'Greenhouse' Gas Found Rising Over Antarctica BY KOZO MIZOGUCHI    TOKYO (AP) -- A group of Japanese researchers has found that carbon dioxide levels over the Antarctica rose by over 2.6 percent from six years ago - the first such detection of an increase in a "greenhouse" gas above the southern continent, group members said Tuesday.    Many scientists fear carbon dioxide, produced by burning fossil fuels and other industrial processes, may be causing global warming by trapping heat in the Earth's atmosphere...