An Econometric Study of the Impact of Climate Change on Agricultural Production in Syria 1990–2020

Alaa Hamo ¹^* and Naji Al-Faraj²

¹Department of Agricultural Economics, Faculty of Agricultural Engineering, University of Damascus, Damascus, Syria.

²Department of Agricultural Economics, Faculty of Agricultural Engineering in Al-Hasakah, Al-Furat University, Al-Hasakah, Syria.

(*Corresponding author: Alaa Hamo, Email: alaasuliman@outlook.com, Phone: +963951850626)

Received: 27/ 06/ 2025 Accepted: 3/ 08/ 2025

Abstract

The agricultural sector in Syria is a vital part of the economy, yet it faces growing challenges due to climate change. This study aimed to analyze the impact of climate change on agricultural production in Syria from 1990 to 2020 using a Cobb-Douglas production function. The study relied on annual data from the FAO and World Bank databases. The results showed a steady rise in temperatures, peaking in 2010 with an average increase of 1.5°C. In contrast, precipitation rates exhibited sharp fluctuations, ranging from the highest recorded level in 1988 (450 mm) to the lowest in 2008 (150 mm). The findings also revealed significant seasonal variations in the impact of climatic factors. Winter and autumn rainfall contributed to a 0.15% increase in production per 1% rise in precipitation, while increased rainfall in spring and summer led to a decline in output (−0.054% and −0.0208%, respectively). Regarding temperature effects, the production function indicated that higher temperatures in spring and summer had a positive correlation with agricultural output (T2, T3), while winter temperatures also positively influenced production (T1). However, rising spring temperatures were associated with reduced agricultural productivity (elasticity of −0.069%). Additionally, the results demonstrated that both cultivated area and labor had a significant positive impact on agricultural production. In contrast, fertilizer and pesticide use showed an inverse relationship with output, suggesting either excessive or inefficient application of these inputs. Furthermore, the De Martonne aridity index highlighted worsening drought conditions, with the dry season extending from May to October and peaking in July and August. The study recommends integrating climate change into agricultural planning to ensure sector sustainability, promoting rainfed agriculture to optimize natural water resources, and developing early drought warning systems to mitigate the adverse effects of climate variability. Finally, farmers should receive financial and technical support to effectively implement these adaptive measures

Keywords: Climate change, agricultural production, Cobb-Douglas function, Syria, food security.

Full paper in Arabic: pdf

The impact of climate change on declining rainfall effectiveness and increasing severity and frequency of drought in Qamishli during the period 1958-2018

Michel Skaff¹, Rana Saker ^1*, Laila Abboud ¹and Eileen Mahfoud¹

¹Faculty of Agricultural Engineering, Latakia University, Latakia , Syria

(*Corresponding author: Rana Saker, E-mail:rana.saker@tishreen.edu.sy ,0993294699).

Received: 19/ 05/ 2025 Accepted: 21/ 07/ 2025

Abstract:

Monthly meteorological data for temperature and precipitation for the period 1958-2018 were used to study changes in temperature and precipitation and their impact on the precipitation effectiveness and drought characteristics in Qamishli. The Thornthwaite index was used to calculate precipitation effectiveness. The Standardized Precipitation Indicex (SPI) and Reconnaissance Drought Index (RDI) were used to estimate drought severity and frequency during the study period. Box plots and descriptive statistical analysis were used to study temperature and precipitation characteristics.Trends were used to estimate the direction and value of change in elements and indicators.The significance of change was verified using the Mann-Kendall test.The point change analysis was also used to determine the periods of change.To compare and detect changes between the periods 1958-1988 and 1988-2018, the T-test with probability and the difference in the percentage of drought recurrence were used. The results showed a sharp and significant trend towards declining rainfall efficiency due to rising temperatures and decreasing precipitation. The results also indicated an increase in the severity and frequency of droughts in the last decades.

Keywords: Climate change, Precipitation effectiveness, drought. Syria.

Full paper in Arabic: pdf

Climate Changes and its Impact on the Productivity of Some ‎Economic Crops In the Republic of Yemen

Abdulwahid A. Saif^*(1) Hazem H. Al-Ashwal⁽¹⁾ and Mohammed A. Al-Khorasani⁽²⁾

(1). Northern Highlands Agricultural Research Station, Sanaa, Yemen.

(2). Natural Resources Center, Dahmar, Yemen.

(*Corresponding author: Dr. Abdulwahid A. Saif. E-Mail: amozaid@yahoo.com).

Received: 08/03/2020 Accepted: 23/04/2020

Abstract

The impact of climate changes on two strategic crops; wheat and sorghum which are grown in the Northern Highlands (Sana’a), Central (Dhamar) of Yemen were studied using the AquaCrop model. The effectiveness of this model also was included in this study to simulate yield of these two strategic crops due to the expected climatic changes over the short term (2020-2030) and medium term (2040-2050) in comparison to the base years (1985-2005). The study was conducted under different irrigation systems in two different environments (Northern Highlands and Central Highlands), for this reason an average data for three climate models and average of the two scenarios (RCP 4.5 and RCP-8.5) to each model were used. Daily climate data (for 10 years past) associated with (T_max), (T_min), Relative Humidity (RH%), wind speed m/sec, radiation MJ/m².day, rainfall mm/day and crop yield and crop data were used for the calibration. Timing and amount of irrigation, soil water content and field management (level of fertilization and weed control) were the only calibrated parameters in order to obtain a relative correspondence between the actual and estimated values of yield by the program. The above data were collected from the weather stations located near the research farms which belong to Al-Erra Station –Sana’a and the Central Highlands Research Station-Dhamar, which were the selected sites of the study. They were different in terms of elevation above sea level, climatic and ecological nature. Some statistical indicators were used to assess accuracy and correctness at calibration of AquaCrop. Results of this study showed that the two crops will had a significant decrease in average yields, water productivity and water consumption at fixed concentration of CO₂. Growth period will also decrease as a result of high temperature in the three models over medium term 2040-2050 compared with the base years 1985-2005, this decrease is more significant in the scenario (RCP-8.5) compared to the scenario (RCP 4.5). Wheat yield and water productivity in Dhamar and Sana’a will be improved with the increased concentration of CO₂ over the medium term (2040-2050) under both irrigation and supplementary irrigation. For sorghum, it was noticed that yield and water productivity were decreased with the increased concentration of CO₂ in both scenarios and it was lower in Sana’a than in Dhamar due to the fluctuation of rain precipitation and drought occurrence, as sorghum, its cultivation depends on rain.

Key words: Climate change, Economic crops, Productivity.

Full paper in Arabic: PDF