Science Fiction novel by
John Varley.
* * * 1/2
The future sucks.
Pollution is so bad in the year 3000 that human lungs have adapted to toxic pollutants; they can't survive without them. But of course those same pollutants are destroying their bodies.
The solution?
Time Travel!
The denizens of the future travel into the past, to places that are about to experience a terrible catastrophe, such as an airliner just before it crashes. The doomed passengers are herded off the plane into the future, and replaced with dummies. The dummies get to experience the crash, while the passengers are
frozen for some reason known only to the
Big Computer.
This scheme goes well until someone leaves a piece of future tech on an airplane, and an
NTSB investigator finds it....
This novel was also made into a half-decent movie, which was fairly faithful to the storyline. Except the movie comes off as parody, where the novel really isn't.