The precarious nature of things

Despite its cheery yellow borders and air of family fun and wide-eyed wonder, National Geographic magazine is a sobering read nowadays, unflinching in its coverage of a world in crisis, detailed in full-color spreads of endangered species and despoiled landscapes. To be sure, it also continues to run stories about pirate treasure and exotic lands, but I have learned, if I am in a sensitive mood, to approach it with caution.

As much is true of "National Geographic's Strange Days on Planet Earth," beginning tonight on PBS -- a valuable series, but tough sledding, despite its "exciting" visual style and odd rays of hope. Its subject is ecological balance, fine-tuned across millenniums and upset by accelerating change in a shrinking world, pumped full of synthetic compounds whose effects are as poorly understood as their immediate usefulness is obvious. There's no more important or critical subject, this being the subject that contains all other subjects. Time, in this matter, does not grow any less of the essence.

The four episodes deal in turn with alien species (plants and animals living where they don't belong), global warming, the consequences of the elimination of large predators, and the poisoning of the water supply. Their common theme is that all these damaging events are being helped along, if not entirely driven by, homo supposedly sapiens. "Humans expand, nature contracts," says one of the series' many scientist-heroes. "The obvious endpoint of that is a world without nature."

"For every voice of doom, someone else will tell you that the planet is doing pretty well, thank you," says narrator-host Edward Norton, though nothing that follows particularly supports the latter assertion. It may be "responsible journalism" to acknowledge a range of opinion, but here it has a hollow ring of preemptory appeasement. The narration is careful to say that the havoc wreaked upon the natural world has been done with "the best intentions," and that it's "without realizing it" that "we've turned up the global thermometer."

"In this confusing era," Norton says, "only one thing is certain -- these are strange days on Planet Earth."