TOKYO (AP) – Carbon dioxide levels over Antarctica have risen 2.6 percent from six years ago – the first greenhouse gas increase above the southern continent ever detected, a group of Japanese researchers said Tuesday.

Carbon dioxide from populated continents was apparently making its way down to the atmosphere above Antarctica, said Takashi Yamanouchi, a professor at the National Institute of Polar Research.

“Everywhere on Earth is now being polluted by carbon dioxide,” Yamanouchi said. “That may be contributing to the expansion of global warming, although we must check whether temperatures in the atmosphere are in fact rising.”

Many climate scientists believe carbon dioxide has caused global warming by trapping heat in the Earth’s atmosphere.

Global climate models show air pollution from industry and traffic will drive up average world temperatures by a degree or two this century. Many scientists are concerned about what that will mean for global weather patterns.

Antarctica, with well-preserved ice averaging 6,000 feet thick, is one of the few places where scientists can examine climate change over time, because chemicals from the air have been frozen in layers of ice year after year for centuries.

Researchers have confirmed before that the density of carbon dioxide in Antarctica’s ground had increased, but they hadn’t proved the same for the atmosphere, Yamanouchi said.

A balloon with a monitoring device sent nine to 19 miles above Japan’s research base in Antarctica in January showed that the atmosphere had an average 367.9 parts per million of carbon dioxide, up 9.4 ppm – or 2.6 percent – from levels in a similar survey conducted in 1998, Yamanouchi said.

About 60 scientists stationed at Japan’s Showa Base are studying ozone holes, sea life and world climate and weather patterns. More than a dozen other countries – including the United States and Russia – also have scientific teams working there.