GCRI · Systemic Risk Management

Scenario and stress testing

A stress test asks what happens to an organisation, system or plan under a severe but plausible event, before a real shock answers the question. Scenarios describe how such events might unfold; stress tests measure the effect on capital, capacity, services or people. This page sets out how scenarios are designed, how stress tests propagate shocks through dependencies, and how results serve the boards, ministries and supervisors that must act on them.

01Register

Scenario and stress testing on the record.

02The question

Scenario and stress testing: how the risk develops.

Challenging plans and assumptions. The dossier below sets out how the risk develops, what is measured, where the data come from, how it is modelled and who decides.

Mechanism

Scenarios set the question

A scenario fixes the trigger, its severity, its timing and the conditions around it. Choosing only familiar or mild scenarios produces reassuring results that say little about real vulnerability.

Mechanism

Shocks travel through the model

The stress spreads through dependencies represented in the test: suppliers, counterparties, infrastructure and staff. What the model leaves out cannot fail, so omissions bias results toward resilience.

Mechanism

Responses change the outcome

Institutions react during a crisis by selling assets, cutting services or drawing on reserves, and those reactions affect others. Tests that hold behaviour fixed miss these second-round effects.

Mechanism

Reverse tests find breaking points

Reverse stress testing starts from failure and asks which combinations of events would cause it. It reveals vulnerabilities that forward scenarios chosen in advance may never reach.

03Geography

Hazards and exposure in Asia.

Daytime surface heat, population density and flood water over Asia, from NASA GIBS. Each layer carries its own date.

The interactive map needs JavaScript; the layer list and sources are below.

Layers 3

Hazards and exposure, for this page

About this layer
Evidence
Observed (persistent cloud still leaves gaps)
Source
VIIRS NOAA-20 Level 3, 8-day (NASA LANCE)
Provider
NASA LANCE
Licence
NASA open data
Vintage
8-day; Satellite 8-day composite; persistent cloud still leaves gaps
Newest at build
2026-09-14
Resolution
about 1 km grid
Uncertainty
Satellite skin temperature of the ground over the 8 days ending on the date shown, a heat exposure indicator; not air temperature, heat index or a heat warning.
Reached through
gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
Evidence
Estimated
Source
Gridded Population of the World v4.11 (NASA SEDAC (CIESIN, Columbia University))
Provider
NASA SEDAC (CIESIN, Columbia University)
Licence
CC BY 4.0
Vintage
null; Census-based estimate, static (2020)
Resolution
about 1 km grid
Uncertainty
Census-based estimate of people per square kilometre in 2020, shown as exposure context; not a count of people affected by any hazard.
Reached through
gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
Evidence
Observed (clouds leave gaps)
Source
VIIRS Global Flood Product (NASA LANCE)
Provider
NASA LANCE
Licence
NASA open data
Vintage
daily; Satellite detection; clouds leave gaps
Newest at build
2026-10-14
Resolution
about 250 m grid
Uncertainty
Satellite detection; clouds leave gaps. Satellite or model raster as the provider publishes it. Clouds, swath gaps and retrieval error leave gaps and noise; values are indicators, not measurements at a place.
Reached through
gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
Evidence
Observed
Source
VIIRS NOAA-20 corrected reflectance (NASA LANCE)
Provider
NASA LANCE
Licence
NASA open data
Vintage
daily; Satellite image
Newest at build
2026-10-14
Resolution
about 250 m grid
Uncertainty
Satellite image. Satellite or model raster as the provider publishes it. Clouds, swath gaps and retrieval error leave gaps and noise; values are indicators, not measurements at a place.
Reached through
gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
Evidence
Estimated
Source
GPM IMERG (NASA GES DISC)
Provider
NASA GES DISC
Licence
NASA open data
Vintage
daily; Satellite estimate, near real time
Newest at build
2026-10-12
Resolution
about 2 km grid
Uncertainty
Satellite estimate, near real time. Satellite or model raster as the provider publishes it. Clouds, swath gaps and retrieval error leave gaps and noise; values are indicators, not measurements at a place.
Reached through
gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
Evidence
Observed
Source
GHRSST MUR25 (NASA JPL PO.DAAC)
Provider
NASA JPL PO.DAAC
Licence
NASA open data
Vintage
daily; Satellite analysis
Newest at build
2026-10-12
Resolution
about 2 km grid
Uncertainty
Satellite analysis of how far sea temperature departs from its usual value for the date shown; a marine heat indicator, not a coral bleaching alert.
Reached through
gibs.earthdata.nasa.gov, only after you allow the live map

Latest available

NASA GIBS / EOSDIS · ASTER GDEM (METI, NASA) · Blue Marble (NASA) · © OpenStreetMap contributors (ODbL) · Natural Earth

Loading the latest NASA imagery.

