Passages below come from Abrams et al. (2026), Reviews of Geophysics 64(4), e2025RG000900, https://doi.org/10.1029/2025RG000900, CC BY 4.0. Hyphens and spacing as pdftotext gives them. The OTHER REVIEW lines hold short passages from Bathiany et al., Loriani et al. and J. F. Abrams et al., each CC BY 4.0. THE REVIEW: terms ### solar: 1 in body, 0 in references p.18 [body]: ...le and near‐infrared wavelengths (0.4–2.5 μm) form the backbone of vegetation monitoring, measuring reflected solar radiation to derive indices of vegetation health, productivity, and phenology. Key products include the Norma... ### sun: 0 in body, 0 in references ### sunspot: 0 in body, 0 in references ### sunlight: 0 in body, 0 in references ### irradiance: 0 in body, 0 in references ### insolation: 0 in body, 0 in references ### geomagnet*: 0 in body, 0 in references ### magnet*: 3 in body, 0 in references p.18 [body]: ...biological systems through remote sensing technologies, primarily satellite‐based sensors that observe electromagnetic radiation reflected or emitted from the Earth's surface. For tipping point detection, EO provides unparalle... p.18 [body]: ... systems approach critical thresholds. Modern EO systems employ diverse sensor technologies across the electromagnetic spectrum, each providing unique insights into terrestrial system properties relevant to tipping point detec... p.35 [body]: ...pping processes, key properties that can be remotely sensed, and applicable sensing methods across the electromagnetic spectrum. Filled circles (●) indicate primary sensing approaches for each system‐property combination. Curr... ### pole / poles: 0 in body, 0 in references ### pole shift: 0 in body, 0 in references ### polar: 1 in body, 0 in references p.20 [body]: ...putational demands for fine‐scale analysis Scale mismatches between satellite pixels and ecological processes Polar regions have seasonal gaps; some sensors have inconsistent global coverage; edge effects Sensor degradation; ... ### cosmic: 0 in body, 0 in references ### galactic: 0 in body, 0 in references ### aurora: 0 in body, 0 in references ### space weather: 0 in body, 0 in references ### ionosph*: 0 in body, 0 in references ### excursion: 0 in body, 0 in references ### reversal: 0 in body, 0 in references ### volcan*: 1 in body, 1 in references p.7 [body]: ...subsurface or extra‐terrestrial). One example of such singular high‐magnitude perturbations is given by large volcanic eruptions (Rymer et al., 2005). Those processes are not parts of the climatic system in the strict sense bu... p.46 [refs]: ...cke, C. A., Brenes, J., & Williams‐Jones, G. (2005). Magma plumbing processes for persistent activity at Poás volcano, Costa Rica. Geophysical Research Letters, 32(8). https://doi.org/10.1029/2004GL022284 Saintilan, N., Horton... ### eruption: 1 in body, 0 in references p.7 [body]: ...e or extra‐terrestrial). One example of such singular high‐magnitude perturbations is given by large volcanic eruptions (Rymer et al., 2005). Those processes are not parts of the climatic system in the strict sense but may lead ... ### bolide: 1 in body, 0 in references p.5 [body]: ...ter values is required Ubiquitous in all natural systems (Scheffer et al., 2012) Extreme/rare weather events; bolide collision (Halekotte & Feudel, 2020; Lucarini et al., 2022; Romanou et al., 2025) Seasonal timing effects in ... ### asteroid: 1 in body, 0 in references p.7 [body]: ...). Probably the most remarkable example of this tipping scenario occurred in the Earth's deep history when an asteroid collided with Earth about 65 Ma ago; that singular event led to a dramatic global climate change, in particul... ### extra-terrestrial: 1 in body, 1 in references p.7 [body]: ...a part of the same statistics, as they may be generated by processes of different origin (e.g., subsurface or extra‐terrestrial). One example of such singular high‐magnitude perturbations is given by large volcanic eruptions (Rymer et al... p.39 [refs]: ...10059. https://doi.org/10.1098/rspa.2021.0059 Alvarez, L. W., Alvarez, W., Asaro, F., & Michel, H. V. (1980). Extraterrestrial cause for the cretaceous‐tertiary extinction. Science, 208(4448), 1095–1108. https://doi.org/10.1126/science.... ### subsurface: 11 in body, 0 in references p.7 [body]: ...t necessarily a part of the same statistics, as