Beyond the Short-Term Horizon: A Critical Review of Biogeochemical Feedback and Ecological Tipping Points in Terrestrial and Geological Carbon Sequestration

Background. Terrestrial ecosystems and geological reservoirs underpin gigaton-scale atmospheric CO₂ removal, but biogeochemical feedbacks and ecological tipping points may erode or reverse sequestration over decadal-to-centennial timescales. These nonlinearities are conceptualized, detected, and modelled unevenly across domains, and no harmonized early-warning framework exists.Aim. We synthesize how feedbacks and tipping points are defined, detected, and modelled in terrestrial versus geological carbon sinks, expose methodological asymmetries and validation gaps, and propose a harmonized multi-decadal observatory architecture.Methods. Web of Science, Scopus, and GeoRef were searched for ۲۰۱۰–۲۰۲۶: ۵۰۱ records identified, ۳۴۰ screened after de-duplication, and ۲۴۷ assessed at full text. Exclusion of ۱۷۹ records (unrelated focus, ۷۸; unindexed, ۴۱; non-English, ۹; insufficient detail, ۲۸; redundant, ۲۳) left ۶۸ core empirical studies and ۲۲ theoretical anchors. Screening in Rayyan (dual review, third adjudicator) and quality appraisal followed PRISMA ۲۰۲۰; synthesis was thematic, with attributes mapped onto Tables ۱–۲ and Figures ۲–۴.Results. Terrestrial ecology has converged on critical slowing-down indicators (rising autocorrelation and variance), whereas geological storage frames feedback as progressive mineral trapping and caprock fatigue, with bifurcation typologies poorly operationalized. Soil science excels in manipulative experiments and microbially explicit models (MIMICS); subsurface work relies on short-window geophysical imaging and reactive-transport simulations lacking long-duration validation (۱۰–۲۵ y pilots: Sleipner, Otway, CarbFix, versus ۳۰–۴۰ y terrestrial observatories). Centennial feedbacks remain empirically unvalidated. We integrate microbial carbon-use efficiency, mineral dissolution–precipitation kinetics, and plant-community state shifts into NEST-CARB, a unified framework tracking hysteresis.Conclusions. Calibrating decadal data to predict centennial permanence, the "short-term horizon," systematically biases stability estimates toward optimism. NEST-CARB, a tiered nested observatory coupling standardized early-warning protocols, joint geophysical inversion, and compound-specific isotope tracing, supplies decadal-to-centennial validation infrastructure. Closing the gap requires methodological harmonization and temporal seriousness, not merely more data

کلیدواژه ها:

Carbon dioxide removal (CDR) ، Carbon sink permanence ، Ecological tipping points ، Early warning signals ، Geological carbon storage