Presentation on theme: "Sanai Li APEC Climate Center, Busan, , Republic of Korea"— Presentation transcript:
1Sanai Li APEC Climate Center, Busan, 612-020, Republic of Korea Chinese Academy of Agricultural Sciences.Chinese Academy of Agricultural Sciences.Chinese Academy of Agricultural Sciences.Assessment of climate change impacts on agriculture and a case study on crop impacts in ChinaSanai LiAPEC Climate Center, Busan, , Republic of KoreaErda LINChinese Academy of Agriculture Science, Beijing, China
2Outline Why is climate change such an important issue for agriculture? Introduce the crop models- the response of crop to temperature- the response of crop CO2- the response of crop waterAssess the impacts of climate change on agriculture –case study in ChinaAdaptation strategies in agriculture
3Importance of Agriculture 70% of the global land use is for agriculture, rangeland and forestry– 12% for arable and permanent crops– 31% for forest and woodlands– 27% for permanent pasture.Agriculture remains the major source of livelihoods of majority of world’s rural poor.-agriculture accounts for 70 percent of full-time employment in Africa, 33 percent of total GDP, and 40 percent of total export earnings.-Asia-Pacific region 60 percent of the population (2.2 billion) is relying on agriculture as a source of livelihoodAgriculture is one of the most sensitive sectors to impacts of climate change
4Climate Change & Agricultural productivity Climates factors directly affect agricultural productivity:-average increase in temperature-change in rainfall amount and patterns-rising atmospheric [CO2]-increase in climatic variability and extreme events-pollution levels such as ozone
5What is the current impact of climate change on agriculture production ? changes in maize and wheat production1980–2008Currently global maize and wheat production declined by 3.8 and 5.5%, respectively relative to without climate trends ( increase in temperature and CO2, changes in rainfall)soybeans and rice, winners and losers largely balanced outSource: Lobell et al., 2011
6Current observed impacts of climate change on agriculture in China In northeast China winter wheat planted has been extended to north by 2-3 latitude (about 250km)Frequent freezing damages to wheat production in China- for example In 2004 and 2005, the wheat freezing damage area reach 3.33 million hectares in 6 provinces including Henan, Shangdong and Hebei provincesPlant diseases and pests are currently causing a 20%-25% average annual loss to China’s agriculture output valueClimatic regionalization of winter wheat in Liaoning province (Ji et al., 2003)
7Future challenges -to feed the world -to enhance rural livelihoods We need sustained growth in the agricultural production-to feed the world-to enhance rural livelihoods-to stimulate economic growthThe demand for food will doublewithin the next years,Food security, remains achallenge, particular indeveloping countries
8Climate and Agriculture Studies of the effect of weather and climate on agriculture are often limited by the availability of climatological data and experimental results.The interactions between the plant and its environment cannot be reflected by the simple crop-climate regressionCrop models provide useful tools for analysing crop and its relationship with the climate.
9Crop growth and development Growth-increase in sizenormal measure in dry weightalso Leaf Area IndexLeaf area index (LAI) is the total one-sided green leaf area per unit ground surface areaLAI= total green leaf area / ground surface area
10Development-progress to maturity Through different stages-eg: emergency, flowering, graining filling, harvestThe time-span of each development phase depends on genotype, temperature, day-length and sowing dategraining filling(71-87)Flowering(61-69)Emergency(9days)harvest (97-110)
11Outline Why is climate change such an important issue for agriculture? Introduce the crop models- the response of crop to temperature- the response of crop CO2-the response of crop waterAssess the impacts of climate change on agriculture –case study in ChinaAdaptation strategies in agriculture
12Crop simulation models Site based crop models (e.g DSSAT) :Seek to simulate the complex dynamics of crop growth and development, and its response to environmental variablesLarge area crop modes (e.g. GLAM):Applied some simple assumptions and empirical relationships to predict the complex crop growth and development
13Site based Crop models High input data requirement Complexity of incorporating the spatial variability of inputClimate model output is coarse compared with input to crop modelThis method is difficultto apply ata regional level(Yang.P).
