Scientists say air from the oldest ice core confirms human activity has increased the CO2 in the atmosphere to levels not seen before for hundreds of thousands of years.
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.
"It is from air bubbles that we know for sure that carbon dioxide has increased by about 35 percent in the last 200 years," said Dr Eric Wolff of the British Antarctic Survey and the leader of the science team for the 10-nation European Project for Ice Coring in Antarctica.
"Before the last 200 years, which man has been influencing, it was pretty steady," he added.
The natural level of CO2 over most of the past 800,000 years has been 180-300 parts per million by volume (ppmv) of air. But today it is at 380 ppmv.
Use Disqus to post new comments, the old comments are listed below.
Re: Ice core evidence of human impact on CO2 levels by Anonymous on Wednesday, September 06 2006 @ 02:40:15 CEST
Ok it has peaked in the past at 300ppmv, and today it is 26% higher than that. I call that high, and worth tackling, but the scientific community better learn to moderate the sensationalism. It's high, but it's not astronomical multiples of all times in the past.
I like the truth. We need to deal with it. Declaring the end of the world is getting real old, real fast. And when people stop listening, you've lost. So get a clue.