PPT - LCIRAH

The global health impacts of future food scenarios
Marco Springmann (U Oxford)
Peter Scarborough (U Oxford)
Daniel Mason-D’Croz (IFPRI)
—
4th Annual LCIRAH Conference
June 2014 (updated)
Marco Springmann
Global health impacts
Global food system
The food system will face multiple pressures in the future:
Environmental pressures: climate change (droughts, yield
losses, floods, etc)
Social pressures: population growth to over 9 billion
Economic pressures: growth in food demand and food
transition to more animal-based products
Marco Springmann
Global health impacts
Global food system
The food system will face multiple pressures in the future:
Environmental pressures: climate change (droughts, yield
losses, floods, etc)
Social pressures: population growth to over 9 billion
Economic pressures: growth in food demand and food
transition to more animal-based products
The food system also exceeds pressures:
Environmental impacts: deforestation, GHG emissions
Economic and social impacts: food production and demand
Health impacts: malnutrition (undernourished, overweight)
and related diseases
Marco Springmann
Global health impacts
Global food system
The food system will face multiple pressures in the future:
Environmental pressures: climate change (droughts, yield
losses, floods, etc)
Social pressures: population growth to over 9 billion
Economic pressures: growth in food demand and food
transition to more animal-based products
The food system also exceeds pressures:
Environmental impacts: deforestation, GHG emissions
Economic and social impacts: food production and demand
Health impacts: malnutrition (undernourished, overweight)
and related diseases
Marco Springmann
Global health impacts
Global food system
The food system will face multiple pressures in the future:
Environmental pressures: climate change (droughts, yield
losses, floods, etc)
Social pressures: population growth to over 9 billion
Economic pressures: growth in food demand and food
transition to more animal-based products
The food system also exceeds pressures:
Environmental impacts: deforestation, GHG emissions
Economic and social impacts: food production and demand
Health impacts: malnutrition (undernourished, overweight)
and related diseases
Marco Springmann
Global health impacts
Study outline
This study:
Construct global health model to analyse the health impacts
of future food scenarios (subject to climate change and
socio-economic pressures).
Marco Springmann
Global health impacts
Study outline
This study:
Construct global health model to analyse the health impacts
of future food scenarios (subject to climate change and
socio-economic pressures).
Methods:
Agricultural model (IMPACT) to produce future food
scenarios [IFPRI]
Markov modelling to analyse health impacts [U Oxford]
Marco Springmann
Global health impacts
Agricultural model
International Model for Policy Analysis of Agricultural
Commodities and Trade (IMPACT):
Marco Springmann
Global health impacts
Agricultural model
High spatial resolution:
Marco Springmann
Global health impacts
Agricultural model
Environmental pressures:
Marco Springmann
Global health impacts
Agricultural model
Environmental pressures:
Health-related output:
∆population → ∆deaths
∆malnutrition among children → ∆childhood mortality
∆food consumption → ∆weight → ∆diet and weight-related
diseases (CHD, stroke, cancer, etc)
Marco Springmann
Global health impacts
Health context
Leading risk factors for death in 2010 (GBD, 2013):
Marco Springmann
Global health impacts
Global health model
State-transition Markov model:
Divide process into distinct states.
Assign transition probabilities to movements between states.
Marco Springmann
Global health impacts
Global health model
State-transition Markov model:
Divide process into distinct states.
Assign transition probabilities to movements between states.
Marco Springmann
Global health impacts
Global health model
For one country:
Marco Springmann
Global health impacts
Global health model
For all countries:
Marco Springmann
Global health impacts
Global health model
Marco Springmann
Global health impacts
Global health module
State-transition diagram:
Marco Springmann
Global health impacts
Global health module
Calibration of baseline model:
UN population data
WHO data on mean BMI and percentage overweight and
obese
Estimate complete BMI distribution by fitting data to a
log-normal distribution
WHO data on malnourished children (age <5)
WHO data on age-specific death rates
Use GBD data to separate disease-specific mortality from
all-cause mortality
Meta-analyses of diet (meat, FV) and weight-related risk
factors
Marco Springmann
Global health impacts
Global health module
Calibration of baseline model:
UN population data
WHO data on mean BMI and percentage overweight and
obese
Estimate complete BMI distribution by fitting data to a
log-normal distribution
WHO data on malnourished children (age <5)
WHO data on age-specific death rates
Use GBD data to separate disease-specific mortality from
all-cause mortality
Meta-analyses of diet (meat, FV) and weight-related risk
factors
⇒ Years of life lost (YLL) due to four causes of death (CHD,
stroke, cancer, other) for all WHO countries
Marco Springmann
Global health impacts
Global health module
Marco Springmann
Global health impacts
Future food scenarios and model coupling
Model scenarios:
Business as usual (NoCC):
BAU pathway to 2050 following SSP2 (Intermediate
challenges, ’middle of the road’) → ∆Pop, ∆Growth
Climate change (IPSL, HDGM):
SSP2 plus rising radiative-forcing pathway leading to 8.5
W/m2 in 2100 (RCP8.5, highest RCP)
Two general circulation models (IPSL, HDGM) → ∆Temp,
∆Prec
Crop-model suite (DSSAT) → ∆Yield
IMPACT → ∆Area, ∆Prod, ∆Cons, ∆Maln
Marco Springmann
Global health impacts
Future food scenarios and model coupling
Model scenarios:
Business as usual (NoCC):
BAU pathway to 2050 following SSP2 (Intermediate
challenges, ’middle of the road’) → ∆Pop, ∆Growth
Climate change (IPSL, HDGM):
SSP2 plus rising radiative-forcing pathway leading to 8.5
W/m2 in 2100 (RCP8.5, highest RCP)
Two general circulation models (IPSL, HDGM) → ∆Temp,
∆Prec
Crop-model suite (DSSAT) → ∆Yield
IMPACT → ∆Area, ∆Prod, ∆Cons, ∆Maln
Model coupling:
Direct inputs: ∆Cons and ∆Maln
Estimated inputs: ∆Weight from estimating shift in weight
distribution depending on food consumption.
