Introduction

Abstract

AbstractThis book analyzes potential yields of six major food crops- rice, wheat, maize, potato, soybean and rapeseed worldwide using both qualitive and quantitive approaches to study both China’s and global food security under climate change. Firstly, it reviews previous studies on potential yields of rice, wheat, maize, potato, soybean and rapeseed worldwide to provide a detailed information of studying on China’s and global food security based on the product’s supply and demand of these crops. Secondly, average and top (national) yields of rice, wheat, maize, potato, soybean and rapeseed since 1961 on global scale are employed to analyze their temporal and spatial variation trends and potential limits. Thirdly, the effects of global warming in climate change on both average and top yields of rice, wheat, maize, potato, soybean and rapeseed since 1961 at global level are analyzed using regression model, and their differences between average and top yields among these crops are identified and compared. The results show that from 1961 to 2019 six major food crops are affected by global warming as follows. Average yield of world rice is impacted by global warming negatively less than the top, which makes the gap between these two yields gradually narrowed. Avergae yield of world wheat is affected by global warming positively while the top negatively, which drives the gap between these two yields recently shrunk. Average yield of world maize rises with global warming less than the top, which makes the gap between these two yields obviously widened. Average yield of world potato increases with global warming faster than the top, which drives the gap between these two yields gradually narrowed. Average yield of world soybean is affected by global warming positively while the top negatively, which makes the gap between these two yields greatly closed. Global warming exerts a positive effect on average yield of world rapeseed while a negative impact on the top, which drives the gap between these two yields slightly shrunk. Fourthly, the yields and per capita quantities of rice, wheat, maize, potato, soybean and rapeseed in major producer-countries and the world are analyzed to assess the situation and trend of international trade for the products of these crops, respectively. Fifthly, potential yields of rice, wheat, maize, potato, soybean and rapeseed worldwide by 2030 are projected using both trend-regressed model and Auto-regressive Integrated Moving Average (ARIMA) model to estimate the per capita quantities of these crops based on the projection of world population and assess the status of Chinese and global food security in that future. The results show that between 2020 and 2030 average and top yields of six major food crops are projected respectively in the following. Average yield of world rice is projected to be from 4793 kg/ha to 5159 kg/ha while the top from 10105 kg/ha to 10269 kg/ha; average yield of world wheat is projected to be from 3479 kg/ha to 3817 kg/ha while the top from 9856 kg/ha to 10042 kg/ha; average yield of world maize is projected to be from 5937 kg/ha to 6748 kg/ha while the top from 36711 kg/ha to 46022 kg/ha; average yield of world potato is projected to be from 20430 kg/ha to 22378 kg/ha while the top from 50070 kg/ha to 51422 kg/ha; average yield of world soybean is projected to be from 2776 kg/ha to 3071 kg/ha while the top from 4104 kg/ha to 4237 kg/ha; and average yield of world rapeseed is projected to be from 2155 kg/ha to 2453 kg/ha while the top from 4178 kg/ha to 4273 kg/ha. In 2030: the per capita quantity will be 95 kg of rice, 83 kg of wheat, 176 kg of maize, 59 kg of potato, 58 kg of soybean and 14 kg of rapeseed in the world, respectively; in other words, total per capita quantity of three staple cereals (viz. rice, wheat and maize) by 2030 (projected 354 kg) will be very close to that in 2019 (actual 353 kg), while that of four staple grains (viz. rice, wheat, maize and soybean) by 2030 (projected 412 kg) will be 3.78% higher than that in 2019 (actual 397 kg), and that of the six major food crops by 2030 (projected 485 kg) will risen by 6.59% relative to actual 455 kg in 2019. Finally, it provides policy implications and advice on food security for China and the world directing food production by 2030 under climate change.