50 years on: The Keeling Curve legacy

By Helen Briggs
Science reporter, BBC News

It is a scientific icon, which belongs, some claim, alongside E=mc2 and the double helix.

Its name - the Keeling Curve - may be scarcely known outside scientific circles, but the jagged upward slope showing rising carbon dioxide (CO2) levels in the atmosphere has become one of the most famous graphs in science, and a potent symbol of our times.

It was 50 years ago that a young American scientist, Charles David Keeling, began tracking CO2 in the Earth's atmosphere at two of the world's last wildernesses - the South Pole and the summit of the Mauna Loa volcano in Hawaii.

His very precise measurements produced a remarkable data set, which first sounded alarm bells over the build-up of the gas in the atmosphere, and eventually led to the tracking of greenhouse gases worldwide.

The curve set the scene for the debate over climate change, and policies, sometimes controversial, that address the human contribution to the greenhouse effect.

More...