- Japan 2026
- Chapter 1
Japan’s risk is seismic, climatic and demographic at once
Part I describes systems and their couplings. It assesses no authority and ranks no prefecture.
Contents
- ·Edition home
- ·Executive summary
- 1Japan’s risk is seismic, climatic and demographic at once
- 2Key findings
- 3Systems and sectors at baseline
- 4Risks and capability
- 5Great earthquake in an ageing region
- 6Lenses and readings
- 7The 2027 agenda
- 8Systems in depth
- AMethodology
- BData appendix
- CReferences and record
- ·Complete edition, for print
1.1The questions this part answers
Key questions
- Where is Japan’s risk concentrated, and in which systems?
- Which couplings carry shocks from one system to the next?
- Which capabilities hold under compound stress, and which are only documented?
- What must the 2027 programme measure first?
In this part
- Narrative
- Headline finding
- Lead figure
- Five system chapters
- Twelve-domain reading
- Sector screens
- Dependency matrix
- Risk objects
- Capability ladder
- Scenario
- Three lenses
- Portfolio
1.2The argument
Japan is usually described as the most disaster-prepared country in the world, and in many respects it is. This baseline reads its exposure as three slow and fast forces acting together: great earthquakes and tsunamis, a warming climate that intensifies heat and rain, and a population that is shrinking and ageing faster than almost any other.
The seismic layer dominates the tail. The 2025 revision of the Nankai Trough estimate puts worst-case losses at about 298,000 deaths and ¥292 trillion in damage9, and the national evaluation keeps the probability of such an event within thirty years high10. The Noto Peninsula earthquake of January 2024 showed the shape of the risk in miniature: water, roads, power and care failed together in a remote, ageing region, and heavy rain struck the same area again in September11.
The climate layer is rising. 2024 was the warmest year on record, and the long-term trend is about 1.4 °C per century67. About 97,600 people were taken to hospital by ambulance for heatstroke in the summer of 202412, and heavy-rain disasters such as Typhoon Hagibis in 2019 have breached levees at scale20.
The demographic layer changes everything else. 29.3% of the population is 65 or over, and births fell to about 686,000 in 20241415. An older, smaller population means more people who need help to evacuate, fewer workers to respond, and rural infrastructure that is harder to maintain.
Beneath all three sits import dependence. Japan imports almost all of its fossil fuel and grows only 38% of its food on a calorie basis516. Emissions have fallen to a record low, and renewables and nuclear passed 30% of electricity in FY202312, but energy and food security still depend on sea lanes and world prices.
This edition therefore reads Japan’s risk as a property of the couplings between these forces. The matrix, risk objects, capability ladder and scenario that follow ask the same two questions: where does a shock travel next, and who holds the capability to stop it?
Net emissions fell by 378 Mt between FY2013 and FY2023. About 257 Mt more must go by FY2030, two-thirds of a decade’s progress in seven years13.
| Item | Bar, scaled to the largest value | Value |
|---|---|---|
| FY2013 | 1395 | |
| FY2023 gross | 1071 | |
| FY2023 net | 1017 | |
| FY2030 target (net) | 760 |
Source: as cited in the note to this figure. Year FY2023.
Figure ID FIG-COUNTRY-JPN-2026-BASELINE-01-003
1.3Twenty couplings between five systems
The Japan matrix types the twenty couplings between the five core systems. Strengths are Nexus estimates from the cited evidence and analogue events; they set the starting graph that the Q1 2027 Foundry cut will test.
Each line is one coupling from one system to another, drawn by the strength the edition assigns. Strengths are Nexus estimates from the cited evidence and analogue events.
