Chester. Global warming poses an existential threat to two-thirds of North American bird species, but there is still time to protect them. The "Birds and Climate Change," presented by Melissa Peterson and Jody Susler, discusses factors affecting bird populations and what we can do as citizens to help birds and fight climate change if we act now. The program starts at 1 p.m. on Saturday, Feb. 29, at the Chester Public Library, 1784 Kings Highway, Chester.