The 18th annual Chicago Humanities Festival, which addresses global warming with the theme “The Climate of Concern,” starts Saturday, October 27, and runs through November 11, offering dozens of lectures, readings, and discussions by an international assortment of writers, artists, and scholars as well as film screenings and theatrical and musical performances at multiple venues around the city. Programs are $5 in advance ($2 surcharge may be applied to purchases at the door) unless otherwise noted. Tickets can be ordered by phone at 312-494-9509 or online at (Tickets for sold-out programs often become available due to attrition; arrive at the venue no later than 30 minutes before the program to buy available seats, to be sold on a first-come, first-served basis.)

Events kick into high gear over the first two weekends in November; visit the festival Web site for a complete schedule. See our Music, Movies, Theater & Performance, Dance, and Galleries & Museums listings for more events.

Among the highlights through October 31: The 2007 Children’s Humanities Festival (see listing in Theater) opens with Newbery Honor-winning author Gary Paulsen (Hatchet) receiving the Chicago Tribune Young Adult Book Prize (Sat 10/27, 10:30 AM, Harold Washington Library Center, auditorium, 400 S. State).

Among the parent festival’s science-oriented “Wonder Cabinet” programs is “Are Whales Singing Their Last Song?” presented by Ocean Alliance president Roger Payne (Sat 10/27, 1 PM, also at Harold Washington Library, auditorium).

Sculptor Maya Lin, who designed the Vietnam War Memorial in Washington, D.C., and installation artist Roni Horn discuss their current projects in “Global Vantages”; CHF artistic director Lawrence Weschler moderates (Sat 10/27, 3 PM, also in the Harold Washington Library auditorium).

Freshman Metropolitan Water Reclamation District commissioner Debra Shore discusses “quantity, quality, and conservation” of water in a Region of Concern program (Sun 10/28, noon, Notebaert Nature Museum, 2430 N. Cannon); be sure to ask about BP.

Under the heading Acts of Concern, Next Theatre Company performs specially commissioned topical one-acts by playwrights Sarah Ruhl and Lisa Dillman; discussions follow (Sun 10/28, 2 and 7 PM, Noyes Cultural Arts Center, 927 Noyes, Evanston).

And the Chicago Sinfonietta’s concert uses music to address the festival’s concern with global climate change. The program includes James DeMars’s Two World Concerto, with Native American soloist R. Carlos Nakai on cedar flute; Michael Abels’s Global Warming; and Beethoven’s Fifth Symphony, reimagined as a “musical metaphor” for climate change with visuals created by the museum (Mon 10/29, 7:30 PM, Orchestra Hall, Symphony Center, 220 S. Michigan, $15).