Illustrative: plants and ports, the routes between them and goods moving along; one node is disrupted and its routes stall

Risk Academy, led by the Nexus Consortium · Course catalogue · Systems and Nexus Studies

Systemic Risk and Complexity

Systemic, compound and cascading risk

Systemic, compound and cascading risk, taught twice over: as the working methods of the field and as its frontier since 2024, with labs on the Academy's tools, open data and the Nexus Standards.

Core course Frontier course

The discipline

01Core course · L2 Intermediate

Systemic, compound and cascading risk: foundations and practice

This area covers risk that arises from the interdependence of systems: compound events in which hazards combine, cascading failures across infrastructure, economies and societies, shock propagation through networks, tipping points, and the governance and assessment of systemic risk at national and global level.

Level
L2 Intermediate
Study time
about 24 hours (planning estimate)
Status
In authoring
Prerequisites
An L1 course in the area, or an entry review

Why now

It is a documented case of cascading failure in a changing power system, with lessons for interdependent infrastructure. ENTSO-E, Final Report on the Grid Incident in Spain and Portugal on 28 April 2025, 20 March 2026

Learning outcomes

  1. Define systemic risk and the other key terms of the discipline and use them correctly in a written case
  2. Explain systemic risk concepts and compound events with a worked example and its source
  3. Apply the discipline's method to a documented case and explain each result with its source
  4. Analyse a named case against cascading failure, stating evidence, date and limits

Modules

  1. Systemic risk concepts
    • Systemic risk concepts
    • Compound events
    • Cascading failure
  2. Shock propagation
    • Shock propagation
    • Interdependency mapping
    • Tipping points
  3. Systemic risk governance
    • Systemic risk governance
    • Global systemic risk assessment
  4. Lab: the discipline's method
    • A failure in one system removes a share of the function of the systems that depend on it; when the dependence runs both ways the loss feeds back, and above a critical coupling the cascade size jumps from a fraction of the first shock to most of both systems.
    • Work the method through a documented case and explain each result
    • Read the method's sources and stated values

Labs with Academy tools

Nexus Standards

Teaches

  • NRS-C6 Systemic and cascading risk
  • NRS-H60 Hazard family: Supply-chain and flow disruption
  • NRS-H61 Hazard family: Cascading failure
  • NRS-H62 Hazard family: Compound and multi-hazard events
  • NRS-H120 Hazard family: Structural fragility of interconnected systems
  • NRS-M7 Method fabric: Networks, dependency and systemic risk

Relies on

  • NS-1 The UNI and the artefact catalogue
  • NS-16 UNI application profile (how articles, documents, code, data, APIs and interfaces carry the UNI)
  • NRS-C1 Risk vocabulary and ontology
  • NRS-C2 Risk assessment method
  • NRS-C3 Hazard, exposure, vulnerability and capacity data
  • NRS-C4 Risk data model, identifiers and exchange
  • NRS-C7 Early warning, triggers and anticipatory action
  • NRS-C8 Evidence, uncertainty and provenance

Assessment

  • 40%Lab recordWork the discipline's method through a documented case and explain each result with its source and date
  • 40%Case memoApply the discipline's methods to a named place or organisation, stating evidence and limits
  • 20%Key terms checkShort answers on the key terms, marked against the definitions

Delivery

  • Self-paced online, with the labs in the browser
  • Cohort study over six to eight weeks, with a weekly lab review
  • Co-delivered with a partner institution, inside its own courses

Partner on this course

  • Co-teach a module and bring a current case from your work
  • Host a cohort for your learners, with your own schedule and review
  • Contribute a lab: a dataset your institution publishes openly, or a model
  • Review the course content and its references before it opens
  • Translate the course and adapt its cases to your region

How institutions and experts take part

In the Academy LMS

Course on the learning platform
Intermediate, 4 topics
Cohort group
A community group for each cohort of learners
Achievement
Recorded on completion of the assessed work

Open now in this discipline

References

  1. ENTSO-E, Final Report on the Grid Incident in Spain and Portugal on 28 April 2025, 20 March 2026
  2. Buldyrev, Parshani, Paul, Stanley and Havlin, Catastrophic cascade of failures in interdependent networks, 2010
  3. Rinaldi, Peerenboom and Kelly, Identifying, understanding, and analysing critical infrastructure interdependencies, 2001
  4. Helbing, Globally networked risks and how to respond, 2013
02Live map

Hazards and exposure in China

Flood water, active fires and surface heat beside population and night-time lights, over China.

