Methodology
How the edition was made: methods, the model card, the evidence cut and its age, the acceptance record and the glossary.
Contents
- ·Edition home
- ·Executive summary
- 1Observation is where evidence begins
- 2Key findings
- 3Systems and sectors at baseline
- 4Risks and capability
- 5Observation gap under an extreme season
- 6Readings from the other desks
- 7The 2027 agenda
- 8Systems in depth
- AMethodology
- A.1 Methods
- A.2 Model card, Earth Observation Sector Model v0
- A.3 The baseline evidence cut
- A.4 Evidence age and coverage
- A.5 Evidence cards, two anchor sources
- A.6 Publication acceptance record
- A.7 Status words
- A.8 How the edition is made, released and corrected
- A.9 Glossary and abbreviations
- A.10 Technical annex
- BData appendix
- CReferences and record
- ·Complete edition, for print
A.1Methods
The global baseline uses published values and four simple derivations. Each is shown in full so that any reader can reproduce it.
| No. | Derivation | Calculation | Result |
|---|---|---|---|
| (1) | Sea level rise rate, 2012 to 2025 against 1993 to 2011 | 4.75 ÷ 2.65 | ≈1.8 times |
| (2) | Earth Observation Programme share of CM25 subscriptions | 3.4 ÷ 22.3 | ≈15% |
| (3) | Growth in registered users of the Copernicus Data Space Ecosystem, 2024 | nearly 290,000 ÷ 84,000 | ≈3.5 times |
| (4) | Difference between the Copernicus and WMO 2025 temperature values | 1.47 − 1.43 °C | 0.04 °C |
| Strength | Definition |
|---|---|
| STRONG | a disruption in the source system has historically changed the target system’s service or output within one season, in more than one region |
| MODERATE | an effect is documented but buffered or slower |
| WEAK | an effect is plausible but not documented at global scale |
| Label | Rule |
|---|---|
| Reported | value as issued by its source, with year |
| Inferred | reasoned from cited evidence; never a measurement |
| Estimated | Nexus analytical value with stated method |
| Scenario | conditional on stated assumptions |
| Expert input | structured editorial judgement awaiting evidence |
A.2Model card, Earth Observation Sector Model v0
- Model ID
- MDL-GS12-EO · v0.1
- Purpose
- represent the global Earth observation system and its couplings to water, food, health and biodiversity
- Family
- graph-based system of systems
- Inputs
- the cited sources of this edition; no proprietary data
- Method
- expert-specified coupling strengths (STRONG · MODERATE · WEAK) from assessments and analogue events
- Validation
- none yet, first validation against federation evidence in 2027
- Uncertainty
- qualitative; strengths are hypotheses, not measurements
- Domain of validity
- global scale; not for asset-, site- or country-level use
- Reproducibility
- strength table and sources published in this edition
20couplings
typed in v0
3strong
documented within one season
7moderate
documented, buffered
10weak
plausible, undocumented
A.3The baseline evidence cut
Every Nexus edition is published from a frozen evidence cut. The global baseline cut is documentary: it pins the exact edition of every source cited. Federation cuts begin with the first national Foundry cuts in 2027.
- Cut ID
- DC-SECTOR-EO-GLOBAL-2026-B0
- Type
- baseline documentary cut
- Resolution policy
- pinned · as of 30 September 2026
- Sources pinned
- 45 cited sources, each at the edition and access date in the references
- Model runs
- none at baseline, analytical values are stated with their method
- Digest
- computed at freeze and recorded in the publication record
- Supersedes
- nothing, first cut of the series
- Superseded by
- the 2027 Earth observation annual cut
Lineage
- 01
source edition
- 02
pinned citation
- 03
finding
- 04
page
- 05
publication record
| Element | Baseline 2026 | 2027 global annual |
|---|---|---|
| Sources | cited global publications, pinned by edition | national, regional and sector cuts through one graph |
| Analysis | stated methods and editorial estimates | typed analysis specifications |
| Models | Earth Observation Sector Model v0 specification | model runs with receipts |
| Findings | twelve baseline findings | findings re-bound to federation evidence |
| Review | five passes scheduled | five passes on the exact digest |
A.4Evidence age and coverage
A 2026 global edition rests on evidence observed in many different years. This page shows each time base, so that no single year label hides older evidence.
