Ye liming — simulated effects of climate change on food security in china toward 2050
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Simulated Effects of Climate Change on Food Security in China toward 2050 Liming Ye Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081, China ICCCFS 2011, 7‐8 November 2011, Beijing China
Simulated Effects of Climate Change on Food Security in China toward 2050
Liming Ye
Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural Sciences
Beijing 100081, China
ICCCFS 2011, 7‐8 November 2011, Beijing China
9.6 million km2
1.3 billion people
30% flat surface
560 p./km2
Introduction
Presenter
Presentation Notes
China is the 3rd largest country of the world. It occupies a land surface of 9.6 million sq km. High mountains and hilly areas take nearly 70% of its land surface. Most of its 1.3 billon people are living in the eastern part of the country. Population density in these flat areas is as high as 560 persons per sq km.
Cropland: 14% of Land Area
0.1 ha./ capita
Cropland in China
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Presentation Notes
Cropland in China, which is represented by the green color on this map, takes only 14% of the total land area. This corresponds to a per capita cropland area of merely 0.1 hectares.
Challenges for Food Security
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There are 7 billion people living on our planet Earth; among them, around 1 b go to bed with an empty stomach everyday. Majority of these undernourished people are from Asia and Africa. The world food production has to increase by 70% to feed 9 billion people in 2050. The challenge is even bigger in 2100; the world population will likely reach 10 b by then.
Danger of Food Insecurity
Per Capita Values
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Presentation Notes
China is the most populous country of the world. While the per capita consumption of food, as indicated by the red line on this slide, has been steadily increasing in recent years, the per capita production has been greatly fluctuating during, e.g., the late 1990s and the beginning of the new millennium, displaying strong effect of unfavorable climatic conditions on crop production.
Research Settin
gs
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Presentation Notes
Therefore, we have set up a research framework to simulate the effect of climate change on food production in China. The framework consists of two parts: (1) yield forecasting and (2) food security analysis. Crop yield is simulated by using the crop-specific CERES models and by considering the biophysical processes involving the changes in natural resources, in farming systems and in the agro-environment under climate change. Food security status is analyzed from a supply-demand point of view, usually using production scenarios of population growth, urbanization rate, cropland area, cropping intensity and so on.
Crop Modeling
Yield Observation Stations
Yield Simulation Error
Rice
Yield simulated using CERES model and compared to observed yield.
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Presentation Notes
This slides shows the crop yield simulation settings and the simulation error. The root mean squared error is mostly lower than 15% for the case of rice.
Cropping Area and Irrigation Probability
Irrigated Maize
Rainfed Maize
Cropping area extraction using satellite imagery and the cross entropy theory.
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Presentation Notes
This slides shows the cropping areas of the irrigated and rainfed maize extracted using satellite imagery and the cross entropy theory.
Cropping Area and Irrigation Probability
IrrigationProbability
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Presentation Notes
The irrigation probability map can be produced from the area maps. The redish color represents the rainfed maize and greenish color represents the irrigated maize.
Yield Growth Rate under Climate Change
Wheat
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This slide shows the spatial patterns in projected yield change rates of wheat under SRES A2, relative to the 1961-1990 baseline. Climate change would have a negative effect on maize yield in China, as suggested by the light brownish color.
Yield Growth Rate under Climate Change
Wheat
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Presentation Notes
Similarly, climate change is projected to have a negative effect on wheat yield under SRES B2.
Yield Growth Rate under Climate Change: Summary
Crop Yield under Climate Change: Summary
Scenario Settings
Food Self‐Sufficiency Outlooks
Great Leap Forward
1st 5‐yr pl.Start of reforms
Self‐sufficiency (%
)14
012
010
090
SS increases only as population decreases!
Presenter
Presentation Notes
This slide shows the critical fluctuation of the per capita food surplus, or food security index (FSI) as termed here, during 1949 and 2050. The FSI values is projected to decrease until 2030 to a level similar to the food security status in the pre-reform era under either A2 or B2. The FSI is projected to increase during 2030-2050, but this increase is only achieved with decrease in population size.
Concluding Remarks
Effect of CC on food production in China is mainly reflected by the decrease in yield growth rate and the increase in spatial and temporal uncertainties;Population growth rate controls the future food self‐sufficiency level in China. A growth in population size will likely drag the SS down under CC;CC effect on yield is nonlinear, either spatially or temporally. Attention is thus called to use proper scale for decision making.
