL reconstructions but differing from GIA model predictions. Potential drivers of the Late-Holocene RSL fall and subsequent rise to present include global ice-sheet expansion, regional ocean-atmosphere interactions and the subsidence of Sundaland. Future research should refine far-field RSL reconstructions to determine the extent and drivers of Late-Holocene RSL lowstands.

Abstract For more than 40 years, scientists have projected future sea‐level change. Documenting how sea‐level projections have evolved is vital for tracking progress, uncertainties, and future research needs. Here, we update and analyze a database of global‐mean sea level (GMSL) projections dating from 1982 to 2025, identifying five key findings. First, GMSL projection generation has been concentrated in a small number of developed countries, with 95% of projections produced in the United States, United Kingdom, European Union, or Australia. Second, while GMSL projections for 2050 and 2100 have been published regularly since the early 1980s, only 30 of 103 studies have produced projections extending beyond 2100; all but one of these 30 studies postdates 2010. Third, among studies providing multiple estimates, the range of highest GMSL projections for 2100 has broadened since 2007, reaching 0.6–2.0 m across publications since the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6). Fourth, GMSL projections from the IPCC have historically been conservative compared to projections from individual studies. Prior to AR6, ∼66% of 2100 projections at the upper end of uncertainty intervals from individual studies exceeded the corresponding upper projections from IPCC reports. However, the inclusion of “low‐confidence” GMSL projections in AR6 to assess higher amounts of GMSL change of poorly known likelihood reduces this problem: the 83rd percentile of these low‐confidence projections is exceeded by <25% of upper estimates from individual studies. Finally, analyses suggest that the arrival time of key GMSL milestones are often similar for projections spanning multiple eras and using various methodologies.

Abstract Despite its strong influence on relative sea-level (RSL) rise, there is still low confidence in estimates of vertical land motion (VLM) and its contribution to RSL change. To address this problem, we synergize diverse VLM data, which now cover almost 65% of the coastal population, and are key to resolve small scale subsidence, including East, South, and Southeast Asian cities and populated deltaic regions, largely not covered by earlier geodetic measurements. We find that the average modern (1995-2020) global RSL rise experienced by coastal populations (6 mm/year) is about twice the climate-driven absolute sea-level rise. This reflects a strong tendency for higher rates of subsidence in densely populated areas, with 71% of the global coastal population living in subsiding regions. Paired with community efforts to extend consistent observations, these data are essential to ensure reliable estimates of present and future RSL rise to support risk and adaptation assessment.

Holocene sea‐level reconstructions from tidal marshes are commonly derived from proxy indicators that have a consistent and quantifiable relationship with tidal elevation. While microfossils are most commonly employed, using multiple indicators leads to more robust reconstructions. We explore the utility of elemental geochemistry obtained through x‐ray fluorescence as a proxy indicator in tidal marshes at Port Alberni, British Columbia, Canada and Willapa Bay, Washington, United States. The elemental composition of bulk surface sediment collected from 141 stations along 10 transects was determined using an ITRAX Core Scanner. Partitioning Around Medoids cluster analysis on the elemental data distinguished between tidal flat, low marsh, and high marsh zones at both locations, similar to zones established from previously published microfossil (foraminifera, diatoms) data sets on the same samples. The elemental composition of low elevation samples from the tidal flat is dominated by lithogenic (Si, K, Ti, Fe) and biogenic (Sr) elements, whereas higher elevation samples have high proportions of organic content (Br, incoherent and coherent scattering ratio). Principal Component Analysis points to differences in organic versus inorganic content, a function of tidal elevation, as the main driver of geochemistry‐derived zones. Approximately 70% of the elemental variability within both marshes is controlled by the inorganic content, as indicated by lithogenic and biogenic elements versus organic content. The elemental composition of bulk surface sediment from two regions spaced ∼300 km apart shows a promising relationship with tidal elevation over a wider spatial scale and highlights the potential of this proxy for use in sea‐level reconstructions.

Constraining sea level at the Last Glacial Maximum (LGM) is spatially restricted to a few locations. Here, we reconstruct relative sea-level (RSL) changes along the Atlantic coast of Africa for the last similar to 30 ka BP using 347 quality-controlled sea-level datapoints. Data from the continental shelves of Guinea Conakry and Cameroon indicate a progressive lowering of RSL during the LGM from -99.4 +/- 5.2 m to -104.0 +/- 3.2 m between similar to 26.7 ka and similar to 19.1 ka BP. From similar to 15 ka to similar to 7.5 ka BP, RSL shows phases of major accelerations up to similar to 25 mm a(-1) and a significant RSL deceleration by similar to 8 ka BP. In the mid to late Holocene, data indicate the emergence of a sea-level highstand, which varied in magnitude (0.8 +/- 0.8 m to 4.0 +/- 2.4 m above present mean sea level) and timing (5.0 +/- 1.0 to 1.7 +/- 1.0 ka BP). We further identified misfits between glacial isostatic adjustment models and the highstand, suggesting the interplay of different ice-sheet meltwater contributions and hydro-isostatic processes along the wide region of Atlantic Africa are not fully resolved.

