Climate change and agriculture: from challenges to solutions. Jean-François Soussana Scientific Director for Environment INRA, Paris

Transcription

1 Climate change and agriculture: from challenges to solutions Jean-François Soussana Scientific Director for Environment INRA, Paris

2 Outline Climate change impacts Adaptation and resilience GHG mitigation Soil carbon sequestration Food and nutritional security under climate change

3 CLIMATE CHANGE IMPACTS

4 Observed impacts on crop yields (% per decade)

5 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.05

6 Climate impacts on world food prices

7 Non-stationary risk in agriculture 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 UK-US Taskforce on Extreme Weather and Global Food System Resilience 7

8 Projected climate change impacts on wheat yields in Europe by 2030 (JRC, 2012) ECHAM5 HADCM3 Without adaptation With adaptation Adaptation: earlier sowing dates

9 2016 crop harvest in France A 30% decline in wheat yield and a 20% drop in cereal production A series of climate hazards: Warm winter and early crop development Cold during wheat flowering, impairing grain formation (meïosis) Excess water in May-June: anoxic conditions and local flooding Heavy fungal disease pressure Low solar radiation reducing grain filling Heat and drought in July and August, affecting summer crops (e.g. corn) How to adapt to increased climatic variability?

10 Increased frequency of heat waves in Europe by the end of the century Number of summer heat waves (>5 days) compared to Heat waves are defined as periods of more than 5 consecutive days with daily maximum temperature exceeding the mean maximum temperature of the May to September season of the control period ( ) by at least 5 C compared to Mean of 8 and 9 regional climate models, Eurocordex ///// Significant (P<0.05) \\\\\ Robust (>2 models out of 3).. (Jacob et al., 2013; Eurocordex)

11 Increased frequency of heavy precipitation in Europe by the end of the century Heavy precipitation change (%) in heavy precipitation defined as the 95th percentile of daily precipitation (only days with precipitation > 1mm/day are considered) compared to for winter (DJF). Mean of 8 and 9 regional climate models, Eurocordex ///// Significant (P<0.05) \\\\\ Robust (>2 models out of 3) RCP4.5 RCP8.5 (Jacob et al., 2013; Eurocordex)

12 Increased frequency of droughts by the end of the century (Jacob et al., 2013; Eurocordex) Annual duration of droughts Projected changes in the 95th percentile of the length of dry spells for the period compared to (in days). Dry spells are defined as periods of at least 5 consecutive days with daily precipitation below 1mm compared to Mean of 8 and 9 regional climate models, Eurocordex ///// Significant (P<0.05) \\\\\ Robust (>2 models out of 3) RCP4.5 RCP8.5 RCP 4.5 RCP 8.5

13 Adaptation: remote sensing, drought monitoring Rapid developments in satellite imagery, e.g.: Soil moisture (microwave, SMOS) Leaf area index and drought (Sentinel 2.0), global cover, 10 days return time, ca. 20 m resolution Infrared imaging of drought (Thirsty project, INRA, ESA & NASA) Crop and pasture monitoring to deliver near real time advice to farmers Sentinel 2.0 satellite

14 Plant breeding for heat and drought tolerance Crop programs in France: from genomics to phenotyping

15 Increasing resilience to climatic hazards Precision agriculture and modern breeding Breeding shows negative trade-offs between plant (or animal) potential productivity and resilience to climatic hazards, Water and nutrients use efficiency should be increased, but soil and water resources also are at risk, Crop monitoring, remote sensing and improved weather forecast have large potential Soil and water conservation Integrated water management at catchment scale, Conservation agriculture (no-till, cover-crops, mulch, green manure, etc.), Crop-livestock integration, perennial crops, etc. Diversification: increased resilience at farm scale Crop rotation, grass leys, permanent grasslands, specialized crops, Mixed cultivars, grass-legume mixtures, etc. Agroforestry (improved micro-climate), Diversified landscapes (reduced pest and disease pressure)

16 Hurricane impacts in Central America on monocultures vs. agroecological terraces (Nicholls et al., 2015, ASD) 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)

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

18 Reducing GHG emissions FROM AGRICULTURE

19 A large gap in emissions reduction by 2030 for 2 C [UNEP] By 2030, a gap of 12 Gt CO 2e with NDCs prevents reaching the targeted +2 global warming target 129 countries include the AFOLU (agriculture, forestry and land use) sector in their Nationally Determined Contributions At least 25% of total committed GHG mitigation [as estimated by the International Institute for Applied Systems Analysis, IIASA] 19

20 Emissions intensity of AFOLU products is declining as agriculture and forestry become more efficient Note that ruminant meat has a GHG intensity much higher than other agricultural products But also note that these are direct emissions only. If we include the emissions from the human-edible feed for mono-gastric animal products, they move closer to ruminant meat IPCC WGIII AR5

21 At global scale, without soil carbon sequestration, it is not possible to reach the global target for agricultural mitigation by 2030 N 2 O and CH 4 mitigation Only 21 to 40 % of the target (Wollenberg et al., 2016, GCB)

