Investigating the Effects of Climate Change on Agricultural Market in Semi-arid Regions

Understanding the temporal and spatial fluctuations of climatic parameters (such as temperature, precipitation, relative humidity, etc.) and its impact on agricultural sector is essential for managing agricultural resources and adopting appropriate strategies. Precipitation directly affects the production of dry crops by supplying the required moisture for the plant, and indirectly affects the production of aquatic crops through supplying surface and underground water resources. Climate change has an effect on temperature and precipitation distribution and consequently affects the plants water requirement and agricultural water consumption. Overall, climate change is influenced by both temperature and precipitation. Due to the changing rainfall pattern and average temperature of the atmosphere, this phenomenon can damage the production of agricultural products that maintain the major food sources of the country. Given the important role of agriculture in the country's economy and the existence of the ongoing water crisis and drought in the country, climate change can have major impacts on their aggravation. The purpose of the present study is to investigate the effects of climate change and water scarcity on agricultural production, price and income in Iran.

The multi-market model, sometimes referred to as the "finite general equilibrium" or "multi-market partial equilibrium model", has reduced the complexities of computable general equilibrium (CGE) models. The AMM template was used for this purpose. To simulate the effects of climate change, crop yields were calculated using yield response coefficients. Then, the demand function of different products was calculated using estimated elasticities and finally climate change has been simulated for 2025.

The results showed that climate change would increase, yield of rainfed wheat, blue barley, dry barley and maize grain in semi-arid climate and subtropical climate, in addition dry barley and barley products in warm semi-arid climate and subtropical climate, and finally rainfed barley and corn products Grain in temperate semi-arid climates and subtropicals climate by 2025 relative to current levels. Climate change also would decrease yields of dry wheat and barley in temperate semi-arid climates and subtropicals, and also wheat in warm and semi-arid climates and subtropicals for 2025 compared to the present value. The results also showed that climate change would expand the water available for the blue wheat crop in the semi-arid climate and sub-climates, besides the blue barley crop in the semi-arid, semi-arid, and temperate semi-arid climates for 2025 compared to the present value. Climate change also might reduce the amount of water available for the blue wheat crop in the climate and sub-arid and semi-arid sub-climates, therefor the corn yield in the cold and semi-arid sub-climates and sub-climates for 2025 compared to the present value. The results also revealed that climate change would diminish cultivation of maize crop in semi-arid climate and temperate climates in addition irrigated and rainfed wheat crop in warm and semi-arid sub-climate and also rainfed wheat crop in semi-arid climate by 2025 relative to the present situation. Also the area under cultivation of blue barley and dry barley crops in warm and semi-arid climates, cold and semi-arid climates, and blue wheat crop in semi-arid climates and rainfed wheat crop in temperate and semi-arid climates would decrease by 2025.

The results also demonstrated that with the climate change, the amount of maize crop production in cold and semi-arid climates and sub-climates, and the production of blue and dry wheat crops in warm and semi-arid climates, cold semi-arid, temperate and dry semi-arid climates for 20 years would decrease relative to current value. Also, the production of irrigated and rainfed barley in warm and semi-arid climates, sub-climates and temperate semi-arid climates for 2025 would increase compared to the present situation. Thus the first hypothesis of the study: "Climate change and water scarcity reduces agricultural production" is not approved in Iran. The results also explained that with the climate change the prices of wheat, barley and maize crops in the semi-arid and temperate climates for the year 2025 would also rise, so the second hypothesis of the study "Climate change and scarcity of water resources will increase the prices of agricultural products in Iran” is confirmed. The results also show that with climate change, farmers 'incomes in cold and semi-arid climates, temperate and warm semi-arid climates would increase by 2025 relative to their present value, so the third research hypothesis that "climate change and water scarcity reduces farmers' income" In Iran, " is not confirmed. The results also indicated that wheat, barley and maize exports remained negative by the creation of net climate change for 2025 and that the country's climate change created an importer of these products.