Introduction: Excessive exploitation of natural resources, rapid urbanization, and reliance on fossil fuels are major factors that disrupt ecological balance and pose serious threats to environmental sustainability. One of the modern approaches to measuring environmental sustainability is the use of the Load Capacity Factor (LCF). This indicator, defined as the ratio of bio-capacity to ecological footprint, reflects whether a country operates within its bio-capacity or exploits natural resources beyond their regenerative capacity. In recent years, researchers have increasingly preferred using the Load Capacity Factor (LCF) over indicators such as pollution emissions and ecological footprint, as LCF offers a more comprehensive perspective on the relationship between economic development, energy consumption, and environmental sustainability. In this study, the effects of economic growth, renewable energy, exports, and imports on LCF were examined within the framework of the Environmental Kuznets Hypothesis (EKC) for the period 1990–2021. The findings provide valuable insights into the current state of environmental sustainability and can support future research and fact-based and effective environmental planning.
In this study, data on the load capacity factor (i.e., the ratio of biocapacity to ecological footprint), GDP per capita, renewable energy consumption, urbanization, exports, and imports were obtained from reliable sources for the period 1990–2021. After testing the stationarity of the variables and performing the necessary econometric analyses, the Autoregressive Distributed Lag (ARDL) model was employed to estimate the coefficients.
Results: Iran’s environmental sustainability has been on a declining trend over the past thirty years, with the sustainability level reduced to one-third by the end of the period. This highlights environmental unsustainability as a serious threat in the country. The study’s findings show that the use of clean energy has a positive effect on the stability of the load capacity factor, as expected. Specifically, a 1% increase in clean energy use, while holding other factors constant, is associated with an approximately 0.14% increase in the environmental sustainability indicator in the long run. Also, the results indicate that a 1% increase in imports is expected to raise environmental sustainability by approximately 0.43% in the long run. In contrast, an increase in exports of goods and services leads to greater environmental instability. Specifically, a 1% rise in exports is associated with about a 0.25% decline in the environmental sustainability indicator.
Discussion: Policies aimed at replacing fossil fuels (oil, gas, and coal) with renewable energy sources such as solar, wind, geothermal, and hydropower can help reduce environmental risks. By mitigating risks such as greenhouse gas emissions, air pollution, and climate change, it becomes possible to achieve sustainable economic growth and development. The findings confirm that Iran’s export portfolio is largely composed of low-tech, energy-intensive, and polluting products that consume significant amounts of energy and natural resources, contributing to environmental degradation. The findings confirm that Iran’s export portfolio is largely composed of low-tech, energy-intensive, and polluting products that consume significant amounts of energy and natural resources, contributing to environmental degradation. Therefore, a comprehensive review of export policies, including the imposition of duties and environmental taxes on polluting export goods, is essential for achieving sustainable development. More broadly, the environmental implications of research on the effects of renewable energy and commodity trade on environmental sustainability should be carefully considered in macroeconomic policymaking.