| Indicator | Observed | Released | Cadence | Next release |
|---|---|---|---|---|
| Global temperature and sea level | 2025 | Mar 2026 | annual | next State of the Global Climate |
| Copernicus temperature | 2025 | Jan 2026 | annual | next Global Climate Highlights |
| Orbital environment | 2025 | May 2026 | annual | next Space Environment Report |
| Copernicus data access | 2024 | Dec 2025 | annual | next annual report |
| Landsat statistics | FY2025 | Mar 2026 | annual | next USGS update |
| ESA funding | 2025 | Dec 2025 | triennial | next ministerial meeting |
| Space budgets and market | 2023 | Dec 2024 | annual | next ESA space economy report |
| Early warning status | 2025 | Nov 2025 | annual | next status report |
| Forest extent and loss | 2025 | Oct 2025 and Apr 2026 | annual | 2027 |
| Observing-system gaps | 2022 | 2022 | periodic | next GCOS status report |
| System | Coverage | Thinnest dimension |
|---|---|---|
| Climate state | GOOD | one basis across issuers |
| Orbital environment | GOOD | operating satellites by class |
| Data access | GOOD | 2025 use statistics |
| Funding | PARTIAL | national budgets on one basis |
| Continuity | PARTIAL | funding outcomes after evidence close |
| Early warning | PARTIAL | reach and service quality |
| In situ networks | THIN | compliance and station reporting |
| Data-driven products | THIN | independent validation |
| Field | Source that would fill it | Blocker |
|---|---|---|
| Final FY2026 funding outcome for NASA Earth science and Landsat Next | NASA and USGS budget documents; Congress appropriations11 | only the FY2026 request is read; the final outcome was not retrieved |
| Outcome of NASA reviews of Terra, Aqua and Aura operations | NASA Earth Science Division12 | the end-of-science projections are read; any later decision was not retrieved |
| Status of defence satellite microwave data after 31 July 2025 | NASA Earthdata status update on DMSP data38 | the status page returned an access error; only the NSIDC notice was read |
| Global compliance with the basic surface observing network, 2025 | WMO and SOFF compliance reports43 | no retrievable global figure found at evidence close |
| Count of operating Earth observation satellites by mission class | CEOS database; operator registers | database pages need scripts and could not be read |
| Economic value of Earth observation to users | OECD space economy work36; World Bank | OECD pages returned an access error; figures in memory are not used |
| Disaster losses avoided through observation-based warning | UNDRR Global Assessment Report 202535 | the report page returned an access error and no figure is used |
| Copernicus Data Space Ecosystem use in 2025 | CDSE annual report for 20259 | not found as a primary document; only the 2024 report was read |
| Methane detection coverage after the loss of MethaneSAT | UNEP International Methane Emissions Observatory | the observatory document returned an access error |
| Energy, water and carbon footprint of Earth observation data processing | operators and data centres | not published on a common basis |
| Independent validation of data-driven Earth observation products | peer-reviewed benchmarks2930 | only developer preprints were read |
| Cyber incidents on satellite ground segments and data hubs | operators and national authorities | incident data are not published on a common basis |
| Skills and workforce for Earth observation analytics | national statistics offices; agencies | no consolidated series found |
| National Earth observation budgets on one basis | OECD36; national agencies | not accessible; ESA series cover public space budgets only24 |
A.5Evidence cards, two anchor sources
Issued by WMO on 23 March 2026 from consolidated temperature, ocean, sea level and greenhouse gas datasets. Annual. Role: binds CLI-001 and CLI-002. Only the one-page summary was opened.
EVD-GS12-001
WMO State of the Global Climate 20253
Issued by the ESA Space Debris Office on 1 May 2026 from catalogue and model data. Annual. Role: binds INF-003. Figures use a reference epoch of August 2024 for modelled objects.
EVD-GS12-002
ESA Space Environment Report1
| Dimension | EVD-GS12-001 | EVD-GS12-002 |
|---|---|---|
| Completeness | consolidated from eight temperature datasets; summary form | catalogued objects plus modelled population |
| Timeliness | about 3 months after the year | about 4 months after the year |
| Revision | annual update; interim COP updates | annual issue; reference epoch moves |
| Method transparency | dataset list published in the full report | methodology section published |
| External validation | multiple independent datasets | sensor and model comparison |
Evidence cards to follow in 2027
- WMO3: full report tables behind the one-page summary
- ESA1: mission-class counts and active payload definitions
- USGS10: archive access by user class
- GCOS16: observing gap tables by region
A.6Publication acceptance record
Editorial self-check at evidence close. Every applicable item carries a disposition; the remaining items are review, approval and deposit.
