This study aimed to investigate the relationship among CO₂ emissions, exports of goods and services, and foreign direct investment (FDI) inflows in countries in the MENA region over the period 2002–2014. To that end, spatial panel simultaneous equations model based on the adjacency-based and distance-based weight matrices was used. The findings indicated that the results of spatial panel simultaneous equations with distance-based weight matrix were more fitting than those with adjacency-based weight matrix. The empirical findings approved a two-way linkage between CO₂ emissions and exports and a one-way linkage between CO₂ emissions and FDI inflows and also, between FDI inflows and exports. Furthermore, the existence of the spatial correlations among the CO₂ emissions, exports and FDI inflows across countries was confirmed. It was further indicated that fossil fuel energy consumption was the main determinant of CO₂ emissions, and accession to the WTO played a major role in enhancing exports and FDI inflows. The present study can provide new insights for policymakers and planners to not only consider the economic benefits of exporting goods and services and FDI inflows, but also attend their environmental impacts on local and neighboring countries.

The objective of this study is to analyze the energy use efficiency and carbon footprint of irrigated wheat systems in different Iranian provinces. The authors resort to the k-means clustering technique to fulfil the said objective. The empirical results reveal that the average total input energy (59.5 GJ ha⁻¹) is higher than the average energy output (45.82 GJ ha⁻¹) from wheat production, resulting in an average energy efficiency of 0.77, thus rendering the production of irrigated wheat in Iran energy-inefficient on average. Among the thirty wheat-producing Iranian provinces considered in this analysis, only six—East Azerbaijan, Golestan, Ardabil, Kohgiluyeh and Boyer-Ahmad, Alborz, and West Azerbaijan—register an energy use efficiency greater than unity. The average total of greenhouse gas (GHG) emissions from irrigated wheat is 2243.54 kg CO₂-eq ha⁻¹ (with electricity and diesel fuel contributing 52.4% and 29.4%, respectively). The authors categorize the clusters into five groups ranging from sustainable to unsustainable. Five of the six provinces referred to earlier fall into the ‘sustainable’ category, with Bushehr being the sixth. The wheat production units in the ‘sustainable’ category can serve as a benchmark for the clusters in the other categories, which can move up the ladder of sustainability. The authors also recommend measures that policymakers can undertake to ensure the sustainable development of wheat production in Iran, fulfilling the social imperative of food self-sufficiency while truncating the environmental footprint and ensuring economic feasibility.