they may be generated by processes of different origin (e.g., subsurface or extra‐terrestrial). One example of such singular high‐magnitude perturbations is given by large volcanic e... p.10 [body]: ...thout broad forcing gradient High High Moderate–high Variable: Moderate– high for surface expression; low for subsurface drivers 250 m–1 km Amazon rainforest (vegetation‐moisture), West African savanna (vegetation‐monsoon) 30 m–1 ... p.18 [body]: ... understanding some ecosystem state transitions. Microwave sensors provide unique capabilities for monitoring subsurface properties and penetrating atmospheric interference. Passive microwave instruments measure naturally emitted ... p.20 [body]: ...products System observability Key state variables and drivers must be remotely sensible; feedbacks detectable Subsurface features are largely hidden; some variables only indirectly observable System understanding Baseline conditio... p.31 [body]: ... years) for robust temporal EWS detection, and high natural variability obscures resilience signals. Critical subsurface processes (water table dynamics, soil biogeochemistry) remain unobservable from space. Spatial approaches lev... p.31 [body]: ...ental gradients may prove more tractable than temporal methods, but substantial advances in record length and subsurface sensing would be needed before wetlands become a high priority. 4.3.1. Peatlands Current EO studies focus pri... p.31 [body]: ... and wetness can be monitored, critical variables including water table depth, peat temperature profiles, and subsurface carbon dynamics remain largely unobservable from space (Crichton et al., 2025). Detection requires integratin... p.33 [body]: .... Permafrost observational coverage remains limited, with surface expressions often detectable remotely while subsurface thermal and hydrological dynamics remain difficult to observe directly (Loriani et al., 2025; Nitze et al., 2... p.33 [body]: ... Despite this, EO applications to permafrost systems have used spatial patterns of vegetation change to infer subsurface thaw dynamics. Studies across Alaska and Siberia have utilized latitudinal temperature gradients to understan... p.35 [body]: ...here observational or theoretical gaps limit current capabilities. Low detection potential affects permafrost subsurface processes (Brovkin et al., 2025; Loriani et al., 2025), peatland water table dynamics (Crichton et al., 2025;... p.38 [body]: ...pecific observational requirements identified for different tipping systems, including enhanced monitoring of subsurface processes, improved integration of multiple sensor types, and development of analysis‐ready data sets with ap... ### orbital: 3 in body, 0 in references p.18 [body]: ...older Sentinel‐1 data (Rucci et al., 2012; Torres et al., 2012) operating in particular sensing modes, due to orbital mechanics and sensor capabilities. Commercial high‐resolution satellites are often specifically tasked to per... p.19 [body]: ...erm consistency in observation methodology and processing algorithms (Popp et al., 2020). Sensor degradation, orbital drift, and calibration changes can introduce artificial trends in higher‐order statistics that may be misinte... p.20 [body]: ...dge effects Sensor degradation; multi‐sensor harmonization challenges; atmospheric effects Algorithm updates; orbital drift; changing sensor characteristics Analysis readiness Properly calibrated, validated, and corrected data;... ### Milankovitch: 0 in body, 0 in references ### ENSO: 1 in body, 1 in references p.32 [body]: ...s to re‐establish has been compromised by rapidly rising sea levels coupled with increased severe weather and ENSO events (Chung et al., 2023; Duke et al., 2022). Forested wetlands are maintained by specific hydrological reg... p.41 [refs]: ...22 Duke, N. C., Mackenzie, J. R., Canning, A. D., Hutley, L. B., Bourke, A. J., Kovacs, J. M., et al. (2022). ENSO‐driven extreme oscillations in mean sea level destabilise critical shoreline mangroves—An emerging threat. PL... ### El Nino: 3 in body, 0 in references p.26 [body]: ...r Congo systems. Observable vulnerability manifests primarily through drought‐fire interactions during strong El Niño events, when reduced precipitation combines with human ignition sources to create fire conditions that can sh... p.27 [body]: ... creating