- Germany 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
- 1Germany’s risk is coupled, not cumulative
- 2Key findings
- 3Systems and sectors at baseline
- 4Risks and capability
- 5Hot, dry summer with low Rhine water
- 6Lenses and readings
- 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) | 2030 target in tonnes | 1,251 × 0.35 | ≈ 438 Mt |
| (2) | Annual cut needed to 2030 | (649 − 438) ÷ 6 | ≈ 35 Mt a year |
| (3) | Change in emissions, 2023 to 2024 | 649 ÷ 672 − 1 | ≈ −3.4% |
| (4) | Homes without natural-hazard cover | 100 − 54 | ≈ 46% |
| 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-DEU-NATIONAL · v0.1
- Purpose
- represent Germany 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 Land, plant or asset-level use
- Reproducibility
- strength table and sources published in this edition
typed in v0
documented within one season
documented, buffered
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-DEU-2026-Q0-1
- Type
- baseline documentary cut
- Resolution policy
- pinned · as of 30 September 2026
- Sources pinned
- 40 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-DEU-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 |
|---|---|---|---|---|
| Greenhouse-gas emissions | 2024 | Mar 2025 | annual | Mar 2026 |
| Warmest year on record | 2024 | Dec 2024 | annual | annual |
| Heat-related deaths | 2022 | 2023 | annual | annual |
| Renewable electricity share | 2024 | 2025 | annual | annual |
| Water abstraction by sector | 2019 | 2022 | three-yearly | next survey |
| Natural-hazard cover | 2024 | 2024 | annual | annual |
| July 2021 flood losses | 2021 | 2022 | one-off | , |
| Population | end 2024 | 2025 | annual | annual |
| Insect biomass | 1989–2016 | 2017 | one-off | new studies |
| Forest damage | 2018–2021 | 2022 | periodic | forest survey |
| System | Coverage | Thinnest dimension |
|---|---|---|
| Climate forcing | GOOD | local heavy-rain extremes |
| Energy | GOOD | flexibility after coal |
| Water | GOOD | small-catchment flood exposure |
| Food | PARTIAL | yield losses by Land |
| Health | GOOD | surge capacity |
| Biodiversity | GOOD | recent insect trends |
| Finance | GOOD | loss sharing under reform |
| Digital and cyber | THIN | dependency mapping |
A.5Evidence cards, two anchor sources
Issued by the Umweltbundesamt each March and checked by the expert council on climate [3]. Coverage 1990–2024. Role: binds CLI-001 and CLI-002.
EVD-DEU-001
Greenhouse-gas emissions 2024, provisional estimate1
Issued by the federal interior ministry with the Länder. Covers deaths, damage, relief and reconstruction. Role: binds WAT-004.
EVD-DEU-002
Report on the 2021 flood disaster14
| Dimension | EVD-CAN-001 | EVD-CAN-002 |
|---|---|---|
| Completeness | all sectors and gases | deaths, damage and relief |
| Timeliness | about three months after the year | about a year after the event |
| Revision | final inventory replaces the estimate | reconstruction figures updated |
| Method transparency | methods published | sources listed |
| External validation | expert council review3 | Land reports |
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 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 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 |
|---|---|
| BBK | Federal Office of Civil Protection and Disaster Assistance |
| BfG | Federal Institute of Hydrology |
| BfN | Federal Agency for Nature Conservation |
| BMEL | Federal Ministry of Food and Agriculture |
| BMI | Federal Ministry of the Interior |
| BNetzA | Federal Network Agency |
| Destatis | Federal Statistical Office |
| DWD | German Meteorological Service |
| ERK | Expert Council on Climate Change |
| GDV | German Insurance Association |
| KAnG | Federal Climate Adaptation Act |
| KSG | Federal Climate Change Act |
| RKI | Robert Koch Institute |
| UBA | German Environment Agency |
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-DEU-HDR-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 | Land notes | atlas cards for the sixteen Länder | Q2 2027 |
| A.8 | Review statements | pass-by-pass review record | AT RELEASE |
A.1 · indicator definition, greenhouse-gas emissions
- Construct
- annual greenhouse-gas emissions in Germany, excluding land use
- Unit
- Mt CO₂e
- Scope
- Climate Change Act perimeter
- Source
- UBA provisional estimate1
- Revision
- replaced by the final inventory
- Known limits
- excludes emissions embodied in imports
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
- 1Umweltbundesamt (ed.), Treibhausgas-Emissionen in Deutschland 2024: Vorjahresschätzung. UBA, Dessau-Roßlau, March 2025.back
- 14Bundesministerium des Innern und für Heimat (ed.), Bericht zur Hochwasserkatastrophe 2021: Katastrophenhilfe, Wiederaufbau und Evaluierungsprozesse. BMI, Berlin, 2022.back
- 3Expertenrat für Klimafragen (ed.), Prüfbericht zur Berechnung der deutschen Treibhausgasemissionen für das Jahr 2024. ERK, Berlin, 2025.back
- 13Gesamtverband der Deutschen Versicherungswirtschaft (ed.), Naturgefahrenreport 2024. GDV, Berlin, 2024.back
- 4Robert Koch-Institut (ed.), “Hitzebedingte Mortalität in Deutschland 2022,” Epidemiologisches Bulletin. RKI, Berlin, 2023.back
- 5Robert Koch-Institut (ed.), Hitzebedingte Mortalität in Deutschland 2023 und 2024. RKI, Berlin, 2024–2025.back
- 12Statistisches Bundesamt (ed.), Nichtöffentliche und öffentliche Wasserversorgung und Abwasserentsorgung 2019. Destatis, Wiesbaden, 2022.back
- 20Thünen-Institut (ed.), Satellitengestützte Erfassung der Waldschäden in Deutschland 2018–2021. Thünen-Institut, Braunschweig, 2022.back