By the end of the 21st century, the search for the Northwest Passage - a quest that has consumed many lives and fostered many legends - will seem nearly unimaginable. The northern route across the Arctic Ocean from the Atlantic to the Pacific is most likely to be plain sailing in summer, a continent of ice having been swept away by the effects of global warming. That may sound like good news, but it's not. A study of arctic warming, commissioned by the Arctic Council, paints a grim picture. The northern polar region is heating up faster than are other areas of the planet. As the ice melts, enormous volumes of cold, fresh water will be released into the oceans with consequences that are hard to predict.

Like many studies of global warming, this one notes some possible benefits, like longer growing seasons. But these few pluses have to be weighed against the destruction of an entire ecosystem. The life patterns of native people and native species in the Arctic have shifted drastically over the past half-century. Warming on the scale projected by this study could well mean the extinction of some species of seals and polar bears, and a certain end to traditional ways of life.

These are sobering thoughts. Ice cores show that over history the polar climate has fluctuated, often severely. But this fluctuation is caused by human activity. Even if we were to sharply and immediately reduce carbon dioxide emissions, some arctic warming would continue.

The solution to this problem rests on our ability to imagine and purposefully shape the future. One obvious way is to create international agreements and recognize that immediate restraint on our part may make the difference. The Bush administration has denied the severity of global warming and the science behind it. On this vital matter, the president needs to look a painful reality squarely in the face.