22 Soils contain two to three times more carbon than the atmosphere (Harmonized World Soil Map, UNEP, FAO, JRC 2010)

23 Why Soil Carbon? Co-benefits for adaptation, land degradation neutrality and food security 1.4 billion metric tons carbon could be stored annually in agricultural soils, equivalent to a storage rate of 0.48%/year in top soil [after IPCC, 2007, 2014]. 4 per mil (0.4%) target Cost competitive at 100 US$ per ton CO 2 Half of the agricultural soils are estimated to be degraded [FAO, 2006] The annual cost of fertilizer to replace nutrients lost to erosion is US $ 110 US $ 200 billion (ITPS, 2016) million metric tons additional grains per ton C stored in soils OM in developing countries [Lal, 2006] Reduced yield variability after soil restoration leading to increased soil organic matter [Pan et al., 2009] 23

24 A negative trade-off between agricultural GHG (CH 4, N 2 O) mitigation and food security by C target 1.5 C target (Frank et al., submitted to Nature Climate Change)

25 With soil carbon sequestration, food security is not threathened, even for a 1.5 C global warming target SOC, soil organic C sequestration; SOC+, including its benefits for yields (Frank et al., submitted to Nature Climate Change)

26 What is «The 4 per 1000 initiative : Soils for food security and climate»? => A multi-stakeholder Initiative launched by France at COP21 with the support of FAO One of the 6 initiatives of the Agriculture focus of the Lima Paris Action Agenda (LPAA) 1 objective: increase soil fertility thanks to carbon sequestration in soils => 3 major outcomes: - Improve food security - Adapt agriculture to climate change - Mitigate GHG emissions 26

27 Limits and co-benefits of soil carbon sequestration Co-benefits with food security (lower mitigation costs) and climate change adaptation (water infiltration and retention), SOC will increase only over a finite period (30-50 yrs locally), up to the point when a new SOC equilibrium is approached, The additional SOC stock will need to be monitored and improved practices will need to be maintained over several decades, Soil phosphorus (P) and nitrogen (N) should be available (root symbioses could help), Soil and water management need to be combined, especially in dry regions.

28 Synergies across four objectives contributing to food and nutritional security under climate change (Soussana, 2016; background Chapter, SOFA report, FAO)

29 Synergies across four objectives contributing to food and nutritional security under climate change Better managing this major cycle through agriculture, forestry and aquaculture can bring multiple benefits for food security, climate stabilization and the resilience of rural populations to climate change. To this end, four highly complementary objectives need to be pursued: Conserve and restore, through agricultural and forestry management, carbon rich soils and carbon rich landscapes, Increase agricultural production efficiency and minimize farm scale GHG emission intensity, Guide food systems towards reduced food losses and wastes and towards healthier diets in order to reach food and nutritional security, Enhance the resilience of agricultural production systems to climate change and to climatic variability, especially through the diversification of crops and landscapes. (Soussana, 2016; background Chapter, SOFA report, FAO)

30 Implications Reaching these objectives cannot be achieved solely by bridging yield gaps. Priorities for the agriculture and food sector need to be revisited to include: Soil conservation and restoration, which is a key priority for climate change mitigation and adaptation and for food security; More efficient livestock systems and better crop-livestock integration to abate GHG emissions while preserving rural livelihoods; Nutritionally sound diets, that will contribute to climate change adaptation through the diversification of agricultural systems and to climate change mitigation by avoiding excess saturated fats from animal products; Reduced wastes and losses and increased recycling of by-products and coproducts in order to increase the overall efficiency of bio-based processes providing food, fibers, bio-energies and bio-chemicals. (Soussana, 2016; background Chapter, SOFA report, FAO)

31 Barriers Nevertheless, there are multiple socio-economic, institutional and behavioral barriers in the AFOLU sector that may prevent rapid transitions. A first step to lower these barriers would be to revisit paradigms currently in use, since they do not fully reflect the challenges ahead: Sustainable Intensification, should better encompass the understanding gained through the Save and Grow concept and similar approaches (e.g. ecological intensification, agro-ecology), thereby recognizing the needs to better use ecosystem services and natural resources in agriculture, Food and nutritional security, could be extended to include the environmental dimensions of security, since food systems need to preserve and restore soils and water resources in order to reach climate adaptation and mitigation targets. Climate Smart Agriculture could be revisited to better include food system dimensions, on the one hand, and the integrated management of landscapes, on the other.

32 Thank you for your attention! Séminaire Alimentation et Changement Climatique, Allenvi

33 COP21 Une étape importante dans la négociation climat Protocole de Kyoto : engagements chiffrés des seuls pays développés. Moins de 15% des émissions mondiales de GES. Ratification au bout de 7 ans. Accord de Paris : inclusif, 195 pays + UE Ratification en un an : dès la COP22 (Novembre 2016)

34 Les 4 piliers de l accord de Paris Accord universel juridiquement contraignant permettant des engagements vérifiables des Etats, révisés tous les 5 ans pour augmenter l ambition Contributions nationales (NDC) Plan d action Lima Paris : initiatives de la société civile, soutien possible des Etats Paquet financier pour soutenir les pays en développement

35 L Accord de Paris entrera en vigueur le 4 Novembre prochain

36 Un déficit de réduction des émissions en 2030 pour rester sur la trajectoire des 2 C [UNEP] D ici à 2030, un déficit d engagement (NDC) des pays de 12 Gt CO 2e au regard de la trajectoire probable pour contenir le réchauffement global à +2 Un quart des engagements porte sur le secteur des terres. 36