Global Cities Risk and Resilience Report 2026: Baseline Edition, The State of the World’s Cities and Urban Systems.

S.1Abstract

S.2Key messages

Six readings that frame the cities baseline, and the eight questions this edition answers, each with its status and source.

1. It depends on the definition: 45% in cities on the UN grid method, 57.8% on national definitions.¹²

   How urban is the world?Reported

2. Two thirds of growth to 2050 is in cities, mostly small and medium ones in Asia and Africa.¹⁷

   Where is growth?Reported

3. About 1.12 billion people live in slums or informal settlements.⁵

   Who lacks adequate housing?Reported

4. About 29 GtCO2-eq in 2020 on a consumption basis, 67 to 72% of the global share.⁶

   How much do cities emit?Reported

5. Urban heat exposure rose nearly 200% in 34 years; 1.81 billion people face a 1-in-100-year flood.¹⁴¹³

   How hot and how wet is the risk?Reported

6. Subnational governments make 39.5% of public investment; cities receive less than 20% of climate finance need.²²¹²

   Who pays for urban resilience?Reported

7. Tree cover offsets 41 to 49% of the potential heat island but is thin in low-income cities.¹⁵¹⁷

   Can green cover help?Reported

8. A heat wave followed by flooding in a subsiding coastal city. SCN-GS10-HTF-01

   What will 2027 test first?Expert input

S.3Headline finding

ReportedEQL 4NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-HLT-004

About 1.12 billion people lived in slums or informal settlements in 2022, 24.8% of the urban population.

The share barely moved between 2015 and 2022, so the number rose by about 130 million. Informal settlements are also the places least covered by adaptation plans, and the UN expects Sub-Saharan Africa to add 360 million slum residents by 2030⁵¹².

S.4At a glance

S.5What each steward reads in it

S.6What this edition is, and is not

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

1. 1UN DESA Population Division (ed.), World Urbanization Prospects 2025: Summary of Results (publication page and press release; 45% of 8.2 billion people in cities, 33 megacities, more than 12,000 cities, Degree of Urbanisation). United Nations, New York, November 2025. Observation year 2025. Accessed 2026-11-03.back
2. 2DATA VINTAGE AFTER CLOSE: World Bank (ed.), World Development Indicators, API extract of urban population, total population, urban agglomerations, urban access to electricity, clean cooking, safely managed drinking water and sanitation, slum share (database updated 8 October 2026). World Bank, Washington. Observation year 2025 (population) and 2024 (access). Accessed 2026-11-03.back
3. 5UN DESA (ed.), Sustainable Development Goal 11: make cities and human settlements inclusive, safe, resilient and sustainable (Goal page; slum population, land consumption rate, targets). United Nations, New York. Observation year 2022 (slums) and 2025 (land consumption). Accessed 2026-11-03.back
4. 6IPCC (ed.), Urban systems and other settlements, chapter 8 in Climate Change 2022: Mitigation of Climate Change, Contribution of Working Group III to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
5. 13Rentschler, J., Salhab, M. and Jafino, B.A., Flood exposure and poverty in 188 countries, Nature Communications 13, 3527 (open access full text, PMC). Springer Nature, London, 2022. Observation year 2020 (population grid). Accessed 2026-11-03.back
6. 14Tuholske, C. et al., Global urban population exposure to extreme heat, Proceedings of the National Academy of Sciences 118(41), e2024792118 (open access full text, PMC). National Academy of Sciences, Washington, 2021. Observation year 2016 (series 1983 to 2016). Accessed 2026-11-03.back
7. 22OECD and UCLG (eds.), World Observatory on Subnational Government Finance and Investment, 2022 highlights (135 countries; 2020 data). Organisation for Economic Co-operation and Development, Paris, and United Cities and Local Governments, Barcelona. Observation year 2020. Accessed 2026-11-03.back
8. 12UN-Habitat (ed.), World Cities Report 2024: Cities and Climate Action, key messages (report page; cities receive less than 20% of climate finance needed). United Nations Human Settlements Programme, Nairobi. Observation year 2024. Accessed 2026-11-03.back
9. 17Romanello, M. et al., The 2023 report of the Lancet Countdown on health and climate change: the imperative for a health-centred response in a world facing irreversible harms, The Lancet 402 (open access full text, PMC). Elsevier, London, 2023. Observation year 2022. Accessed 2026-11-03.back
10. 7IPCC (ed.), Cities, settlements and key infrastructure, chapter 6 in Climate Change 2022: Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
11. 15Trees halve the urban heat island effect globally but unequal benefits only modestly mitigate climate-change warming, Nature Communications (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (analysis of 8,919 large urban areas). Accessed 2026-11-03.back
12. 3UN Statistics Division (ed.), Global SDG Indicators Database, API extract of series EN_LND_SLUM, EN_ATM_PM25, EN_ACS_URB_OPENSP, SP_TRN_PUBL, EN_REF_WASCOL and SD_CPA_UPRDP (release 2026.Q3.G.01). United Nations, New York. Observation year 2024 (slums), 2023 (PM2.5) and 2020 (transport, open space). Accessed 2026-11-03.back

1.1The questions this part answers

Key questions

• Where is cities risk concentrated?
• Which couplings carry cities shocks into other systems?
• Which cities capabilities hold under compound stress?
• What must 2027 evidence measure first?

In this part

• Narrative
• Headline finding
• Lead figure
• Five coupling chapters
• Twelve-domain reading
• Sector screens
• Dependency matrix
• Risk objects
• Capability ladder
• Scenario
• Three lenses
• Portfolio

1.2The argument

1.3Twenty couplings between five systems

The cities-centred matrix types the twenty couplings between the five core systems, read for their cities content. Strengths are Nexus estimates (ESTIMATED) from the cited evidence and analogue events; they set the graph that 2027 evidence will test.

Transmission paths

1. 01

   CLI → INF → HLT

   A heat wave raises cooling demand while services fail; older and poorer residents are hit first.

   Reported urban heat exposure up 199% 1983 to 2016¹⁴; 61,672 excess deaths in Europe in 2022¹⁰

2. 02

   CLI → WAT → INF

   Flood and storm surge reach drainage, power and transport at once in low-lying cities.

   Reported 1 billion in low-lying cities at risk by 2050⁷; 1.81 billion flood-exposed¹³

3. 03

   WAT → BIO → INF

   Subsiding land raises relative sea level beneath coastal cities.

   Reported delta subsidence study¹⁶; 48 coastal cities²⁶

4. 04

   FIN → INF → HLT

   Under-funded municipalities defer service upgrading, and informal settlements stay uncovered.

   Inferred cities receive under 20% of climate finance need¹²

5. 05

   BIO → HLT

   Tree cover and canopy continuity are associated with lower heat harm and child mortality.

   Reported canopy and child mortality in 57 countries¹⁹; greenness and heat mortality¹⁸

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

1. 2DATA VINTAGE AFTER CLOSE: World Bank (ed.), World Development Indicators, API extract of urban population, total population, urban agglomerations, urban access to electricity, clean cooking, safely managed drinking water and sanitation, slum share (database updated 8 October 2026). World Bank, Washington. Observation year 2025 (population) and 2024 (access). Accessed 2026-11-03.back
2. 3UN Statistics Division (ed.), Global SDG Indicators Database, API extract of series EN_LND_SLUM, EN_ATM_PM25, EN_ACS_URB_OPENSP, SP_TRN_PUBL, EN_REF_WASCOL and SD_CPA_UPRDP (release 2026.Q3.G.01). United Nations, New York. Observation year 2024 (slums), 2023 (PM2.5) and 2020 (transport, open space). Accessed 2026-11-03.back
3. 7IPCC (ed.), Cities, settlements and key infrastructure, chapter 6 in Climate Change 2022: Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
4. 1UN DESA Population Division (ed.), World Urbanization Prospects 2025: Summary of Results (publication page and press release; 45% of 8.2 billion people in cities, 33 megacities, more than 12,000 cities, Degree of Urbanisation). United Nations, New York, November 2025. Observation year 2025. Accessed 2026-11-03.back
5. 14Tuholske, C. et al., Global urban population exposure to extreme heat, Proceedings of the National Academy of Sciences 118(41), e2024792118 (open access full text, PMC). National Academy of Sciences, Washington, 2021. Observation year 2016 (series 1983 to 2016). Accessed 2026-11-03.back
6. 13Rentschler, J., Salhab, M. and Jafino, B.A., Flood exposure and poverty in 188 countries, Nature Communications 13, 3527 (open access full text, PMC). Springer Nature, London, 2022. Observation year 2020 (population grid). Accessed 2026-11-03.back
7. 16Global subsidence of river deltas, Nature (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (40 deltas, satellite radar). Accessed 2026-11-03.back
8. 26Sinking cities, rising seas, Communications Engineering (2022), commentary on a Nature Sustainability study of relative land subsidence in 48 major coastal cities (open access full text, PMC). Springer Nature, London. Observation year 2022. Accessed 2026-11-03.back
9. 5UN DESA (ed.), Sustainable Development Goal 11: make cities and human settlements inclusive, safe, resilient and sustainable (Goal page; slum population, land consumption rate, targets). United Nations, New York. Observation year 2022 (slums) and 2025 (land consumption). Accessed 2026-11-03.back
10. 12UN-Habitat (ed.), World Cities Report 2024: Cities and Climate Action, key messages (report page; cities receive less than 20% of climate finance needed). United Nations Human Settlements Programme, Nairobi. Observation year 2024. Accessed 2026-11-03.back
11. 6IPCC (ed.), Urban systems and other settlements, chapter 8 in Climate Change 2022: Mitigation of Climate Change, Contribution of Working Group III to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
12. 15Trees halve the urban heat island effect globally but unequal benefits only modestly mitigate climate-change warming, Nature Communications (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (analysis of 8,919 large urban areas). Accessed 2026-11-03.back
13. 4United Nations (ed.), The Sustainable Development Goals Report 2025, Goal 11 (housing, flood, local risk reduction strategies, waste collection, national urban policies). United Nations, New York. Observation year 2024 (indicator data 2010 to 2024). Accessed 2026-11-03.back
14. 10WHO (ed.), Climate change, heat and health, fact sheet (about 489,000 heat-related deaths a year, 2000 to 2019; Europe summer 2022). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
15. 19Urban tree canopy fragmentation and child mortality in low- and middle-income countries, Proceedings of the National Academy of Sciences (2026), open access full text, PMC. National Academy of Sciences, Washington. Observation year 2026 (420,000 children, 57 countries). Accessed 2026-11-03.back
16. 18The role of greenness in heat-related mortality: a systematic review and meta-analysis, Annals of Global Health (2026), open access full text, PMC. Ubiquity Press, London. Observation year 2026 (11 studies). Accessed 2026-11-03.back

2.1Headline finding

ReportedEQL 4NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-HLT-004

About 1.12 billion people lived in slums or informal settlements in 2022, 24.8% of the urban population.

