Dr. Kimberly Oremus and co-author, Dr. Anna Papp, recently published a study in Science using citizen-science data from over 45,000 cleanups. They found that plastic bag policies reduce the share of plastic bags found in cleanups by 25–47% in jurisdictions with policies compared to those without. The analysis also showed that state-level policies are more effective than county or town-level ones, and that full bans and fees outperform partial bans, which still allow thicker plastic bags at checkout. These policies are most effective in areas with high baseline levels of plastic bag litter. This is encouraging, as the number of U.S. bag policies has grown to over 600, now covering about 1 in 3 Americans. However, while the rate of increase in plastic bag litter is slower in areas with policies, the overall trend is still upward. The authors conclude that narrow bag policies alone are insufficient and call for a broader approach—such as regulating plastic production. Countries are set to reconvene negotiations on a potential global plastics treaty this August.