GCRI · Global challenges
Water, energy, food, health and nature
Water, energy, food, health and nature keep people alive and economies running. Energy pumps and treats water. Water cools power plants and grows food. Healthy ecosystems regulate water and disease. Health systems need all of them. The Global Centre for Risk and Innovation (GCRI) studies the five together as the core of the integrated approach, each with an established platform. Part of global challenges.
01Register
Water, energy, food, health and nature on the record.
The Global Centre for Risk and Innovation
- 01InstitutionThe Global Centre for Risk and Innovation (GCRI)
- 02The five systemsOne coupled core, five specialist communities
- 03CouplingsThe physical links between the five systems, with the quantities that carry them
- 04How the core failsFailure modes that only show when the five are read together
- 05Methods and dataHow nexus analysis is done, and what the data can carry
- 06GCRI’s partFive platforms, one evidence standard, and where findings are designed to go
- 07Why togetherSingle-sector plans can move risk instead of reducing it
02The five systems
One coupled core, five specialist communities.
| System | Depends on | Specialist platform |
|---|---|---|
| Water | Rainfall and groundwater, ecosystems that regulate flow, energy for pumping and treatment | Water Nexus |
| Energy | Water for cooling and hydropower, fuels and minerals, digital control | Energy Nexus |
| Food | Water, soils and pollinators, fertiliser and fuel, ports and cold chains | Food Nexus |
| Health | Clean water and sanitation, reliable power, medical supply chains, a healthy environment | Health Nexus |
| Nature | Land-use choices, water flows, climate and pollution levels | Biodiversity Nexus |
The five field platforms are established and published by GCRI at their current addresses.
03Geography
Water now worldwide.
Land cover, plant growth and population density across the world, from NASA GIBS. Each layer carries its own date.
The interactive map needs JavaScript; the layer list and sources are below.
Layers 3
Water now, for this page
About this layer
- Evidence
- Modelled (latest year GIBS publishes)
- Source
- MODIS Terra and Aqua land cover (MCD12Q1) (NASA LP DAAC)
- Provider
- NASA LP DAAC
- Licence
- NASA open data
- Vintage
- yearly; Satellite classification; latest year GIBS publishes
- Newest at build
- 2024-01-01
- Resolution
- about 500 m grid
- Uncertainty
- Satellite land cover classes for the year shown, including croplands; a classification with known errors, not a farm register.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
- Evidence
- Modelled (latest 8-day period GIBS publishes)
- Source
- MODIS Aqua GPP (MYD17) (NASA LP DAAC)
- Provider
- NASA LP DAAC
- Licence
- NASA open data
- Vintage
- 8-day; Satellite-driven model; latest 8-day period GIBS publishes
- Newest at build
- 2026-09-30
- Resolution
- about 500 m grid
- Uncertainty
- Model estimate of carbon taken up by plants over the 8-day period shown; an indicator of growth, not harvest or production.
- 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 (clouds leave gaps)
- Source
- MODIS Terra NDVI (NASA LANCE)
- Provider
- NASA LANCE
- Licence
- NASA open data
- Vintage
- daily; Satellite index; clouds leave gaps
- Newest at build
- 2026-10-13
- Resolution
- about 250 m grid
- Uncertainty
- Satellite greenness index over the 8 days to the date shown; an indicator of crop and pasture condition, not a yield estimate or a food security warning.
- Reached through
- gibs.earthdata.nasa.gov, only after you allow the live map
About this layer
- Evidence
- Modelled
- Source
- SMAP Level 4 (NASA NSIDC DAAC)
- Provider
- NASA NSIDC DAAC
- Licence
- NASA open data
- Vintage
- daily; Model with satellite data assimilated
- Newest at build
- 2026-10-11
- Resolution
- about 2 km grid
- Uncertainty
- Model with satellite data assimilated. 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
Keyboard, with the map focused
Hold Ctrl or ⌘ and scroll to zoom
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.
Water now, framed on the world.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 · 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
- MODIS land products (vegetation indices, gross primary production, land cover), NASA LP DAAC and 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
- 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
- SMAP Level 4 soil moisture and snow mass, NASA Global Modeling and Assimilation Office; distributed by the NASA National Snow and Ice Data Center 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.
- 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.
- Past year, daily temperature (ERA5 via Open-Meteo): Contains modified Copernicus Climate Change Service information 2026.
- Past year, daily temperature and sunshine (NASA POWER): These data were obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program..
- 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 (14 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 cover type (IGBP), yearly: MODIS Terra and Aqua land cover (MCD12Q1), NASA LP DAAC · 2024
- Gross primary production, 8-day total: MODIS Aqua GPP (MYD17), NASA LP DAAC · 30 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
- Vegetation greenness (NDVI), rolling 8 days: MODIS Terra NDVI, NASA LANCE · 13 Oct 2026
- Root-zone soil moisture, 0 to 100 cm: SMAP Level 4, NASA NSIDC DAAC · 11 Oct 2026
04Couplings
The physical links between the five systems, with the quantities that carry them.