Drag to move. Ctrl or ⌘ and scroll, pinch or the buttons to zoom; hover for the values under the pointer; reset returns to the region.

Hazards and exposure, framed on Asia.Satellite and model products as NASA publishes them, each with its own date. They are indicators, not assessments of any place.

Data: NASA GIBS · ASTER GDEM · Blue Marble · © OpenStreetMap contributors · Natural Earth · NASA EONET · U.S. Geological Survey · NASA JPL OPERA DIST-ALERTSources and licences

  • We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS). Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
  • We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS). Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
  • VIIRS near-real-time products (flood, land surface temperature, snow cover, corrected reflectance), NASA LANCE; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
  • Center for International Earth Science Information Network (CIESIN), Columbia University. 2018. Gridded Population of the World, Version 4 (GPWv4): Population Density, Revision 11. NASA Socioeconomic Data and Applications Center (SEDAC). Licensed under CC BY 4.0. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). doi:10.7927/H49C6VHW. CC BY 4.0
  • GPM IMERG precipitation, NASA Precipitation Processing System; distributed by the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC); imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
  • GHRSST Level 4 MUR analyses, NASA Jet Propulsion Laboratory; distributed by the NASA Physical Oceanography DAAC (PO.DAAC); imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
  • ASTER GDEM is a product of METI and NASA (ASTER Global Digital Elevation Model V003, NASA LP DAAC); imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). Cite as: NASA/METI/AIST/Japan Spacesystems and U.S./Japan ASTER Science Team (2019). ASTER Global Digital Elevation Model V003. doi:10.5067/ASTER/ASTGTM.003. NASA open data
  • Made with Natural Earth. Free vector and raster map data @ naturalearthdata.com. Public domain
  • © OpenStreetMap contributors (ODbL), via NASA GIBS (coastlines, boundaries, roads and place names). Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). ODbL
  • Blue Marble, NASA Earth Observatory; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into hexagonal cells where shown (modified). NASA open data
  • Context on the globe and flat map: coastlines, boundaries, roads and place names from NASA GIBS reference layers (OpenStreetMap data, ODbL, © OpenStreetMap contributors); Blue Marble imagery as an optional base; 3D terrain and the elevation read-out from the ASTER GDEM elevation colour index (5 m to 200 m classes, exaggerated for legibility). Boundaries are drawn as published and imply no position on any territory.
  • Live events: NASA Earth Observatory Natural Event Tracker (EONET); events are indicative and keep their original source links.
  • Live: NASA EONET Events are indicative, not authority warnings.
  • Live: U.S. Geological Survey Events are indicative, not authority warnings.
  • Observed (EO): NASA JPL OPERA DIST-ALERT (contains modified Copernicus Sentinel data 2026). We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS).
  • NASA GIBS: We acknowledge the use of imagery provided by services from NASA’s Global Imagery Browse Services (GIBS), part of NASA’s Earth Science Data and Information System (ESDIS).
  • River discharge forecast, 30 days with range (GloFAS via Open-Meteo): Contains modified Copernicus Emergency Management Service information 2026; not a flood warning.
  • Weather data by Open-Meteo.com (https://open-meteo.com/), licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/).
  • Optional layers (11 sources in the layer list: live, forecast, observed and context) print their provider credit on the map and here when switched on; forecasts are model output and derived indices are estimates.

