Research On Global Food Production Forecast And Irrigation Increasing Potential Under Future Climate Scenarios

Factors such as climate change,population growth and changing dietary structure pose serious challenges to global food security;the outbreak of COVID-19 epidemics and international shocks in recent years have exacerbated the food security crisis.To address the issues of future food supply and demand projections and irrigation yield increase potential under different climate change scenarios,this paper uses the SSP2-45,SSP3-70 and SSP5-85 scenarios as the climate background to simulate future yields of wheat,rice,maize,soybean and potato crops using the Aqua Crop water-driven crop model;based on the high correlation between GDP per capita and caloric demand per capita,the Future global food demand is projected using future GDP values and population size of each country to analyze the balance of food supply and demand in 2030,2040 and 2050 and to quantify the supply-demand gap.The irrigation demand index is used as the basis for judging the degree of farmland water shortage to elaborate the regional farmland water shortage,and then the feasibility and coverage area of irrigated farmland expansion is judged based on the amount of water available to humans and its spatial and temporal distribution characteristics.The yield after irrigation expansion is simulated,and the amount of supply-demand gap can be reduced by the increased yield of irrigation expansion is calculated.Since predicting only the future world food supply and demand balance under historical development trends is one-sided,this study predicts the future world food supply and demand balance under four food security scenarios containing the most desirable to the worst,and calculates the supply and demand gap.The main conclusions obtained from the study are as follows:(1)Food production in all future climate scenarios cannot meet demand,and the gap between supply and demand gradually widens over time.Food production in the SSP2-45,SSP3-70,and SSP5-85 scenarios all show an increasing trend over time,from 2030 to 2050,from 2.488-2.551 billion tons to 2.648-2.707 billion tons for each scenario,an increase of about 13%.During the same period,food demand increases from 5.152 to 6.461 billion tons,with a higher growth rate than production,resulting in an expanding gap between food supply and demand,with the gap between supply and demand at 2.645 billion tons in 2030 and increasing to 3.776 billion tons in 2050,an expansion of the gap by about 43% over 20 years.(2)The global water shortage on farmland under each climate scenario gradually deepens from 2030 to 2050,and the irrigation expansion potential gradually decreases.2030 has the lowest water shortage,the highest irrigation potential,and the widest irrigation expansion area,Central Africa and southern Southeast Asia have the lowest irrigation demand,while northern North America,southern South America and eastern Europe have relatively high irrigation demand,and central South Asia has the highest demand.The regions with irrigation expansion conditions are mainly concentrated in East Asia,Southeast Asia,eastern Central Asia,western Europe,eastern North America and northwestern and eastern South America,among which Asia has the highest potential for irrigation expansion.(3)The gap between supply and demand decreases for all climate scenarios after irrigated expansion of agricultural land,but the gap between supply and demand still widens with time.Grain production after irrigation expansion reaches 2.852 billion tons in 2030 and increases to3.044 billion tons by 2050.the largest increase in production among the years is in 2030,which increases by 372 million t,or about 14.86%.Increased irrigation reduces the supply-demand gap by 333 million tons,325 million tons,and 372 million tons in 2030,2040,and 2050,respectively,narrowing the supply-demand gap by 8.8-14.1 percent,but irrigation expansion increases production at a slower rate than demand,so the supply-demand gap still increases over time.(4)Among the four scenarios covering the most desirable and worst food security scenarios,the Ecological Utopia Scenario(ECO)and the 1% World Scenario(ONEPW)are relatively dominant in the food security status of the SSP3-70 and SSP5-85 climate scenarios.The "too little,too late scenario"(TLTL)has the smallest gap between supply and demand in all climate scenarios,with an average value of about 2.7 billion tons in 2050,but it is an unequal unsustainable worst-case world,and the "food for all for a while scenario"(FFANF)with a rapidly growing economy and the largest food demand and supply-demand gap,about3.3 billion tons,is an unsustainable world."The Ecological Utopia scenario and the 1% World scenario have a relatively moderate food supply and demand situation,and the gap between supply and demand is smaller than the gap between supply and demand in the future world according to historical trends,especially in the SSP3-70 and SSP5-85 climate scenarios.The"ecological utopia scenario" is the most ideal scenario,and the "1% world scenario" is relatively easier to achieve.