The water-energy-food nexus entered policy through the Bonn 2011 conference and FAO’s 2014 framing; the IPBES Nexus Assessment of 2024 widened it to biodiversity, water, food, health and climate change. Each link below is a physical or biological flow that can be measured.
| Link | How it works | Quantity and unit |
|---|---|---|
| Water for energy | Thermal plants withdraw cooling water; hydropower depends on inflow and storage | Withdrawal and consumption in cubic metres per megawatt-hour; reservoir storage in cubic hectometres |
| Energy for water | Pumping, desalination, treatment and distribution draw electricity | Energy intensity in kilowatt-hours per cubic metre delivered |
| Water for food | Irrigation and livestock use most freshwater withdrawals in many basins | Withdrawal in cubic kilometres per year; crop water productivity in kilograms per cubic metre |
| Energy for food | Fertiliser synthesis, mechanisation, processing and cold chains | Energy per tonne of product; natural gas per tonne of ammonia |
| Nature for water and health | Wetlands and forests regulate flow and quality; habitat change alters disease transmission | Ecosystem extent and condition under the UN SEEA Ecosystem Accounting; zoonotic spillover events recorded |
| All five for health | Safe water, power for hospitals and cold chains, diets and a stable disease ecology | Population using safely managed water services; health facilities with reliable electricity |
05Twin and cascade simulator
Model water, energy, food, health and nature 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)
Systems and couplings
- Global and systemic risk
- Compound and cascading hazard standards Mechanism
- Financial stability and prudential risk Mechanism
- Supply chain and trade risk Cascade
- Future generations and long-term risk Common driver
Controls
NS-0Constitution and principlesNS-3Risk record UNIs (grammar, legacy crosswalk, allocation authority)NS-9Contextual UNIs (deployments, instances, programme instances)NS-10Policies and clauses (machine-readable obligations: definition, binding, evaluation and enforcement)NS-11Verification and monitoring (evidence, attestations, zero-trust conformance observation)NS-14Conformance and crosswalk to external standardsNRS-H120Hazard family: Structural fragility of interconnected systems (NHS-1 sys.fragility)NRS-C6Systemic and cascading riskNRS-H61Hazard family: Cascading failure (NHS-1 sys.cascade)NRS-H62Hazard family: Compound and multi-hazard events (NHS-1 sys.compound)NRS-H94Hazard family: Systemic cyber events (NHS-1 cyber.systemic-cyber)NRS-H60Hazard 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
06How the core fails
Failure modes that only show when the five are read together.
- Synchronous stress. A hot, dry season can lower river flows, warm cooling water, raise power demand and cut crop yields in the same weeks. The IPCC Sixth Assessment Report treats such compound events as a growing share of climate risk.
- Displaced risk. Groundwater pumping subsidised to secure harvests can deplete the aquifer a city depends on; a biofuel mandate can raise food prices; a dam built for power can reshape fisheries downstream.
- Common inputs. Electricity and diesel sit underneath water treatment, irrigation, cold chains and clinics, so a fuel or grid shock reaches all five.
- Slow erosion. Soil loss, aquifer decline and habitat loss reduce buffers for years before a shock exposes them. Richardson and colleagues reported in 2023 that six of nine planetary boundaries are transgressed, which is a statement about lost buffers, not a forecast of collapse.
07Risk and response
Coupled risk, applied response.
The sectors drought touches and how strongly they depend on each other: what a study has to observe and model together.
Choose a context
ACoupled risk across six sectors10 / 15 relations
Sectors · DroughtStress
applied to
BApplied response across six pillars18 / 18 handoffs
Pillars · DroughtKPI
In this contextDependence or handoff, heavier is strongerOutside this context
Programme yearAll phases
Context
Drought
Low river flows cut irrigation, cooling water and hydropower at once; food prices, nutrition and ecosystems follow.
W · E · I · F · H · B
Risk
- Sectors
- 5 of 6
- Relations
- 10 of 15
- Coupling
- 0.68 share of total
Hover a corner, a line or a row to trace it across both sides.
Route
Applied to drought
L · F · U · S · R · A
Response
- Pillars
- 6 of 6
- Handoffs
- 18 of 18
- Loops
- 17 closed
Expected value
- What is at stake
- –no published benchmark
- Return on resilience
- $7.1Tnet benefitsGlobal Commission on Adaptation, Adapt Now, 2019
- Avoided loss
- –no published benchmark
Hover a pillar, a line or a row to read how it is applied.
