Climate change and energy use efficiency in arid and semiarid agricultural areas: A case study of Hamadan-Bahar plain in Iran

Climate change characterized by decreasing rainfall and rising temperature has become a dominant phenomenon in many Middle Eastern countries, including Iran. It may also affect energy use efficiency and productivity in the agricultural sector. This study investigated the effects of climate change on energy input and output in the agricultural sector of Hamadan-Bahar Plain in western Iran. Different physiological, meteorological, hydrological, and economical dimensions were considered within various time horizons and climate scenarios. As a result of a 14.8% reduction in precipitation and a 14.1% increase in temperature in the most optimistic scenarios on the horizon of 2090, climate change has affected water resource availability and agricultural production in the plain. As a result of these changes, agricultural energy use efficiency and energy productivity in the region have declined by 36.79% and 25.74%, respectively, as compared to the base year (2018). Furthermore, the results of this study indicate conventional approaches to cope with this phenomenon are mostly associated with higher energy input and lower energy output. For example, if deficit irrigation methods are used, the rate of reduction in energy efficiency and productivity in 2090 in the most optimistic scenario would be 39.21% and 28.02%, respectively. In other words, within the framework of the existing strategies, solving the problem of water scarcity is only possible at the expense of reduced energy efficiency. Hence, the continuation of current conditions would lead to higher production costs and environmental pollution as well as food insecurity in the coming decades.