Methodology

How the edition was made: methods, the model card, the evidence cut and its age, the acceptance record and the glossary.

9 min read0 figures12 tables6 notesNR-STRATEGIC-POLYCRISIS-GLOBAL-2026-BASELINE.

Contents

A.1Methods

The global baseline uses published values and four simple derivations. Each is shown in full so that any reader can reproduce it.

Table A.1Methods
No.	Derivation	Calculation	Result
(1)	Insured share of 2025 losses	108 ÷ 224	≈ 48%
(2)	Uninsured 2025 losses	224 − 108	US$116 bn
(3)	Insured share in Asia	9 ÷ 73	≈ 12%
(4)	Insured share in North America	93 ÷ 133	≈ 70%

Table A.2Coupling strength scale (matrix and model card)
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

Table A.3Status grammar
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, Polycrisis System Model v0

Model ID: MDL-SR01-POLYCRISIS · v0.1
Purpose: represent the world as coupled water, energy, food, health and biodiversity systems with forcing and transmission layers
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 country, regional or asset-level use
Reproducibility: strength table and sources published in this edition

20couplings

typed in v0

11strong

documented within one season

5moderate

documented, buffered

4weak

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-STRATEGIC-POLYCRISIS-GLOBAL-2026-B0
Type: baseline documentary cut
Resolution policy: pinned · as of 30 September 2026
Sources pinned: 47 cited sources, each at the edition and retrieval 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 polycrisis annual cut

Lineage

01
source edition
02
pinned citation
03
finding
04
page
05
publication record

Table A.4From the baseline cut to the federation cut
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	Polycrisis System 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.

Table A.5Evidence age and coverage
Indicator	Observed	Released	Cadence	Next release
Global mean temperature	2025	Mar 2026	annual	Mar 2027
Natural-disaster losses	2025	Jan 2026	annual	Jan 2027
Total GHG emissions	2023	Oct 2024	annual	annual
Energy-related CO₂	2024	Mar 2025	annual	annual
Hunger and food insecurity	2024	Jul 2025	annual	annual
Safely managed water	2022	Jul 2023	biennial	biennial
Air-pollution deaths	2019–2020	periodic	periodic	next WHO update
Wildlife population index	1970–2020	Oct 2024	biennial	2026 edition
Forced displacement	2024	Jun 2025	annual	annual
Public debt	2024	2025	annual	annual

Table A.6Coverage by system at baseline
System	Coverage	Thinnest dimension
Climate forcing	GOOD	regional extremes and tipping proximity
Energy	GOOD	compute demand and water use
Finance	GOOD	losses in low-income regions
Food	GOOD	concurrency of shortfalls
Water	PARTIAL	groundwater and basin stress
Health	PARTIAL	heat mortality outside high-income regions
Biodiversity	PARTIAL	ecosystem condition beyond protected areas
Digital and cyber	THIN	dependency mapping

A.5Evidence cards, two anchor sources

Issued by the World Meteorological Organization from nine international temperature datasets and contributions from national meteorological services, regional climate centres and UN partners. Annual, released each March. Role: binds CLI-001 and the record ocean-heat and energy-imbalance signals.

EVD-SR01-001

State of the Global Climate 2025¹

Issued by Munich Re from its global natural-disaster loss database, maintained since 1980. Overall and insured losses with fatalities, by peril and region; 10- and 30-year inflation-adjusted averages. Role: binds FIN-002 and FIN-003.

EVD-SR01-002

NatCatSERVICE 2025 full-year figures²

Table A.7Quality dimensions at baseline
Dimension	EVD-SR01-001	EVD-SR01-002
Completeness	near-global; gaps filled statistically	reported and estimated losses
Timeliness	about three months after the year	weeks after the year
Revision	datasets revised as records improve	event estimates revised
Method transparency	datasets and methods published	summary methodology published
External validation	multiple independent datasets	compared with other loss providers

Evidence cards to follow in 2027

SOFI 2025⁷, hunger estimation and uncertainty
JMP⁸, water and sanitation service ladders
Living Planet Index⁹, population trend method
A World of Debt¹³, interest and social spending comparisons

A.6Publication acceptance record

Editorial self-check at evidence close. Every applicable item carries a disposition; the remaining items are review, approval and deposit.

Table A.8Publication acceptance record
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

Table A.9The status every value carries
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	Nexus Standards reviews the parts applied: identifiers, citation, metadata, figures and crosswalks, cited as preparatory working drafts. 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 five sites	Only then do the five Reports sites show the edition as published, each reading it through its own lens.
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 Nexus Standards (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

Table A.10Series terms
Term	Meaning
Baseline Edition	the inaugural annual edition that fixes the reference state for the series
WEFH+B	water, 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

Table A.11Abbreviations used in this edition
Abbreviation	Expansion
AMIS	Agricultural Market Information System
BBNJ	Biodiversity Beyond National Jurisdiction (High Seas Agreement)
C3S	Copernicus Climate Change Service
ENSO	El Niño–Southern Oscillation
GAR	Global Assessment Report on Disaster Risk Reduction
GDACS	Global Disaster Alert and Coordination System
GIEWS	Global Information and Early Warning System on Food and Agriculture
IHR	International Health Regulations (2005)
IPBES	Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services
IPCC	Intergovernmental Panel on Climate Change
ISSB	International Sustainability Standards Board
JMP	WHO/UNICEF Joint Monitoring Programme
SOFI	The State of Food Security and Nutrition in the World
WMO	World Meteorological Organization

A.10Technical annex

Table A.12Technical 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-SR01-BBF-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	Regional notes	regional baseline cards	WITH REGIONAL EDITIONS
A.8	Review statements	pass-by-pass review record	AT RELEASE

A.1 · indicator definition, global mean near-surface temperature

Construct: annual global mean near-surface air temperature anomaly
Unit: °C relative to 1850–1900
Method: synthesis of nine international datasets
Source: WMO State of the Global Climate 2025¹
Uncertainty: ±0.13 °C (90% range)
Known limits: a single year above 1.5 °C does not mean the Paris limit is passed

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.

1WMO (ed.), State of the Global Climate 2025, WMO-No. 1391. World Meteorological Organization, Geneva, March 2026.back
2Munich Re (ed.), Natural disasters in 2025: NatCatSERVICE full-year figures. Munich Re, Munich, January 2026.back
7FAO, IFAD, UNICEF, WFP and WHO (eds.), The State of Food Security and Nutrition in the World 2025. FAO, Rome, 2025.back
8WHO and UNICEF (eds.), Progress on Household Drinking Water, Sanitation and Hygiene 2000–2022. Joint Monitoring Programme, New York and Geneva, 2023.back
9WWF (ed.), Living Planet Report 2024: A System in Peril. WWF, Gland, 2024.back
13UNCTAD (ed.), A World of Debt 2025: It Is Time for Reform. UNCTAD, Geneva, 2025.back

Cite this annex

Valadbaygi, S. (Ed.). (2026). Annex A: Methodology. In Strategic Systems Report 2026: Global Polycrisis and Cascading Systems Risk (Baseline Edition 2026, Report No. NR-STRATEGIC-POLYCRISIS-GLOBAL-2026-BASELINE) [Draft under review]. The Global Centre for Risk and Innovation (GCRI).

Every citation form of the whole report, BibTeX and RIS included, is on the edition home. Cite this report.