Implication

The share barely moved between 2015 and 2022, so the number rose by about 130 million. Informal settlements are also the places least covered by adaptation plans, and the UN expects Sub-Saharan Africa to add 360 million slum residents by 2030⁵¹².

What would move it

The next SDG database release, national urban policies that fund settlement upgrading, and the share of slum households with safely managed services would each move this finding.

2.2Systemic

1. ReportedEQL 5NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-SYS-001

   Cities hold 45% of the world’s 8.2 billion people on the UN Population Division grid-based definition, up from 20% in 1950, while the World Bank series on national definitions shows 57.8% urban in 2025 (4.75 billion people).¹²

2. ReportedEQL 4NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-SYS-002

   There were 33 megacities in 2025, against 8 in 1975, 19 of them in Asia, but 96% of the more than 12,000 cities analysed have fewer than 1 million people and small and medium cities hold more people than megacities.¹

3. ReportedEQL 4NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-SYS-003

   Two thirds of global population growth to 2050 is projected to occur in cities, and the IPCC assessment adds 2.5 billion urban residents by 2050, up to 90% of them in Asia and Africa.¹⁷

4. Expert inputEQL 2NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-SYS-012

   The leading compound pathway for 2027 testing is a heat wave followed by flooding in a low-lying, subsiding coastal city with stressed power and drainage. § scenario

2.3Health

1. ReportedEQL 4NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-HLT-004

   About 1.12 billion people lived in slums or informal settlements in 2022, 24.8% of the urban population in the UN database and 23.2% in the World Bank series.³⁵²

2. ReportedEQL 4NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-HLT-008

   Population-weighted PM2.5 averaged 27.3 µg/m3 in urban areas and 15.7 µg/m3 in rural areas in 2023, and 99% of the world’s people lived where WHO guideline levels were not met in 2019.³⁸

2.4Climate forcing

1. ReportedEQL 4NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-CLI-005

   Urban areas produced about 29 GtCO2-eq in 2020, 67 to 72% of the global share on a consumption basis, and about 100 high-emitting urban areas account for about 18% of the global carbon footprint.⁶

2. ReportedEQL 4NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-CLI-006

   Urban exposure to extreme heat rose by 199% between 1983 and 2016, from 40 to 119 billion person-days, with population growth contributing 66% and urban warming 34% of the annual increase.¹⁴⁷

2.5Water

1. ReportedEQL 4NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-WAT-007

   About 1.81 billion people (23% of world population) are exposed to a 1-in-100-year flood, and the UN reports 1 billion people in areas prone to severe riverine flooding in 2025, half of them in cities.¹³⁴

2.6Finance

1. ReportedEQL 4NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-FIN-009

   Subnational governments made 39.5% of public investment and 21.5% of public spending in 2020, while cities receive less than 20% of the finance needed for climate action.²²¹²

2.7Infrastructure

1. ReportedEQL 4NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-INF-010

   In 2024, 83.4% of urban residents used safely managed drinking water and 65.8% used safely managed sanitation, and 60.9% of people had convenient access to public transport in 2020.²³

2.8Biodiversity

1. ReportedEQL 4NRF-SECTOR-CITIES-GLOBAL-2026-BASELINE-BIO-011

   Current tree cover offsets 41 to 49% of the potential urban heat island effect across 8,919 large urban areas, and the share of urban centres in low-income countries with moderate or higher greenness fell from 18% in 2015 to 13% in 2022.¹⁵¹⁷

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

1. 3UN Statistics Division (ed.), Global SDG Indicators Database, API extract of series EN_LND_SLUM, EN_ATM_PM25, EN_ACS_URB_OPENSP, SP_TRN_PUBL, EN_REF_WASCOL and SD_CPA_UPRDP (release 2026.Q3.G.01). United Nations, New York. Observation year 2024 (slums), 2023 (PM2.5) and 2020 (transport, open space). Accessed 2026-11-03.back
2. 5UN DESA (ed.), Sustainable Development Goal 11: make cities and human settlements inclusive, safe, resilient and sustainable (Goal page; slum population, land consumption rate, targets). United Nations, New York. Observation year 2022 (slums) and 2025 (land consumption). Accessed 2026-11-03.back
3. 2DATA VINTAGE AFTER CLOSE: World Bank (ed.), World Development Indicators, API extract of urban population, total population, urban agglomerations, urban access to electricity, clean cooking, safely managed drinking water and sanitation, slum share (database updated 8 October 2026). World Bank, Washington. Observation year 2025 (population) and 2024 (access). Accessed 2026-11-03.back
4. 12UN-Habitat (ed.), World Cities Report 2024: Cities and Climate Action, key messages (report page; cities receive less than 20% of climate finance needed). United Nations Human Settlements Programme, Nairobi. Observation year 2024. Accessed 2026-11-03.back
5. 1UN DESA Population Division (ed.), World Urbanization Prospects 2025: Summary of Results (publication page and press release; 45% of 8.2 billion people in cities, 33 megacities, more than 12,000 cities, Degree of Urbanisation). United Nations, New York, November 2025. Observation year 2025. Accessed 2026-11-03.back
6. 7IPCC (ed.), Cities, settlements and key infrastructure, chapter 6 in Climate Change 2022: Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
7. 8WHO (ed.), Ambient (outdoor) air pollution, fact sheet (4.2 million premature deaths in 2019; 99% of people above guideline levels). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
8. 6IPCC (ed.), Urban systems and other settlements, chapter 8 in Climate Change 2022: Mitigation of Climate Change, Contribution of Working Group III to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
9. 14Tuholske, C. et al., Global urban population exposure to extreme heat, Proceedings of the National Academy of Sciences 118(41), e2024792118 (open access full text, PMC). National Academy of Sciences, Washington, 2021. Observation year 2016 (series 1983 to 2016). Accessed 2026-11-03.back
10. 13Rentschler, J., Salhab, M. and Jafino, B.A., Flood exposure and poverty in 188 countries, Nature Communications 13, 3527 (open access full text, PMC). Springer Nature, London, 2022. Observation year 2020 (population grid). Accessed 2026-11-03.back
11. 4United Nations (ed.), The Sustainable Development Goals Report 2025, Goal 11 (housing, flood, local risk reduction strategies, waste collection, national urban policies). United Nations, New York. Observation year 2024 (indicator data 2010 to 2024). Accessed 2026-11-03.back
12. 22OECD and UCLG (eds.), World Observatory on Subnational Government Finance and Investment, 2022 highlights (135 countries; 2020 data). Organisation for Economic Co-operation and Development, Paris, and United Cities and Local Governments, Barcelona. Observation year 2020. Accessed 2026-11-03.back
13. 15Trees halve the urban heat island effect globally but unequal benefits only modestly mitigate climate-change warming, Nature Communications (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (analysis of 8,919 large urban areas). Accessed 2026-11-03.back
14. 17Romanello, M. et al., The 2023 report of the Lancet Countdown on health and climate change: the imperative for a health-centred response in a world facing irreversible harms, The Lancet 402 (open access full text, PMC). Elsevier, London, 2023. Observation year 2022. Accessed 2026-11-03.back

3.1Where each system stood at evidence close

3.2Domain posture

Each of the twelve coupled domains is read through cities, in words, not scored. The coupling column names the dependency that carries cities risk into each domain.

3.3Sector screens

All sixteen sectors are screened for their dependence on cities, on the same grammar as every national edition. The evidence column describes coverage of the baseline evidence, not the performance of the sector.

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

1. 1UN DESA Population Division (ed.), World Urbanization Prospects 2025: Summary of Results (publication page and press release; 45% of 8.2 billion people in cities, 33 megacities, more than 12,000 cities, Degree of Urbanisation). United Nations, New York, November 2025. Observation year 2025. Accessed 2026-11-03.back
2. 2DATA VINTAGE AFTER CLOSE: World Bank (ed.), World Development Indicators, API extract of urban population, total population, urban agglomerations, urban access to electricity, clean cooking, safely managed drinking water and sanitation, slum share (database updated 8 October 2026). World Bank, Washington. Observation year 2025 (population) and 2024 (access). Accessed 2026-11-03.back
3. 5UN DESA (ed.), Sustainable Development Goal 11: make cities and human settlements inclusive, safe, resilient and sustainable (Goal page; slum population, land consumption rate, targets). United Nations, New York. Observation year 2022 (slums) and 2025 (land consumption). Accessed 2026-11-03.back
4. 6IPCC (ed.), Urban systems and other settlements, chapter 8 in Climate Change 2022: Mitigation of Climate Change, Contribution of Working Group III to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
5. 13Rentschler, J., Salhab, M. and Jafino, B.A., Flood exposure and poverty in 188 countries, Nature Communications 13, 3527 (open access full text, PMC). Springer Nature, London, 2022. Observation year 2020 (population grid). Accessed 2026-11-03.back
6. 22OECD and UCLG (eds.), World Observatory on Subnational Government Finance and Investment, 2022 highlights (135 countries; 2020 data). Organisation for Economic Co-operation and Development, Paris, and United Cities and Local Governments, Barcelona. Observation year 2020. Accessed 2026-11-03.back
7. 7IPCC (ed.), Cities, settlements and key infrastructure, chapter 6 in Climate Change 2022: Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
8. 12UN-Habitat (ed.), World Cities Report 2024: Cities and Climate Action, key messages (report page; cities receive less than 20% of climate finance needed). United Nations Human Settlements Programme, Nairobi. Observation year 2024. Accessed 2026-11-03.back
9. 24FAO, IFAD, UNICEF, WFP and WHO (eds.), The State of Food Security and Nutrition in the World 2026 (publication page; 645 million people faced hunger in 2025; about 2.7 billion cannot afford a healthy diet). Food and Agriculture Organization, Rome. Observation year 2025. Accessed 2026-11-03.back
10. 10WHO (ed.), Climate change, heat and health, fact sheet (about 489,000 heat-related deaths a year, 2000 to 2019; Europe summer 2022). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
11. 8WHO (ed.), Ambient (outdoor) air pollution, fact sheet (4.2 million premature deaths in 2019; 99% of people above guideline levels). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
12. 9WHO (ed.), Road traffic injuries, fact sheet (page dated 20 July 2026; about 1.16 million deaths a year). World Health Organization, Geneva. Observation year 2026 (page date). Accessed 2026-11-03.back
13. 4United Nations (ed.), The Sustainable Development Goals Report 2025, Goal 11 (housing, flood, local risk reduction strategies, waste collection, national urban policies). United Nations, New York. Observation year 2024 (indicator data 2010 to 2024). Accessed 2026-11-03.back
14. 3UN Statistics Division (ed.), Global SDG Indicators Database, API extract of series EN_LND_SLUM, EN_ATM_PM25, EN_ACS_URB_OPENSP, SP_TRN_PUBL, EN_REF_WASCOL and SD_CPA_UPRDP (release 2026.Q3.G.01). United Nations, New York. Observation year 2024 (slums), 2023 (PM2.5) and 2020 (transport, open space). Accessed 2026-11-03.back
15. 17Romanello, M. et al., The 2023 report of the Lancet Countdown on health and climate change: the imperative for a health-centred response in a world facing irreversible harms, The Lancet 402 (open access full text, PMC). Elsevier, London, 2023. Observation year 2022. Accessed 2026-11-03.back
16. 15Trees halve the urban heat island effect globally but unequal benefits only modestly mitigate climate-change warming, Nature Communications (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (analysis of 8,919 large urban areas). Accessed 2026-11-03.back

