This document discusses the importance of nexus thinking in addressing global challenges at the intersection of water, energy, food, and the environment. It notes that food, fuel, and fertilizer crises are increasing in frequency and severity. Climate change is exacerbating water stress and declining water storage. There is a growing need for integrated approaches that consider these interconnected systems. The NEXUS Gains initiative aims to develop and scale innovations through five workstreams, including boosting water productivity, energizing food systems sustainably, and strengthening cross-sectoral governance.

1. Importance of Nexus thinking
in a global context
Claudia Ringler, NEXUS Gains co-lead and
International Food Policy Research
Institute
Systems Analysis for Reducing Footprints and Enhancing Resilience
IIASA | Nov 17, 2022

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Water/Energy/Food/Environment (WEFE)
Nexus Challenges in a Climate Crisis
Source: Rystad Energy—photo from COP27

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Water/Energy/Food/Environment (WEFE)
Nexus Challenges in a Climate Crisis
2007-08 food, fuel &
fertilizer crisis
2011-12 food, fuel &
fertilizer crisis
2021-22 food, fuel &
fertilizer crisis
-4%
-2%
0%
2%
4%
6%
8%
10%
12%
14%
0
50
100
150
200
250
300
350
400
450
GDP
growth
in
LMICs
Food,
fuel
&
fertilizer
price
indices
(2000=100)
Source: Headey and Hirvonen (2022) using data from FAO, the World Bank and the IMF.

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150 million more people hungry in 2021
compared to 2019
Source: SOFI (2022).

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Water Stress increasing
Source: Ringler et al. (2016).
36%
39%
22%
2.5
US$9.4
TRILLION
Water stress risk
BILLION
PEOPLE
TODAY
Total population living in water
scarce areas
Global GDP generated in water
scarce regions
52%
49%
45%
US$63
TRILLION
Total population living in water
scarce areas
4.7 BILLION PEOPLE
90%
570%
By 2050
Global GDP generated in water scarce
regions
population
grain production
global GDP

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Storage/needs availability declining
Source: GWP (2022).

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Impact of eliminating GW depletion on risk of
hunger (projected 2050)
Source: In preparation

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Growing ag water pollution (nitrogen 2005)
Xie and Ringler (2017).

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Climate change grows need for Nexus
approaches
Maximum temperature (°C) Annual precipitation (mm)
Change in rainfed maize yields before economic
adjustments
Change in rainfed maize yields after
economic adjustments
Source: IMPACT (various yrs)

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NEXUS Gains Workstreams
1. Co-developing and scaling NEXUS innovations
using foresight methodologies and trade-off
analyses
2. Boosting water productivity and expanding
storage across scales (farm to watershed to basin)
and sectors using a whole systems lens
3. Energizing food and water systems sustainably
and inclusively
4.Strengthening cross-sectoral, multi-stakeholder
governance at community, national and regional
levels
5. Developing Capacity for WEFE Actors, Including
Emerging Women Leaders
Photo credit: Anton Jankovoy / Shutterstock.com

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Integrated storage diagnostic for WEFE
Source: based on McCartney and Smakhtin (2010)

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3. Private investors and policymakers use scalable gender-sensitive clean
energy business and finance models to accelerate sustainable rural
clean energy access in at least 3 focal regions
• Inclusive business models for sustainable clean energy access in
agri-food systems
4. Policymakers and other stakeholders are using science-policy dialogues,
multi-stakeholder forums, co-developed groundwater governance toolbox
and guidelines to strengthen nexus governance across systems,
sectors and boundaries in all basins
• Groundwater governance toolbox to address growing competition,
degradation and depletion of resources in hotspots
• Establish and facilitate cross-sectoral, inclusive multi-stakeholder
platforms to leverage integrated
5. At least 40 emerging women leaders in government, private sector,
investors, research and NGOs have increased capacity to identify, assess
and implement one or more nexus innovations
End of Initiative Outcomes and Examples
of Core Innovations
Photo credit: Hamish John Appleby, IWMI

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➢ Climate justice→ which solutions truly work for the poor if we
go beyond words
➢ More serious engagement between NDCs and nutrition and
health impacts
➢ Much better understanding of better water management as it
relates to adaptation and mitigation → UN Water conference
2023
➢ More serious engagement between ecosystem and the rest of
the Nexus beyond words
COP27 thoughts

14. NEXUS Gains
Realizing Multiple Benefits
Across Water, Energy, Food and
Ecosystems (Forests, Biodiversity)
Contact:
Matthew McCartney, IWMI, Lead: m.mcartney@giar.org
Claudia Ringler, IFPRI, Co-Lead: c.ringler@cgiar.org