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

South America’s risk travels through shared rivers, grids and gas

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

8 min read2 figures2 tables16 notesNR-REGIONAL-SAM-2026-BASELINE

Contents
  1. ·Edition home
  2. ·Executive summary
  3. 1South America’s risk travels through shared rivers, grids and gas
    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. 5Basin drought across the Paraná corridor 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 South America’s risk concentrated, and in which systems?
  • Which couplings carry shocks across member borders?
  • Which capabilities hold under compound stress, and which are only documented?
  • What must the 2027 programme measure first?

In this part

  • Narrative
  • Headline finding
  • Lead figure
  • Member system cards
  • Shared basins and grids
  • Hub list
  • Regional pathway
  • Twelve-domain reading
  • Sector screens
  • Dependency matrix
  • Risk objects
  • Capability ladder
  • Scenario
  • Three lenses
  • Portfolio

1.2The argument

Brazil had 212.8 million residents in 2025 and Argentina 45.9 million1. Brazil holds 82.3% of the two members’ population (ESTIMATED, Nexus arithmetic), and their GDP together was about USD 2,963 billion in 202512. This baseline reads South America as a region whose members share basins, an aquifer, power links and gas supply with neighbours, so that a shock in one reaches the others.

The forcing layer is visible in recent records. WMO reported record heat, persistent drought, accelerating glacier retreat and rising seas across Latin America and the Caribbean in 202515. Floods in Rio Grande do Sul in 2024 caused BRL 88.9 billion of damage and loss16. About 400 mm of rain fell in eight hours on Bahía Blanca on 7 March 2025, against a previous daily record of 175 mm17. The Negro River at Manaus fell to 12.66 m in October 202424.

Heat and rain add a health layer. By 26 March 2024 the Americas had over 3.5 million dengue cases, and Brazil held 83% of them18. The figure is a count of reported cases, not an estimate of burden.

The water layer rests on large stocks and uneven access. Brazil had 26,918 m³ of renewable freshwater per person in 2022 and Argentina 6,431 m³9. In 2024, 88.6% of Brazil’s population used safely managed drinking water8. The Argentine value is not bound.

The energy layer is mostly low-carbon in Brazil and mixed in Argentina. Low-carbon sources supplied 89% of Brazil’s electricity and 42% of Argentina’s in 20251314. A 2,200 MW converter at Garabí and pipelines through Bolivia connect the members2728. Binational plants on shared rivers tie hydropower to river flow41.

This edition therefore reads South America’s risk as a property of the couplings between these forces. The matrix, risk objects, capability ladder and scenario that follow ask two questions: where does a shock travel next across a border, and who holds the capability to stop it?

Figure 1.1How do low-carbon shares of electricity differ? Share of generation, 2025 (%)

Low-carbon sources supplied 89% of Brazil’s electricity in 2025 and 42% of Argentina’s1314. Wind and solar supplied 27% in Brazil and 16% in Argentina. The World Bank renewable output series ends in 2021 with 77.4% for Brazil and 25.5% for Argentina5. The series use different definitions and are not directly additive.

ItemBar, scaled to the largest valueValue
Brazil, low-carbon89
Argentina, low-carbon42
Brazil, wind and solar27
Argentina, wind and solar16

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

Figure ID FIG-REGIONAL-SAM-2026-BASELINE-01-003

89%

Brazil low-carbon share of electricity, 202513

42%

Argentina low-carbon share of electricity, 202514

52%

Brazil hydro share of electricity, 202513

77.4%

Brazil renewable share of electricity output, 20215

1.3Twenty couplings between five systems

The South America matrix types the twenty couplings between the five core systems. Strengths are Nexus estimates from the cited evidence and analogue events; they set the starting graph that the Q1 2027 Foundry cut will test.

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·STRONG
hydro · thermal cooling		STRONG
irrigation · rain-fed yield		STRONG
safe water · sanitation		STRONG
flows · wetlands
ENE EnergyMODERATE
pumping · desalination		·STRONG
fuel · fertiliser · cold chain		STRONG
air pollution · cooling		MODERATE
land use · mining
FOO FoodSTRONG
≈70% of withdrawals		WEAK
bioenergy feedstock		·STRONG
nutrition · food safety		STRONG
land conversion
HLT HealthWEAK
workforce		WEAK
workforce		MODERATE
labour · disease		·WEAK
residues
BIO BiodiversitySTRONG
regulation · filtration		MODERATE
biomass · hydrology		STRONG
pollination · soils		MODERATE
zoonoses · medicines		·
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

    CLI → WAT → ENE

    Drought lowers river levels and hydropower output and raises thermal generation.

    Inferred Negro River 202424; Paraná 202125

  2. 02

    CLI → HLT

    Warm and wet spells raise dengue transmission and load health services.

    Reported dengue 202418

  3. 03

    TRD → ENE → FIN

    A change in gas routes reaches power prices and public budgets.

    Inferred Argentine exports via Bolivia28; no volume bound

  4. 04

    INF → ENE → all

    A fault or shortfall crosses the frequency converter.

    Inferred Garabí link27; no event bound

  5. 05

    CLI → INF → FIN

    Flooding damages lifelines and the loss falls on insurers and budgets.