diverse microclimates. Vulnerability remains through drought‐fire interactions, particularly during El Niño events. Southeast Asian rainforests are assessed as unlikely to experience regional‐scale tipping due to abun... p.31 [body]: ...ty of mangroves to compound climate stressors. Large‐scale dieback events have been documented, including the El Niño‐linked 2015–2016 dieback in the Gulf of Carpentaria (Duke et al., 2017), drought‐hurricane compound events (A... ### natural variab*: 4 in body, 0 in references p.1 [body]: ...ombining multiple types of satellite data. Key challenges include distinguishing genuine warning signals from natural variability, monitoring critical underground processes that satellites cannot directly observe, and developing metho... p.20 [body]: ...bles and forcing factors; understanding of system boundaries Clear definition of reference state and range of natural variability Account for external drivers and confounding factors; separate anthropogenic from natural signals Limite... p.20 [body]: ...derstanding of many terrestrial systems; unclear system boundaries Shifting baselines due to ongoing changes; natural variability is often poorly characterized Multiple interacting stressors; difficulty separating climate from land‐us... p.31 [body]: ...arly warning. Satellite methane records are too short (<15 years) for robust temporal EWS detection, and high natural variability obscures resilience signals. Critical subsurface processes (water table dynamics, soil biogeochemistry) ... ### internal variab*: 0 in body, 0 in references ### natural signal/forcing: 1 in body, 0 in references p.20 [body]: ...ange of natural variability Account for external drivers and confounding factors; separate anthropogenic from natural signals Limited mechanistic understanding of many terrestrial systems; unclear system boundaries Shifting baselines ... ### non-anthropogenic: 0 in body, 0 in references ### anthropogenic: 8 in body, 0 in references p.2 [body]: ...ion, and soil processes. Anticipating these transitions is increasingly important as climate change and other anthropogenic pressures intensify, and may provide critical insights into what constitutes “dangerous” levels of global war... p.2 [body]: ... of global warming beyond established policy thresholds (Solé & Levin, 2022). There is a growing concern that anthropogenic climate forcing and land‐use change are pushing key components of the terrestrial biosphere toward critical t... p.8 [body]: ...calized tipping may still occur near‐synchronously in larger clusters, due to a spatially coherent climate or anthropogenic forcing reaching a common threshold, for example, thermokarst and lake formation in degrading permafrost. Thi... p.10 [body]: ...isease vectors); in extreme cases produces domino cascades Spatial coupling is weaker but coherent climate or anthropogenic forcing reaches a common threshold across similar patches near‐synchronously, producing clusters of co‐tipped... p.20 [body]: ...ference state and range of natural variability Account for external drivers and confounding factors; separate anthropogenic from natural signals Limited mechanistic understanding of many terrestrial systems; unclear system boundaries... p.26 [body]: ...use grid cells (yellow) are overlaid to show the relationship between resilience loss, rainfall patterns, and anthropogenic pressure. Areas exhibiting the greatest resilience loss are associated with lower precipitation and closer pr... p.29 [body]: ...cadal EO records demonstrate that dryland vegetation patterns are dynamic and responsive to both climatic and anthropogenic pressures. Tiger bush systems in Niger provide one of the best‐documented examples, with changes in pattern w... p.34 [body]: ...usal dynamics of high‐altitude systems and the challenges of distinguishing climate‐driven changes from other anthropogenic pressures such as grazing. 