This study investigates the environmental Kuznets curve (EKC) relationship between economic development and plastic pollution using the stochastic impacts of regression on population, affluence, and technology (STIRPAT) model. The research analyzes the effects of sociodemographic factors on plastic pollution using a panel dataset of 128 countries from 1993 to 2017. Scenario analyses were conducted to project plastic pollution by 2050 under different conditions. The results confirmed the EKC relationship, showing that plastic pollution increases with economic development up to a certain point, after which it decreases. Population structure and urbanization significantly affect plastic pollution. Under the business-as-usual scenario, global plastic pollution is projected to reach 66.1 million metric tons (MT) by 2050. Low-income countries and sub-Saharan Africa are expected to become major contributors to plastic pollution, leading to a global trend of increasing plastic pollution. The study highlights the need for targeted policies to reduce plastic pollution, particularly in low- and middle-income countries. The findings suggest that high-income countries may reduce plastic pollution significantly, while low-income countries and sub-Saharan Africa will continue to contribute to the problem. The study also emphasizes the importance of addressing urbanization and population structure in plastic pollution management. The results provide insights for policymakers to develop effective strategies to reduce future global plastic pollution.This study investigates the environmental Kuznets curve (EKC) relationship between economic development and plastic pollution using the stochastic impacts of regression on population, affluence, and technology (STIRPAT) model. The research analyzes the effects of sociodemographic factors on plastic pollution using a panel dataset of 128 countries from 1993 to 2017. Scenario analyses were conducted to project plastic pollution by 2050 under different conditions. The results confirmed the EKC relationship, showing that plastic pollution increases with economic development up to a certain point, after which it decreases. Population structure and urbanization significantly affect plastic pollution. Under the business-as-usual scenario, global plastic pollution is projected to reach 66.1 million metric tons (MT) by 2050. Low-income countries and sub-Saharan Africa are expected to become major contributors to plastic pollution, leading to a global trend of increasing plastic pollution. The study highlights the need for targeted policies to reduce plastic pollution, particularly in low- and middle-income countries. The findings suggest that high-income countries may reduce plastic pollution significantly, while low-income countries and sub-Saharan Africa will continue to contribute to the problem. The study also emphasizes the importance of addressing urbanization and population structure in plastic pollution management. The results provide insights for policymakers to develop effective strategies to reduce future global plastic pollution.