4.1Risk objects

Each risk is read across the chain from hazard to consequence, with its status and evidence-quality level.

1. ReportedEQL 4RSK-GS10-CLI-001

   Extreme urban heat on dense, under-cooled housing

   Driver

   warming combined with population growth in already-warm cities⁷¹⁴; 2025 was projected to be the second or third warmest year on record²⁵

   Exposure

   urban heat exposure rose to 119 billion person-days in 2016¹⁴

   Vulnerability

   informal settlements are hotter in some cities; over-65 heat mortality rose about 85%¹⁰

   Capacity

   tree cover offsets 41 to 49% of the potential heat island¹⁵

   Cascade

   CLI → HLT, ENE

   Horizon

   1 to 10 years

2. ReportedEQL 4RSK-GS10-WAT-002

   Coastal and river flooding on subsiding land

   Driver

   sea-level rise, storm surge, intense rainfall and land subsidence⁷¹⁶

   Exposure

   more than 1 billion people in low-lying cities by 2050⁷; 1.81 billion flood-exposed¹³

   Vulnerability

   informal settlements are left out of adaptation plans¹²

   Capacity

   110 countries report local risk reduction strategies; 73% average implementation⁴

   Cascade

   WAT → INF, HLT, FIN

   Horizon

   1 to 10 years

3. InferredEQL 3RSK-GS10-HLT-003

   Service gaps in fast-growing informal settlements

   Driver

   urban population grew by more than 397 million between 2015 and 2020, over 90% in less developed regions⁷

   Exposure

   1.12 billion people in slums or informal settlements⁵

   Vulnerability

   65.8% of urban residents have safely managed sanitation²

   Capacity

   166 countries report a national urban policy or regional plan³; 68 meet at least one qualifier of the indicator⁴

   Cascade

   HLT → FIN, WAT

   Horizon

   1 to 10 years

4. ReportedEQL 3RSK-GS10-FIN-004

   Municipal finance gap for resilience and climate action

   Driver

   cities receive less than 20% of the finance needed for climate action¹²

   Exposure

   subnational governments make 39.5% of public investment²²

   Vulnerability

   grants are more than half of subnational revenue in many countries; debt is low²²

   Capacity

   land-based revenue and national grants; urban finance reform¹²²²

   Cascade

   FIN → INF → HLT

   Horizon

   1 to 10 years

4.2Capability ladder

Existence is not readiness. Each of the fifteen capability functions is placed on the ladder by the strongest public evidence for cities at the global level.

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

1. 7IPCC (ed.), Cities, settlements and key infrastructure, chapter 6 in Climate Change 2022: Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
2. 14Tuholske, C. et al., Global urban population exposure to extreme heat, Proceedings of the National Academy of Sciences 118(41), e2024792118 (open access full text, PMC). National Academy of Sciences, Washington, 2021. Observation year 2016 (series 1983 to 2016). Accessed 2026-11-03.back
3. 25WMO (ed.), 2025 set to be second or third warmest year on record (press release; January to August 2025 about 1.42 °C above pre-industrial). World Meteorological Organization, Geneva. Observation year 2025. Accessed 2026-11-03.back
4. 10WHO (ed.), Climate change, heat and health, fact sheet (about 489,000 heat-related deaths a year, 2000 to 2019; Europe summer 2022). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
5. 15Trees halve the urban heat island effect globally but unequal benefits only modestly mitigate climate-change warming, Nature Communications (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (analysis of 8,919 large urban areas). Accessed 2026-11-03.back
6. 16Global subsidence of river deltas, Nature (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (40 deltas, satellite radar). Accessed 2026-11-03.back
7. 13Rentschler, J., Salhab, M. and Jafino, B.A., Flood exposure and poverty in 188 countries, Nature Communications 13, 3527 (open access full text, PMC). Springer Nature, London, 2022. Observation year 2020 (population grid). Accessed 2026-11-03.back
8. 12UN-Habitat (ed.), World Cities Report 2024: Cities and Climate Action, key messages (report page; cities receive less than 20% of climate finance needed). United Nations Human Settlements Programme, Nairobi. Observation year 2024. Accessed 2026-11-03.back
9. 4United Nations (ed.), The Sustainable Development Goals Report 2025, Goal 11 (housing, flood, local risk reduction strategies, waste collection, national urban policies). United Nations, New York. Observation year 2024 (indicator data 2010 to 2024). Accessed 2026-11-03.back
10. 5UN DESA (ed.), Sustainable Development Goal 11: make cities and human settlements inclusive, safe, resilient and sustainable (Goal page; slum population, land consumption rate, targets). United Nations, New York. Observation year 2022 (slums) and 2025 (land consumption). Accessed 2026-11-03.back
11. 2DATA VINTAGE AFTER CLOSE: World Bank (ed.), World Development Indicators, API extract of urban population, total population, urban agglomerations, urban access to electricity, clean cooking, safely managed drinking water and sanitation, slum share (database updated 8 October 2026). World Bank, Washington. Observation year 2025 (population) and 2024 (access). Accessed 2026-11-03.back
12. 3UN Statistics Division (ed.), Global SDG Indicators Database, API extract of series EN_LND_SLUM, EN_ATM_PM25, EN_ACS_URB_OPENSP, SP_TRN_PUBL, EN_REF_WASCOL and SD_CPA_UPRDP (release 2026.Q3.G.01). United Nations, New York. Observation year 2024 (slums), 2023 (PM2.5) and 2020 (transport, open space). Accessed 2026-11-03.back
13. 22OECD and UCLG (eds.), World Observatory on Subnational Government Finance and Investment, 2022 highlights (135 countries; 2020 data). Organisation for Economic Co-operation and Development, Paris, and United Cities and Local Governments, Barcelona. Observation year 2020. Accessed 2026-11-03.back
14. 20European Parliament and Council (eds.), Directive (EU) 2024/1275 of 24 April 2024 on the energy performance of buildings (recast), Official Journal of the European Union (downloaded text; Articles 7 and 12 read). Publications Office of the European Union, Luxembourg. Observation year 2024. Accessed 2026-11-03.back
15. 1UN DESA Population Division (ed.), World Urbanization Prospects 2025: Summary of Results (publication page and press release; 45% of 8.2 billion people in cities, 33 megacities, more than 12,000 cities, Degree of Urbanisation). United Nations, New York, November 2025. Observation year 2025. Accessed 2026-11-03.back
16. 29UNVERIFIED, not opened: WMO (ed.), State of the Global Climate 2025 (released 23 March 2026), known from search results only; no figure is used. World Meteorological Organization, Geneva. Observation year 2025. Accessed 2026-11-03.back
17. 31UNVERIFIED, not opened: UNDRR (ed.), Global Assessment Report on Disaster Risk Reduction 2025; the page returned an access error and no figure is used. United Nations Office for Disaster Risk Reduction, Geneva. Observation year 2025. Accessed 2026-11-03.back
18. 21United Nations General Assembly (ed.), New Urban Agenda, resolution 71/256, adopted at Habitat III in Quito on 20 October 2016 and endorsed on 23 December 2016 (downloaded text). United Nations, New York. Observation year 2016. Accessed 2026-11-03.back
19. 23European Commission (ed.), EU Mission: climate-neutral and smart cities (mission page; 112 cities, 107 labelled). European Commission, Brussels. Observation year 2026 (page). Accessed 2026-11-03.back
20. 6IPCC (ed.), Urban systems and other settlements, chapter 8 in Climate Change 2022: Mitigation of Climate Change, Contribution of Working Group III to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back

5.1Assumptions

Scenario SCN-GS10-HTF-01: what is assumed, and what is held constant.

Baseline

the 2026 reference state in this edition

Drivers

a multi-day heat wave in a dense coastal city, followed within weeks by intense rainfall or storm surge on land that is subsiding

Analogues

Europe 2022 heat¹⁰; urban heat exposure record¹⁴; coastal subsidence evidence¹⁶²⁶

Interventions

none modelled: the specification describes the unmitigated case

Run state

narrative specification; quantified run scheduled for 2027

5.2The cascade, step by step

1. 1

   CLI → HLT

   heat raises illness and deaths among older and poorer residents

   2022

2. 2

   CLI → ENE

   cooling load peaks and local power is stressed

   2022

3. 3

   CLI → WAT

   heavy rain or surge meets drains and low ground weakened by subsidence

   2022 to 2026

4. 4

   WAT → INF

   flood reaches roads, clinics, drainage and power

   2022

5. 5

   WAT → HLT

   water-borne illness and injury rise in informal settlements

   2022

6. 6

   INF → FIN

   repair bills and lost output strain municipal budgets

   2022

5.3The scenario as a table of steps

How the shock in scenario SCN-GS10-HTF-01 would travel through Global Cities and Urban Systems‘s coupled systems, step by step, under the assumptions the edition states.

