GLOBAL OCEAN 4D Environmental-Risk and Marine Carbon-Removal Assessment for Halifax–Tufts Cove, Atlantic Canada

GLOBAL OCEAN is an independently developed, global-to-regional, four-dimensional ocean modelling, reconstruction, forecasting, environmental-risk, biological-exposure, marine carbon-removal, and scientific decision-support framework spanning longitude, latitude, depth, and time. The framework integrates physical, chemical, biogeochemical, geochemical, biological, ecological, climatic, and spatiotemporal information within a common scientific architecture. This record documents a governed regional application of GLOBAL OCEAN to ocean alkalinity enhancement (OAE) environmental-risk assessment in the Halifax–Scotian Shelf setting of Atlantic Canada, with particular relevance to the Halifax–Tufts Cove receiving environment. The assessment uses previously completed GLOBAL OCEAN outputs and does not involve retraining, refitting, recalibration, tuning, interpolation, imputation, or modification of the underlying GLOBAL OCEAN reconstruction, forecast, or source datasets. The integrated Halifax–Scotian Shelf assessment produced a dangerous-effect potential score of 92.36/100, classified within the governed STEP12 framework as EXTREME_DANGEROUS_EFFECT_POTENTIAL. The core oxygen–carbonate screening was classified as NO_GO_PRECAUTION, comprising 9 core variables in NO-GO status and 2 in HIGH-CAUTION status. The biological exposure overlay contained 1,926 occurrence/exposure records across 18 taxa/groups and was classified as HIGH_BIOLOGICAL_EXPOSURE_PRECAUTION. The assessment incorporates oxygen–carbonate vulnerability, carbonate-buffer stress, pH and saturation-state stress pathways, deoxygenation, biological exposure, MRV detectability and uncertainty, and unresolved turbidity/total-suspended-solids pathways. A separate 2026 H01–H12 forecast-based MRV assessment identified one strong detectability signal associated with hypoxia, one moderate signal associated with deoxygenation, and nine variables characterized as weak/background detectability relative to historical variability. This work is a precautionary environmental-risk screening and not a damage-attribution study. It does not claim that observed environmental harm or fish mortality has occurred; that a particular project caused an environmental crisis; that physical spreading from a specific outfall has been demonstrated; or that legal liability has been established. Physical transport beyond the local source area requires independent event-specific source-term, hydrodynamic, tracer, particle-behaviour, and chemistry/turbidity evidence. The scientific conclusion of the governed assessment is that OAE deployment or scaling in the Halifax–Scotian Shelf regional setting should not be presumed environmentally compatible solely from potential carbon-removal performance. The assessment supports precautionary independent review, direct local validation, rigorous carbonate-chemistry and dissolved-oxygen monitoring, turbidity/TSS monitoring, biological assessment, hydrodynamic/tracer validation, before–after–control–impact study design, and uncertainty-aware MRV before continued or expanded deployment. These findings were communicated to Canadian governmental environmental authorities on September 26, 2026, under the subject “Independent GLOBAL OCEAN 4D Assessment — Precautionary Findings for Halifax OAE and Request for Independent Scientific Review.” The present Zenodo record documents the scientific assessment and its provenance. It does not state or imply governmental acceptance, endorsement, adoption, or validation of the findings. The underlying non-public GLOBAL OCEAN methodology, proprietary architecture, algorithms, analytical workflows, and undisclosed marine carbon-removal concepts are not released through this record. Raw third-party source datasets are not redistributed. Reserved DOI: 10.5281/zenodo.22979050Version: v1.0Author and developer: Mehdi Heidari, Independent Researcher — GLOBAL OCEAN