- Brazil 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
- 1Brazil’s risk runs through water, forest and fire
- 2Key findings
- 3Systems and sectors at baseline
- 4Risks and capability
- 5Strong El Niño drought across rivers, hydropower and fire
- 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) | Gap to the upper end of the 2035 range | 1,490 − 1,050 | ≈ 440 Mt |
| (2) | Gap to the lower end of the 2035 range | 1,490 − 850 | ≈ 640 Mt |
| (3) | Net emissions below 2005 (indicative) | 1 − 1.49 ÷ 2.56 | ≈ 42% |
| (4) | Hydropower share of generation, 2025 | 401.4 ÷ 775.9 | ≈ 51.7% |
| (5) | Population aged 65 or over, Census 2022 | 22,169,101 ÷ 203,080,756 | ≈ 10.9% |
| 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-BRA-NATIONAL · v0.1
- Purpose
- represent Brazil 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 state 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-BRA-2026-Q0-1
- Type
- baseline documentary cut
- Resolution policy
- pinned · as of 30 September 2026
- Sources pinned
- 48 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-BRA-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 |
|---|---|---|---|---|
| GHG emissions (SEEG) | 2024 | Nov 2025 | annual | Nov 2026 |
| Energy balance | 2025 | Jun 2026 | annual | Jun 2027 |
| Amazon deforestation estimate | Aug 2024 to Jul 2025 | Oct 2025 | annual | Nov 2026 |
| Deforestation, MapBiomas | 2025 | May 2026 | annual | May 2027 |
| Burned area, MapBiomas | 2025 | Jul 2026 | annual | Jul 2027 |
| Population estimate | 1 Jul 2026 | Aug 2026 | annual | Aug 2027 |
| Poverty and inequality | 2024 | Dec 2025 | annual | Dec 2026 |
| Dengue 2024 | 2024 | Jan 2025 | weekly | ongoing |
| Food insecurity, FAO | 2023 to 2025 | Jul 2026 | annual | Jul 2027 |
| System | Coverage | Thinnest dimension |
|---|---|---|
| Climate forcing | GOOD | rainfall extremes by basin |
| Energy | GOOD | reservoir storage and gas imports |
| Biodiversity | GOOD | degradation outside clear-cut loss |
| Food | PARTIAL | fertiliser and feed dependence |
| Health | PARTIAL | heat-attributable deaths |
| Water | PARTIAL | sewage collection and withdrawals |
| Finance | PARTIAL | disaster insurance take-up |
| Digital | THIN | dependency mapping |
A.5Evidence cards, two anchor sources
Issued by the Energy Research Company (EPE) for the Ministry of Mines and Energy. Annual, calendar-year basis; published 3 June 2026 and updated 31 July 2026. Role: binds ENE-005 and the energy emissions figures.
EVD-BRA-001
Energy balance 2026, summary report10
Issued by INPE under the PRODES programme. Annual; August to July year; estimate from 282 of 516 priority tiles. Role: binds BIO-003, labelled as an estimate before consolidation.
EVD-BRA-002
Amazon deforestation estimate 202511
| Dimension | EVD-BRA-001 | EVD-BRA-002 |
|---|---|---|
| Completeness | all energy sources and sectors | priority tiles, about 90% of prior loss |
| Timeliness | about 5 months after the year | about 3 months after the period |
| Revision | annual back-revision | consolidated the following year |
| Method transparency | published methodology | published technical note |
| External validation | national energy accounting | independent land-cover networks |
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 |
|---|---|
| ANA | National Water and Sanitation Agency |
| ANDA | National Association for Fertiliser Dissemination |
| BEN | Balanço Energético Nacional (National Energy Balance) |
| CMN | National Monetary Council |
| CONAB | National Supply Company |
| DaLA | Damage and Loss Assessment |
| ECLAC | Economic Commission for Latin America and the Caribbean |
| EPE | Energy Research Company |
| IBGE | Brazilian Institute of Geography and Statistics |
| IDB | Inter-American Development Bank |
| INMET | National Institute of Meteorology |
| INPE | National Institute for Space Research |
| ONS | National Electric System Operator |
| PRODES | Amazon deforestation monitoring programme of INPE |
| SEEG | Greenhouse Gas Emissions and Removals Estimating System |
| SGB | Geological Service of Brazil |
| SINISA | National Sanitation Information System |
| TFFF | Tropical Forest Forever Facility |
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-BRA-DRT-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 | State notes | atlas cards for every state | Q2 2027 |
| A.8 | Review statements | pass-by-pass review record | AT RELEASE |
A.1 · indicator definition, net greenhouse-gas emissions
- Construct
- annual emissions minus removals by protected areas and secondary forests (SEEG definition)
- Unit
- Mt CO₂e or Gt CO₂e, 100-year potentials
- Scope
- calendar year, economy-wide
- Source
- SEEG 139; target basis in the contribution8
- Revision
- back-revised in each SEEG release
- Known limits
- differs in method from the national inventory; land-use values carry wide uncertainty
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
- 10Empresa de Pesquisa Energética (ed.), Balanço Energético Nacional 2026: Relatório Síntese, ano base 2025. EPE and Ministério de Minas e Energia, Rio de Janeiro, 3 June 2026, updated 31 July 2026. Observation year: 2025.back
- 11Instituto Nacional de Pesquisas Espaciais (ed.), Estimativa de desmatamento na Amazônia Legal para 2025 é de 5.796 km², Nota técnica, Programa BiomasBR (PRODES). INPE, São José dos Campos, October 2025. Observation year: 2025 (August 2024 to July 2025).back
- 9Observatório do Clima (ed.), SEEG 13: Análise das emissões brasileiras de gases de efeito estufa e suas implicações para as metas climáticas do Brasil, 1970 a 2024. Observatório do Clima, São Paulo, November 2025, read from press reports and search excerpts of the release because the report PDF returned HTTP 403. Observation year: 2024.back
- 12MapBiomas Alerta (ed.), Relatório Anual do Desmatamento no Brasil, RAD 2025: Destaques (factsheet, version of 26 May 2026). MapBiomas, São Paulo, 2026. Observation year: 2025.back
- 14MapBiomas (ed.), RAF 2025: segunda edição do Relatório Anual do Fogo no Brasil, released 21 July 2026, as reported by Correio Braziliense, “Área queimada no Brasil cai para 12,7 milhões de hectares em 2025, aponta MapBiomas,” July 2026. Observation year: 2025.back
- 17Ministério da Saúde (ed.), Painel de Monitoramento das Arboviroses, data to 28 December 2024, as reported by Agência Brasil, “Casos de dengue em 2024 passam de 6,4 milhões; mortes somam 5,9 mil,” January 2025. Observation year: 2024.back
- 8Federative Republic of Brazil (ed.), Brazil’s Nationally Determined Contribution: National determination to contribute and transform (second NDC). Submission to the UNFCCC, Brasília, November 2024. Observation year: 2024 (2005 reference; target year 2035).back