- Strong
- Moderate
- Weak
Source: this edition’s coupling matrix (Table 1.1); status Estimated.
| From, to | WAT | ENE | FOO | HLT | BIO |
|---|---|---|---|---|---|
| WAT Water | · | STRONG nuclear cooling · hydro | STRONG irrigation · rain-fed yield | MODERATE drinking water | STRONG flows · wetlands |
| ENE Energy | MODERATE pumping · treatment | · | STRONG fuel · fertiliser · cold chain | STRONG facility power · cooling | MODERATE reservoirs · land use |
| FOO Food | MODERATE withdrawals · nutrients | WEAK biofuel feedstock | · | STRONG nutrition · food safety | STRONG land conversion |
| HLT Health | WEAK workforce | WEAK workforce | MODERATE labour · disease | · | WEAK residues |
| BIO Biodiversity | STRONG regulation · filtration | MODERATE fire on lines · biomass | STRONG pollination · soils | MODERATE zoonoses · smoke | · |
| Strength: strong, moderate or weak; a Nexus estimate (status Estimated) from cited evidence and analogue events. The scale is defined in Annex A. | |||||
Transmission paths
- 01
SEI → WAT → HLT
An earthquake breaks pipes; care homes and hospitals lose water for weeks.
Reported Noto 202411
- 02
SEI → ENE → all
A great earthquake shuts coastal plants and refineries.
Reported Tōhoku 2011
- 03
CLI → WAT → INF
Heavy rain breaches levees and cuts transport.
Reported Hagibis 201920
- 04
CLI → HLT
Heat waves load ambulances and care settings.
Reported summer 202412
- 05
TRD → ENE → FOO
Fuel and fertiliser price shocks pass into food costs.
Inferred 2022 price shock
1.4Reinforcing loops
A shock entering either system of a loop can return amplified through the other.
| Loop | First direction | Second direction |
|---|---|---|
| WAT and BIO | Water to biodiversity: flows · wetlands | Biodiversity to water: regulation · filtration |
| FOO and BIO | Food to biodiversity: land conversion | Biodiversity to food: pollination · soils |
| A causal-loop reading of the matrix (Sterman, Business Dynamics, 2000): structural, from estimated strengths, not a measured feedback. | ||
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
- 9Central Disaster Management Council, Working Group on Nankai Trough Megaquake Countermeasures (ed.), Revised damage estimates for a Nankai Trough megaquake. Cabinet Office, Tokyo, March 2025.back
- 10Headquarters for Earthquake Research Promotion (ed.), Long-term evaluation of earthquakes along the Nankai Trough (revised). MEXT, Tokyo, 2025.back
- 11Cabinet Office (ed.), “Damage situation of the 2024 Noto Peninsula Earthquake.” Cabinet Office, Tokyo, retrieved 2026-09-30.back
- 6Japan Meteorological Agency (ed.), Climate Change Monitoring Report 2024. JMA, Tokyo, 2025.back
- 7Japan Meteorological Agency (ed.), “Characteristics of the climate in Japan in 2024.” JMA, Tokyo, January 2025.back
- 12Fire and Disaster Management Agency (ed.), “Heatstroke emergency transports, May–September 2024.” FDMA, Tokyo, October 2024.back
- 20Ministry of Land, Infrastructure, Transport and Tourism (ed.), White Paper on Land, Infrastructure, Transport and Tourism in Japan 2025. MLIT, Tokyo, 2025.back
- 14Ministry of Health, Labour and Welfare (ed.), Vital Statistics 2024 (births). MHLW, Tokyo, 2025.back
- 15Statistics Bureau of Japan (ed.), Population Estimates as of 1 October 2024. Ministry of Internal Affairs and Communications, Tokyo, 2025.back
- 5Agency for Natural Resources and Energy (ed.), Annual Report on Energy (Energy White Paper) 2025. METI, Tokyo, 2025.back
- 16Ministry of Agriculture, Forestry and Fisheries (ed.), Food self-sufficiency ratio, FY2023. MAFF, Tokyo, August 2024.back
- 1Ministry of the Environment and National Institute for Environmental Studies (eds.), Japan’s National Greenhouse Gas Emissions and Removals in FY2023. MoE, Tokyo, April 2025.back
- 2Ministry of the Environment (ed.), Progress of the Plan for Global Warming Countermeasures in FY2023. MoE, Tokyo, 2025.back
- 3Government of Japan (ed.), Japan’s Nationally Determined Contribution (targets for FY2035 and FY2040). Submission to the UNFCCC, February 2025.back
- 29Government of Japan (ed.), Act on the Promotion of a Smooth Transition to a Decarbonised Growth-Oriented Economic Structure (GX Promotion Act), Act No. 32 of 2023. Tokyo, 2023.back