April is jam-packed with environmentally-focused events on the North Shore, highlighted by the celebration of Earth Day.Although the ecological high-holiday is April 22 on the calendar, many organizations sponsor Earth-friendly events throughout the month.Today, Salem State College will hold its Earth Day celebration with speakers, an environmental career fair, student displays, movies and other activities, mostly centered on the Salem campus at Ellison Hall.Marblehead High School will host its Livegreen event on Saturday, April 14, marked by a rally for action on climate change. Live music and other entertainment is scheduled for Devereux Beach.On Saturday, April 21, North Shore Community College holds is Lynn Woods Earth Fest from 9 a.m. to 2 p.m. Participants should enter the woods at Pennybrook Road in Lynn. Among the slated activities are a woods cleanup, Curious Creatures demonstration, tree planting, and a breakfast for the early birds.Volunteers for the woods cleanup will be treated to breakfast and lunch, according to Karen L. Searles from the Friends of Lynn Woods.The Swampscott public library on Burrill Street is host to a Healthy Home Party on Monday, April 23, with presentations by Alliance for a Healthy Tomorrow related to safer products for children, homes, gardens and personal care.On Saturday, April 28, another Earth Day celebration and open house will be held at the Carlton School, 10 Skerry St. in Salem, from 10 a.m. to 1 p.m. The school has won several environmental and building awards for its “green” design and operation.Swampscott-based HealthLink, an environmental and public health advocacy group, will sponsor a table at the Carlton School event, along with a Wind Wigglers crafts demonstration for children.The April 28 event will also include a presentation from noon to 2 p.m. entitled “How a Bill Becomes Law: Interactive Training Session.” It is sponsored by Alliance for a Healthy Tomorrow. Lunch will be served. To make a reservation, call (978) 598-1115.The ecological events continue into May and June on the North Shore, with school open houses, a Mother’s Day Lobby at the State House in Boston, and an Earth Day Fiesta on Saturday, June 9 at the Coast Guard Life-saving Station in Nahant. The latter sponsored by Safer Waters in Massachusetts.