    Inferred floods 202416; loss series not bound

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 · rain-fed yieldFood to water: ≈70% of withdrawals
WAT and BIOWater to biodiversity: flows · wetlandsBiodiversity to water: regulation · filtration
FOO and BIOFood to biodiversity: land conversionBiodiversity 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. 1World Bank (ed.), Population, total (SP.POP.TOTL), Brazil, Argentina and Latin America & Caribbean aggregate, World Development Indicators API. World Bank, Washington, DC. Observation year 2025. Accessed 2026-11-03.back
  2. 2World Bank (ed.), GDP, current US$ (NY.GDP.MKTP.CD), Brazil, Argentina and Latin America & Caribbean aggregate, World Development Indicators API. World Bank, Washington, DC. Observation year 2025. Accessed 2026-11-03.back
  3. 15World Meteorological Organization (ed.), State of the Climate in Latin America and the Caribbean 2025 (series page, published 18 May 2026, updated 12 June 2026; key messages only, the full report was not opened). WMO, Geneva. Observation year 2025. Accessed 2026-11-03.back
  4. 16Inter-American Development Bank, with ECLAC and the World Bank Group (eds.), Damage and loss assessment of the April and May 2024 floods in Rio Grande do Sul (BRL 88.9 billion), as reported by Agência Brasil on 29 November 2024; the assessment itself was not opened. IDB, Washington, DC. Observation year 2024. Accessed 2026-11-03.back
  5. 17NASA Earth Observatory (ed.), Bahía Blanca inundated (image of the day, 17 March 2025; about 400 mm in 8 hours on 7 March 2025, previous daily record 175 mm in 1930; page updated 31 January 2026). NASA, Washington, DC. Observation year 2025. Accessed 2026-11-03.back
  6. 24UNVERIFIED, not opened: Associated Press (ed.), Drought has dried a major Amazon River tributary to its lowest level in over 122 years (Negro River at the port of Manaus 12.66 m, October 2024; the page opened returned not found). AP, New York. Observation year 2024. Accessed 2026-11-03.back
  7. 18Pan American Health Organization (ed.), PAHO calls for collective action in response to record increase in dengue cases in the Americas (news release, 28 March 2024; data as of 26 March 2024). PAHO, Washington, DC. Observation year 2024. Accessed 2026-11-03.back
  8. 9World Bank (ed.), Renewable internal freshwater resources per capita, cubic metres (ER.H2O.INTR.PC), Brazil and Argentina, World Development Indicators API. World Bank, Washington, DC. Observation year 2022. Accessed 2026-11-03.back
  9. 8World Bank (ed.), People using safely managed drinking water services, % of population (SH.H2O.SMDW.ZS), Brazil and Argentina, World Development Indicators API (no value returned for Argentina). World Bank, Washington, DC. Observation year 2024. Accessed 2026-11-03.back
  10. 13Ember (ed.), Brazil electricity country page (low-carbon share 89%, hydro 52%, wind and solar 27%, fossil 11% of generation in 2025; no generation total on the page). Ember, London. Observation year 2025. Accessed 2026-11-03.back
  11. 14Ember (ed.), Argentina electricity country page (low-carbon share 42%, wind and solar 16%, fossil 58% of generation in 2025; no generation total on the page). Ember, London. Observation year 2025. Accessed 2026-11-03.back
  12. 27UNVERIFIED, not opened: Hitachi Energy (ed.), Brazil-Argentina HVDC interconnection, Garabí converter station (2,200 MW back-to-back; 60 Hz and 50 Hz; first phase 2000, second phase 2002; flows mainly Brazil to Argentina per a World Bank case study); taken from search summaries. Hitachi Energy, Zurich. Observation year 2023. Accessed 2026-11-03.back
  13. 28UNVERIFIED, not opened: Energy Intelligence (ed.), Argentina’s piped gas exports to Brazil take step forward (first Vaca Muerta gas to Brazil through Bolivian pipelines, early 2026; 3 million m3 a day transit offer; taken from search summaries). Energy Intelligence, London. Observation year 2026. Accessed 2026-11-03.back
  14. 41UNVERIFIED, not opened: Treaty of Itaipú between Brazil and Paraguay on the hydroelectric use of the Paraná river, signed in 1973. Observation year 1973. Accessed 2026-11-03.back
  15. 5World Bank (ed.), Renewable electricity output, % of total electricity output (EG.ELC.RNEW.ZS), Brazil and Argentina, World Development Indicators API (latest value returned is 2021). World Bank, Washington, DC. Observation year 2021. Accessed 2026-11-03.back
  16. 25UNVERIFIED, not opened: Associated Press and trade press (eds.), Drought hits South America river, threatening vast ecosystem (Paraná at its lowest level in nearly 80 years, 2021; reports of 77 and 80 years differ; Itaipú output). AP, New York, August 2021. Observation year 2021. Accessed 2026-11-03.back

Cite this chapter

Valadbaygi, S. (Ed.). (2026). Chapter 1: South America’s risk travels through shared rivers, grids and gas. In South America Regional Systems Risk and Resilience Report 2026: Baseline Edition, The State of South America’s Interdependent Systems. (Baseline Edition 2026, Report No. NR-REGIONAL-SAM-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 South America.

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 deskRegional Systems Risk & Resilience Report

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