The document discusses the importance of systems thinking to address crises related to water, energy, food, and the environment. It notes that food, fuel, and fertilizer crises have occurred repeatedly in recent years due to their interconnected nature. Climate change is exacerbating challenges across these systems. The Nexus Gains initiative aims to develop innovations and governance approaches to strengthen cross-sectoral integration and boost the resilience of these linked systems through various workstreams. Scenario analyses show the potential impacts of policies like fossil fuel taxes on hunger, unmet water needs, and other outcomes across different world regions.

1. The essentiality of systems
thinking to address crises and
grow resilience
Claudia Ringler, NEXUS Gains co-lead and
International Food Policy Research
Institute
Water Security and Climate Change Conference
AIT | Dec 2, 2022

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

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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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Water stress and associated risks 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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Nasdaq Veles California Water Index (US$/AF)
Source: https://www.nasdaq.com/solutions/nasdaq-veles-water-index
From a historic cost of US$0.2
per cubic meter to US$1.0
recently with several poor
communities in California
having to spend millions of
US$ on the open market to
keep their taps running

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Water trades in the Western US 2015-2022:
Water flows to urban areas:
Source: https://www.nasdaq.com/solutions/nasdaq-veles-water-index https://www.cnn.com/2022/11/01/us/california-water-cost-profiteering-climate

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Domestic-irrigation competition in Arizona
(using groundwater)
https://www.dailymail.co.uk/news/article-11395273/Water-
drying-Arizona-foreign-owned-megafarms-sucking-crops.html
https://www.cnn.com/2022/11/05/us/ariz
ona-water-foreign-owned-farms-climate

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Source: Miller (under review)
Water insecurity is associated with lower
dietary diversity

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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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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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WEFE Scenario Analyses: Fossil fuel tax
Source: Ringler et al. (2016)
East Asia and Pacific
South Asia
Africa South of Sahara
0 20 40 60 80 100 120 140 160 180
Latin America and the Caribbean
Middle East and North Africa
East Asia and Pacific
South Asia
Africa South of Sahara
HEP-6CC BasenoCC BaseCC HEPCC HEPadapCC
Scenario Specification
1a Baseline without climate change (BasenoCC)
1b Baseline with climate change (BaseCC)
BAU (SSP2): 9.1 billion people in 2050
BAU (SSP2) with high emissions scenario (RCP8.5); HadGEM2-ES
2a High fossil fuel price without CC (HEPnoCC)
2b High fossil fuel price with CC (HEPCC)
Fossil fuel taxes in GLOBE impacting GDP and price of agricultural
chemicals (70% tax on coal, 50% on crude oil; 30% on natural gas)
Additional changes in IMPACT: Gradual reduction of GW
withdrawal capacity over 2015-2050; by 2050 20% lower than
baseline to reflect adverse impacts of higher fuel prices on GW
pumping
3a High fossil fuel price with increased biofuel use
and increased hydropower production w/o CC
(HEPadaptnoCC)
3b High fossil fuel price with increased biofuel use
and increased HP production with CC (HEPadapCC)
Same as Scenario 2 plus
Increase in First GEN biofuel demand to compensate for reduced
fossil fuel availability, doubled by 2050 (GLOBE and IMPACT)
Gradual, linear increase in hydropower production (10% by 2050)
with associated 10% increase in storage and SW withdrawal
capacity

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WEFE Scenario Analyses: Number of people at
risk of hunger, fossil fuel tax scenarios
Source: Ringler et al. (2016)
0 20 40 60 80 100 120 140 160 180
Latin America and the Caribbean
Middle East and North Africa
East Asia and Pacific
South Asia
Africa South of Sahara
HEP-6CC BasenoCC BaseCC HEPCC HEPadapCC

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WEFE Scenario Analyses: Share of unmet water
needs (%), fossil fuel tax scenarios
Source: Ringler et al. (2016)
0
5
10
15
20
North AM EAP EUR LAC MENA SAS SSA WLD
2010 BaseNoCC BaseCC HEPCC HEPadapCC

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

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Growing access to (clean) energy technologies
Source: Shilp Verma

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Strengthening cross-sectoral, multi-
stakeholder governance
1. Groundwater toolbox with a focus on
scaling promising approaches
2. Multi-stakeholder platforms focusing on
cross-sectoral integration
3. Support to IPBES, Ramsar, CBD and other
ecosystem health initiatives on Nexus
integration
4. Policy dialogues on the Nexus (f.ex. the
need to consider nutrition/energy and other
linkages in Nepal’s irrigation policy reform)
Women’s group playing the game, March 2021
Photo credit: Fekadu Gelaw

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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
--Capacity needs assessment
--Training materials
--Winter/Summer schools
--MA theses/teaching
Developing capacity for WEFE actors

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Conclusions
1. A systems approach is central to addressing overlapping crises
2. It is impossible to work on all systems at the same time, but linkages
need to be clear when focusing on one area (f. ex. water storage or
expanding clean energy solutions)
3. “Decoupling” of systems, reducing downward spirals or upward price
spikes through clean energy interventions, improved agronomic
practices/breeding, improved institutions and other innovations (such as
cultured milk protein)