A: a teaching cascade (shock 0.6, gain 0.35, four rounds) over teaching values for a typical city-region, not measurements. B: illustrative applications and the KPI each pillar answers for; values are published benchmarks, cited, not forecasts. Open events: NASA EONET, live.
08Methods and data
How nexus analysis is done, and what the data can carry.
| Approach | Use | Limit |
|---|---|---|
| Integrated assessment of basin systems (water allocation, power dispatch and crop models linked) | Trade-offs between irrigation, hydropower, cooling and environmental flows | Linking models multiplies uncertainty; results are scenario evidence, not plans |
| Natural capital and ecosystem accounts (UN SEEA) | Extent, condition and services of ecosystems in national accounts terms | Accounts exist for a minority of countries; condition indicators differ |
| Material and energy flow accounting | Where water and energy are embodied in traded food | Coefficients are averages; local practice can differ widely |
| One Health surveillance integration | Linking human, animal and environmental signals of disease | Surveillance systems are run separately and share data unevenly |
Primary series come from the custodians. Water: UN-Water and FAO AQUASTAT. Energy access: the Tracking SDG 7 partners. Food: FAOSTAT and the annual State of Food Security and Nutrition in the World. Health: WHO. Biodiversity: the CBD monitoring framework. Each is published with its own lag and gaps, and the domain pages say which.
09GCRI’s part
Five platforms, one evidence standard, and where findings are designed to go.
GCRI runs one established platform for each system: Water Nexus, Energy Nexus, Food Nexus, Health Nexus and Biodiversity Nexus. They share one rule for evidence labels and one place for methods, so a finding about a basin can be read by the energy and health teams without translation. National agendas, data and decisions stay national; GCRI helps a country see its couplings, and the country decides what to do.
Cross-system findings are designed for the Country Systems Risk and Resilience series and the Global Sector Risk and Resilience series. Contributions that help most are basin or district case material with sources, local measurements that fill a gap in the custodians’ series, and challenges to an assumed coupling.
10Why together
Single-sector plans can move risk instead of reducing it.
Trade-offs
One gain, another cost
Irrigation expansion can raise food output while drawing down aquifers that cities and power plants rely on.
Co-benefits
One action, several gains
Restoring a watershed can reduce flood peaks, protect water quality and support livelihoods at once.
Common failure
One shock, several systems
A heatwave can strain power, water, crops and hospitals in the same week.
11How the work connects
From the core to specialist fields and other sites.
Each field platform applies named methods, from hydrology to epidemiology and ecology. Field gateways bring the three institutions together, for example the water field gateway. Infrastructure that links the systems is covered under infrastructure dependencies, and the wider dynamics under systemic and cascading risks.
12Counterparts
Governance and finance views of the core.
The Global Risks Forum (GRF) examines shared governance, including its water and food security governance chapter. The Global Risks Alliance (GRA) examines protection gaps and finance readiness, for example under protection gaps.
13Sources
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.
- Hoff, Understanding the Nexus, background paper for the Bonn2011 Nexus Conference (Stockholm Environment Institute, 2011)
- The Water-Energy-Food Nexus: a new approach in support of food security and sustainable agriculture (FAO, 2014)
- IPBES Assessment Report on the Interlinkages among Biodiversity, Water, Food and Health (the Nexus Assessment, IPBES, 2024)
- IPCC Sixth Assessment Report, Synthesis Report (IPCC, 2023)
- Richardson and others, Earth beyond six of nine planetary boundaries, Science Advances 9 (2023)
- United Nations World Water Development Report 2025, Mountains and glaciers: water towers (UNESCO for UN-Water, 2025)
- Tracking SDG 7: The Energy Progress Report 2025 (IEA, IRENA, UNSD, World Bank and WHO, 2025)
- The State of Food Security and Nutrition in the World 2025 (FAO, IFAD, UNICEF, WFP and WHO, 2025)
- World Health Statistics 2025 (WHO, 2025)
- One Health Joint Plan of Action 2022–2026 (FAO, UNEP, WHO and WOAH, 2022)
- Kunming-Montreal Global Biodiversity Framework, CBD decision 15/4 (2022)
14Questions
Questions and answers.
Why these five systems?
They sustain life and every economic activity, and they are tightly coupled. Studying them together reveals trade-offs, co-benefits and common points of failure that sector plans miss.
Where does critical infrastructure fit?
Infrastructure is the physical and digital fabric that links the five systems. GCRI examines it alongside them, and it has its own challenge page and a specialist platform.
How do I join a field community?
Start on the platform for your field or write to the expert application form. Joining a community does not confer membership of a national programme.
Do the platforms publish country data?
Platforms publish reviewed, rights-cleared work. Country views appear only where a programme exists and its data owners have agreed to publication.
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