food and nutritional security in the context of climate change · food and nutritional security in...
TRANSCRIPT
Food and nutritional security in the context of climate change:
eco-efficiency or agroecology?
Jean-François Soussana,
Scientific Director Environment,
INRA, Paris, France
Session 4. Which model(s) for agriculture?
Two Goals of Our Time
1. Achieving Food and Nutritional Security
– 800 million chronically undernourished, more with micronutrients deficits,
– Far reaching implications of obesity on chronical diseases,
– Food production to increase 50-70% by 2050,
– Adaptation to climate change is critical
2. Avoiding Dangerous Climate Change
- The ’ 2°C railguard ’ requires major emission cuts,
- Agriculture and land use contribute to 24% of GHG emissions...
...and need to be part of the solution
Which model(s) for agriculture?
Outline
Global dimension
• Food supply and demand under climate change by 2050
• GHG emissions and soil carbon sequestration
• Emerging risks of climatic variability
Which agricultural models?
• Eco-efficiency and sustainable intensification
• Agroecology and organic farming
• Climate smart agriculture
The global food system: past and future AgRIPE framework: • Mass balance of supply, demand and GHG emissions • Mathematical identities to capture drivers of Supply and Demand
Years
1960 1970 1980 1990 2000 2010
Da
ta s
tan
da
rdiz
ed
to
19
61
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0Population (P)
Agricultural land (L)
Food affluence (a.)
Technology (t.)
Carbon intensity (g., Direct emissions)
Indirect GHG (Land use change, Pre-chain)
Global food system dynamics over 1961-2011
:
. .
Supply Demand t a P
Supply Demand
L
GHG g g
(Soussana, Ben Ari et al., in prep.)
A more efficient global food system (1961-2011)
(Soussana, Ben Ari et al., in prep.)
• The conversion efficiency into plant and animal food of total raw (arable and grassland) proteins has increased from 12 to 19%,
• The fraction of feed which is edible by humans has increased from 24 to 42% (increased reliance on grains
of livestock systems) • Since the 1990’s, direct GHG emissions per unit food have declined (i.e. lower carbon intensity of agricultural production) at a slow pace (0.75% per year) Note that global grassland and arable soil carbon stock changes since 1961 are not known
Pro
tein
use e
ffic
iency
0.12
0.13
0.14
0.15
0.16
0.17
0.18
0.19
0.20
Fraction human edible livestock feed
Fra
ctio
n h
um
an
ed
ible
liv
esto
ck f
ee
d
0.22
0.24
0.26
0.28
0.30
0.32
0.34
0.36
0.38
0.40
0.42
0.44
Protein conversion efficiency
Years
1960 1970 1980 1990 2000 2010 2020Carb
on inte
nsity (
ton C
O2 e
quiv
ale
nts
ton
-1 p
rote
in)
0
20
40
60
80
100
120
gCH4
gN2O
g Prechain
g. direct
gLUC
g.
Carbon intensity components
SSP1 is the sustainable world with strong development goals that include reducing fossil fuel dependency and rapid technological changes directed towards environmentally friendly processes including yield-enhancing technologies.
SSP2 is the continuation of current trends with some effort to reach development goals and reduction in resource and energy intensity. On the demand side, investments in education in not sufficient to slow rapid population growth. In SSP2 there is only an intermediate success in addressing vulnerability to climate change.
SSP3 is a fragmented world characterized by strongly growing population and important regional differences in wealth with pockets of wealth and regions of high poverty. Unmitigated emissions are high, low adaptative capacity and large number of people vulnerable to climate change. Impact on ecosystems are severe.
Shared socio-economic pathways 1-3
Food protein supply: projections for 2050’s (IIASA, GLOBIOM model & AgRipe with CO2 effect)
Food protein supply
Past SSP1 SSP2 SSP3
Sta
nda
rdiz
ed
da
ta
1.0
1.2
1.4
1.6
1.83.0
3.2
3.4
3.6
Animal protein supply
Plant protein supply
Large variation across Shared Socioecon. Pathways (SSPs) • Plant food supply scales with population • Animal food supply is more variable:
- Less demand of meat under SSP1 - Higher prices under SSP3 (slow
productivity growth) - Largest supply and demand under
middle of the road scenario (SSP2) Climate change impacts are stronger with grain crops than with grasslands (Havlik et al., FAO 2014) Plant proteins supply: -12 to -15% Animal proteins: supply 0 to -10%
Relative effects of climate change on food protein supply
SSP1 SSP2 SSP3
Sta
nd
ard
ize
d d
ata
0.80
0.85
0.90
0.95
1.00
1.05
1.10
Animal proteins
Plant proteins
2050, Land use change emissions (CO2 eq.)