A teaching model of a conditional scenario under the edition’s stated assumptions: not a forecast, not a prediction and not a warning. Sources: Global Cities 2026, scenario SCN-GS10-HTF-01 (2026); Global Cities 2026, references (NR-CIT-1) (2026).

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

1. 10WHO (ed.), Climate change, heat and health, fact sheet (about 489,000 heat-related deaths a year, 2000 to 2019; Europe summer 2022). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
2. 14Tuholske, C. et al., Global urban population exposure to extreme heat, Proceedings of the National Academy of Sciences 118(41), e2024792118 (open access full text, PMC). National Academy of Sciences, Washington, 2021. Observation year 2016 (series 1983 to 2016). Accessed 2026-11-03.back
3. 16Global subsidence of river deltas, Nature (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (40 deltas, satellite radar). Accessed 2026-11-03.back
4. 26Sinking cities, rising seas, Communications Engineering (2022), commentary on a Nature Sustainability study of relative land subsidence in 48 major coastal cities (open access full text, PMC). Springer Nature, London. Observation year 2022. Accessed 2026-11-03.back

6.1The other desks’ editions of this subject

Federation: each desk writes its own edition for the subjects in its remit. Until a desk releases, its edition shows its frame and the reading this edition printed for it.

6.2Three lenses

One edition, read by each steward. The lens of this site comes first.

6.3Standards, Academy and steward contributions

How the Nexus Standards drafts, the Risk Academy and the three stewards feed each quarterly edition for cities. The standards are a preparatory working draft (2026) and are cited as drafts, never as adopted standards.

6.4GCRI reading: the model card

GCRI’s reading of this edition is its model card: what the national model is, what it computes and where it stops. It is printed in full in Annex A, with the methods it belongs to. Annex A, methodology

6.5Global Risks Forum reading: editorial essays

Four signed essays by the Reports editorial team set out the positions this edition takes. They are interpretation, labelled as such; the evidence they draw on is in the findings register.

6.6Global Risks Alliance reading: 2027 cities readiness pack

The registers that open the 2027 global cycle. At baseline each is initialised from this edition.

Publication dispositions

• Publish
• Hold
• Needs evidence
• Restricted
• Superseded

6.7Nexus Standards reading: standards and regulatory watch

Instruments and published guidance that shape the systems in this edition, by status on the retrieval date. The edition assesses no one’s compliance.

• IN FORCE
• ADOPTED
• PUBLISHED · GUIDANCE
• PUBLISHED · VOLUNTARY

6.8Risk Academy reading: literature and evidence review, science and assessments

The review behind this edition covers cities assessments, peer-reviewed science and the institutional reports that bind its findings. Systematic reviews for each agenda item begin in 2027.

Review protocol

Question

What does the published evidence establish about the world’s cities and urban systems and its couplings?

Sources searched

agency flagships; assessment chapters; peer-reviewed urban and climate literature; statistics

Window

releases available at evidence close, 30 September 2026

Selection

sources that bind or contextualise a finding in this edition

Next step

systematic reviews for agenda items 01 to 05 in 2027

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

1. 22OECD and UCLG (eds.), World Observatory on Subnational Government Finance and Investment, 2022 highlights (135 countries; 2020 data). Organisation for Economic Co-operation and Development, Paris, and United Cities and Local Governments, Barcelona. Observation year 2020. Accessed 2026-11-03.back
2. 12UN-Habitat (ed.), World Cities Report 2024: Cities and Climate Action, key messages (report page; cities receive less than 20% of climate finance needed). United Nations Human Settlements Programme, Nairobi. Observation year 2024. Accessed 2026-11-03.back
3. 21United Nations General Assembly (ed.), New Urban Agenda, resolution 71/256, adopted at Habitat III in Quito on 20 October 2016 and endorsed on 23 December 2016 (downloaded text). United Nations, New York. Observation year 2016. Accessed 2026-11-03.back
4. 20European Parliament and Council (eds.), Directive (EU) 2024/1275 of 24 April 2024 on the energy performance of buildings (recast), Official Journal of the European Union (downloaded text; Articles 7 and 12 read). Publications Office of the European Union, Luxembourg. Observation year 2024. Accessed 2026-11-03.back
5. 23European Commission (ed.), EU Mission: climate-neutral and smart cities (mission page; 112 cities, 107 labelled). European Commission, Brussels. Observation year 2026 (page). Accessed 2026-11-03.back
6. 32UNVERIFIED, not opened: UNDRR (ed.), Sendai Framework for Disaster Risk Reduction 2015 to 2030; the page returned an access error and the entry is cited from memory without figures. United Nations Office for Disaster Risk Reduction, Geneva. Observation year 2015. Accessed 2026-11-03.back
7. 34UNVERIFIED, not opened: ISO 37120:2018, Sustainable cities and communities: indicators for city services and quality of life, cited from memory. International Organization for Standardization, Geneva. Observation year 2018. Accessed 2026-11-03.back
8. 35UNVERIFIED, not opened: ISO 37123:2019, Sustainable cities and communities: indicators for resilient cities, cited from memory. International Organization for Standardization, Geneva. Observation year 2019. Accessed 2026-11-03.back
9. 36UNVERIFIED, not opened: ISO 37101:2016, Sustainable development in communities: management system for sustainable development, cited from memory. International Organization for Standardization, Geneva. Observation year 2016. Accessed 2026-11-03.back
10. 1UN DESA Population Division (ed.), World Urbanization Prospects 2025: Summary of Results (publication page and press release; 45% of 8.2 billion people in cities, 33 megacities, more than 12,000 cities, Degree of Urbanisation). United Nations, New York, November 2025. Observation year 2025. Accessed 2026-11-03.back
11. 6IPCC (ed.), Urban systems and other settlements, chapter 8 in Climate Change 2022: Mitigation of Climate Change, Contribution of Working Group III to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
12. 3UN Statistics Division (ed.), Global SDG Indicators Database, API extract of series EN_LND_SLUM, EN_ATM_PM25, EN_ACS_URB_OPENSP, SP_TRN_PUBL, EN_REF_WASCOL and SD_CPA_UPRDP (release 2026.Q3.G.01). United Nations, New York. Observation year 2024 (slums), 2023 (PM2.5) and 2020 (transport, open space). Accessed 2026-11-03.back
13. 4United Nations (ed.), The Sustainable Development Goals Report 2025, Goal 11 (housing, flood, local risk reduction strategies, waste collection, national urban policies). United Nations, New York. Observation year 2024 (indicator data 2010 to 2024). Accessed 2026-11-03.back
14. 13Rentschler, J., Salhab, M. and Jafino, B.A., Flood exposure and poverty in 188 countries, Nature Communications 13, 3527 (open access full text, PMC). Springer Nature, London, 2022. Observation year 2020 (population grid). Accessed 2026-11-03.back
15. 14Tuholske, C. et al., Global urban population exposure to extreme heat, Proceedings of the National Academy of Sciences 118(41), e2024792118 (open access full text, PMC). National Academy of Sciences, Washington, 2021. Observation year 2016 (series 1983 to 2016). Accessed 2026-11-03.back
16. 15Trees halve the urban heat island effect globally but unequal benefits only modestly mitigate climate-change warming, Nature Communications (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (analysis of 8,919 large urban areas). Accessed 2026-11-03.back
17. 16Global subsidence of river deltas, Nature (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (40 deltas, satellite radar). Accessed 2026-11-03.back
18. 26Sinking cities, rising seas, Communications Engineering (2022), commentary on a Nature Sustainability study of relative land subsidence in 48 major coastal cities (open access full text, PMC). Springer Nature, London. Observation year 2022. Accessed 2026-11-03.back
19. 18The role of greenness in heat-related mortality: a systematic review and meta-analysis, Annals of Global Health (2026), open access full text, PMC. Ubiquity Press, London. Observation year 2026 (11 studies). Accessed 2026-11-03.back
20. 19Urban tree canopy fragmentation and child mortality in low- and middle-income countries, Proceedings of the National Academy of Sciences (2026), open access full text, PMC. National Academy of Sciences, Washington. Observation year 2026 (420,000 children, 57 countries). Accessed 2026-11-03.back
21. 40UNVERIFIED, not opened: Seto, K.C., Guneralp, B. and Hutyra, L.R., Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools, Proceedings of the National Academy of Sciences 109(40), 16083 to 16088, 2012, cited from memory without figures. National Academy of Sciences, Washington. Observation year 2012. Accessed 2026-11-03.back
22. 41UNVERIFIED, not opened: Guneralp, B. et al., Global scenarios of urban density and its impacts on building energy use through 2050, Proceedings of the National Academy of Sciences 114(34), 8945 to 8950, 2017, cited from memory without figures. National Academy of Sciences, Washington. Observation year 2017. Accessed 2026-11-03.back
23. 42UNVERIFIED, not opened: Nicholls, R.J. et al., A global analysis of subsidence, relative sea-level change and coastal flood exposure, Nature Climate Change 11, 338 to 342, 2021, cited from memory without figures. Springer Nature, London. Observation year 2021. Accessed 2026-11-03.back
24. 7IPCC (ed.), Cities, settlements and key infrastructure, chapter 6 in Climate Change 2022: Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
25. 30UNVERIFIED, not opened: UN-Habitat (ed.), World Cities Report 2022: Envisaging the Future of Cities, cited from memory without figures. United Nations Human Settlements Programme, Nairobi. Observation year 2022. Accessed 2026-11-03.back
26. 39UNVERIFIED, not opened: OECD and European Commission (eds.), Cities in the World: A New Perspective on Urbanisation, cited from memory without figures. OECD, Paris. Observation year 2020. Accessed 2026-11-03.back
27. 31UNVERIFIED, not opened: UNDRR (ed.), Global Assessment Report on Disaster Risk Reduction 2025; the page returned an access error and no figure is used. United Nations Office for Disaster Risk Reduction, Geneva. Observation year 2025. Accessed 2026-11-03.back
28. 45UNVERIFIED, not opened: UCLG (ed.), GOLD VI report: Pathways to urban and territorial equality, cited from memory without figures. United Cities and Local Governments, Barcelona, 2022. Observation year 2022. Accessed 2026-11-03.back
29. 2DATA VINTAGE AFTER CLOSE: World Bank (ed.), World Development Indicators, API extract of urban population, total population, urban agglomerations, urban access to electricity, clean cooking, safely managed drinking water and sanitation, slum share (database updated 8 October 2026). World Bank, Washington. Observation year 2025 (population) and 2024 (access). Accessed 2026-11-03.back
30. 11World Bank (ed.), Urban development overview (cities generate 80% of global GDP; infrastructure needs up to USD 2.7 trillion a year in low- and middle-income countries; slums about a quarter of urban population). World Bank, Washington. Observation year 2026 (page; individual figures undated). Accessed 2026-11-03.back
31. 8WHO (ed.), Ambient (outdoor) air pollution, fact sheet (4.2 million premature deaths in 2019; 99% of people above guideline levels). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
32. 9WHO (ed.), Road traffic injuries, fact sheet (page dated 20 July 2026; about 1.16 million deaths a year). World Health Organization, Geneva. Observation year 2026 (page date). Accessed 2026-11-03.back
33. 10WHO (ed.), Climate change, heat and health, fact sheet (about 489,000 heat-related deaths a year, 2000 to 2019; Europe summer 2022). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
34. 24FAO, IFAD, UNICEF, WFP and WHO (eds.), The State of Food Security and Nutrition in the World 2026 (publication page; 645 million people faced hunger in 2025; about 2.7 billion cannot afford a healthy diet). Food and Agriculture Organization, Rome. Observation year 2025. Accessed 2026-11-03.back
35. 17Romanello, M. et al., The 2023 report of the Lancet Countdown on health and climate change: the imperative for a health-centred response in a world facing irreversible harms, The Lancet 402 (open access full text, PMC). Elsevier, London, 2023. Observation year 2022. Accessed 2026-11-03.back
36. 43UNVERIFIED, not opened: Romanello, M. et al., The 2025 report of the Lancet Countdown on health and climate change; the journal page returned an access error and no figure is used. Elsevier, London, 2025. Observation year 2024. Accessed 2026-11-03.back
37. 38UNVERIFIED, not opened: United Nations General Assembly (ed.), Transforming our world: the 2030 Agenda for Sustainable Development, resolution 70/1, cited from memory without figures. United Nations, New York. Observation year 2015. Accessed 2026-11-03.back
38. 37UNVERIFIED, not opened: UNFCCC (ed.), Paris Agreement, adopted December 2015, cited from memory without figures. UNFCCC, Bonn. Observation year 2015. Accessed 2026-11-03.back
39. 27UNVERIFIED, not opened: UNEP and GlobalABC (eds.), Global Status Report for Buildings and Construction 2024 to 2025; the report page returned an access error and the figures seen only in search summaries (buildings about 32% of energy and 34% of CO2) are not used. United Nations Environment Programme, Nairobi, 2025. Observation year 2023. Accessed 2026-11-03.back
40. 28UNVERIFIED, not opened: UNEP (ed.), Global Waste Management Outlook 2024; the report page returned an access error and the figures seen only in search summaries are not used. United Nations Environment Programme, Nairobi, 2024. Observation year 2023. Accessed 2026-11-03.back
41. 33UNVERIFIED, not opened: IEA (ed.), The Future of Cooling: Opportunities for energy-efficient air conditioning, cited from memory without figures. International Energy Agency, Paris, 2018. Observation year 2018. Accessed 2026-11-03.back
42. 44UNVERIFIED, not opened: WHO (ed.), WHO global air quality guidelines: particulate matter, ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide, 2021; the fact-sheet page did not state the guideline values and no value is used. World Health Organization, Geneva. Observation year 2021. Accessed 2026-11-03.back
43. 29UNVERIFIED, not opened: WMO (ed.), State of the Global Climate 2025 (released 23 March 2026), known from search results only; no figure is used. World Meteorological Organization, Geneva. Observation year 2025. Accessed 2026-11-03.back
44. 5UN DESA (ed.), Sustainable Development Goal 11: make cities and human settlements inclusive, safe, resilient and sustainable (Goal page; slum population, land consumption rate, targets). United Nations, New York. Observation year 2022 (slums) and 2025 (land consumption). Accessed 2026-11-03.back

