Food and nutritional security in the context of climate change: eco-efficiency or agroecology?

Transcription

1 Session 4. Which model(s) for agriculture? Food and nutritional security in the context of climate change: eco-efficiency or agroecology? Jean-François Soussana, Scientific Director Environment, INRA, Paris, France

2 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?

3 A more efficient global food system ( ) The conversion efficiency into plant and animal food of total raw (arable and grassland) proteins has increased from 12 to 19%, Protein use efficiency Protein conversion efficiency The fraction of feed which is edible by humans has increased from 24 to 42% (increased reliance on grains of livestock systems) Fraction human edible livestock feed Fraction human edible livestock feed 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 (Soussana, Ben Ari et al., in prep.) Carbon intensity (ton CO 2 equivalents ton -1 protein) Carbon intensity components Years gch4 gn2o g Prechain g. direct gluc g.

4 Environmental risks associated to agriculture and food systems

5 Eco-efficiency (sustainable intensification): the standard paradigm Specialisation (since 1960 s) Sustainable intensification (since 1980 s) Simplified systems Increased inputs Substitution Eco-efficiency Reduced commodity costs increased volumes Reduced emissions per unit product 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)

6 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.

7 Agroecology (and organic farming): an alternative paradigm Heterogeneity in space & time System diversification Ecological infrastructures Balanced ecosystem services Recoupling C-N-P cycles (eg. crop-livestock-integration) Functional diversity Facilitation, niche complementarity, Root symbioses.. Reduced emissions per unit land 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)

8 Agroecology (land sharing) paradigm 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 extramonitoring time, reorganization of up- and downstream industries.

9 Climate change: a game changer for agricultural systems? Increasing risks from climatic variability and associated price volatility, Increasing demands for drastic GHG mitigation in agricultural and food systems, Increased pressures on soils, water resources and biodiversity, Changes in plant product composition that could affect nutritional security

10 Observed climate change impacts on crop yields (% per decade) IPCC, AR5, WGII SPM, 2014

11 Extreme climatic events since 2000: heat and drought Summer 2003 Europe (no equivalent since 1500) Summer 2010 Russia (no equivalent since 1500) Summer 2012 USA

12 Non-stationary risk in agriculture (J. Elliott, Chicago University) 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 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 12

13 A view from the insurance industry: Lloyd s emerging risk report 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

14 Hurricane impacts in Central America on monocultures vs. agroecological terraces (after Nicholls, in press, FAO) 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)

15 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

16 Transition in adaptation strategies: layering risk Transformative Systemic Incremental Transitions in types of adaptation Agoecology? Ecoefficiency? (Cattaneo, OECD, 2011 & Vermeulen et al., 2014, PNAS)

17 What is the potential of the mitigation options for reducing GHG emissions in the AFOLU sector? Global economic mitigation potentials in agriculture in 2050 are estimated to be GtCO 2 eq/yr. (current global emissions reach 49 GtCO 2 eq/yr) Reducing food losses & wastes: GHG emission savings of GtCO 2 eq/yr. Changes in diet: GHG emission savings of GtCO 2 eq/yr. Forestry mitigation options are estimated to contribute GtCO 2 /yr. IPCC, AR5, WGIII SPM, 2014

18 Shared socio-economic pathways 1-3 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. 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.

19 Food security and land use change projections for 2050 (IIASA, GLOBIOM model) Chronically undernourished number 1.4e+9 1.2e+9 1.0e+9 8.0e+8 6.0e+8 4.0e+8 2.0e , Chronic undernourishment No climate change RCP 8.5 Tons CO 2 equivalents 3e+9 2e+9 1e , Land use change emissions (CO 2 eq.) No climate change RCP SSP1 SSP2 SSP3 0 SSP1 SSP2 SSP3

20 Global food system emissions may prevent climate stabilization (IIASA, GLOBIOM model) 60 Agriculture and LUC: 2050, % total GHG emissions % of total GHG emissions RCP2.5 RCP SocioEconomic Pathways SSP1 SSP2 SSP3

21 * Agroecology option * * * * * * * * * * Coût (en euros par tonne de CO2e évité) et potentiel d'atténuation annuel en 2030 à l échelle du territoire métropolitain (en Mt de CO2e évité) des actions instruites. * Of total mitigation potential: Ecoefficiency: 60% Agroecology: 59% Options in common: 19%

22 Soil organic matter: multiple benefits Food Security Soil Carbon UNCCD 22

23 Restoring degraded soils provides an agroecological win-win option Terraprima project ( Portuguese carbon fund Sown biodiverse leys fertilized with P 50,000 ha were sown (1,000 farmers) Estimated carbon sequestration : 1 million tons since 2009

24 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 are still unclear.

25 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.

26 Acknowledgements: - Tamara Ben Ari, Inra - Petr Havlik, IIASA - Pierre Gerber, FAO - Joshua Elliot, Chicago University Thank you for your attention!