14General Large Area Model for annual crops (GLAM; Challinor et al, 2004) Aims to combine:the benefits of more empirical approaches (low input data requirements, validity over large spatial scales) withthe benefits of capturing intra-seasonal variability, and so cope with changing climates)Field management -Yield Gap ParameterGroundnut, wheat, maize, soybeangeneral circulation modelcrop model
15Irrigation Models Irrigation strategies – farm level CROPWAT (FAO)Crop water requirements, irrigation requirements based on climate, soil type, rainfall, reference ET, cropping patternsAIMM (Alberta Irrigation Management Model)Irrigation and scheduling decisions for 52 different cropsWeather, soil moisture, ET, irrigation application methodsWaSIM (UK)Water balance simulation model
16Site based crop models Wageningen models (CSIRO, Australia) DSSAT Simulate potential production under measured climatic conditionsLimitations in simulating cropping systems and dynamics in soil water, nutrients and soil organic matterDSSATInclude CROPGRO and CERES models, 17 cropsSimulate crop growth, development and yield as well as soil water and nitrogen balances.Yield limiting factors such as pests, diseases and field management, are not included
17Site based crop models APSIM CropSyst (U. Washington) Produce accurate yield simulation in response to management and predict the long-term impact of farming practice on the soil resourceCropSyst (U. Washington)Simulate the impact of climate, soils and management on cropping systems productivity and the environment.Representation of crop rotations
18Risk modelling -NADSS (National Agricultural DSS) USDA and UNL Web-based toolsIdentify patterns of drought at regional and national level in the USADrought indices, crop production risk analysisMap and tabular format
19Risk modelling - AgRisk (OSU) PC softwarePredict farm’s gross revenue at harvest time (corn, soybean, wheat) under different pre-harvest risk management strategies (crop insurance, current and future market information)
20GPFARM (Great Plains Framework for Agr Resource Management) - USDA PC software, farm level useThree components:Crop growth, animal growth, water balance, water erosion, environmental impactsEconomic analysis tool – estimate costs of rangeland crop production, various cost-benefit analysesAgricultural information system – web-based links to information on crops, pests, agricultural chemicals
21Whopper Cropper (Australia) PC softwareUses both seasonal climate forecasting and crop system modelling to estimate production risks in upcoming season7 crops in AustraliaUses “what if” scenarios to help farmers decide which crops to plant, when to plant, which varieties to plant and how much to invest on various inputs (nitrogen)
22Outline Why is climate change such an important issue for agriculture? Introduce the crop models- the response of crop to temperature- the response of crop CO2-the response of crop waterAssess the impacts of climate change on agriculture –case study in ChinaAdaptation strategies in agriculture
23Temperature and crop growth All plants have maximum, optimum and minimum temperature limits. The limits are cardinal temperature pointsOptimum temperature is required for maximum dry matter accumulation
24Temperature and crop development The development rate of crop is mainly dominated by temperature
25Cardinal temperature values for selected annual crops under conditions in which temperature is the only limiting variable
26Linear trend in temperature from 1961-2009 during rice growing season in Asia In Asia maximum temperatures has increased by roughly 0.5-1o since 1961 in rice growing regionminimum temperatures has increased by roughly o
27The impact of current warming trend on rice yield in Asian countries for 1961-2009 Correlations between temperature and rice yield from in Asia countries
28What is the current impact of warming trend on rice yield in Asian counties? In Asia rice yield has declined by % due to the warming trend in maximum temperature from 1961 to 2009In Japan and Srilanka the warming trend has a positive impact on rice yield
29Impact of extreme temperature on rice yield Relation between average daily maximum temperature and spikelet fertility during the flowering period under different CO2 concentrations(Horie 1993).
30Impact of cooling on rice yield Relation between cooling degree-days and percentage spikelet sterility between the booting and flowering stages (Horie 1988)
31Global mean temperature is increasing Effects Shift in vegetational zones Heat stresses on plants Soil moisture Pests and diseases
32Outline Why is climate change such an important issue for agriculture? Introduce the crop models- the response of crop to temperature- the response of crop CO2-the response of crop waterAssess the impacts of climate change on agriculture –case study in ChinaAdaptation strategies in agriculture
33Modelling growth: photosynthesis Photosynthesis: A chemical process by which a plant turns light energy from the sun into chemical energy in the form of sugar.
34Crop radiation interception Regard a crop as a machine that intercepts solar radiation and convert its energy stored in plant materialIncident radiation is intercepted by the crop or transmitted to the soilIntercepted radiation is then reflected or absorbedFractions: incident=1Intercepted=incident -transmittedIntercepted=1- transmittedAbsorbed=intercepted-reflectedAbsorbed=1- transmitted -reflected
35Modelling growth: Radiation Use Efficiency The potential or maximum photosynthesis of a crop canopy can be estimated from a set of parameters describing the photosynthesis-light curve of single leaves.
