Scientists say the ice cap on the Arctic Ocean is shrinking. Each summer it melts back some. But long-term observations show that the maximum extent of the summer ice - its total area - is getting smaller over time, and this summer reached a new record. Here is a graphic representation of what's been happening in recent years.

The experts blame human-induced global warming for at least some portion of this phenomenon. And there is concern about its impact on habitat for polar bears, seals and many smaller creatures that depend on the ice and cold waters. The phenomenon appears to feed on itself. Ice reflects solar energy back into space. The more dark, open water becomes exposed to the summer sun, the more the Arctic Ocean heats up, slowing the formation of more ice in winter, speeding its spring melt, and opening still more ocean to the sun.

This could all have a profound impact on climate and weather, not to mention commerce if shippers one day find an ice-free summertime shortcut, through the arctic, between the North Atlantic and the North Pacific. Explorers looked for one for centuries. They may finally get it.

The Sun carries a New York Times wire story on the latest discoveries on page A3 today.