4.6. Cross‐System Synthesis Several patterns emerge across terrestrial tipping sys... ### ozone: 0 in body, 0 in references ### UV: 0 in body, 0 in references ### ultraviolet: 0 in body, 0 in references ### radiation: 3 in body, 0 in references p.18 [body]: ...l systems through remote sensing technologies, primarily satellite‐based sensors that observe electromagnetic radiation reflected or emitted from the Earth's surface. For tipping point detection, EO provides unparalleled capabili... p.18 [body]: ... near‐infrared wavelengths (0.4–2.5 μm) form the backbone of vegetation monitoring, measuring reflected solar radiation to derive indices of vegetation health, productivity, and phenology. Key products include the Normalized Diff... p.18 [body]: ... properties and penetrating atmospheric interference. Passive microwave instruments measure naturally emitted radiation to monitor soil moisture, freeze‐thaw cycles, and vegetation water content via indices such as Vegetation Opt... ### tectonic: 0 in body, 0 in references ### earthquake: 0 in body, 0 in references ### mainstream: 0 in body, 0 in references ### false positive/alarm/signal: 5 in body, 0 in references p.21 [body]: ...eracting stressors, exhibit spatial heterogeneity, and contain numerous feedback mechanisms that can generate false signals or mask genuine early warning indicators. 3.3.4. Validation and Uncertainty Challenges Validation presents u... p.21 [body]: ...s in establishing confidence in early warning signals and distinguishing genuine approaching transitions from false alarms. Compounding these challenges, uncertainty propagation through complex processing chains remains poorly unde... p.21 [body]: ... on system type, data quality, and analytical approaches. Recent reviews highlight significant concerns about false positive rates and the difficulty of distinguishing genuine early warning signals from statistical noise in complex en... p.35 [body]: ...y et al., 2024). Success rates vary considerably across systems and regions, with some studies reporting high false positive and negative rates that undermine operational confidence (Boettiger & Hastings, 2012; Clements & Ozgul, 2018)... p.37 [body]: ...eracting stressors, exhibit spatial heterogeneity, and contain numerous feedback mechanisms that can generate false signals or mask genuine early warning indicators (Dakos et al., 2010). Current theory, largely developed for idealiz... THE REVIEW: drivers named in the body climate change / warming 32 hits on pp. 1, 2, 4, 5, 6, 7, 8, 15, 21, 23, 25, 26, 27, 30, 31, 32, 33, 34 land use / land-use 8 hits on pp. 2, 20, 25, 26, 27, 28, 36 deforestation 3 hits on pp. 25, 31 fire 54 hits on pp. 2, 5, 6, 8, 9, 10, 14, 17, 18, 25, 26, 27, 28, 31, 34 drought 10 hits on pp. 17, 25, 26, 27, 31 grazing / overgrazing / herbivory 11 hits on pp. 6, 28, 29, 30, 34 insect / bark beetle 5 hits on pp. 27, 34 disease 3 hits on pp. 8, 10, 34 invasive species 2 hits on pp. 8, 10 aquaculture / coastal development 2 hits on pp. 31 sea-level rise 7 hits on pp. 31, 32 human activities / anthropogenic 10 hits on pp. 2, 8, 10, 20, 26, 29, 31, 34 THE REVIEW: in its reference list? Brook et al. 2013 no Montoya et al. 2018 no Hillebrand et al. 2020 no Kopp et al. 2025 no Ben-Yami et al. 2024 no Hastings & Wysham 2010 no Boettiger & Hastings 2012, limits to detection yes Boettiger & Hastings 2012, prosecutor's fallacy no Feng et al. 2021 yes Higgins & Scheiter 2012 yes Nitzbon et al. 2024 yes Runge et al. 2025 yes T. Smith et al. 2023, multi-instrument yes Lenton & Williams 2013 no Hughes et al. 2013 no Tao et al. 2023 no OTHER REVIEW: lenton-2024-natcommun solar 0 geomagnet* 0 magnet* 0 pole shift 0 cosmic 0 aurora 0 space weather 0 OTHER REVIEW: bathiany-2024-survgeophys solar 3 geomagnet* 0 magnet* 1 pole shift 0 cosmic 0 aurora 0 space weather 0 solar: ...r active. Passive remote sensing measures the properties of solar radiance reflected by the Earth surface... solar: ... multispectral and SAR-based indices, novel indices such as solar-induced chlorophyll fluorescence (SIF) ... solar: ...n of absorbed photosynthetic radiation (fAPAR) derived from solar-reflective measurements, or vegetation ... OTHER REVIEW: loriani-2025-survgeophys solar 1 geomagnet* 0 magnet* 0 pole shift 0 cosmic 0 aurora 0 space weather 0 solar: ...ing ground material with lower albedo, leading to increased solar radiation absorption ensuing higher amb... OTHER REVIEW: dakos-2024-esd solar 0 geomagnet* 0 magnet* 0 pole shift 0 cosmic 0 aurora 0 space weather 0 OTHER REVIEW: abrams-2026-commsust solar 1 geomagnet* 0 magnet* 0 pole shift 0 cosmic 0 aurora 0 space weather 0 solar: ...mple: when ice cover decreases, darker surfaces absorb more solar radiation, causing further warming and ...