The documentary “Bag It” will be screened Thursday in the Plimoth Cinema at Plimoth Plantation. The film follows an ordinary consumer as he tries to understand the world’s increasing dependence on single-use plastic bags. The bags litter city streets, use up petroleum in their manufacture, and clog the ocean waters near remote Pacific islands. The screening will be followed by a panel discussion moderated by Bruce Gellerman, former host of Public Radio International’s “Living on Earth,” a news show about science and the environment. “It gives you some bad news,” said Nancy Carroll, a member of the Plymouth Network of Open Space Friends, one of the event’s sponsoring groups. “But it also shows you examples of the things you can do about it” -- such as bringing a reusable cloth bag to the grocery store or supporting deposit fees on plastic containers. The screening is at 7 p.m. Tickets are $7.50 and can be reserved by calling 508-746-1622, ext. 8346.