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

Pressure builds across the system

Part I describes systems and their couplings. It ranks no country or operator and assesses no authority.

7 min read2 figures2 tables15 notesNR-STRATEGIC-PLANETARY-GLOBAL-2026-BASELINE

Contents
  1. ·Edition home
  2. ·Executive summary
  3. 1Pressure builds across the system
    1. 1.1 The questions this part answers
    2. 1.2 The argument
    3. 1.3 Twenty couplings between five systems
    4. 1.4 Reinforcing loops
  4. 2Key findings
  5. 3Systems and sectors at baseline
  6. 4Risks and capability
  7. 5Ocean heat and reef loss that overlaps stress on the Atlantic circulation and the Amazon
  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

1.1The questions this part answers

Key questions

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

In this part

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

1.2The argument

The Earth system is usually reported by topic: climate, ocean, forests, water, chemicals. The 2023 to 2026 evidence reads them as one system with nine linked processes. Seven of the nine are beyond their boundary in the 2025 assessment, and all seven show rising pressure21.

The causes repeat. Fossil carbon raises CO2 and warms the surface108, and the same carbon acidifies the ocean2. Land conversion and fertiliser use press on the biosphere and on nutrient cycles315. Novel chemicals and plastics are released faster than they can be assessed22.

Thresholds are now part of the record. Warm-water coral reefs have passed the central estimate of their thermal threshold7. Ice sheets sit near thresholds of about 1.5 degrees C6. Studies disagree on the Atlantic circulation161718, and the Amazon faces compounding disturbance19.

The edition therefore asks four questions of every result: what is the common cause, how does it spread, what is shared, and what threshold lies ahead. It makes no forecast and ranks no country.

Figure 1.1How do observed and projected warming compare with the reef threshold? Degrees C

Observed warming is close to the central reef threshold and projected warming is well above it. The bars mix observation and projection, so they show scale only7814.

ItemBar, scaled to the largest valueValue
Projected, current policies (up to)2.8
Projected, new pledges fully met (upper end)2.5
Observed, 2025 (Copernicus)1.47
Reef tipping point, central estimate1.2

Source: as cited in the note to this figure. Year 2025.

Figure ID FIG-STRATEGIC-PLANETARY-GLOBAL-2026-BASELINE-01-003

2.8degrees C

projected, current policies (up to)14

2.3 to 2.5degrees C

projected, new pledges met14

1.47degrees C

observed, 20258

1.2degrees C

reef central threshold7

1.3Twenty couplings between five systems

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

Figure 1.2Couplings between the five systems

Each line is one coupling from one system to another, drawn by the strength the edition assigns. Strengths are Nexus estimates from the cited evidence and analogue events.

  • Strong
  • Moderate
  • Weak

Source: this edition’s coupling matrix (Table 1.1); status Estimated.

Table 1.1Coupling matrix: from the row system to the column system
From, toWATENEFOOHLTBIO
WAT Water·MODERATE
hydropower · cooling		STRONG
irrigation · green water		STRONG
safe supply · sanitation		STRONG
wetlands · river flows
ENE EnergyMODERATE
pumping · treatment		·MODERATE
machinery · processing		MODERATE
clinics · cooling		STRONG
warming · acidification
FOO FoodSTRONG
withdrawals · nutrient runoff		WEAK
bioenergy		·MODERATE
nutrition · food safety		STRONG
land conversion · nitrogen
HLT HealthWEAK
effluent		WEAK
demand		WEAK
labour		·WEAK
residues
BIO BiodiversitySTRONG
moisture recycling · natural infrastructure		WEAK
hydrology		STRONG
pollination · soils		MODERATE
zoonoses · heat buffering		·
Strength: strong, moderate or weak; a Nexus estimate (status Estimated) from cited evidence and analogue events. The scale is defined in Annex A.

Transmission paths

  1. 01

    ENE → BIO → FOO

    Fossil carbon warms and acidifies, and living systems that feed people lose integrity.

    Reported Planetary Health Check2

  2. 02

    FOO → WAT, BIO

    Fertiliser and land conversion push nutrient and water limits.

    Reported boundary values3

  3. 03

    CLI → BIO

    Warming passes the central reef threshold estimate.

    Reported Tipping Points Report7

  4. 04

    BIO → WAT → FOO

    Forest loss weakens moisture recycling and the rain that crops need.

    Inferred Amazon transitions19 · green water23

  5. 05

    CLI → CLI

    Ice-sheet and ocean circulation changes feed back on warming and rainfall.

    Inferred tipping reassessment6 · AMOC studies17

1.4Reinforcing loops

A shock entering either system of a loop can return amplified through the other.

Table 1.2Pairs of systems where both directions are rated strong
LoopFirst directionSecond direction
WAT and FOOWater to food: irrigation · green waterFood to water: withdrawals · nutrient runoff
WAT and BIOWater to biodiversity: wetlands · river flowsBiodiversity to water: moisture recycling · natural infrastructure
FOO and BIOFood to biodiversity: land conversion · nitrogenBiodiversity to food: pollination · soils
A causal-loop reading of the matrix (Sterman, Business Dynamics, 2000): structural, from estimated strengths, not a measured feedback.

