Chinese and South Korean shipping through the Arctic Ocean to Europe has increased this year, although unpredictable ice, high costs and lapses in demand have exposed the challenges of navigating the route, an environmental research group has found. During the late summer and early autumn shipping season, delays forced one Chinese operator to extend some journeys from 20 days to 30 days, the Oslo-based Bellona Foundation said in a report. Traffic along the Arctic seaway has been busier than last...