Washington: There could be a brief time this summer when there is no ice on the North Pole, said a U.S. scientist, blaming global warming that has melted the Arctic ice sheet over decades. "We could have no ice at the North Pole at the end of this summer,' Mark Serreze, a scientist with the National Snow and Ice Data Center in Boulder, Colorado, told AFP. "And the reason here is that the North Pole area right now is covered with very thin ice and this ice we call first year ice, the ice that tends to melt out in the summer.' He put the chances of there being no ice at one point at 50 per cent, saying it could see "ships sail from Alaska to the North Pole, that's possible.' The ice on the north pole has melted before, "but certainly not in modern times,' said Mr. Serreze. "Clearly if you look over what we have seen in the past three years and where we were headed, we are in ... this long-term decline and we may have no ice at all in the Arctic Ocean in summer by 2030 or so.' Meanwhile, China's third Arctic expedition will set sail from Shanghai next month to study the polar region's distinctive maritime resources and air quality.