The Age of Miracles by Karen Thompson Walker

It is unusual for a novel with an apocalyptic premise to feel uplifting, but that is the case with The Age of Miracles. In her fiction debut, Karen Thompson Walker has imagined what would happen if planet Earth slowed in its rotation. And then kept slowing down. Days would get longer and longer and so would nights. Gravity would be affected.

"Much study has been devoted to the physical effects of gravity sickness, but more lives than history will ever record were transformed by the subtler psychological shifts that also accompanied the slowing. For reasons we've never fully understood, the slowing -- or its effects -- altered the brain chemistry of certain people, disturbing most notably the fragile balance between impulse and control."

Told from the retrospective viewpoint of Julia, who was 11 and living in California when the slowing began, the story remains rooted in realism despite the momentous environmental and societal changes happening around her. Julia observes the changes in her parents' relationship as well as her own coming of age.

"Maybe it had begun to happen before the slowing, but it was only afterward that I realized it: My friendships were disintegrating. Things were coming apart. It was a rough crossing, the one from childhood to the next life. And as with any other harsh journey, not everything survived."

Readalike: Life As We Knew It (Susan Beth Pfeffer) is similar in some ways -- imagining how a planet-wide catastrophic event would alter daily life, from the viewpoint of a young person -- but Pfeffer's book is definitely YA and The Age of Miracles is an adult book that teens would also enjoy. The difference is subtle. Julia is looking back on that extraordinary time, not recording it as it happens. Also, the changes that are affecting the adults around Julia are an import part of the story and that scope takes it into adult novel territory.

Note added July 14, 2012: Year of Wonders (Geraldine Brooks) is another readalike, even though it is historical, because it also character-driven, documents the disintegration of society in the face of horrific circumstances, plus an illicit love affair (which I didn't mention in my review) and yet the mood remains surprisingly upbeat. The (similar) titles of both books fit their shared mood of awe.