شیدا رستگاری

Changes in the global climate have become one of the most crucial challenges facing agriculture in the twenty-first century. Climatic change is mainly characterized by a rise in greenhouse gas emissions and global average temperature as well as changes in precipitation levels and patterns. Undoubtedly, these changes affect the growth and productivity of agricultural production, and thus food security in many parts of the world like Iran. At present, supplying sufficient food and meeting food security in Iran relies on the management of climatic variables that affect agricultural production. Therefore, it is necessary to study the effects of climate change on agricultural production and food security in arid and semi-arid regions of this country such as the Khorasan region. Given the importance of this issue, the objective of the current study is to investigate climate change and its impacts on the yield and yield risk of selected crops, as well as on food security in the Khorasan region.

The daily observed data for maximum temperature, minimum temperature, and precipitation is provided from the Meteorological Organization of Iran for 1961–2010. The daily reanalysis data for the period (1961–2005) are obtained from the National Centers for Environmental Prediction (NCEP). The large-scale daily predictors for the CanESM2 model were developed by the CCCma for selected station. These data are used to predict climate parameters under three climatic scenarios (RCP 2.6, RCP 4.5 and 8.5) for 2030. This study used SDSM to downscale GCM-CanESM2 outputs. SDSM model, one of the most widely used models in the world, is applied to downscale future climate projections using the 26 predictors derived from a large-scale climate model. In the current study, a production function technique developed by Just and Pope is applied to investigate the effects of climate variables on the mean and variance of crop yields. This technique consists of two parts: the first component is relating to the yield levels and the second part is related to the yield variance.

The results showed that maximum temperature, minimum temperature, and precipitation have a significant impact on the yield of the studied crops, so these factors will lead to a decrease in the production of irrigated wheat, irrigated barley, and dryland barley in 2030 compared to the base year. Findings indicate that per capita availability of wheat will decrease from 148.22 to 104.44, 107.51,109.83 and for barley will decrease from 74.28 to 47.94, 54.19, 62.79, and for potato will change from 26.44 to 25.37, 25.53, and 27.24 (kg per person) under climate scenarios RCP2.6, RCP4.5 and RCP8.5, respectively. In addition, the results show that climate change in 2030 will reduce the production of irrigated wheat, barley, and rain-fed barley, while these changes will improve the production of potatoes and rain-fed wheat. Furthermore, the findings of the study reveal that the improvement of technology will be able to reduce the negative effects of climate change on the production of vulnerable products. Also, due to population growth in this region as well as climate change, the per capita availability of crops in 2030 will decrease, which will increase the dependence of this region on other regions of the country and imports to meet food needs.