7.1Questions for the operational series

1. C-01

   How would a heat wave followed by flooding travel through housing, power, drainage and health in a subsiding coastal city?

   INI-GS10-HTF-01 · heat then flood; first output: concurrency analysis for six city regions.

2. C-02

   Can urban population be reported on one definition across the UN and national series?

   INI-GS10-DEF-02 · definition bridge; first output: crosswalk table by country.

3. C-03

   Where do informal settlements lack services that the national averages hide?

   INI-GS10-INF-03 · informal settlement services; first output: service-tier table.

4. C-04

   What share of urban climate finance reaches municipalities, and in what form?

   INI-GS10-FIN-04 · municipal finance; first output: flow map with sources.

5. C-05

   How much do buildings add to urban load and emissions, and where are codes in force?

   INI-GS10-BLD-05 · buildings and cooling; first output: code coverage register.

6. C-06

   Which urban heat deaths are avoidable with cooling and green cover?

   To be admitted in 2027; first output: scoping note.

7. C-07

   Which cities have adaptation plans that are funded and implemented?

   To be admitted in 2027; first output: plan register.

8. C-08

   Which urban capabilities have been tested in real heat or flood events, and which are only planned?

   Urban capability register; first output: rung evidence for 15 functions.

7.2Portfolio proposed for the Q1 2027 alignment

Five initiatives and one Universe mission candidate are proposed for the 2027 cities portfolio. They are programme objects: no partner, funder or member is attached to them in this edition.

7.3The pathway

The cities edition reads national urban chapters, regional city-system evidence and the global edition through one governed evidence graph. At baseline the federation is designed. This page states what exists today and what comes next.

1. 01

   National urban chapters

   urban system of each national edition

   PLANNED · national baselines

2. 02

   City-system evidence

   delta, coastal and metropolitan regions that cross borders

   PLANNED · regional Baseline Editions

3. 03

   Urban sector model

   the global urban system of systems

   v0 SPECIFIED · v1 with federation evidence

4. 04

   Global and strategic links

   GLB · SR-11 Cities, Demography and Human Systems · SR-02 Critical Infrastructure and Lifeline Systems

   PLANNED · strategic baselines

5. 05

   Universe

   annual proving environment

   CANDIDATE MISSION · mandate in 2027

6. 06

   Global Cities Report

   this series

   BASELINE DRAFT · 2027 annual edition

7. 07

   Evidence and correction

   one graph, many projections

   OPEN · first correction cycle in 2027

7.4Universe 2027: evidence pack for the cities candidate mission

1. 01

   Mandate

2. 02

   Core Build · 1 month

3. 03

   Action · 1 week

4. 04

   Evidence seal

5. 05

   Portfolio correction

6. 06

   Next mandate

Mission

ID

MSN-GS10-2027-01 · Heat then flood Universe mission

Role spine

Leadership sponsor · Institutional anchor · Mission lead: drawn from national pathways

Receiving actors

to be identified with the mandate

7.5Handoffs and routing

Where the baseline’s findings go next. A handoff routes a finding for awareness, review or work; it transfers no authority.

7.6Feeds and signal register

Escalation routes

• none · keep monitoring
• research question
• project
• risk object
• annual publication
• signal report

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

1. 14Tuholske, C. et al., Global urban population exposure to extreme heat, Proceedings of the National Academy of Sciences 118(41), e2024792118 (open access full text, PMC). National Academy of Sciences, Washington, 2021. Observation year 2016 (series 1983 to 2016). Accessed 2026-11-03.back
2. 5UN DESA (ed.), Sustainable Development Goal 11: make cities and human settlements inclusive, safe, resilient and sustainable (Goal page; slum population, land consumption rate, targets). United Nations, New York. Observation year 2022 (slums) and 2025 (land consumption). Accessed 2026-11-03.back
3. 12UN-Habitat (ed.), World Cities Report 2024: Cities and Climate Action, key messages (report page; cities receive less than 20% of climate finance needed). United Nations Human Settlements Programme, Nairobi. Observation year 2024. Accessed 2026-11-03.back

8.1Cities and water

Drinking supply, sanitation and drainage carry urban health, and floods test them. Cities sit on rivers and coasts, and some of the land beneath them is sinking.

Related editions

• GLB Global Systems
• GS-01 Water
• GS-02 Energy
• GS-04 Health and One Health
• GS-08 Disaster and Resilience
• SR-11 Cities, Demography and Human Systems

8.2Cities and energy

Cities concentrate the demand for power, cooling and cooking fuel, and the buildings that use them. Access is high, and the next question is the load and emissions of the building stock.

Related editions

• GLB Global Systems
• GS-01 Water
• GS-02 Energy
• GS-04 Health and One Health
• GS-08 Disaster and Resilience
• SR-11 Cities, Demography and Human Systems

8.3Cities and food

City residents buy most of their food. Cost, market access and cold storage matter, and housing costs compete for the same budget.

Related editions

• GLB Global Systems
• GS-01 Water
• GS-02 Energy
• GS-04 Health and One Health
• GS-08 Disaster and Resilience
• SR-11 Cities, Demography and Human Systems

8.4Cities and health

Heat, polluted air, road traffic and poor housing shape urban health. The same neighbourhoods often carry all four burdens.

Related editions

• GLB Global Systems
• GS-01 Water
• GS-02 Energy
• GS-04 Health and One Health
• GS-08 Disaster and Resilience
• SR-11 Cities, Demography and Human Systems

8.5Cities, nature and climate

Cities emit and are exposed. They also hold the levers of land use, buildings and green cover. Nature is the least measured side of the urban ledger in this edition.