Future sea-level rise will generate hazards for coastal populations, economies, and infrastructure in Singapore and Southeast Asia. However, regional projections remain highly uncertain due to complex regional to local factors, including ocean dynamics, and extreme sea-level events. Here, we review our 4-year project funded by Singapore’s National Sea Level Programme, which focused on enhancing the accuracy of regional sea-level rise projections by 2100. Our approach includes: 1) attributing historical sea-level changes to anthropogenic and natural forcings[1]; 2) quantifying drift uncertainty in global climate model simulations[2]; 3) investigating tide-surge interaction in Singapore and surrounding regions[3]; and 4) addressing ambiguity in sea-level rise projection by fusing multiple projections used in the Intergovernmental Panel on Climate Change 6th Assessment Report (IPCC AR6)[4]. First, using large ensemble climate model simulations we detected and attributed historical (1950–2014) sea-level changes over the Indo-Pacific warm pool region providing insights for future projections. We discovered that the historical rise in sea level is predominantly driven by the influence of greenhouse gases, although aerosols tend to moderate the rate of rise. Notably, the rate of sea-level rise and the time of emergence of anthropogenic signals vary spatially in the region. We also highlight the important role of manometric sea-level changes in shallow and coastal regions in Southeast Asia. Second, we develop a Monte Carlo drift correction technique to quantify uncertainty in drift correction for global climate models, using climate model data. Our findings highlight that drift uncertainty can significantly impact energy balance estimates and sea-level rise, underscoring the need to account for drift uncertainty when analyzing climate model outputs. Third, using a statistical framework, we study tide-surge interaction at seven tide gauges along the coast of Singapore and the east coast of Peninsular Malaysia, focusing on the timing of extreme non-tidal residual relative to tidal high water. We found that tide-surge interaction influences coastal water levels in this region, and our semi-empirical model provides insight into the mechanisms of tidal phase alteration. Finally, we propose a new approach to quantify the best estimate of the scientific uncertainty associated with sea-level rise by fusing the complementary strengths of the ice sheet models and expert elicitations used in IPCC AR6. Under a high-emissions scenario, the very likely range is 0.5–1.9 m. The 95th percentile projection of 1.9 m can inform a high-end storyline, supporting decision-making for activities with low uncertainty tolerance. We plan to use our findings to offer policymakers and coastal planners a robust, high-confidence toolset for long-term adaptation strategies in Singapore and Southeast Asia. [1] Samanta et al., (2024), https://doi.org/10.1029/2023EF003684 [2] Grandey et al., (2023), https://doi.org/10.5194/gmd-16-6593-2023 [3] Koh et al., (2024), https://doi.org/10.5194/os-20-1495-2024 [4] Grandey et al., (2024), https://doi.org/10.1029/2024EF005295

Climate-driven sea-level rise is increasing the frequency of coastal flooding worldwide, exacerbated locally by factors like land subsidence from groundwater and resource extraction. However, a process rarely considered in future sea-level rise scenarios is sudden (over minutes) land subsidence associated with great (>M8) earthquakes, which can exceed 1 m. Along the Washington, Oregon, and northern California coasts, the next great Cascadia subduction zone earthquake could cause up to 2 m of sudden coastal subsidence, dramatically raising sea level, expanding floodplains, and increasing the flood risk to local communities. Here, we quantify the potential expansion of the 1% floodplain (i.e., the area with an annual flood risk of 1%) under low (~0.5 m), medium (~1 m), and high (~2 m) earthquake-driven subsidence scenarios at 24 Cascadia estuaries. If a great earthquake occurred today, floodplains could expand by 90 km2 (low), 160 km2 (medium), or 300 km2 (high subsidence), more than doubling the flooding exposure of residents, structures, and roads under the high subsidence scenario. By 2100, when climate-driven sea-level rise will compound the hazard, a great earthquake could expand floodplains by 170 km2 (low), 240 km2 (medium), or 370 km2 (high subsidence), more than tripling the flooding exposure of residents, structures, and roads under the high subsidence scenario compared to the 2023 floodplain. Our findings can support decision-makers and coastal communities along the Cascadia subduction zone as they prepare for compound hazards from the earthquake cycle and climate-driven sea-level rise and provide critical insights for tectonically active coastlines globally.

Implementing responses to sea-level rise requires accessible, credible and relevant sea-level information to facilitate effective use by practitioners and decision-makers. However, recent consultations have highlighted the need to better translate sea-level information to meet the physical and cultural diversity of decision-making and planning across the world. This includes communicating sea-level rise across a range of timescales, providing information tailored to different risk tolerances and better linking sea-level rise to impacts analysis to provide useful and usable metrics (e.g., Weeks et al., 2023, Environ. Res. Commun.). The presence of ambiguity in sea-level projections means there are limitations in the use of probabilistic approaches in coastal planning and decision-making (Kopp et al., 2023, Nature Climate Change). Storylines (physically consistent and plausible pathways of future climate events) are increasingly being used as a distillation tool presented alongside probabilistic sea level projections, for example to address the challenge of “deep uncertainty” associated with the future response of the ice sheets. Here, we focus on the regionalisation of sea-level projections into a set of discrete, actionable future pathways, to meet the needs of coastal adaptation planners and decision-makers. Building on the work of Palmer et al., (2020) (Earth’s Future), we generate a set of sea-level storylines for coastal city locations in the UK, South Africa and Southeast Asia, constrained by different emissions scenarios and high-end sea-level rise estimates. Locations are chosen based on their population density and geographical spread, whilst the regions allow consideration of the different risk profiles and contexts for decision-making. This work explores a range of decision-making contexts and how the storyline framework can be tailored to different user needs.

