Several studies have estimated global inputs of plastic into the environment, relying on national statistics and modeling approaches. However, these estimates exhibit uncertainty driven by limited primary municipal solid waste management data. The study compared mismanaged plastic estimates from three global studies (Jambeck et al. (2015), Lebreton and Andrady (2019), and Borrelle et al. (2020)), finding significant differences. The limitations of global plastic pollution estimates are well-known in the scientific community, and some variation is expected. However, these discrepancies limit policy design and mitigation. Thus, municipal, national, and international monitoring of plastic management and pollution must be improved.