Layers and dates

  • Land surface temperature, day, 8-day composite: VIIRS NOAA-20 Level 3, 8-day, NASA LANCE · 14 Sep 2026
  • Population density, 2020: Population: CIESIN, Columbia University, Gridded Population of the World v4.11 (2018), NASA SEDAC, CC BY 4.0 · static
  • Flood water, 3-day composite: VIIRS Global Flood Product, NASA LANCE · 14 Oct 2026
  • True colour: VIIRS NOAA-20 corrected reflectance, NASA LANCE · 13 Oct 2026
  • Precipitation rate, daily mean: GPM IMERG, NASA GES DISC · 12 Oct 2026
  • Sea surface temperature anomaly: GHRSST MUR25, NASA JPL PO.DAAC · 12 Oct 2026

04Across the domains

Stress tests that cross domains test the joins, not the parts.

Scenario work is designed for the Scenario and Stress-Test series, always labelled as scenario evidence. Financial supervisors use the NGFS scenarios for climate stress testing; national cross-sector tests need storylines built with each sector’s experts.

  • Storylines with the assumptions each sector’s experts checked.
  • Results of past stress tests a public body has published.
05Simulator

Stocks, flows, delays and a tipping threshold.

Two stocks, pressure and adaptive capacity, joined by a reinforcing growth loop, a delayed balancing response and damage when pressure outruns capacity; past the threshold the system can tip. Teaching model with stated illustrative values, not a prediction. The map on this page shows Asia; the model itself is not tied to a place.

Controls

Growth of pressure
6.0% a year
Efficacy of capacity in reducing pressure
4.0% a year
Investment response to perceived pressure
20%
Perception delay
4.0 years
Tipping threshold of pressure
60 index
Amplification past the threshold
2.0 times
Years simulated
50 years

Readouts

Peak pressure
113 index
Capacity at the end
186 index
Years over the threshold
15.8 years
Numbers, methods and sources
YearPressureCapacityPerceived
020.050.020.0
423.344.921.2
827.242.224.0
1231.742.327.7
1636.845.532.2
2042.351.537.2
2447.960.342.6
2853.271.348.0
3257.884.353.1
3666.498.458.4
4082.7115.969.7
4497.8139.783.8
48109.1169.497.3

Methods

  1. System dynamics Forrester (1961), Industrial Dynamics, MIT Press; Sterman (2000), Business Dynamics
  2. Critical transitions and tipping points Scheffer and others (2009), Early-warning signals for critical transitions, Nature 461
  3. Causal loop diagram Sterman (2000), Business Dynamics, McGraw-Hill
  4. Uncertainty fan (parameter Monte Carlo) Spiegelhalter, Pearson and Short (2011), Visualising uncertainty about the future, Science 333
  5. One-at-a-time sensitivity (tornado) Saltelli and others (2008), Global Sensitivity Analysis: The Primer, Wiley

Data

No observed data enters this model: it runs on the teaching values set by the controls, to be replaced with a programme’s own evidence.

Stocks, flows, delays and a tipping threshold. Illustrative teaching model: it runs on the values set by the controls, not on measured data. Methods: System dynamics (Forrester (1961), Industrial Dynamics, MIT Press; Sterman (2000), Business Dynamics); Critical transitions and tipping points (Scheffer and others (2009), Early-warning signals for critical transitions, Nature 461); Causal loop diagram (Sterman (2000), Business Dynamics, McGraw-Hill).
06Indicators

What is measured, and how well.

Each indicator carries its unit, its cadence, the kind of source behind it and the evidence label a value would carry. No values are shown: a programme supplies them under its own authority.

IndicatorUnitCadenceSource typeLabel
Scenarios tested per cyclecount by hazard typeannualStress testing programme recordsREPORTED
Capacity or capital shortfall under stressunits of the tested resourceper scenarioStress test outputsMODELLED
Time to breach a critical thresholddaysper scenarioStress test outputsMODELLED
Dependencies represented in the testpercent of mapped critical dependenciesper testTest design documentationDECLARED
Actions taken after the testcount of management actions recordedannualFollow-up recordsREPORTED
Reverse stress test conditions identifiedcount of failure conditionsper testReverse stress test recordsMODELLED
07Twin and cascade simulator

Model scenario and stress testing as a system. Run the cascade.

Assembled from the Nexus Standards area profile Global and systemic risk: the hazards it names, the systems and sectors that carry the loss, the controls that dampen it and the data that observe it. Choose the components, pick an initiating hazard and step through the cascade. The Map view places the run on an example geography with open data. Every coupling weight is a stated assumption you can change. A teaching model, not a forecast, an assessment or a certification. To model a place of your own choosing, open the full System Builder.