36Modelling growth: biomass Biomass=RUE* intercepted solar radiationRUE normally increase with more NRUE decreased by significant stress eg. watervan Ittersum,2003
37Increased CO2 concentration increase the CO2 gradient between the atmosphere and the inside of leaves,Increase rate of photosynthesisincrease growth rate and productivity of plantsdecrease transpirationincrease crop water use efficiency and yield
38photosynthesis will saturate" Photosynthetic response to rising CO2At a certain level of CO2photosynthesis will saturate"
39Free Air CO2 Enrichment (FACE) FACE is the technology by which the environment around growing plants may be modified to realistically simulate future concentrations of atmospheric carbon dioxide (CO2).Long et. all 2006
40The response of winter wheat to rising CO2 -FACE experimental results in China at 550 ppm CO2 Han Xue et al 2012
41Outline Why is climate change such an important issue for agriculture? Introduce the crop models- the response of crop to temperature- the response of crop to CO2-the response of crop to waterAssess the impacts of climate change on agriculture –case study in ChinaAdaptation strategies in agriculture
42Importance of Rainfall Rainfall is especially important for rainfed or dry land agricultureArid and semi-arid areas account for about 40% the land surface of the world, especially some African countries, where rain-fed agriculture is already limited by water availability (Gamo, 1999).Importance of RainfallLow Rainfall – Poor CropSufficient Rainfall – Good Crop
43Water stress on cropStress during early growth can stimulate root growth, extreme drought can delay planting and damage seed germinationStress at flowering may be more sensitive (maize)During the grain filling period, water deficit can reduce grain weight by accelerated senescence rate and shortened growth duration
44The response of rice yield to seasonal total rainfall from 1961-2009 in Asian countries In india, Laos, Nepal,Thailand and Asia, seaonsal total rainfall has a positive impact on rice yield, viriability of rice yield depends on the amount of rainfallIn Japan, rice yield showed a negative response to seasonal total rainfall
45Impact of extremes: rainfall distribution 1975Total rainfall: 394mmModel: 1059 kg/haObs: 1360 kg/ha1981Total rainfall 389mmModel: 844 kg/haObs: 901 kg/ha
46Drought mitigation and adaptation Avoid stress at sensitive stages-floral initiation and pollinationAdjusting planting structure or sowing dateSeed Engineering-choice of cultivar tolerance to droughtRainfall collection based water savingMembrane coverageProtected cultivation（Less tillage and no tillage ）
47Outline Why is climate change such an important issue for agriculture Introduce the crop models- the response of crop to temperature-photosynthesis,CO2 and crop-the response of crop to waterImpact of climate change on Agriculture –case study in ChinaAdaptation strategies in agricultureim
48Integrated impact assessment including socio-economic scenarios Impacts of Climate Change onChinese Agriculture – Phase IIIntegrated impact assessment including socio-economic scenariosClimate Change;CO2 fertilization effects;Water Availability;Agricultural land conversion;All drivers togetherOverview of UK-China Climate Change and Agriculture Project March 2008
49SOCIO-ECONOMIC SCENARIOS CLIMATE SCENARIOS from PRECIS GDP, Pop., Water demand, Land useCERES crop modelVIC hydrological modelADAPTATION POLICIESImprovements in Agric. Tech.IMPACTS ON CROP YIELDS, WATER AVAILABILITY, AND ARABLE LANDLand use change policiesIMPACTS ON TOTAL PRODUCTIONWater allocation policiesOverview of UK-China Climate Change and Agriculture Project March 2008
5017 GCMs from IPCC and PRECIS (A2 emissions) Comparison of PRECIS results and GCM output for ChinaAnnual change in temperature and rainfall in China: 2020s, 2050s, and 2080s17 GCMs from IPCC and PRECIS (A2 emissions)Overview of UK-China Climate Change and Agriculture Project March 2008
51Change in total cereal production with different combinations of drivers Climate ChangeWith CO2Climate ChangeWith CO2 and waterAll driversOnly Climate ChangeClimate ChangeWith WaterClimate ChangeWater & LandOverview of UK-China Climate Change and Agriculture Project March 2008
52Changes in cereal production per capita in China under combinations of drivers Overview of UK-China Climate Change and Agriculture Project March 2008
53Future impacts of climate change on agriculture in China The reduction in crop yield by ℃ temperature increase during 2080s can be offset by elevated CO2 at ppm and other adaptation, but very high costs may need.An increase in investments of 8 ~ 34.8 billion US dollars per year (in 1990 price) is necessary, otherwise the agriculture will lose 32.3 ~ 80 billion US dollars per year (Lin, & Zhang, 2005)
54How we are responding to climate change Action to address climate changeMitigation: Reducing greenhouse gas emissionsAdaptation: A process of adjusting to changes in variables
