Ice core evidence of human impact on CO2 in air

NORWICH (Reuters) - Air from the oldest ice core confirms human activity has increased the greenhouse gas carbon dioxide (CO2) in the atmosphere to levels not seen for hundreds of thousands of years, scientists said on Monday.

Bubbles of air in the 800,000-year-old ice, drilled in the Antarctic, show levels of CO2 changing with the climate. But the present levels are out of the previous range