Hazards

  • Dam failure
  • Financial contagion
  • River flood (set off downstream)
  • Flash flood (set off downstream)
  • Mass displacement (set off downstream)
  • Widespread power outage (set off downstream)
  • Water supply shortfall (set off downstream)
  • Sovereign debt crisis (set off downstream)
  • Currency crisis (set off downstream)

Controls

  • NS-0 Constitution and principles
  • NS-3 Risk record UNIs (grammar, legacy crosswalk, allocation authority)
  • NS-9 Contextual UNIs (deployments, instances, programme instances)
  • NS-10 Policies and clauses (machine-readable obligations: definition, binding, evaluation and enforcement)
  • NS-11 Verification and monitoring (evidence, attestations, zero-trust conformance observation)
  • NS-14 Conformance and crosswalk to external standards
  • NRS-H120 Hazard family: Structural fragility of interconnected systems (NHS-1 sys.fragility)
  • NRS-C6 Systemic and cascading risk
  • NRS-H61 Hazard family: Cascading failure (NHS-1 sys.cascade)
  • NRS-H62 Hazard family: Compound and multi-hazard events (NHS-1 sys.compound)
  • NRS-H94 Hazard family: Systemic cyber events (NHS-1 cyber.systemic-cyber)
  • NRS-H60 Hazard family: Supply-chain and flow disruption (NHS-1 sys.supply-chain)

Observation

  • INFORM Risk Index (listed for reference)
  • World Bank Open Data and World Development Indicators API (listed for reference)
  • IMF data services (WEO, IFS, FSI via SDMX) (listed for reference)
  • Direct economic loss attributed to disasters in relation to global GDP
  • Macroeconomic Dashboard

Example geography

  • Bangladesh: 134 hexagonal cells
  • Night lights tonight, outages (VIIRS Day/Night Band), NASA GIBS
  • Surface water through cloud, 30 m (OPERA DSWx-S1 radar), NASA GIBS
  • Rain rate, last half hour (IMERG), NASA GIBS
  • Surface soil moisture (SMAP), NASA GIBS
08Sources

Where the evidence comes from.

Named public datasets and institutional records, each with its licence class. Sources by agreement are used only under their terms and never republished.

SourceWhat it givesLicence class
NGFS climate scenariosReference climate transition and physical risk pathways for financial and policy stress testsOpen, attribution, NGFS terms of use
IPCC Shared Socioeconomic Pathways and the scenario databaseLong-term socioeconomic and emissions pathwaysOpen, licence per database (to check)
Published supervisory stress test methodologies and resultsScenario design and aggregate outcomes from central banks and supervisorsPublic records, terms per authority
National risk assessment reasonable worst-case scenariosGovernment-published planning scenarios for civil contingenciesPublic records, licence per government
UNDRR guidance on scenario-based exercisesDesign guidance for exercises that test preparednessPublic, UN terms of use
09Methods and evidence

How scenario and stress testing is modelled, measured and tested.

The model, its assumptions, its data and its uncertainty, in the form a scientist or engineer would check. Structures follow published methods. The values drawn are illustrative, not findings.

Model, equations and assumptions

The model structure used for scenario and stress testing, the assumptions it makes and how each is tested.

Risk of element iRi = f(Hi, Ei, Vi, Ci)hazard, exposure, vulnerability and coping capacity
Expected annual lossEAL = ∑k pk · Lkover events k with annual probability pk
Coupled systemsxt+1 = A xt + B ut + εtA carries the couplings, u the shock, ε the error
AssumptionWhy it is madeHow it is tested
Hazard and exposure are independent within an eventKeeps the loss integral tractableCompare with a copula fit on joint records
Couplings are linear near the operating pointLets shocks propagate through APerturb beyond the linear range and compare
Vulnerability curves transfer between placesLocal curves are rarely availableValidate against observed losses where they exist
Inputs
versioned datasets with provenance
Outputs
distributions, never single numbers
Code
released with the model card and tests
Reproduction
same data, code, environment and seed
Standard risk and state-space formulations; the assumptions listed are typical of the method, stated for review, not results.
FAIR guiding principles · GO FAIR and FORCE11W3C PROV · World Wide Web ConsortiumGuidance on consistent treatment of uncertainties · IPCCCEOS Analysis Ready Data · Committee on Earth Observation Satellites
10Decisions

Who decides, and what the evidence serves.