Related editions

• GLB Global Systems
• GS-01 Water
• GS-02 Energy
• GS-04 Health and One Health
• GS-08 Disaster and Resilience
• SR-11 Cities, Demography and Human Systems

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

1. 13Rentschler, J., Salhab, M. and Jafino, B.A., Flood exposure and poverty in 188 countries, Nature Communications 13, 3527 (open access full text, PMC). Springer Nature, London, 2022. Observation year 2020 (population grid). Accessed 2026-11-03.back
2. 2DATA VINTAGE AFTER CLOSE: World Bank (ed.), World Development Indicators, API extract of urban population, total population, urban agglomerations, urban access to electricity, clean cooking, safely managed drinking water and sanitation, slum share (database updated 8 October 2026). World Bank, Washington. Observation year 2025 (population) and 2024 (access). Accessed 2026-11-03.back
3. 4United Nations (ed.), The Sustainable Development Goals Report 2025, Goal 11 (housing, flood, local risk reduction strategies, waste collection, national urban policies). United Nations, New York. Observation year 2024 (indicator data 2010 to 2024). Accessed 2026-11-03.back
4. 16Global subsidence of river deltas, Nature (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (40 deltas, satellite radar). Accessed 2026-11-03.back
5. 26Sinking cities, rising seas, Communications Engineering (2022), commentary on a Nature Sustainability study of relative land subsidence in 48 major coastal cities (open access full text, PMC). Springer Nature, London. Observation year 2022. Accessed 2026-11-03.back
6. 20European Parliament and Council (eds.), Directive (EU) 2024/1275 of 24 April 2024 on the energy performance of buildings (recast), Official Journal of the European Union (downloaded text; Articles 7 and 12 read). Publications Office of the European Union, Luxembourg. Observation year 2024. Accessed 2026-11-03.back
7. 6IPCC (ed.), Urban systems and other settlements, chapter 8 in Climate Change 2022: Mitigation of Climate Change, Contribution of Working Group III to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
8. 33UNVERIFIED, not opened: IEA (ed.), The Future of Cooling: Opportunities for energy-efficient air conditioning, cited from memory without figures. International Energy Agency, Paris, 2018. Observation year 2018. Accessed 2026-11-03.back
9. 24FAO, IFAD, UNICEF, WFP and WHO (eds.), The State of Food Security and Nutrition in the World 2026 (publication page; 645 million people faced hunger in 2025; about 2.7 billion cannot afford a healthy diet). Food and Agriculture Organization, Rome. Observation year 2025. Accessed 2026-11-03.back
10. 10WHO (ed.), Climate change, heat and health, fact sheet (about 489,000 heat-related deaths a year, 2000 to 2019; Europe summer 2022). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
11. 8WHO (ed.), Ambient (outdoor) air pollution, fact sheet (4.2 million premature deaths in 2019; 99% of people above guideline levels). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
12. 9WHO (ed.), Road traffic injuries, fact sheet (page dated 20 July 2026; about 1.16 million deaths a year). World Health Organization, Geneva. Observation year 2026 (page date). Accessed 2026-11-03.back
13. 3UN Statistics Division (ed.), Global SDG Indicators Database, API extract of series EN_LND_SLUM, EN_ATM_PM25, EN_ACS_URB_OPENSP, SP_TRN_PUBL, EN_REF_WASCOL and SD_CPA_UPRDP (release 2026.Q3.G.01). United Nations, New York. Observation year 2024 (slums), 2023 (PM2.5) and 2020 (transport, open space). Accessed 2026-11-03.back
14. 5UN DESA (ed.), Sustainable Development Goal 11: make cities and human settlements inclusive, safe, resilient and sustainable (Goal page; slum population, land consumption rate, targets). United Nations, New York. Observation year 2022 (slums) and 2025 (land consumption). Accessed 2026-11-03.back
15. 15Trees halve the urban heat island effect globally but unequal benefits only modestly mitigate climate-change warming, Nature Communications (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (analysis of 8,919 large urban areas). Accessed 2026-11-03.back
16. 17Romanello, M. et al., The 2023 report of the Lancet Countdown on health and climate change: the imperative for a health-centred response in a world facing irreversible harms, The Lancet 402 (open access full text, PMC). Elsevier, London, 2023. Observation year 2022. Accessed 2026-11-03.back
17. 19Urban tree canopy fragmentation and child mortality in low- and middle-income countries, Proceedings of the National Academy of Sciences (2026), open access full text, PMC. National Academy of Sciences, Washington. Observation year 2026 (420,000 children, 57 countries). Accessed 2026-11-03.back

A.1Methods

The global baseline uses published values and four simple derivations. Each is shown in full so that any reader can reproduce it.

A.2Model card, Cities Sector Model v0

Model ID

MDL-GS10-CITIES · v0.1

Purpose

represent the global urban system and its couplings to water, energy, food, health and nature

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 assessments and analogue events

Validation

none yet, first validation against federation evidence in 2027

Uncertainty

qualitative; strengths are hypotheses, not measurements

Domain of validity

global scale; not for asset-, site- or country-level use

Reproducibility

strength table and sources published in this edition

A.3The baseline evidence cut

Every Nexus edition is published from a frozen evidence cut. The global baseline cut is documentary: it pins the exact edition of every source cited. Federation cuts begin with the first national Foundry cuts in 2027.

Cut ID

DC-SECTOR-CITIES-GLOBAL-2026-B0

Type

baseline documentary cut

Resolution policy

pinned · as of 30 September 2026

Sources pinned

45 cited sources, each at the edition and access 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

the 2027 cities annual cut

Lineage

1. 01

   source edition

2. 02

   pinned citation

3. 03

   finding

4. 04

   page

5. 05

   publication record

A.4Evidence age and coverage

A 2026 global edition rests on evidence observed in many different years. This page shows each time base, so that no single year label hides older evidence.

A.5Evidence cards, two anchor sources

Evidence cards to follow in 2027

• UN DESA¹: country and city tables for towns and rural areas
• UNEP²⁷: buildings energy and emissions shares from the report
• UN Statistics Division³: inadequate housing series and later transport values
• WHO¹⁰: city-level heat deaths where published

A.6Publication acceptance record

Editorial self-check at evidence close. Every applicable item carries a disposition; the remaining items are review, approval and deposit.

A.7Status words

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.

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

A.10Technical annex

A.1 · indicator definition: proportion of urban population living in slums

Construct

share of the urban population living in households with one or more housing deprivations

Unit

share of urban population

Method

custodian indicator from household surveys and censuses, with modelled estimates

Source

SDG database and Goal 11 page³⁵

Uncertainty

the World Bank series differs by 1.6 percentage points for 2022²

Known limits

a proxy; does not capture tenure security, eviction risk or neighbourhood quality

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

1. 1UN DESA Population Division (ed.), World Urbanization Prospects 2025: Summary of Results (publication page and press release; 45% of 8.2 billion people in cities, 33 megacities, more than 12,000 cities, Degree of Urbanisation). United Nations, New York, November 2025. Observation year 2025. Accessed 2026-11-03.back
2. 27UNVERIFIED, not opened: UNEP and GlobalABC (eds.), Global Status Report for Buildings and Construction 2024 to 2025; the report page returned an access error and the figures seen only in search summaries (buildings about 32% of energy and 34% of CO2) are not used. United Nations Environment Programme, Nairobi, 2025. Observation year 2023. Accessed 2026-11-03.back
3. 28UNVERIFIED, not opened: UNEP (ed.), Global Waste Management Outlook 2024; the report page returned an access error and the figures seen only in search summaries are not used. United Nations Environment Programme, Nairobi, 2024. Observation year 2023. Accessed 2026-11-03.back
4. 4United Nations (ed.), The Sustainable Development Goals Report 2025, Goal 11 (housing, flood, local risk reduction strategies, waste collection, national urban policies). United Nations, New York. Observation year 2024 (indicator data 2010 to 2024). Accessed 2026-11-03.back
5. 43UNVERIFIED, not opened: Romanello, M. et al., The 2025 report of the Lancet Countdown on health and climate change; the journal page returned an access error and no figure is used. Elsevier, London, 2025. Observation year 2024. Accessed 2026-11-03.back
6. 33UNVERIFIED, not opened: IEA (ed.), The Future of Cooling: Opportunities for energy-efficient air conditioning, cited from memory without figures. International Energy Agency, Paris, 2018. Observation year 2018. Accessed 2026-11-03.back
7. 24FAO, IFAD, UNICEF, WFP and WHO (eds.), The State of Food Security and Nutrition in the World 2026 (publication page; 645 million people faced hunger in 2025; about 2.7 billion cannot afford a healthy diet). Food and Agriculture Organization, Rome. Observation year 2025. Accessed 2026-11-03.back
8. 3UN Statistics Division (ed.), Global SDG Indicators Database, API extract of series EN_LND_SLUM, EN_ATM_PM25, EN_ACS_URB_OPENSP, SP_TRN_PUBL, EN_REF_WASCOL and SD_CPA_UPRDP (release 2026.Q3.G.01). United Nations, New York. Observation year 2024 (slums), 2023 (PM2.5) and 2020 (transport, open space). Accessed 2026-11-03.back
9. 8WHO (ed.), Ambient (outdoor) air pollution, fact sheet (4.2 million premature deaths in 2019; 99% of people above guideline levels). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
10. 44UNVERIFIED, not opened: WHO (ed.), WHO global air quality guidelines: particulate matter, ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide, 2021; the fact-sheet page did not state the guideline values and no value is used. World Health Organization, Geneva. Observation year 2021. Accessed 2026-11-03.back
11. 7IPCC (ed.), Cities, settlements and key infrastructure, chapter 6 in Climate Change 2022: Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
12. 11World Bank (ed.), Urban development overview (cities generate 80% of global GDP; infrastructure needs up to USD 2.7 trillion a year in low- and middle-income countries; slums about a quarter of urban population). World Bank, Washington. Observation year 2026 (page; individual figures undated). Accessed 2026-11-03.back
13. 31UNVERIFIED, not opened: UNDRR (ed.), Global Assessment Report on Disaster Risk Reduction 2025; the page returned an access error and no figure is used. United Nations Office for Disaster Risk Reduction, Geneva. Observation year 2025. Accessed 2026-11-03.back
14. 22OECD and UCLG (eds.), World Observatory on Subnational Government Finance and Investment, 2022 highlights (135 countries; 2020 data). Organisation for Economic Co-operation and Development, Paris, and United Cities and Local Governments, Barcelona. Observation year 2020. Accessed 2026-11-03.back
15. 6IPCC (ed.), Urban systems and other settlements, chapter 8 in Climate Change 2022: Mitigation of Climate Change, Contribution of Working Group III to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
16. 10WHO (ed.), Climate change, heat and health, fact sheet (about 489,000 heat-related deaths a year, 2000 to 2019; Europe summer 2022). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
17. 5UN DESA (ed.), Sustainable Development Goal 11: make cities and human settlements inclusive, safe, resilient and sustainable (Goal page; slum population, land consumption rate, targets). United Nations, New York. Observation year 2022 (slums) and 2025 (land consumption). Accessed 2026-11-03.back
18. 2DATA VINTAGE AFTER CLOSE: World Bank (ed.), World Development Indicators, API extract of urban population, total population, urban agglomerations, urban access to electricity, clean cooking, safely managed drinking water and sanitation, slum share (database updated 8 October 2026). World Bank, Washington. Observation year 2025 (population) and 2024 (access). Accessed 2026-11-03.back

B.1The indicator set

B.2Global source register

The governed source set behind this edition. Each source keeps its authority, coverage, cadence and role; categories describe origin, not truth.