Marco Springmann
Global health impacts
Future food scenarios
Scenario inputs for health model (global):
Large changes in risk factors; small effect of climate change.
Marco Springmann
Global health impacts
Results
Business-as-usual (NoCC) scenario:
Global years of life lost (YLL)
Regional years of life lost (YLL)
Change in causes of death
Climate-change (IPSL) scenario:
Differences in YLL to NoCC scenario.
Marco Springmann
Global health impacts
Global YLL: 2010 vs NoCC-2050
Life-years saved due to WGH; Life-years lost due to CNS.
Marco Springmann
Global health impacts
Global YLL: 2010 vs NoCC-2050
Large improv in UND; high burden of OVW/OBS; MTC exceeds FVC.
Marco Springmann
Global health impacts
Regional YLL: 2010 vs NoCC-2050
High losses in AFR; net life-years saved in SEA.
Marco Springmann
Global health impacts
Regional YLL: 2010 vs NoCC-2050
SEA gains due to less UND; more OVW/OBS and MTC elsewhere.
Marco Springmann
Global health impacts
Causes of death: 2010 vs NoCC-2050
Continued shift towards YLLs from non-communicable diseases.
Marco Springmann
Global health impacts
Climate-change impacts: IPSL-2050 vs NoCC-2050
80 million more YLL due to more UND and less FVC.
Marco Springmann
Global health impacts
Climate-change impacts: IPSL-2050 vs NoCC-2050
Climate change responsible for 5% of global YLL; 13% less FVC gains.
Marco Springmann
Global health impacts
Climate-change impacts: IPSL-2050 vs NoCC-2050
Greatest absolute life-year losses in SEA, AFR, and WPR.
Marco Springmann
Global health impacts
Climate-change impacts: IPSL-2050 vs NoCC-2050
Relative life-year losses exceed 10% in SEA and WPR.
Marco Springmann
Global health impacts
Conclusions
Future food scenarios have large impacts on health:
Specific aspects (of weight and consumption changes) have
large impacts but oppose each other.
Decreases in underweight yield life-year gains; increases in
overweight, obesity, and meat consumption yield life-year
losses (more than 35 bill YLL).
Large life-year losses in AFR (due to more OVW, OBS,
MTC), large gains in SEA (due to less UND).
Marco Springmann
Global health impacts
Conclusions
Future food scenarios have large impacts on health:
Specific aspects (of weight and consumption changes) have
large impacts but oppose each other.
Decreases in underweight yield life-year gains; increases in
overweight, obesity, and meat consumption yield life-year
losses (more than 35 bill YLL).
Large life-year losses in AFR (due to more OVW, OBS,
MTC), large gains in SEA (due to less UND).
Climate change has an impact:
5% more life-years lost globally, mostly due to less fruit and
vegetables consumption and more underweight.
Climate change impacts neutralize health gains (due to
changes in MAL) in AFR and SEA.
Marco Springmann
Global health impacts
Conclusions
Future food scenarios have large impacts on health:
Specific aspects (of weight and consumption changes) have
large impacts but oppose each other.
Decreases in underweight yield life-year gains; increases in
overweight, obesity, and meat consumption yield life-year
losses (more than 35 bill YLL).
Large life-year losses in AFR (due to more OVW, OBS,
MTC), large gains in SEA (due to less UND).
Climate change has an impact:
5% more life-years lost globally, mostly due to less fruit and
vegetables consumption and more underweight.
Climate change impacts neutralize health gains (due to
changes in MAL) in AFR and SEA.
⇒ Large potential for gaining back YLL by focussing on OVW,
OBS, MTC; and on climate impacts on food prod.
Marco Springmann
Global health impacts
Conclusions
Caveats:
Preliminary results, need further testing.
Sensitivity analysis with respect to weight changes.
Focus was on diet and weight-related risk factors, but other
factors are also important for health.
Marco Springmann
Global health impacts
Contact
Comments and suggestions:
[email protected]
Marco Springmann
Global health impacts
Backup slides
Effect of child underweight (MAL):
Small contribution of MAL to UND due to changing (aging) population
structure.
Marco Springmann
Global health impacts

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