| Group | Area | Items | Pass | N/A | Pending |
|---|---|---|---|---|---|
| D1 | Identity and scope | 8 | 8 | 0 | 0 |
| D2 | Source and data | 12 | 9 | 1 | 2 |
| D3 | Analysis and models | 12 | 3 | 8 | 1 |
| D4 | Findings and claims | 9 | 8 | 0 | 1 |
| D5 | Figures, tables, maps | 10 | 6 | 2 | 2 |
| D6 | Editorial and citations | 10 | 8 | 0 | 2 |
| D7 | Review and approval | 13 | 0 | 0 | 13 |
| D8 | Artefact and design | 12 | 7 | 0 | 5 |
| D9 | Registry and release | 9 | 0 | 0 | 9 |
Publication gate
- Conditions met
- 14 of 23 at evidence close
- Blocking problems
- none recorded
- Open conditions
- reviews, approval of the exact digest, deposit, registry pointer
Not applicable at baseline
- Model runs
- first runs in Q1 2027
- Maps
- plates in Q2 2027
- Waivers
- none
A.7Status words
| Status | What it means |
|---|---|
| Observed | Measured directly and published by the source. |
| Reported | Published statistics of an official or institutional source. |
| Declared | Stated by the body concerned; not independently measured. |
| Estimated | A Nexus estimate from cited evidence, with its method in Annex A. |
| Modelled | Produced by a stated model from cited inputs. |
| Inferred | Reasoned from cited evidence; not measured. |
| Forecast | A projection by the cited source. |
| Simulated | A simulation result under stated assumptions. |
| Scenario | A conditional statement under stated assumptions; never a prediction. |
| Expert input | Expert judgement, recorded with its basis. |
| Candidate | Proposed for a later edition; not yet evidence. |
| Evidence-quality levels (EQL 1 to 5) grade the source behind a value; they are not a score of the subject. | |
A.8How the edition is made, released and corrected
Every edition is built from a sealed evidence cut, reviewed under three keys, signed and deposited before any site shows it as published; corrections go to Nexus Standards as change proposals and feed the next cut.
| Step | What happens | Source |
|---|---|---|
| 01 Evidence arrives from the pillars | Foundry seals observations and indicator series, Universe hands over after-action and scenario findings, and contributions are screened at every gateway, including this site’s. | |
| 02 The cut is sealed | On the cut date the evidence is pinned under one identifier, so anyone can rebuild the edition from exactly what it was built on. | |
| 03 The edition is assembled | The edition is drafted from its template and content pack. Agents may draft; they never publish and never decide. | |
| 04 The keys turn | At the publisher of record the truth key comes first: every value is checked against its source or stated method before the meaning and capital keys turn. No edition moves on until every key has been turned by a named steward. | |
| 05 The gate opens | A named approver releases one exact digest of the edition; any change after this point is a new version, never a silent edit. | |
| 06 Signed and deposited | The PDF, the web edition and the data bundle are signed together with a manifest and an RO-Crate description, and deposited on Zenodo with a concept and a version DOI. | |
| 07 Published on its desk’s site | Only then does the edition show as published on its desk’s Reports site, and the Collection lists it as a part. | |
| 08 Corrections go to Standards | Method and correction findings go to Nexus Standards as change proposals; citations, corrections and new contributions feed the next evidence cut. |
A teaching model of the process, not a forecast and not a record of any run; dates and counts on this page come from the programme record. Sources: Reports governance at GCRI Canada (2026); Zenodo, repository of record for Reports deposits (2026).
Lifecycle, one state at a time: Draft, Computed, Evidence bound, Reviewed, Approved for release, Published, Corrected, Superseded. This edition is a draft.
A.9Glossary and abbreviations
| Term | Meaning |
|---|---|
| Baseline Edition | the inaugural annual edition that fixes the reference state for the series |
| WEFH+B | Earth observation, energy, food, health and biodiversity, the national nexus core |
| Coupling | a typed dependency through which one system transmits to another |
| Protection gap | the share of losses not covered by insurance |
| Capability ladder | LISTED → EXISTS → ADEQUATE → TESTED → DEMONSTRATED |
| EQL | evidence-quality level, 1–5 |
| Evidence cut | a frozen resolution of exact sources and versions |
| NNC · NLC · NWG | National Nexus Consortium · National Leadership Council · National Working Groups |
| Abbreviation | Expansion |
|---|---|
| CDSE | Copernicus Data Space Ecosystem |
| CEOS | Committee on Earth Observation Satellites |
| CM25 | ESA Council at ministerial level, November 2025 |
| EO | Earth observation |
| EOP | ESA Earth Observation Programme |
| ESA | European Space Agency |
| GBON | Global Basic Observing Network |
| GCOS | Global Climate Observing System |
| GEO | Group on Earth Observations |
| PB | petabyte |
| SOFF | Systematic Observations Financing Facility |
| UDP | WMO Unified Data Policy |
A.10Technical annex
| Item | Annex | Contents | Status |
