Death Thieves — Julie Wright

"You're dead, Summer Dawn Rae." When Summer Rae is stolen from the moment of her own death and taken to a future where mankind is dying, it is with the hope that she, and other teenagers like her, can save it. But after only a short time in the future, Summer discovers a darker side to the altruistic reasons behind her abduction. She is determined to fulfill her purpose in a world gone literally mad, but can an ordinary girl save a whole world when she only cares about saving one person?