55An adaptation framework for China to support national and international adaptation projects3 Identify adaptation options1 Assess climate risks2 Integrate development and adaptation goals4 Prioritise optionsNew knowledge/research6 Monitoring and evaluation5 ImplementationIntegrate adaptationinto planning andpolicy framework55
563.1Climate change by 2030 will further aggregate the drought stress in Northeast ChinaPercentage of crop production loss due to drought stress in Northeast China1 （2030）probabilityNortheast China*+35%30%10%Future climateRainfall in spring (mm)Current climatecrop yield loss due to drought million ton6.04.4Economic lossBillion RMB6.58.7Factors causing yield lossDecrease in the amount of rainfallIncrease in extreme drought stressLess investment in agriculture and infrastructures avoiding drought stress1 历史气候：假设2030年具有相同的气候条件; 气候变化：高二氧化碳浓度的情景（2050年 559 ppm）56来源：PRECIS 模型；团队分析
57the economic costs and benefits of drought adaptation -Case study in Northeast China by 2030*(cost/benefit<1)3.7(cost/benefit>1)*evitable loss~56%inevitable loss~44%inevitable loss*******18**10evitable lossBillion RMB**Seed EngineeringPipe delivery water*Long term economic benefitReservoir and pond*Drip IrrigationCanal seepage for irrigationSpray Irrigation*Rainfall collection based water savingProtected cultivation ）Membrane coverage-3.1*In northeast China, yield loss due to drought stress can be avoid by 56% by the above adaptive measures资料来源：麦肯锡分析
58Adaptation Demonstration in China Demo. areasHeilongjiangHeihe basin, GSTailanhe basin, XJNaquTibetBohai CoastCC RiskCooling dec. getting dryerWater consuming increase for oasisMore water coming now and will decreaseGrassland dryer, lake level riseSea level rise, storm tideAdap. TargetGo benef, avoid disasterWater saving & cultivatSaving water and ecolog. protectProtect grassland ecologyBuild design based on sea levelPoten. Adapt.Structure adjustingLow consuming technologyIntegrated water managementpasture animals b. on waterDesign stand with s.le. riseAdp. Asse.31302826Demon.700 hm2 x 420 hm2 land10 reserv. 60 hm2 landsprinkled Irrigat.12hm2Project design in costal ar
59How farming can adapt to the changed climate farmers can:change their crop rotation to make the best use of available water,adjust sowing dates according to temperature and rainfall patterns,use crop varieties better suited to new weather conditions (e.g. more resilient to heat and drought)Public policy must support farmers
60Policy recommendations Improve the capacity of farmers and rural regions to adapt to climate changeDevelop systems for monitoring regional climate change and provide early warning of disastersadapting options to the farming communityproviding advisory services and training.
61Policy recommendations Support the development of low-carbon, high-quality AgricultureComprehensive, long-term strategy based on local circumstancesLong-term subsidies to encourage investment in new technologyMarket incentives: National Voluntary Carbon trading Mechanism to pay impoverished farmers for reducing pollutants and GHG emissions
62Future work: Integrated impacts assessment around the world the socio-economic environment, world trade, population, technology and the natural resources are likely to undergo significant changes over the next few decades (Nakicenovic and Swart, 2000)Integrated impacts studies including socio-economic scenarios, population and improvements in technology are an important aspect for study.
63Future work: assessing costs and benefits of adaptation Assessing availability of water supplies for irrigation and the costs of adaptationthe economic and social costs and benefits of adaptation, and the adaptive capacityTerraceMembrane coverage
64Future work: Sampling uncertainty in impact assessments Possible sources of uncertainty in predicting climate change and its impacts:Scenarios from population, energy,economics models,Coupled climate Models, Impacts modelssample the uncertainty in projections of impact by:using > 1 emissions scenariousing > 1 climate modelusing >1 crop modelby systematically varying parameters in climate or crop modelsimpact is then given by the ensemble mean, and the variability within the ensembleThe term ensemble is now used to describe the use of > 1 model in impacts assessments.
65Key MessagesClimate change and the extreme events have had an impact on agriculture. Yield potential is likely to decline due to even small rises in global temperatureregions that will be more vulnerable--tropical and subtropical , heat and drought stress in summer is likely to increase--in some northern the risk of drought stress would likely increasePrioritisation of adaptation include--adjusting planting systems--increasing water use efficiency--encouraging agroecological sustainable developmentAn increase in investments of agriculture is necessary to secure the food supply--infrastructures against floods and droughts--increasing the support to climate related scientific and technological workScience and technology must spearhead agricultural production in the next 30 years at a pace faster than the Green Revolution’s during the past three decades.” – FAO Director General 2007