Comprehensive assessment of air pollutant emissions, climate scenario projections, and mitigation strategies in Iran

Given the escalating environmental degradation and public health concerns resulting from severe air pollution in Iran, this study presents a comprehensive assessment of historical trends and future projections of air pollutant emissions. Focusing on key greenhouse gases (CO 2 and CH 4 ) and air pollutants (NO 2 and SO 2 ), the research employs Shared Socioeconomic Pathways (SSPs), Representative Concentration Pathways (RCPs), and the innovative Pattern Mining Engine (PME) model. Covering the period from 1960 to 2100, the study identifies pivotal trends and key change points in emission trajectories. The analysis reveals significant surges in CO 2 and NO 2 emissions, particularly during the late 1980s and mid-1990s, driven by socio-economic transitions and policy shifts. PME projections highlight a sharp increase in CO 2 emissions from 96.6 to 359.08 Mt, and a substantial rise in NO 2 emissions under the RCP 1.9 scenario from 10.44 to 68.48 Mt. Similarly, SO 2 emissions experienced notable growth, with critical inflection points in the late 1980s and mid-1990s, while CH 4 emissions exhibited variable patterns, reflecting divergent source behaviors and mitigation measures. Future projections offer a nuanced perspective on potential emission pathways, indicating significant reductions in CH 4 and SO 2 under SSP1 and SSP5 scenarios, contrasted with continued increases under SSP3 and SSP4 due to slower technological progress. Despite the implementation of ambitious climate policies, the anticipated CO 2 reductions of 23–29% by 2050 remain insufficient to meet climate targets, underscoring persistent challenges in aligning policy aspirations with tangible outcomes. Sectoral analyses further identify the industrial sector as a major contributor to NO 2 and SO 2 emissions, although SSP1 and SSP5 scenarios foresee marked declines by 2100, driven by cleaner technologies and stricter regulatory measures. This study distinguishes itself through its comprehensive analysis of emission dynamics across multiple scenarios and its critical insights into the effectiveness of various mitigation strategies. The findings emphasize the urgent need for more aggressive, integrated approaches to emission control and climate policy to effectively address rising pollutant levels and curb environmental degradation. Highlights : • Climate policies aiming for 50% CO 2 reduction by 2050 achieved only 23–29%. • The PME model showed CO 2 rising from 96.6 to 359.08 Mt and NO 2 from 10.44 to 68.48 Mt. • Future projections show major CH 4 and SO 2 declines under SSP1 and SSP5 pathways. • AR6 and SSP4 scenarios closely align with PME predictions for CO 2 and NO 2 . • The industrial sector remains the main source of NO 2 and SO 2 , despite expected declines.