Domains bound by the register

• SYS
• HLT
• CLI
• WAT
• INF
• FIN
• BIO
• ENE
• FOO
• MIN

B.3Regional reading: cities across ten clusters

Map plates follow with the regional Baseline Editions, when boundary sources and public-safe resolutions are bound. This page gives the regional reading in table form and ranks no region.

B.4City-region card: low-lying delta and coastal cities

• delta
• coastal
• low-lying
• subsiding

Systems in view

housing, drainage, power, transport, health

Defining evidence

delta surface-elevation loss across 40 deltas¹⁶; 48 major coastal cities²⁶

Couplings

CLI → WAT flood; WAT → HLT illness; WAT → INF disruption

Capability evidence

110 countries report local risk reduction strategies⁴

Gaps

city-level loss series; adaptation plans in force

Agenda items

C-01 · C-07

B.5How countries appear in the cities edition

Countries enter the cities edition through the urban chapters of their own national editions, on one card grammar. They are read against peer distributions and thresholds, never ranked.

Editions in the 2026 Baseline programme

How to read a country card

• Each system is shown against the distribution of its peers, with thresholds where they exist
• Couplings and risk objects come from the country’s own national edition
• Capability rungs record evidence, not a judgement of institutions
• Evidence age is printed, so older national data are visible as such

B.6Licences

B.7Formats and provenance

Provenance

Edition pack

The edition’s content pack (JSON), from which the print and web editions are built

Evidence cut

DC-SECTOR-CITIES-GLOBAL-2026-B0, closed 30 September 2026

Reproducibility

sourced values cited; analytical values reproducible from stated parameters

Self-check

14 of 23 at evidence close; a fail on any item blocks release

Review

five passes scheduled before release (in Annex C)

Publisher of record

GCRI for the Nexus Consortium

Corrections

Registry correction pathway; upheld corrections are published as notices with a new version

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

1. 1UN DESA Population Division (ed.), World Urbanization Prospects 2025: Summary of Results (publication page and press release; 45% of 8.2 billion people in cities, 33 megacities, more than 12,000 cities, Degree of Urbanisation). United Nations, New York, November 2025. Observation year 2025. Accessed 2026-11-03.back
2. 2DATA VINTAGE AFTER CLOSE: World Bank (ed.), World Development Indicators, API extract of urban population, total population, urban agglomerations, urban access to electricity, clean cooking, safely managed drinking water and sanitation, slum share (database updated 8 October 2026). World Bank, Washington. Observation year 2025 (population) and 2024 (access). Accessed 2026-11-03.back
3. 3UN Statistics Division (ed.), Global SDG Indicators Database, API extract of series EN_LND_SLUM, EN_ATM_PM25, EN_ACS_URB_OPENSP, SP_TRN_PUBL, EN_REF_WASCOL and SD_CPA_UPRDP (release 2026.Q3.G.01). United Nations, New York. Observation year 2024 (slums), 2023 (PM2.5) and 2020 (transport, open space). Accessed 2026-11-03.back
4. 6IPCC (ed.), Urban systems and other settlements, chapter 8 in Climate Change 2022: Mitigation of Climate Change, Contribution of Working Group III to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
5. 14Tuholske, C. et al., Global urban population exposure to extreme heat, Proceedings of the National Academy of Sciences 118(41), e2024792118 (open access full text, PMC). National Academy of Sciences, Washington, 2021. Observation year 2016 (series 1983 to 2016). Accessed 2026-11-03.back
6. 13Rentschler, J., Salhab, M. and Jafino, B.A., Flood exposure and poverty in 188 countries, Nature Communications 13, 3527 (open access full text, PMC). Springer Nature, London, 2022. Observation year 2020 (population grid). Accessed 2026-11-03.back
7. 22OECD and UCLG (eds.), World Observatory on Subnational Government Finance and Investment, 2022 highlights (135 countries; 2020 data). Organisation for Economic Co-operation and Development, Paris, and United Cities and Local Governments, Barcelona. Observation year 2020. Accessed 2026-11-03.back
8. 10WHO (ed.), Climate change, heat and health, fact sheet (about 489,000 heat-related deaths a year, 2000 to 2019; Europe summer 2022). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
9. 4United Nations (ed.), The Sustainable Development Goals Report 2025, Goal 11 (housing, flood, local risk reduction strategies, waste collection, national urban policies). United Nations, New York. Observation year 2024 (indicator data 2010 to 2024). Accessed 2026-11-03.back
10. 7IPCC (ed.), Cities, settlements and key infrastructure, chapter 6 in Climate Change 2022: Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03.back
11. 8WHO (ed.), Ambient (outdoor) air pollution, fact sheet (4.2 million premature deaths in 2019; 99% of people above guideline levels). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03.back
12. 9WHO (ed.), Road traffic injuries, fact sheet (page dated 20 July 2026; about 1.16 million deaths a year). World Health Organization, Geneva. Observation year 2026 (page date). Accessed 2026-11-03.back
13. 12UN-Habitat (ed.), World Cities Report 2024: Cities and Climate Action, key messages (report page; cities receive less than 20% of climate finance needed). United Nations Human Settlements Programme, Nairobi. Observation year 2024. Accessed 2026-11-03.back
14. 20European Parliament and Council (eds.), Directive (EU) 2024/1275 of 24 April 2024 on the energy performance of buildings (recast), Official Journal of the European Union (downloaded text; Articles 7 and 12 read). Publications Office of the European Union, Luxembourg. Observation year 2024. Accessed 2026-11-03.back
15. 23European Commission (ed.), EU Mission: climate-neutral and smart cities (mission page; 112 cities, 107 labelled). European Commission, Brussels. Observation year 2026 (page). Accessed 2026-11-03.back
16. 16Global subsidence of river deltas, Nature (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (40 deltas, satellite radar). Accessed 2026-11-03.back
17. 26Sinking cities, rising seas, Communications Engineering (2022), commentary on a Nature Sustainability study of relative land subsidence in 48 major coastal cities (open access full text, PMC). Springer Nature, London. Observation year 2022. Accessed 2026-11-03.back

C.145 sources

NR-CIT-1, editor first. A DOI is linked where the source has one; Nexus records carry a UNI once the catalogue allocates it (NS-1).