To
ns C
O2 e
qu
iva
len
ts0
1e+9
2e+9
3e+9
No climate change
RCP 8.5
SSP1 SSP2 SSP3
2050, Chronic undernourishment
Ch
ron
ica
lly u
nd
ern
ou
rish
ed
nu
mb
er
0.0
2.0e+8
4.0e+8
6.0e+8
8.0e+8
1.0e+9
1.2e+9
1.4e+9
No climate change
RCP 8.5
SSP1 SSP2 SSP3
Food security and land use change projections for 2050
(IIASA, GLOBIOM model & AgRIPE)
SSP2 and SSP3: ncreased deforestation (LAM and SSA)
SSP2 and SSP3: ncreased undernourishment (SSA, S. Asia) Climate change exacerbates these trends
Global food system and land use emissions may prevent climate stabilization (RCP2.6)
Agriculture and LUC: 2050, % total GHG emissions%
of
tota
l G
HG
em
issio
ns
0
10
20
30
40
50
60
RCP2.5
RCP 8.5
SocioEconomic Pathways SSP1 SSP2 SSP3
(IIASA, GLOBIOM model & AgRIPE)
Biological soil carbon sequestration could smooth the transition to stabilization by 2050
2050, Agricultural and LUC emissions (CO2 eq.)
To
ns C
O2 e
qu
iva
len
ts
0.0
1.0e+9
2.0e+9
3.0e+9
4.0e+9
5.0e+9
6.0e+9
7.0e+9
8.0e+9
9.0e+9
1.0e+10
1.1e+10
No climate change
2050, Potential soil carbon sequestration (CO2 eq.)
Tons C
O2 e
quiv
ale
nts
-8e+9
-6e+9
-4e+9
-2e+9
No climate change
SSP1 SSP2 SSP3 Agriculture Other biomes
This would lead to a massive change in agricultural practices (e.g. agroforestry, continuous soil cover…)
Emissions from agriculture and land use Soil carbon sequestration potential
• Compare past & future distributions from ensembles of global crops models (AgMIP/ISI-MIP) – Extreme (-) percentiles, variance & skewness of distributions
generally getting worse
– Global 1-in-100 year historical event occurs almost 1-in-30 years within only several decades
Non-stationary risk in agriculture (J. Elliott, Chicago University)
12
Reproduced from Extreme weather and resilience of the global food system
Prepared for the UK-US Taskforce on Extreme Weather and Global Food System Resilience
A view from the insurance industry: Lloyd’s emerging risk report - 2015
Experts have developed a worst case scenario of a large ENSO event, combining: - Direct weather impacts on key grain producing regions, - Indirect impacts through crop pathogens (stem rust of wheat), - Consequences for markets and stocks
Eco-efficiency (sustainable intensification):
the standard paradigm
Sustainable intensification (since 1980’s)
Eco-efficiency
Substitution
Reduced emissions per unit product
Specialisation (since 1960’s)
Increased inputs
Simplified systems
Reduced commodity costs increased volumes
Nevertheless, resilience of specialized systems is at risk !
Increased sensitivity to pests and diseases, and to climatic hazards,
Reduced biodiversity and ecosystem services
(apart from production)
Increased GHG emissions per unit land (not necessarily per unit product)
Eco-efficiency (land sparing) paradigm
• Eco-efficiency: the maximization of plant and animal products per unit of inputs or natural resources (e.g. Wilkins, 2008). It would allow: — Environmentally sustainable intensification of agricultural production,
— Land sparing for nature conservation,
— Large production volumes suitable for industries and exports
• In the context of modernized and simplified systems, eco-efficiency can be further developed through: — Genome based plant and animal breeding, advanced phenotyping,
— Precision agriculture and livestock farming,
— ‘Big data’ combining soil, weather, micro-climate, remote sensing, markets, etc… with decision support models.
