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.