1. 1UN DESA Population Division (ed.), World Urbanization Prospects 2025: Summary of Results (publication page and press release; 45% of 8.2 billion people in cities, 33 megacities, more than 12,000 cities, Degree of Urbanisation). United Nations, New York, November 2025. Observation year 2025. Accessed 2026-11-03. Cited in the summary, chapter 1, chapter 2, chapter 3, chapter 4, chapter 6
2. 2DATA VINTAGE AFTER CLOSE: World Bank (ed.), World Development Indicators, API extract of urban population, total population, urban agglomerations, urban access to electricity, clean cooking, safely managed drinking water and sanitation, slum share (database updated 8 October 2026). World Bank, Washington. Observation year 2025 (population) and 2024 (access). Accessed 2026-11-03. Cited in the summary, chapter 1, chapter 2, chapter 3, chapter 4, chapter 6, chapter 8
3. 3UN Statistics Division (ed.), Global SDG Indicators Database, API extract of series EN_LND_SLUM, EN_ATM_PM25, EN_ACS_URB_OPENSP, SP_TRN_PUBL, EN_REF_WASCOL and SD_CPA_UPRDP (release 2026.Q3.G.01). United Nations, New York. Observation year 2024 (slums), 2023 (PM2.5) and 2020 (transport, open space). Accessed 2026-11-03. Cited in the summary, chapter 1, chapter 2, chapter 3, chapter 4, chapter 6, chapter 8
4. 4United Nations (ed.), The Sustainable Development Goals Report 2025, Goal 11 (housing, flood, local risk reduction strategies, waste collection, national urban policies). United Nations, New York. Observation year 2024 (indicator data 2010 to 2024). Accessed 2026-11-03. Cited in chapter 1, chapter 2, chapter 3, chapter 4, chapter 6, chapter 8
5. 5UN DESA (ed.), Sustainable Development Goal 11: make cities and human settlements inclusive, safe, resilient and sustainable (Goal page; slum population, land consumption rate, targets). United Nations, New York. Observation year 2022 (slums) and 2025 (land consumption). Accessed 2026-11-03. Cited in the summary, chapter 1, chapter 2, chapter 3, chapter 4, chapter 6, chapter 7, chapter 8
6. 6IPCC (ed.), Urban systems and other settlements, chapter 8 in Climate Change 2022: Mitigation of Climate Change, Contribution of Working Group III to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03. Cited in the summary, chapter 1, chapter 2, chapter 3, chapter 4, chapter 6, chapter 8
7. 7IPCC (ed.), Cities, settlements and key infrastructure, chapter 6 in Climate Change 2022: Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Sixth Assessment Report of the IPCC (downloaded chapter, executive summary read). IPCC, Geneva, 2022. Observation year 2020. Accessed 2026-11-03. Cited in the summary, chapter 1, chapter 2, chapter 3, chapter 4, chapter 6
8. 8WHO (ed.), Ambient (outdoor) air pollution, fact sheet (4.2 million premature deaths in 2019; 99% of people above guideline levels). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03. Cited in chapter 2, chapter 3, chapter 6, chapter 8
9. 9WHO (ed.), Road traffic injuries, fact sheet (page dated 20 July 2026; about 1.16 million deaths a year). World Health Organization, Geneva. Observation year 2026 (page date). Accessed 2026-11-03. Cited in chapter 3, chapter 6, chapter 8
10. 10WHO (ed.), Climate change, heat and health, fact sheet (about 489,000 heat-related deaths a year, 2000 to 2019; Europe summer 2022). World Health Organization, Geneva. Observation year 2019. Accessed 2026-11-03. Cited in chapter 1, chapter 3, chapter 4, chapter 5, chapter 6, chapter 8
11. 11World Bank (ed.), Urban development overview (cities generate 80% of global GDP; infrastructure needs up to USD 2.7 trillion a year in low- and middle-income countries; slums about a quarter of urban population). World Bank, Washington. Observation year 2026 (page; individual figures undated). Accessed 2026-11-03. Cited in chapter 6
12. 12UN-Habitat (ed.), World Cities Report 2024: Cities and Climate Action, key messages (report page; cities receive less than 20% of climate finance needed). United Nations Human Settlements Programme, Nairobi. Observation year 2024. Accessed 2026-11-03. Cited in the summary, chapter 1, chapter 2, chapter 3, chapter 4, chapter 6, chapter 7
13. 13Rentschler, J., Salhab, M. and Jafino, B.A., Flood exposure and poverty in 188 countries, Nature Communications 13, 3527 (open access full text, PMC). Springer Nature, London, 2022. Observation year 2020 (population grid). Accessed 2026-11-03. Cited in the summary, chapter 1, chapter 2, chapter 3, chapter 4, chapter 6, chapter 8
14. 14Tuholske, C. et al., Global urban population exposure to extreme heat, Proceedings of the National Academy of Sciences 118(41), e2024792118 (open access full text, PMC). National Academy of Sciences, Washington, 2021. Observation year 2016 (series 1983 to 2016). Accessed 2026-11-03. Cited in the summary, chapter 1, chapter 2, chapter 4, chapter 5, chapter 6, chapter 7
15. 15Trees halve the urban heat island effect globally but unequal benefits only modestly mitigate climate-change warming, Nature Communications (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (analysis of 8,919 large urban areas). Accessed 2026-11-03. Cited in the summary, chapter 1, chapter 2, chapter 3, chapter 4, chapter 6, chapter 8
16. 16Global subsidence of river deltas, Nature (2026), open access full text, PMC. Springer Nature, London. Observation year 2026 (40 deltas, satellite radar). Accessed 2026-11-03. Cited in chapter 1, chapter 4, chapter 5, chapter 6, chapter 8
17. 17Romanello, M. et al., The 2023 report of the Lancet Countdown on health and climate change: the imperative for a health-centred response in a world facing irreversible harms, The Lancet 402 (open access full text, PMC). Elsevier, London, 2023. Observation year 2022. Accessed 2026-11-03. Cited in the summary, chapter 2, chapter 3, chapter 6, chapter 8
18. 18The role of greenness in heat-related mortality: a systematic review and meta-analysis, Annals of Global Health (2026), open access full text, PMC. Ubiquity Press, London. Observation year 2026 (11 studies). Accessed 2026-11-03. Cited in chapter 1, chapter 6
19. 19Urban tree canopy fragmentation and child mortality in low- and middle-income countries, Proceedings of the National Academy of Sciences (2026), open access full text, PMC. National Academy of Sciences, Washington. Observation year 2026 (420,000 children, 57 countries). Accessed 2026-11-03. Cited in chapter 1, chapter 6, chapter 8
20. 20European Parliament and Council (eds.), Directive (EU) 2024/1275 of 24 April 2024 on the energy performance of buildings (recast), Official Journal of the European Union (downloaded text; Articles 7 and 12 read). Publications Office of the European Union, Luxembourg. Observation year 2024. Accessed 2026-11-03. Cited in chapter 4, chapter 6, chapter 8
21. 21United Nations General Assembly (ed.), New Urban Agenda, resolution 71/256, adopted at Habitat III in Quito on 20 October 2016 and endorsed on 23 December 2016 (downloaded text). United Nations, New York. Observation year 2016. Accessed 2026-11-03. Cited in chapter 4, chapter 6
22. 22OECD and UCLG (eds.), World Observatory on Subnational Government Finance and Investment, 2022 highlights (135 countries; 2020 data). Organisation for Economic Co-operation and Development, Paris, and United Cities and Local Governments, Barcelona. Observation year 2020. Accessed 2026-11-03. Cited in the summary, chapter 2, chapter 3, chapter 4, chapter 6
23. 23European Commission (ed.), EU Mission: climate-neutral and smart cities (mission page; 112 cities, 107 labelled). European Commission, Brussels. Observation year 2026 (page). Accessed 2026-11-03. Cited in chapter 4, chapter 6
24. 24FAO, IFAD, UNICEF, WFP and WHO (eds.), The State of Food Security and Nutrition in the World 2026 (publication page; 645 million people faced hunger in 2025; about 2.7 billion cannot afford a healthy diet). Food and Agriculture Organization, Rome. Observation year 2025. Accessed 2026-11-03. Cited in chapter 3, chapter 6, chapter 8
25. 25WMO (ed.), 2025 set to be second or third warmest year on record (press release; January to August 2025 about 1.42 °C above pre-industrial). World Meteorological Organization, Geneva. Observation year 2025. Accessed 2026-11-03. Cited in chapter 4
26. 26Sinking cities, rising seas, Communications Engineering (2022), commentary on a Nature Sustainability study of relative land subsidence in 48 major coastal cities (open access full text, PMC). Springer Nature, London. Observation year 2022. Accessed 2026-11-03. Cited in chapter 1, chapter 5, chapter 6, chapter 8
27. 27UNVERIFIED, not opened: UNEP and GlobalABC (eds.), Global Status Report for Buildings and Construction 2024 to 2025; the report page returned an access error and the figures seen only in search summaries (buildings about 32% of energy and 34% of CO2) are not used. United Nations Environment Programme, Nairobi, 2025. Observation year 2023. Accessed 2026-11-03. Cited in chapter 6
28. 28UNVERIFIED, not opened: UNEP (ed.), Global Waste Management Outlook 2024; the report page returned an access error and the figures seen only in search summaries are not used. United Nations Environment Programme, Nairobi, 2024. Observation year 2023. Accessed 2026-11-03. Cited in chapter 6
29. 29UNVERIFIED, not opened: WMO (ed.), State of the Global Climate 2025 (released 23 March 2026), known from search results only; no figure is used. World Meteorological Organization, Geneva. Observation year 2025. Accessed 2026-11-03. Cited in chapter 4, chapter 6
30. 30UNVERIFIED, not opened: UN-Habitat (ed.), World Cities Report 2022: Envisaging the Future of Cities, cited from memory without figures. United Nations Human Settlements Programme, Nairobi. Observation year 2022. Accessed 2026-11-03. Cited in chapter 6
31. 31UNVERIFIED, not opened: UNDRR (ed.), Global Assessment Report on Disaster Risk Reduction 2025; the page returned an access error and no figure is used. United Nations Office for Disaster Risk Reduction, Geneva. Observation year 2025. Accessed 2026-11-03. Cited in chapter 4, chapter 6
32. 32UNVERIFIED, not opened: UNDRR (ed.), Sendai Framework for Disaster Risk Reduction 2015 to 2030; the page returned an access error and the entry is cited from memory without figures. United Nations Office for Disaster Risk Reduction, Geneva. Observation year 2015. Accessed 2026-11-03. Cited in chapter 6
33. 33UNVERIFIED, not opened: IEA (ed.), The Future of Cooling: Opportunities for energy-efficient air conditioning, cited from memory without figures. International Energy Agency, Paris, 2018. Observation year 2018. Accessed 2026-11-03. Cited in chapter 6, chapter 8
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35. 35UNVERIFIED, not opened: ISO 37123:2019, Sustainable cities and communities: indicators for resilient cities, cited from memory. International Organization for Standardization, Geneva. Observation year 2019. Accessed 2026-11-03. Cited in chapter 6
36. 36UNVERIFIED, not opened: ISO 37101:2016, Sustainable development in communities: management system for sustainable development, cited from memory. International Organization for Standardization, Geneva. Observation year 2016. Accessed 2026-11-03. Cited in chapter 6
37. 37UNVERIFIED, not opened: UNFCCC (ed.), Paris Agreement, adopted December 2015, cited from memory without figures. UNFCCC, Bonn. Observation year 2015. Accessed 2026-11-03. Cited in chapter 6
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39. 39UNVERIFIED, not opened: OECD and European Commission (eds.), Cities in the World: A New Perspective on Urbanisation, cited from memory without figures. OECD, Paris. Observation year 2020. Accessed 2026-11-03. Cited in chapter 6
40. 40UNVERIFIED, not opened: Seto, K.C., Guneralp, B. and Hutyra, L.R., Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools, Proceedings of the National Academy of Sciences 109(40), 16083 to 16088, 2012, cited from memory without figures. National Academy of Sciences, Washington. Observation year 2012. Accessed 2026-11-03. Cited in chapter 6
41. 41UNVERIFIED, not opened: Guneralp, B. et al., Global scenarios of urban density and its impacts on building energy use through 2050, Proceedings of the National Academy of Sciences 114(34), 8945 to 8950, 2017, cited from memory without figures. National Academy of Sciences, Washington. Observation year 2017. Accessed 2026-11-03. Cited in chapter 6
42. 42UNVERIFIED, not opened: Nicholls, R.J. et al., A global analysis of subsidence, relative sea-level change and coastal flood exposure, Nature Climate Change 11, 338 to 342, 2021, cited from memory without figures. Springer Nature, London. Observation year 2021. Accessed 2026-11-03. Cited in chapter 6
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44. 44UNVERIFIED, not opened: WHO (ed.), WHO global air quality guidelines: particulate matter, ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide, 2021; the fact-sheet page did not state the guideline values and no value is used. World Health Organization, Geneva. Observation year 2021. Accessed 2026-11-03. Cited in chapter 6
45. 45UNVERIFIED, not opened: UCLG (ed.), GOLD VI report: Pathways to urban and territorial equality, cited from memory without figures. United Cities and Local Governments, Barcelona, 2022. Observation year 2022. Accessed 2026-11-03. Cited in chapter 6

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