The Global Warning Series chronicles the adventures of Lydia Barnes, a 14-year-old who travels with her missionary father, Frank, to exotic locations around the world. Accompanied by her crotchety tutor who tries to rein her in, often meeting up with another missionary family which gives her opportunity to conspire with her best friend, and depending heavily on the wisdom of a strong mother-figure in her life, Lydia gets herself into—and eventually out of—wild adventures that open up world issues to her, challenge her faith, and ultimately change the world.