An Investigation into the Effects of Climate Change on Water-Energy-Food Nexus: A New Mathematical Programming Approach

Agriculture is one of the most important production sectors in the world. Water and energy are two essential inputs for food production. The agricultural sector is influenced by climate change the most. In this regard, this research aimed to present a new mathematical programming approach to studying the effects of climate change on the water-energy-food (WEF) nexus. A sustainable WEF nexus was developed for the basin of Kashfrud in Razavi Khorasan province, Iran for 2019-2020. The present approach was modeled in several climatic-hydrological-economic-environmental sectors. Analyzing the outcomes of a hydrological model in the context of climate change scenarios reveals that, given the current state of irrigated land, there will be a 45% increase in net water demand in the future, accompanied by a 13% decrease in crop yields. Consequently, by embracing a holistic approach that considers the nexus of water, food, and energy, the net water demand drops to 71%, the energy allocation to agriculture decreases to 41%, greenhouse gas emissions are reduced by 32%, and farmers' overall profits decrease by 73% in the face of climate change. This approach would also be effective in avoiding the undesirable effects of single-sectoral development policies in addition to improving resource use efficiencies. Since most non-renewable resources are consumed by the agricultural sector, the development of the nexus approach is also important from an environmental perspective in addition to the sustainability of resource use. A new multi-objective programming model based on WEF nexus management was developed.The application of the proposed model was used to as a case study in Iran.This model could increase the gross profit of farmers while reducing scarce inputs.