Introduction: Ensuring food security— both in terms of quantity and quality—remains a strategic priority for most nations, particularly developing countries facing multifaceted environmental and socio-economic challenges. Iran, characterized by its growing population, urbanization, limited water resources, and vulnerability to climate change, is no exception. These issues, coupled with sanctions and resource mismanagement, have intensified the urgency for policy interventions to sustain and enhance food production systems. This study aimed at investigating the intricate and nonlinear relationship between food security and several influential factors including Human Development Index (HDI), energy consumption from renewable and non-renewable sources, carbon dioxide emissions (as a proxy for climate change), and labor force participation in the agricultural sector. Understanding the asymmetrical impact of these factors over time is essential for formulating robust policies that ensure sustainable food access and resilience against future shocks.
Materials and Methods: This research used annual time-series data from 1990 to 2022 to analyze the dynamic relationships between food security and its potential determinants in Iran. The dependent variable was Food Production Index (FPI), which serves as a proxy for food security. The independent variables included: HDI (Human Development Index), reflecting education, health, and income dimensions; LENE (Log of Non-Renewable Energy Consumption), measured by energy used in the agricultural sector; RNE (Renewable Energy Consumption), expressed as a percentage of total energy consumption; LCO2 (Log of CO₂ Emissions), as a measure of environmental degradation and climate change; and LLAB (Log of Labor in Agriculture), representing workforce capacity in food production. All data were obtained from credible sources such as the World Bank, UNDP, FAO, and OECD. The variables were logarithmically transformed for normalization and to allow for elasticity interpretation. Nonlinear Autoregressive Distributed Lag (NARDL) model was employed as the econometric methodology. This approach enables the differentiation between the effects of positive and negative shocks (asymmetries) in the explanatory variables on food security, both in the short and long runs. Unit root tests (ADF and PP), BDS nonlinearity tests, bounds testing for cointegration, and diagnostic checks (CUSUM, CUSUMSQ) were applied to ensure the robustness and stability of the model.
Results and Discussion: The estimation results highlighted the asymmetric effects of various socio-economic and environmental factors on the food security in Iran. A positive shock in HDI would improve the food security by 3.09 percent, underscoring the importance of education and healthcare in enhancing agricultural productivity. Conversely, a negative HDI shock would cause a sharp 17.06 percent decline, revealing significant vulnerability to social setbacks. In addition, negative shocks in non-renewable energy consumption (LENE) would reduce the food security by 0.34 percent, emphasizing the role of energy access in agriculture, while positive shocks would be statistically insignificant due to potential environmental trade-offs. Similarly, the negative shocks in renewable energy consumption (RNE) would reduce the food security by 0.3 percent, pointing to the sector’s dependency on stable renewable inputs, whereas the positive shocks would remain insignificant, reflecting the underdeveloped role of renewables in agriculture. Interestingly, both the positive and negative shocks in CO₂ emissions would slightly improve the food security (by 0.21 and 0.39 percent, respectively), possibly due to short-term fertilization effects, despite long-term ecological concerns. In terms of labor, the positive shocks would increase the food security by 0.89 percent, and the negative shocks would reduce it by 0.78 percent, reaffirming the labor-intensive nature of Iranian agriculture. Granger causality tests further confirmed a bidirectional relationship between CO₂ emissions and the food security, unidirectional causality from HDI, RNE, and LENE to the food security, and reverse causality from the food security to the labor. These results underlined the complex and asymmetric dynamics shaping the food security, influenced by socio-economic development, energy use, and environmental pressures.
Conclusion and Suggestions: The study concluded that improving human development indicators, expanding the share of renewable energy in agriculture, and maintaining a stable agricultural workforce were vital for enhancing the food security in Iran. The positive effects of CO₂ emissions, while notable in the short term, should not distract policymakers from the long-term risks of climate change. To mitigate vulnerabilities and build resilience, several policy recommendations are made as follows:
·         Enhancing education, healthcare, and income equity to improve HDI;
·         Reducing dependence on fossil fuels and investing in renewable energy technologies for agricultural use;
·         Developing adaptive agricultural systems resilient to climate variability; and
·         Supporting rural employment programs and reversing urban migration by improving rural livelihoods.
Given Iran’s geopolitical challenges and environmental limitations, these strategies must be pursued through coordinated government planning and international cooperation.