Notes

Numbers are the edition’s reference numbers, so a note reads the same in every chapter. The full list, with every source and its licence, is in Annex C. Annex C, references

  1. 2Sakschewski, B., Caesar, L., Rockström, J. et al., Planetary Health Check 2025: A Scientific Assessment of the State of the Planet (publication page; seven of nine boundaries breached). Planetary Boundaries Science, Potsdam. Observation year 2025. Accessed 2026-11-03.back
  2. 1Richardson, K., Steffen, W., Lucht, W., Bendtsen, J., Cornell, S.E., Rockström, J. et al., Earth beyond six of nine planetary boundaries, Science Advances 9(37), eadh2458, 2023 (six of nine boundaries transgressed; ocean acidification near its boundary). Observation year 2023. Accessed 2026-11-03.back
  3. 10NOAA Global Monitoring Laboratory (ed.), Global annual mean CO2 growth data (annual means 2020 to 2025; 425.62 ppm in 2025). NOAA, Boulder. Observation year 2025. Accessed 2026-11-03.back
  4. 8ECMWF and Copernicus Climate Change Service (eds.), Global Climate Highlights 2025 (news release: 1.47 degrees C above 1850 to 1900; third warmest year; 2023 to 2025 average above 1.5). ECMWF, Reading. Observation year 2025. Accessed 2026-11-03.back
  5. 3Globaia (ed.), Planetary boundaries status dashboard (nine boundaries with control-variable values and limits; page last updated 15 June 2026; its summary text still says six while its table shows seven). Observation year 2025. Accessed 2026-11-03.back
  6. 15IPBES (ed.), Global Assessment Report on Biodiversity and Ecosystem Services (media release of 6 May 2019: around one million species threatened; about 75% of land and 66% of marine environment significantly altered). IPBES Secretariat, Bonn. Observation year 2019. Accessed 2026-11-03.back
  7. 22Outside the Safe Operating Space of the Planetary Boundary for Novel Entities, Environmental Science and Technology 56(3), 1510 to 1521, 2022 (abstract read). Observation year 2022. Accessed 2026-11-03.back
  8. 7Lenton, T.M. et al. (eds.), Global Tipping Points Report 2025 (release page read, not the full report; 10 October 2025; coral reef threshold central estimate 1.2 degrees C, range 1 to 1.5). University of Exeter, Exeter. Observation year 2025. Accessed 2026-11-03.back
  9. 6Armstrong McKay, D.I., Staal, A., Abrams, J.F. et al., Exceeding 1.5°C global warming could trigger multiple climate tipping points, Science 377, eabn7950, 2022 (full text read; nine core and seven regional tipping elements). Observation year 2022. Accessed 2026-11-03.back
  10. 16Baker, J. et al., Continued Atlantic overturning circulation even under climate extremes, Nature 638, 987 to 994, 2025 (34 models; collapse this century judged unlikely; weakening still expected; abstract and Met Office release read). Observation year 2025. Accessed 2026-11-03.back
  11. 17van Westen, R.M., Kliphuis, M. and Dijkstra, H.A., Physics-based early warning signal shows that AMOC is on tipping course, Science Advances 10, eadk1189, 2024 (full text read). Observation year 2024. Accessed 2026-11-03.back
  12. 18Ditlevsen, P. and Ditlevsen, S., Warning of a forthcoming collapse of the Atlantic meridional overturning circulation, Nature Communications 14, 4254, 2023 (abstract read: collapse estimated around mid-century; a 2025 erratum is listed and was not read). Observation year 2023. Accessed 2026-11-03.back
  13. 19Critical transitions in the Amazon forest system, Nature 626, 555 to 564, 2024 (authors not recorded here; abstract read: 10% to 47% of forests exposed to compounding disturbances by 2050). Observation year 2024. Accessed 2026-11-03.back
  14. 14UNEP (ed.), Emissions Gap Report 2025: Off Target, 4 November 2025 (read through a summary page of a contributing institute: 2.3 to 2.5 degrees C on new pledges; up to 2.8 on current policies). United Nations Environment Programme, Nairobi. Observation year 2025. Accessed 2026-11-03.back
  15. 23Wang-Erlandsson, L. et al., A planetary boundary for green water, Nature Reviews Earth and Environment 3(6), 380 to 392, 2022 (bibliographic record read, no abstract; no figure taken from it). Observation year 2022. Accessed 2026-11-03.back

Cite this chapter

Valadbaygi, S. (Ed.). (2026). Chapter 1: Pressure builds across the system. In Strategic Systems Report 2026: Planetary Boundaries and Earth-System Tipping Risk (Baseline Edition 2026, Report No. NR-STRATEGIC-PLANETARY-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 Planetary Boundaries and Earth-System Tipping Risk.

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 deskStrategic Systems

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