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

Layers 3

Hazards and exposure

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 China.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 SurveySources 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 H3 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 H3 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 H3 cells where shown (modified). NASA open data
  • NASA Fire Information for Resource Management System (FIRMS), VIIRS 375 m active fire product, NASA LANCE; vector tiles via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 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 H3 cells where shown (modified). doi:10.7927/H49C6VHW. CC BY 4.0
  • VIIRS Black Marble night-time lights, NASA Goddard Space Flight Center; distributed by the NASA Level-1 and Atmosphere Archive and Distribution System (LAADS DAAC); imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 cells where shown (modified). NASA open data
  • MODIS and VIIRS atmosphere products, NASA LANCE and LAADS DAAC; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 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 H3 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 H3 cells where shown (modified). ODbL
  • Blue Marble, NASA Earth Observatory; imagery via NASA GIBS. Colours redrawn from the published colour map; values averaged into H3 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.
  • Globe: MapLibre GL JS 6.9.1, BSD-3-Clause, © MapLibre contributors.
  • 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.
  • 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 (10 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

  • Flood water, 3-day composite: VIIRS Global Flood Product, NASA LANCE · 14 Oct 2026
  • Active fires and thermal anomalies: VIIRS NOAA-20 375 m (FIRMS), NASA LANCE FIRMS · 13 Oct 2026
  • Population density, 2020: Population: CIESIN, Columbia University, Gridded Population of the World v4.11 (2018), NASA SEDAC, CC BY 4.0 · static
  • Land surface temperature, day, 8-day composite: VIIRS NOAA-20 Level 3, 8-day, NASA LANCE · 14 Sep 2026
  • Night-time lights, daily: VIIRS Black Marble (VNP46A2), NASA LAADS DAAC · 12 Oct 2026
  • Aerosol optical depth, daily: VIIRS NOAA-20 Deep Blue AOD, NASA LANCE · 13 Oct 2026

03How learning runs

How learning runs, as a process you can run

Select a scenario and press Play: course, pathway, practice, faculty, cells and record.

04What is changing

Frontier course · L3 advanced, programme courses and standards

Systemic, compound and cascading risk: frontier methods

The methods, data, tools and studies that changed systemic, compound and cascading risk between 2024 and 2026, taught by reproducing them on open data.

Level
L3 Advanced
Study time
about 28 hours (planning estimate)
Status
Planned
Prerequisites
Systemic, compound and cascading risk: foundations and practice; Working knowledge of a scripting language (Python or R) for the labs

Why now

It is a documented case of cascading failure in a changing power system, with lessons for interdependent infrastructure. ENTSO-E, Final Report on the Grid Incident in Spain and Portugal on 28 April 2025, 20 March 2026

Learning outcomes

  1. Explain what changed in systemic, compound and cascading risk since 2024 and cite the studies, data or rules behind each change
  2. Reproduce expert panel finds Iberian blackout arose from interacting voltage failures on open data and state the uncertainty of the result
  3. Evaluate a 2024 to 2026 study: its question, data, method, limits and what it changes for practice
  4. Design an analysis that combines a frontier method with the faculty's instruments, and justify each choice

Modules

  1. Expert panel finds Iberian blackout arose from interacting voltage failures
    • ENTSO-E's final report on the 28 April 2025 blackout of mainland Spain and Portugal attributes it to interacting factors: gaps in voltage and reactive power control, fast overvoltages and cascading generator disconnections, with recommendations on operations, monitoring, coordination and regulation.
    • It is a documented case of cascading failure in a changing power system, with lessons for interdependent infrastructure.
    • ENTSO-E, 20 March 2026
  2. Cloud DNS fault in one region cascaded across dependent services
    • A latent race condition in DynamoDB DNS automation left the US-EAST-1 endpoint without addresses on 19 to 20 October 2025, cascading into EC2 launches, load balancers and services such as Lambda for over 14 hours.
    • Concentration on a few cloud regions turns single faults into shared exposures across many organisations.
    • Amazon Web Services, 20 October 2025
  3. Global Tipping Points Report 2025 says warm-water coral reefs are tipping
    • The 2025 report by 160 authors says warm-water coral reefs are already crossing their thermal tipping point at about 1.4 degrees, the Atlantic overturning circulation risks collapse below 2 degrees, and positive tipping in solar and electric vehicles is under way.
    • Tipping elements create non-linear, cascading risks that linear scenarios and historical loss data will not capture.
    • Global Tipping Points, 1 October 2025
  4. Reproduction lab
    • Extend the discipline's method with one frontier method and compare its results
    • State the uncertainty and the limits of the result
    • Peer review against a shared checklist

