[midworldman]

Some additional plot points: As he travels from planet to planet, he is placed in a kind of hibernation while machines work his body to peak fitness. When he arrives at his destination, he revives in top physical shape (wish such a mechanism really existed). New York's Central Park is completed denuded of trees (which have been cut for firewood). Jet fuel is precious and only used by the military in cases of extreme importance. When the military picks up the protagonist by fighter jet, he remarks how important his mission must be for them to burn jet fuel to come and get him. He spends much interior dialogue in self-loathing for being a self-serving, shallow, hedonistic playboy in a world of global privation. He seems to redeem himself somewhat by book's end. Hope this helps identify this book.