In 2023, global ocean heat content reached unprecedented values since records began in 1960. The translation of global ocean heat into regional and local-scale ocean warming remains poorly understood because of limited observational data, particularly within Southeast Asia. Here, we investigate the 2023 ocean warming event in Southeast Asia using near-continuous 41-month in-situ ocean temperature observations from the Singapore Strait, satellite sea surface temperature (SST) measurements, and high-resolution reanalysis products. We document anomalous ocean warming across the Singapore Strait and surrounding South China Sea and Indonesian Seas to depths of at least 40 m. Peak SSTs of 1.8 °C above the climatological mean were recorded in the central Sunda Shelf in November 2023 for the first time in > 40 years. Concurrent anomalous freshening of the Singapore Strait was observed, with average salinity below the climatological mean from October to December. We identify a southward migration of warm temperature anomalies beginning with the onset of the El Niño in July 2023 near the Luzon Strait. This occurred alongside southward shifts in mean sea-level pressure and near-surface ocean currents in the region. We attribute these observations to the southward shift of the North Equatorial Current bifurcation latitude, which permitted the intrusion of Pacific western boundary currents into the South China Sea and Indonesian seas. Compared to the oceanic drivers, atmospheric forcings played a limited role in driving the ocean warming in 2023. Our study highlights El Niño as the key driver of the ocean warming in Southeast Asia in 2023, and emphasises the need for expanded continuous, in-situ ocean temperature monitoring to enhance understanding of evolving ocean-atmosphere dynamics and impacts in Southeast Asia under a warming climate.

Five sediment cores of 40 cm length were collected from the Singapore Strait and analysed for emerging and persistent contaminants to assess changing pollutant trends and risk to benthic ecology. Data on the sedimentary accumulation of pharmaceuticals are currently lacking and yet present a potential threat to Singapore's coastal ecosystem. Pharmaceuticals occurred in the order hormones>non-steroidal anti-inflammatory>antibiotics and were highest at the sediment surface then decreased down-core. Similar trends were observed for individual antibiotics, azithromycin 0.18-0.51 ng/g-1, clarithromycin 0.02-0.44 ng/g-1 and erythromycin-H2O 0.01-0.04 ng/g-1 as well as anti-inflammatory drug ibuprofen 0.19-8.59 ng/g-1. The non-systematic variation in the hormone estradiol (E2) 3.41-13.83 ng/g-1 and drink/food ingredient caffeine 1.27-9.19 ng/g-1 was attributed to greater mobility and or post depositional degradation. In contrast, polyaromatic hydrocarbons (∑16PAH) 0.322-32.569 mg/kg-1 as well as trace metal mercury (Hg) 0.039-1.022 mg/kg-1 were invariant, except for one core which showed a clear-rise and near surface fall tracking TOC% and clay-silt particles. PAH source ratios and parent to alkylated profiles conferred mainly petroleum combustion sources with minor petroleum inputs. Sedimentary PAH and Hg were mostly below established non-statutory sediment quality benchmarks and deemed unlikely to negatively impact benthic ecology. Together PCA and HCA evaluation confirmed similar physico-chemical association for pharmaceuticals and persistent contaminants except for antibiotics. Sediments from Singapore Strait record a recent shift from predominantly hydrocarbon pollution to more complex mixtures spanning pharmaceuticals and caffeine that are suggested but not unequivocally proven to be from on-shore industrial or waste-water discharge sources.

Sea-level projections are sensitive to statistical dependence between the East Antarctic, West Antarctic, and Greenland ice-sheet components. The dependence is produced by climate uncertainty and ice-sheet process uncertainty. To investigate this dependence, we model the dependence using copulas. We use a vine copula to couple the ice-sheet components of projected sea level in 2100 under the SSP5-8.5 scenario. Assumptions about rank correlation and copula family influence both the centre and the tails of the total ice-sheet contribution. For example, rank correlation can influence the 95th percentile by approximately 50%. We explore three alternative approaches for specifying the dependence: shared dependence on global-mean surface temperature, dependence derived from ice-sheet model ensembles, and dependence derived from expert judgement. Shared dependence on global-mean surface temperature produces little dependence between the ice-sheet components. In contrast, ice-sheet model ensembles suggest that the dependence between the East and West Antarctic ice-sheet components may be strong, amplifying the uncertainty in future sea-level rise.

Existing Late Holocene relative sea-level (RSL) records from the Sunda Shelf suffer from spatial and temporal discontinuities and/or a lack of precision, hindering an understanding of the drivers of RSL change. Here, we present the first RSL record from fossil coral microatolls in Singapore, which has high vertical (