• Socio-economics: capital intensive systems, with low on-farm labor.
Agroecology (and organic farming): an alternative paradigm
Facilitation, niche complementarity, Root symbioses..
Recoupling
C-N-P cycles (eg. crop-livestock-integration)
Reduced emissions per unit land System
diversification
Heterogeneity in
space & time Balanced ecosystem services
Reduced external inputs
Increased resilience to pest & diseases, and to climatic hazards?
Increased on-farm labor
Increased biodiversity and ecosystem services
Reduced GHG emissions per unit land (not necessarily per unit product)
Functional
diversity
Ecological
infrastructures
Agro-ecology: ecologically grounded production systems fitted to local conditions (e.g. Gliessman et al., 2006)
Agroecology would:
Reduce dependency to external inputs and increase resilience to climatic and sanitary hazards,
Share land between production and other ecosystem services, diversify food products and diets,
Increase or preserve labor in farms (smallholders) and in rural areas.
Agroecology could develop through participatory research supported by advanced knowledge of ecological processes in agriculture and by dedicated technologies (e.g. bio-control, soil biota indicators, etc..) at field and lanscape scales
However, it requires capacity building, dedicated tools and extra-monitoring time, reorganization of up- and downstream industries.
Agroecology (land sharing) paradigm
Hurricane impacts in Central America on monocultures vs. agroecological terraces
After Hurricane Mitch in Central America, Honduran farms under monoculture exhibited higher levels of damage in the form of mudslides (left photo) than neighboring biodiverse farms featuring agroforestry systems, contour farming, cover crops, etc. (right photo)
(after Nicholls, in press, FAO)
Is agroecology providing increased resilience to climatic hazards?
Agroecology comes with systems diversification which reduces the impacts of climatic hazards,
Agroecology can directly protect crops and animals against high temperatures (e.g. agroforestry via shade) and soils from heavy precicipitation (e.g. continuous soil cover)
In ecology, the biodiversity insurance hypothesis states that more biodiverse systems are more resilient to hazards (some demonstrations in literature)
Nevertheless, inputs often buffer variability:
Mineral fertilizers replace soil mineralization at e.g. low soil temperature,
Irrigation buffers climatic variability, etc…
Pests and diseases can be directly controled by pesticides/antibiotics
Transition in adaptation strategies: layering risk
(Cattaneo, OECD, 2011
& Vermeulen et al., 2014, PNAS)
Systemic Incremental Transformative
Transitions in types of adaptation
Ecoefficiency? Agoecology?
Coût (en euros par tonne de CO2e évité) et potentiel d'atténuation annuel en 2030 a l’échelle du territoire métropolitain (en Mt de CO2e évité) des actions instruites.
* * * * * * * *
* * *
* Agroecology option
Of total mitigation potential: • Ecoefficiency: 60% • Agroecology: 59% • Options in common: 19% Costs are spread in a similar way
Shares of ‘ecoefficiency’ and ‘agroecology’ options in the mitigation potential for French agriculture
Climate smart agriculture:
bridging agroecology and ecoefficiency?
• Climate smart agriculture (CSA) has been defined as agriculture that sustainably increases productivity and resilience (adaptation), reduces greenhouse gases (mitigation), and enhances food security and development. FAO (2010) Technical input for the Hague Conference on Agriculture, Food Security and Climate Change.
• A sustainable intensification of agriculture, that would allow closure of yield gaps and increasing biological efficiencies can enhance food security, ecosystem services and contribute to mitigating climate change
• During the third science conference on CSA, it was stated that the concept also applies to the challenges of sustainable food systems and landscapes.
• However, the metrics of CSA and how will riks be layered in different systems is still unclear
Conclusions
Climate change has large implications for agriculture and food systems which question both the eco-efficiency (standard) and the agroecology (alternative) models,
Both of these models can offer solutions that could ultimately contribute to climate smart food systems and landscapes,
Rapid changes will be required to create transitions in both agricultural (e.g. soil carbon sequestration) and food (e.g. diet transitions) systems,
Business-as-usual is not an option as it leads to risks of food system shocks with increasingly apparent geopolitical implications.