Systemic Risk Management prepares evidence. The decisions below are taken by the authorities named, under their own rules, and never by the platform.

Who decidesThe questionEvidence this page serves
Boards and executive committeesWhether buffers and plans are adequate for severe but plausible eventsShortfalls and times to breach by scenario; reverse stress conditions
Central banks and financial supervisorsWhich scenarios to set for supervisory exercisesScenario libraries; cross-sector dependency evidence
Civil contingency and emergency plannersWhich planning assumptions to use for national capabilitiesReasonable worst-case scenarios and their basis
Ministries of financeHow much fiscal space to hold for contingent liabilitiesPublic sector stress tests with assumptions stated

Outputs this topic produces

  • Scenario libraries with triggers, severity and assumptions documented
  • Stress test designs that represent cross-sector dependencies
  • Reverse stress test protocols for public services and organisations
  • Exercise reports prepared for review by the institution tested
11Core questions

What scenario designers ask.

  • Is the scenario severe enough to be informative, yet plausible enough to be taken seriously?
  • Does it combine shocks that are likely to occur together, rather than treating them as independent?
  • Does it include the reactions of other actors, which can amplify or damp the shock?
  • What would the organisation actually do, and is that response realistic under stress?
12Mechanisms

Why scenarios reveal what forecasts miss.

Forecasts aim for the most likely outcome and tend to understate extremes. Plans built on them fail when the unusual happens. Scenarios deliberately explore the space of outcomes, including combinations that historical data has not yet shown. Reverse stress testing works backwards: it starts from failure and asks what would have to happen to cause it, which often exposes vulnerabilities that forward scenarios miss.

Stress tests reveal not only losses but behaviour: which decisions would be needed, who would make them, what information they would need and how long it would take. Many failures in real crises come from slow or unclear decisions rather than from the size of the initial shock.

13Methods and limits

How scenarios and stress tests are built.

  1. 01

    Narrative scenarios

    Qualitative stories built by diverse groups around key uncertainties. Limits: can be shaped by group consensus and familiar fears.

  2. 02

    Quantified stress scenarios

    Consistent sets of shocks to model inputs, designed with scenario design and stress testing methods. Limits: model results depend on how the model represents behaviour under stress.

  3. 03

    Reverse stress tests

    Identify scenarios that would cause failure. Limits: many paths can lead to failure, and choosing which to study requires judgement.

  4. 04

    Exercises

    Tabletop and live exercises test decisions and coordination. Limits: participants know it is an exercise.

14Methods

How it is studied, and what the methods cannot say.

  1. Scenario design and stress testingCross-sector scenario design · Reverse stress testing · Second-round effectsApplied here
  2. Network science and contagionDependency network mapping · Centrality and concentration · Failure propagation simulationApplied here
  3. Uncertainty quantification and model validationPropagating input uncertainty · Separating kinds of uncertainty · Deep uncertainty framingApplied here
  4. Probability and statisticsFrequency and severity modelling · Dependence between risks · Combining data and judgementApplied here
15Where this page’s references

Where this page’s references lead.

The bodies and documents this page is read against. Status and editions change; each link goes to the issuing body.

16Questions

Questions and answers.

What is a stress test?
An analysis of how an organisation or system would perform under a severe but plausible adverse scenario, used to find vulnerabilities and test buffers and plans.
What is reverse stress testing?
A test that starts from a defined failure, such as a service stopping or capital falling below a minimum, and works backward to identify the scenarios that would cause it.
Is a scenario a prediction?
No. A scenario is a plausible description of how events might unfold under stated assumptions, chosen to test a decision, and it carries no probability unless one is assigned.
Is a stress test a prediction?
No. It tests what would happen under a chosen scenario. The scenario is a tool for challenge, not a forecast.
How severe should a scenario be?
Severe enough to expose weaknesses, plausible enough that decision-makers act on the results. Reverse stress testing helps calibrate this.
Can the platform design a stress test for my organisation?
No. It publishes methods that organisations and authorities can apply themselves.
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