Perils at the pole.

So was it Dr. Frederick A. Cook or Commander Robert E. Peary and Matthew Henson who first visited the North Pole in 19097 Actually, maybe neither party reached the Pole, writes Andrew C. Revkin in his fascinating and lavishly illustrated book The North Pole Was Here: Puzzles and Perils at the Top of the World (Kingfisher/New York Times, $15.95). Given the conditions these men encountered and the lack of sophisticated instrumentation, it may well be that no one actually visited the Pole until Joseph Fletcher, who arrived via plane in 1952. Revkin's book, aimed at younger readers but suitable for adults, too, contains a brisk account of polar exploration. Its central purpose, however, is to alert the world to the vast changes wrought by global warming. As the weather warms, vast amounts of melting ice raise sea level, imperil polar bears and threaten the Gulf Stream. Each year, Revkin writes, "brings more signs that recent environmental shifts around the Arctic are extraordinary. Dragonflies are showing up for the first time in memory ... Robins are pecking at the tundra."

Revkin shivers his way through a visit to the Pole, supplementing his story with original research and excerpts from his New York Times reporting. His book makes clear that the Arctic was a mystery for most of recorded history. Today, as its secrets are being revealed, the whole region faces massive and uncertain change.