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

A strong El Niño on a 1.5 °C background

A conditional statement under stated assumptions, never a prediction.

2 min read0 figures0 tables3 notesNR-SECTOR-CLIMATE-GLOBAL-2026-BASELINE

Contents
  1. ·Edition home
  2. ·Executive summary
  3. 1Climate sets the terms for the other systems
  4. 2Key findings
  5. 3Systems and sectors at baseline
  6. 4Risks and capability
  7. 5A strong El Niño on a 1.5 °C background
    1. 5.1 Assumptions
    2. 5.2 The cascade, step by step
    3. 5.3 The scenario as a table of steps
  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

5.1Assumptions

Scenario SCN-GS07-ELN-01: what is assumed, and what is held constant.

Baseline
the 2026 reference state in this edition
Drivers
a strong to very strong El Niño that peaks around the turn of 2026 to 2027 on top of record greenhouse gas levels4831
Analogues
the 2023 to 2024 El Niño and the 2024 record year1
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

    ocean heat release lifts global temperature; months above 1.5 °C become frequent

    2023 · 2024 · 2026

  2. 2

    CLI → WAT

    rainfall shifts: deficits in some basins, floods in others

    2023 · 2025

  3. 3

    WAT → FOO

    harvest and pasture shortfalls in exposed regions

    2023 · 2024

  4. 4

    CLI → HLT

    heat waves and peaks of vector-borne disease

    2024 · 2025

  5. 5

    FOO → HLT

    hunger and malnutrition rise where stocks and incomes are thin

    2024

  6. 6

    CLI → FIN

    event losses and relief needs strain public budgets

    2025

5.3The scenario as a table of steps

How the shock in scenario SCN-GS07-ELN-01 would travel through Global Climate and Earth Systems‘s coupled systems, step by step, under the assumptions the edition states.

StepWhat happensSource
01 Climate to waterRainfall shifts: deficits in some basins, floods in others. Analogue or source: 2023 · 2025.Edition GS-07, scenario SCN-GS07-ELN-01, step 2
02 Water to foodHarvest and pasture shortfalls in exposed regions. Analogue or source: 2023 · 2024.Edition GS-07, scenario SCN-GS07-ELN-01, step 3
03 Climate to healthHeat waves and peaks of vector-borne disease. Analogue or source: 2024 · 2025.Edition GS-07, scenario SCN-GS07-ELN-01, step 4
04 Food to healthHunger and malnutrition rise where stocks and incomes are thin. Analogue or source: 2024.Edition GS-07, scenario SCN-GS07-ELN-01, step 5
05 Climate to financeEvent losses and relief needs strain public budgets. Analogue or source: 2025.Edition GS-07, scenario SCN-GS07-ELN-01, step 6

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 Climate 2026, scenario SCN-GS07-ELN-01 (2026); Global Climate 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. 48NOAA Climate Prediction Center, ENSO diagnostic discussion of 10 September 2026. National Weather Service, College Park. Observation year 2026. Opened: discussion page. Accessed 2026-11-03.back
  2. 31WMO (ed.), Greenhouse Gas Bulletin No. 21 (16 October 2025). World Meteorological Organization, Geneva. Observation year 2024. Opened: publication page and bulletin summary with the headline values (CO2 423.9 ppm, CH4 1942 ppb, N2O 338.0 ppb). Accessed 2026-11-03.back
  3. 1Copernicus Climate Change Service (C3S), ECMWF (ed.), Global Climate Highlights 2025 (published 14 January 2026, updated 28 January 2026). ECMWF, Bonn. DOI 10.24381/b3nm-p354. Observation year 2025. Opened in full (PDF). Accessed 2026-11-03. doi:10.24381/b3nm-p354back

Cite this chapter

Valadbaygi, S. (Ed.). (2026). Chapter 5: A strong El Niño on a 1.5 °C background. In Global Climate Risk and Resilience Report 2026: Baseline Edition, The State of the World’s Climate and Earth System. (Baseline Edition 2026, Report No. NR-SECTOR-CLIMATE-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 Climate and Earth 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.

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