Draft, not yet released. In stewardship review. Not indexed until the first approved release.

Key findings

Twelve findings carry the cities baseline. They are grouped by coupling and never ranked. Each resolves to its source or, where Nexus analysis is involved, to its stated method.

5 min read1 figure0 tables14 notesNR-SECTOR-CITIES-GLOBAL-2026-BASELINE

Contents
  1. ·Edition home
  2. ·Executive summary
  3. 1Cities are where the systems meet
  4. 2Key findings
    1. 2.1 Headline finding
    2. 2.2 Systemic
    3. 2.3 Health
    4. 2.4 Climate forcing
    5. 2.5 Water
    6. 2.6 Finance
    7. 2.7 Infrastructure
    8. 2.8 Biodiversity
  5. 3Systems and sectors at baseline
  6. 4Risks and capability
  7. 5Heat wave followed by flooding in a subsiding coastal city
  8. 6Readings from the other desks
  9. 7The 2027 agenda
  10. 8Systems in depth
  11. AMethodology
  12. BData appendix
  13. CReferences and record
  14. ·Complete edition, for print

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.

Figure 2.1Urban population in slums or informal settlements (%)
ItemBar, scaled to the largest valueValue
UN SDG database, 202224.8
World Bank series, 202223.2
UN SDG database, 201525.3

Sources: UN SDG database3 and Goal 11 page5; World Bank World Development Indicators2. The share fell slowly while the number rose.

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

Cite this chapter

Valadbaygi, S. (Ed.). (2026). Chapter 2: Key findings. In Global Cities Risk and Resilience Report 2026: Baseline Edition, The State of the World’s Cities and Urban Systems. (Baseline Edition 2026, Report No. NR-SECTOR-CITIES-GLOBAL-2026-BASELINE) [Draft under review]. The Global Centre for Risk and Innovation (GCRI).

Every citation form of the whole report, BibTeX and RIS included, is on the edition home. Cite this report

ReportsContribute

Send evidence or a correction on Global Cities and Urban Systems.

Reports is the Consortium’s quarterly publication, written by six desks. This page sits with the Global Centre for Risk and Innovation (GCRI) Systems Evidence desk. What you know about this subject can become evidence, a case or a correction in the next edition, credited to you and published under CC BY 4.0 where it is your own work. Sent to the wrong desk, it is forwarded, not refused.

GCRI Systems Evidence deskGlobal Sector Risk and Resilience

Never send personal data, sensitive infrastructure detail or anything you have no right to share. A contribution is reviewed before use; sending it confers no authorship or editorial rights, and sponsorship never buys a finding.

CC BY 4.0 Free to read. Text and figures: CC BY 4.0. Data: CC0 1.0. Authors keep copyright. Published by GCRI Canada.

Sector signature

The sectors behind Global Cities and Urban Systems.

A reading aid: the sectors the findings run through and how strongly they depend on each other.

Select corners · hover lines6 / 15 relations

Context

Infrastructure and its partners

Infrastructure gives pipes, dams and treatment works to water (0.6), transmission and fuel logistics to energy (0.6) and access to care to health (0.5).

W · E · I · F · H · B

Sectors
4 of 6
Relations
6 of 15
Coupling
0.46 share of total

Strongest relations in play

  • Energy → Infrastructure · power for transport and telecoms0.8
  • Water → Energy · cooling water and hydropower0.6
  • Infrastructure → Water · pipes, dams and treatment works0.6
  • Water → Health · drinking water and sanitation0.7
Teaching values for a typical city-region, not measurements for any place. Coupling is the summed strength of the relations in play, as a share of all fifteen.
The Global Centre for Risk and Innovation

Science · evidence · measurement

Not for profit

Our articles, maps and twins are free to read and free to republish. Readers and partners keep it that way.

Partner with us

Who funds us

GCRI is a not-for-profit institution. To ask who funds a piece of work, use the funding questions form.

Independence

Editors and the expert reviewers named on each article decide what we publish. Funders and partners do not review or approve articles before publication.

Corrections policy

Licence

Articles: CC BY 4.0. Figures, maps, twins and data: CC BY 4.0. Other uses: ask through the permissions form.

Privacy choices