An aerial view shows Japan's Shiretoko Peninsula covered in winter snow and surrounded by sea ice.

Each winter, ice forms in the sea between Japan and Russia and flows toward Shiretoko. But over the decade leading up to 2007, the amount of ice forming there shrank by 3.6 percent, the Japan Meteorological Agency reported.

In 2004 the Shiretoko town of Abashiri had just 54 days of drift ice—the second shortest period of ice there since 1946, when recordkeeping began.

• More Photos in the News
• Today's 15 Most Read Stories
• Free Email Newsletter: Focus on Photography