Labs with Academy tools

Nexus Standards

Teaches

  • NRS-C6 Systemic and cascading risk
  • NRS-H60 Hazard family: Supply-chain and flow disruption
  • NRS-H61 Hazard family: Cascading failure
  • NRS-H62 Hazard family: Compound and multi-hazard events
  • NRS-H120 Hazard family: Structural fragility of interconnected systems
  • NRS-M7 Method fabric: Networks, dependency and systemic risk

Relies on

  • NS-1 The UNI and the artefact catalogue
  • NS-16 UNI application profile (how articles, documents, code, data, APIs and interfaces carry the UNI)
  • NRS-C1 Risk vocabulary and ontology
  • NRS-C2 Risk assessment method
  • NRS-C3 Hazard, exposure, vulnerability and capacity data
  • NRS-C4 Risk data model, identifiers and exchange
  • NRS-C7 Early warning, triggers and anticipatory action
  • NRS-C8 Evidence, uncertainty and provenance

Assessment

  • 50%Method reproductionReproduce one frontier method on open data and state the uncertainty of the result
  • 30%Study reviewA critical review of a 2024 to 2026 study: question, data, method, limits, what it changes
  • 20%Peer reviewReview two other learners' reproductions against a shared checklist

Delivery

  • Self-paced online, with the labs in the browser
  • Cohort study over six to eight weeks, with a weekly lab review
  • Co-delivered with a partner institution, inside its own courses

Partner on this course

  • Co-teach a module and bring a current case from your work
  • Host a cohort for your learners, with your own schedule and review
  • Contribute a lab: a dataset your institution publishes openly, or a model
  • Review the course content and its references before it opens
  • Translate the course and adapt its cases to your region

How institutions and experts take part

In the Academy LMS

Course on the learning platform
Expert, 4 topics
Cohort group
A community group for each cohort of learners
Achievement
Recorded on completion of the assessed work

Open now in this discipline

References

  1. ENTSO-E, Final Report on the Grid Incident in Spain and Portugal on 28 April 2025, 20 March 2026
  2. Amazon Web Services, Summary of the Amazon DynamoDB Service Disruption in the Northern Virginia (US-EAST-1) Region, 20 October 2025
  3. Global Tipping Points, Global Tipping Points Report 2025, 1 October 2025
  4. Buldyrev, Parshani, Paul, Stanley and Havlin, Catastrophic cascade of failures in interdependent networks, 2010
  5. Rinaldi, Peerenboom and Kelly, Identifying, understanding, and analysing critical infrastructure interdependencies, 2001
  6. Helbing, Globally networked risks and how to respond, 2013
05Take part

Take part in the work

Start from who you are.

06Questions

Questions, answers and key terms

Is the course free?
Yes. Every course and learning material of Risk Academy, led by the Nexus Consortium, is free to study, self-paced or with a cohort. Ordinary participation has no fee; paid work, internships and fellowships are separate arrangements.
What does completing a course give me?
A completion record: the course, its version, the date and what was assessed, private by default and shared by you. It stacks into discipline, department and programme achievements. A record states what was studied and assessed and does not certify competence; it is not a licence, a professional title or an employment status.
Where do the data and the places come from?
Every faculty teaches on a twin of a real place built from open data; each layer carries its provider, licence and date, and every result on the Academy states its source. Maps and figures are indicators for teaching, never an assessment of a place.
How do I take part beyond the course?
Form a competence cell of three to seven people, study a shared pathway, take a supervised assignment in the National Working Groups, or bring a cohort from your institution. For organisations.

Key terms

Term

Systemic risk

Risk that arises from interactions within and between systems and can affect the whole.

Term

Compound event

A combination of hazards or drivers that together produce an extreme impact.

Term

Cascading risk

Risk of a chain of impacts that spreads from one system to others.

Term

Tipping point

A threshold beyond which a system changes state, often irreversibly.

ReportsContribute

Contribute evidence from this page.

Reports is the Consortium's quarterly publication. What you know about this subject can become evidence, a case or a correction in the next edition, credited to you and published under CC BY 4.0 where it is your own work.

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