Ralph Keeling at the Oxford Climate Society

 You are all familiar with the Keeling Curve of CO₂ measurements in the atmosphere. Well when Ralph Keeling comes to town you want to meet him. Ralph is the son of Charles Keeling, who started the measurements in 1958 and who the graph is named after. Ralph continues his father's work. He is a professor at the Scripps Institution of Oceanography, and leads the Atmospheric Oxygen Research Group and the Scripps CO₂ Program, the measurement program behind the Keeling Curve. Ralph has developed precise instruments and techniques for the measurement of atmospheric oxygen and anthropogenic CO₂ in the ocean, and for the analysis of land and ocean carbon sinks.

The theme of his talk was communicating climate change through CO₂ observations. He talked of the challenges of communicating numbers-based science to the public, whereas having a human story to tell helps a lot. And so he uses his Father's story to communicate on climate change, of how his Father developed a method of CO₂ measurement using then newly-available liquid nitrogen, and placed this equipment at the thennew Mauna Loa observatory in Hawaii. He told of his Father's concern, as the behaviour of CO₂ concentrations was not as expected, but decreased for a few months, before rising again, reflecting the natural annual variation. As well as showing us the great graphs of CO₂ variations diurnally, annually and of course increasing with the years, another interesting aspect to me was realising the variation due to plant respiration, hence to need to take measurements well away from their influence, such as at Mauna Loa, a 3000-m- high mountain with minimal vegetation in the middle of an ocean. Ralph showed the CO₂ levels and temperature going back hundreds, thousands and then millions of years, to show that where we are now and where we are heading is unprecedented. He also showed how simple it is to understand how much CO₂ is being absorbed by plants and the oceans by showing the difference between the amount of atmospheric CO₂ that is expected from fossil fuel burning and the amount that is actually measured in the atmosphere. The latest report will be out soon, to show this year's peak will be just under 415ppm.

Thank you Ralph for continuing this great work, and thank you to the Oxford Climate Society for organising and hosting. The Oxford Climate Society is a University of Oxford society dedicated to developing informed climate leaders. IEAGHG are pleased to be associated with them.