Associated Press: Scientists say a global warming “tipping point” in the Arctic seems to be happening before their eyes. The United States National Snow and Ice Data Centre says sea ice in the Arctic now covers about 5.2 million sq km. The lowest point since satellite measurements began in 1979 was 4.2 million sq km set last September. With about three weeks left in the Arctic summer, this year could wind up breaking that previous record, scientists said. Arctic ice always melts in summer …