Analysis of asymmetries in air pollution with water resources, and energy consumption in Iran.

Iran should pay special attention to its excessive consumption of energy and air pollution due to the limited availability of water resources. This study explores the effects of the consumption of energy and water resources on air pollution in Iran from 1971 to 2014. It utilizes the non-linear autoregressive distributed lag approach to establish a robust relationship between the variables which show that both long- and short-run coefficients are asymmetrical. The positive and negative aspects of the long-run coefficients of energy consumption and water resources were found to be 0.19, - 1.63, 0.18, and 2.36, respectively, while only the negative ones were significant for energy consumption. Based on the cumulative effects, it can be established that there are important and significant differences in the responses of air pollution to positive and negative changes in water productivity and energy consumption. In particular, CO2 gas emissions are affected by negative changes in H2O productivity both in terms of the total and the GDP per unit of energy use in Iran. In regard to short-run results, considerable asymmetric effects occur on all the variables for CO2 emissions. Based on the results obtained, some recommendations are presented, which policymakers can adopt in efforts to address the issues of pollution and consumption.