|---|---|---|---|
| A.1 | Indicator definitions | the global indicator set, with units and sources | IN THIS EDITION |
| A.2 | Coupling strengths | the twenty-cell matrix and its rationale | IN THIS EDITION |
| A.3 | Scenario specification | SCN-GS12-GAP-01 assumptions and signposts | IN THIS EDITION |
| A.4 | Capability placements | rung evidence for fifteen functions | IN THIS EDITION |
| A.5 | Model diagnostics | first runs and validation | 2027 |
| A.6 | Sensitivity analyses | influence of coupling strengths | 2027 |
| A.7 | Observing-network notes | cards for the major shared observing networks and data hubs | WITH REGIONAL EDITIONS |
| A.8 | Review statements | pass-by-pass review record | AT RELEASE |
A.1 · indicator definition: multi-hazard early warning coverage
- Construct
- share of countries that report an existing multi-hazard early warning system
- Unit
- share and number of countries
- Method
- country reports compiled by UNDRR and WMO against Sendai Framework monitoring
- Source
- UNDRR and WMO status report, WMO release2
- Uncertainty
- self-reported by countries
- Known limits
- presence of a system does not measure comprehensiveness or whether people are reached
Notes
Numbers are the edition’s reference numbers, so a note reads the same in every chapter. The full list, with every source and its licence, is in Annex C. Annex C, references
- 11Congressional Research Service (ed.), Landsat, What’s Next? In Focus IN12281, updated 16 June 2025. Congressional Research Service, Washington. Observation year 2025 (FY2026 request). Accessed 2026-11-03.back
- 12NASA (ed.), Terra: The End of an Era (with end-of-science projections for Terra, Aqua and Aura). National Aeronautics and Space Administration, Washington. Observation year 2026. Accessed 2026-11-03.back
- 38UNVERIFIED, not opened: NASA Earthdata (ed.), Status update on DMSP data products. National Aeronautics and Space Administration, Washington. The page returned an access error; later status is unknown in this edition. Observation year 2025. Accessed 2026-11-03.back
- 43UNVERIFIED, not opened: WMO and SOFF (eds.), Global Basic Observing Network compliance monitoring and SOFF annual reporting, taken from search-result summaries; no figure is used. World Meteorological Organization, Geneva. Observation year 2025. Accessed 2026-11-03.back
- 36UNVERIFIED, not opened: OECD (ed.), The Space Economy in Figures: Responding to Global Challenges. OECD Publishing, Paris, 2023. The pages returned an access error and no figure is used. Observation year 2023. Accessed 2026-11-03.back
- 35UNVERIFIED, not opened: UNDRR (ed.), Global Assessment Report on Disaster Risk Reduction 2025: Resilience Pays. United Nations Office for Disaster Risk Reduction, Geneva. The page returned an access error and no figure is used. Observation year 2025. Accessed 2026-11-03.back
- 9Copernicus Data Space Ecosystem (ed.), Annual Report 2024. European Space Agency and consortium partners, Paris. Observation year 2024. Accessed 2026-11-03.back
- 29Brown, C.F. et al., AlphaEarth Foundations: An embedding field model for accurate and efficient global mapping from sparse label data, arXiv preprint 2507.22291, July 2025 (abstract opened; not peer reviewed). Observation year 2025. Accessed 2026-11-03.back
- 30Szwarcman, D. et al., Prithvi-EO-2.0: A Versatile Multi-Temporal Foundation Model for Earth Observation Applications, arXiv preprint 2412.02732, December 2024 (abstract opened; not peer reviewed). Observation year 2024. Accessed 2026-11-03.back
- 24ESA (ed.), The Space Economy in 2023, ESA space economy report, published December 2024 (title page not present in the extracted text; section 2 headed The Space Economy in 2023). European Space Agency, Paris. Observation year 2023. Accessed 2026-11-03.back
- 3WMO (ed.), State of the Global Climate 2025, one-page summary of the report released 23 March 2026. World Meteorological Organization, Geneva. Observation year 2025 (greenhouse gases 2024). Accessed 2026-11-03.back
- 1ESA Space Debris Office (ed.), ESA’s Annual Space Environment Report, issue 10.0, 1 May 2026. European Space Agency, ESOC, Darmstadt. Observation year 2025 (modelled population at reference epoch August 2024). Accessed 2026-11-03.back
- 10USGS National Land Imaging Program (ed.), NLI Update to the National Geospatial Advisory Committee, March and April 2026 (fiscal year 2025 archive statistics; Landsat 8 and 9 status). US Geological Survey, Reston. Observation year 2025. Accessed 2026-11-03.back
- 16GCOS (ed.), The 2022 GCOS Implementation Plan (GCOS-244), abstract and summary of themes, as held in the AWI EPIC repository (the full plan was not opened). World Meteorological Organization, Geneva. Observation year 2022. Accessed 2026-11-03.back
- 2UNDRR and WMO (eds.), Global Status of Multi-Hazard Early Warning Systems 2025, as reported in the WMO press release of 12 November 2025, Early warning systems reach new heights, but critical gaps jeopardise global progress (the report itself was not opened). World Meteorological Organization, Geneva. Observation year 2025. Accessed 2026-11-03.back