- South Africa 2026
- Annex A
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
- 1South Africa’s risk runs through its pipes and its grid
- 2Key findings
- 3Systems and sectors at baseline
- 4Risks and capability
- 5Power shortfall and wastewater stress in a dense province
- 6Readings from the other desks
- 7The 2027 agenda
- 8Systems in depth
- AMethodology
- BData appendix
- CReferences and record
- ·Complete edition, for print
A.1Methods
The 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) | Emissions excluding land use, 2022 | 374.1 + 30.6 + 52.9 + 20.7 | ≈ 478.3 Mt |
| (2) | Emissions including land use, 2022 | 478.3 − 43.2 | ≈ 435.1 Mt |
| (3) | Change excl. land use since 2000 | 478.3 vs 489.2 (2000 sum of sectors) | ≈ −2.2% |
| (4) | Cut to the 2035 range, excl. land use | 1 − 397 ÷ 478.3 and 1 − 337 ÷ 478.3 | ≈ 17% to 29% |
| Strength | Definition |
|---|---|
| STRONG | a disruption in the source system has historically changed the target system’s service or output within one season |
| MODERATE | an effect is documented but buffered or slower |
| WEAK | an effect is plausible but not documented at national 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, National Model v0
- Model ID
- MDL-ZAF-NATIONAL · v0.1
- Purpose
- represent South Africa 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 evidence and analogue events
- Validation
- none yet, first validation against Q1 2027 Foundry evidence
- Uncertainty
- qualitative; strengths are hypotheses, not measurements
- Domain of validity
- national scale; not for province or asset-level use
- Reproducibility
- strength table and sources published in this edition
20couplings
typed in v0
9strong
documented within one season
7moderate
documented, buffered
4weak
plausible, undocumented
A.3The baseline evidence cut
Every Nexus edition is published from a frozen evidence cut. The baseline cut is documentary: it pins the exact edition of every source cited. Model runs begin with the first Foundry cut in Q1 2027.
- Cut ID
- NQ-ZAF-2026-Q0-1
- Type
- baseline documentary cut
- Resolution policy
- pinned · as of 30 September 2026
- Sources pinned
- 49 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
- NQ-ZAF-2027-Q1-1 at the Q1 2027 close
Lineage
- 01
source edition
- 02
pinned citation
- 03
finding
- 04
page
- 05
publication record
| Element | Baseline 2026 | Q1 2027 |
|---|---|---|
| Sources | cited publications, pinned by edition | qualified source bindings with versions |
| Analysis | stated methods and editorial estimates | typed analysis specifications |
| Models | National Model v0 specification | model runs with receipts |
| Findings | twelve baseline findings | findings re-bound to the cut |
| Review | five passes scheduled | five passes on the exact digest |
A.4Evidence age and coverage
A 2026 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 |
|---|---|---|---|---|
| Population and HIV | 2026 | Jul 2026 | annual | Jul 2027 |
| GHG inventory | 2022 | Feb 2025 | periodic | next inventory, draft 1990–2024 not read |
| 2035 climate range | 2025 | Oct 2025 | periodic | next NDC cycle |
| Load-shedding energy | H1 2025 | Sep 2025 | half-yearly | later halves not bound |
| Green Drop results | 2025 | Mar 2026 | periodic | special watch report |
| Non-revenue water | 2025 | Mar 2026 | periodic | 2027 |
| Maize forecast | 2026 | Apr 2026 | periodic | crop estimates |
| Biodiversity assessment | 2025 | Dec 2025 | periodic | figures to be bound |
| Flood deaths | 2025 | Jul 2025 | per event | per event |
| System | Coverage | Thinnest dimension |
|---|---|---|
| Climate forcing | PARTIAL | rainfall extremes by province |
| Energy | PARTIAL | 2025 generation by source |
| Food | PARTIAL | household food insecurity |
| Health | PARTIAL | water-related illness |
| Water | PARTIAL | per-system results; renewable supply |
| Biodiversity | THIN | threat status and condition |
| Finance | THIN | insured share of loss |
| Digital | THIN | dependency mapping |
A.5Evidence cards, two anchor sources
Issued by the Department of Forestry, Fisheries and the Environment under the UNFCCC. Periodic, calendar-year basis. Role: binds CLI-001 and the sector figures.
EVD-ZAF-001
National inventory 2000–20222
Issued by the Department of Water and Sanitation; read through the record of the ministry briefing to the committee. Periodic; released 31 March 2026. Role: binds WAT-005 and WAT-006, labelled as reported.
EVD-ZAF-002
| Dimension | EVD-ZAF-001 | EVD-ZAF-002 |
|---|---|---|
| Completeness | all sectors and gases | all assessed systems |
| Timeliness | about 37 months after the inventory year | about 3 months before the briefing |
| Revision | back-revised with each inventory | revised with each assessment |
| Method transparency | published methodology | risk scores; method not read in full |
| External validation | UNFCCC review process | not stated in the record read |
Evidence cards to follow in Q1 2027
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 | 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 |
| Abbreviation | Expansion |
|---|---|
| CSIR | Council for Scientific and Industrial Research |
| DFFE | Department of Forestry, Fisheries and the Environment |
| DWS | Department of Water and Sanitation |
| EAF | energy availability factor |
| FAO | Food and Agriculture Organization of the United Nations |
| GIEWS | Global Information and Early Warning System |
| IMF | International Monetary Fund |
| LULUCF | land use, land-use change and forestry |
| NBA | National Biodiversity Assessment |
| NDC | nationally determined contribution |
| PMG | Parliamentary Monitoring Group |
| SANBI | South African National Biodiversity Institute |
| SARB | South African Reserve Bank |
| Stats SA | Statistics South Africa |
A.10Technical annex
| Item | Annex | Contents | Status |
|---|---|---|---|
| A.1 | Indicator definitions | the baseline 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-ZAF-PWR-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 | Q1 2027 |
| A.6 | Sensitivity analyses | influence of coupling strengths | Q2 2027 |
| A.7 | Provincial notes | atlas cards for every province | Q2 2027 |
| A.8 | Review statements | pass-by-pass review record | AT RELEASE |
A.1 · indicator definition, wastewater system in a critical state
- Construct
- a treatment system whose Green Drop score falls below 31%
- Unit
- share of assessed systems
- Scope
- municipal wastewater treatment systems assessed in the national round
- Source
- DWS Green Drop results89
- Revision
- reassessed in each national round
- Known limits
- scoring rules were read in a secondary record, not the report itself
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
- 2Department of Forestry, Fisheries and the Environment (ed.), GHG Inventory for South Africa: 2000–2022, 9th National Greenhouse Gas Inventory Report. DFFE, Pretoria, 2025.back
- 8Department of Water and Sanitation (ed.), Green Drop, Blue Drop and No Drop reports 2025, released 31 March 2026. DWS, Pretoria, 2026.back
- 9Parliamentary Monitoring Group (ed.), “Green, Blue and No Drop Reports 2025: Ministry briefing,” Portfolio Committee on Water and Sanitation, 9 June 2026. PMG, Cape Town, 2026.back
- 5Council for Scientific and Industrial Research (ed.), “Loadshedding down 82% in H1 2025 as demand eases and EAF edges up, but tariffs still exceed inflation.” CSIR, Pretoria, 2025.back
- 27Eskom Holdings SOC Ltd (ed.), Integrated Report 2025. Eskom, Johannesburg, 2025.back
- 13South African National Biodiversity Institute (ed.), National Biodiversity Assessment 2025: summary of findings and key messages. SANBI, Pretoria, launched 9 December 2025.back