This OECD technical workshop will bring together leading experts on economic, biophysical, and integrated assessment modelling of the interactions between climate change, biodiversity loss, and pollution. The workshop will take stock of ongoing modelling efforts to develop quantitative pathways to study the drivers and impacts of the triple planetary crisis, and the policies to address it. The aim is to identify robust modelling approaches to inform the work for the upcoming OECD Environmental Outlook.

1. Integrated modelling for interrelated crises
Detlef van Vuuren
1

2. Multiple crisis world
2 mei 2024
2

3. Multiple crisis world
2 mei 2024
3
Planetary
boundaries 3.0
Richardson et al, 2023

4. 4
Planetary
boundaries 3.0
• 800 million people without access to
electricity
• 828 million people suffering from a hunger
(2021)
• 2.2 billion people lacking access to safely
managed clean water (2022)
• 3.6 billion people lack access to adequate
sanitation

5. Model-based scenario analysis successful in specific
domains
2 mei 2024
5

6. 15 mei 2012
Drivers
Human system
Earth system
Impacts
Response

7. Rio+20, 15 mei 2012
IMAGE model
framework
› Exploration of global
environmental change
problems
› Simulation

8. Some examples of studies looking into addressing
multiple crises
› SHAPE (EU sponsored project on achieving SDGs)
› GEO7 (UNEP Global Environmental Outlook)
› IMAGE Planetary Boundary work
2 mei 2024
8
Storylines + modelling

9. Economy driven innovation
• Technology & market driven
• Globalized world with high
economic growth
• Technological solutions
Managing the global commons
• Human services driven
• Strong global institutions
• Efficient technological solutions
Resilient communities
• Post-growth society
• Local solutions
• Human well-being & behavioural
change
› SHAPE scenarios based on SDG
achievement (target space)
› Multiple routes – different
transformations
› Each have strengths and
weaknesses

11. 2 mei 2024
Buildings
Transport
Interventions
• HT = Historical Trends
• SSP2 baseline
• RE = Resource Efficiency
• Reduced (material)
demands
• Efficient design
• Increased Recycling
• ST = Sustainable
Transition (RE + 1.5°C)
Emissions
Example of reduced material demand (GRO)

12. 12
Primary Energy
- Primary Energy stabilizes (efficiency)
- Continued use of fossil fuels
(combined with CCS)
- Rapid transition to renewables
- Focus on large scale renewables
- Long term reduction in demand
- Reduction in demand (behaviour)
- Slower transition to renewables
- Lower trade
- Continued increase in demand
- Continued reliance on fossil (+CCS)
SSP2-RCP1.9
RC
EI
MC
RC
MC
EI
RC
MC
Vassilis Daioglou - The IMAGE Sustainable Development Pathways

13. 13
- Small expansion on agriculture (high
demand and high yields)
- Expansion of forest area
- At expense of pasture area
- Similar to Economic-Innovation but
with more natural land
- Small expansion of agriculture
(lower yield increase)
- Large expansion of forest area
- Decrease of pasture area
- Strong afforestation (single species)
and intensive agriculture
SSP2-RCP1.9
Land Cover
EI
RC
MC
Vassilis Daioglou - The IMAGE Sustainable Development Pathways

14. 14
Emissions
- Slowest mitigation of all the SDPs
- Significant CDR from land, energy
& DAC
- Net negative from 2050
- “Limited” CDR, mostly from BECCS
- Energy demand emissions
approach net zero after 2050
- Limited CDR, mostly from land
sector
- Energy demand emissions
approach net zero after 2050
- “slower” mitigation
- Heavy reliance on CDR
SSP2-RCP1.9
EI
RC
MC
Vassilis Daioglou - The IMAGE Sustainable Development Pathways

15. 15
Synergies and
trade-offs Less irrigation to
restore environmental
flows + NUE
Nature protection (50%
of each eco regions)+
NUE
Diet change
Climate policy
(including
reforestation)

16. 16
Synergies and
trade-offs Less irrigation to
restore environmental
flows + NUE
Nature protection (50%
of each eco regions)+
NUE
Diet change
Climate policy
(including
reforestation)

17. Trade-offs
Climate policy
(including
reforestation)

18. 18
Earth-system process Control variable *
Climate change Forcing - GHGs (W m-2)
Stratospheric ozone
depletion
O3 concentration (DU) 60S-90S
Atmospheric aerosol
loading
Average pm2.5 concentration (g
m-3)
Ocean acidification pH
Biogeochemical flows
-Nitrogen
-Phosphorus N-balance (Tg N yr–1)
P-balance (Tg P yr–1)
Freshwater use Water consumption (km3)
Land system change Area of forested land (Gha)
Change in biosphere
integrity
MSA
Planetary boundaries

19. › Current trends (SSP2)
implies further
worsening of
environmental
situation

20. Category Measure assumed
Climate mitigation Implementation of the 1.5oC target of the Paris Agreement, following
SSP2-1.937
Food consumption
change
a shift towards a healthy diet as defined by EAT-Lancet (80%
implementation in 2050 and 100% in 210038
Reduction of food
waste
a reduction of food loss by consumption group (leading overall to
approximately halving food waste) 39
Water withdrawal
for energy, industry
and households
implementation of efficiency in water use in industry, the residential
sector and electricity generation40
Water withdrawal
for irrigation
reduction of water use for irrigation to ensure environmentally
ecologically sustainable levels41
Use of N-fertilizers an increase in nitrogen use efficiency to maximum levels by 70/80%
(compared to 50% in the baseline)42
Sustainability measures

21. Category Measure assumed
Climate
mitigation
Implementation of the 1.5oC target of the Paris
Agreement, following SSP2-1.937
Food
consumption
change
a shift towards a healthy diet as defined by
EAT-Lancet (80% implementation in 2050 and
100% in 210038
Reduction of
food waste
a reduction of food loss by consumption group
(leading overall to approximately halving food
waste) 39
Water
withdrawal
for energy,
industry and
households
implementation of efficiency in water use in
industry, the residential sector and electricity
generation40
Water
withdrawal
for irrigation
reduction of water use for irrigation to ensure
environmentally ecologically sustainable
levels41
Use of N-
fertilizers
an increase in nitrogen use efficiency to
maximum levels by 70/80% (compared to

22. Some obervations
22
Vassilis Daioglou - The IMAGE Sustainable Development Pathways
➢ Need to develop more integrated scenarios
➢ Major transformations needed (demand + supply)
➢ Critical to focus more of just implementation
➢ Mixed methods can help us to better understand the
transitions (economic / physical models / governance)