Science Centres: Energy

NIWA greenhouse gas research: a tribute to the late Dave Keeling

The American climate scientist whose precise measurements of carbon dioxide (CO2) helped alert the world to the greenhouse effect died last month. Charles David Keeling was 77. His work confirmed that CO2 from increased fossil fuel burning is going into the atmosphere, rather than being completely absorbed by carbon sinks such as forests and oceans.

Dave Keeling was also pivotal in New Zealand’s greenhouse gas research.

He had been measuring CO2 at Mauna Loa Observatory, Hawaii, for about a decade when he started looking for a southern hemisphere site. In 1970, he hired young New Zealand scientist, Dave Lowe, to join a group of American researchers.

Dr Lowe set up what is now NIWA’s atmospheric site at Baring Head, near Wellington. ‘No one had done continuous CO2 measurements in the southern hemisphere before,’ says Dave Lowe, now a NIWA principal scientist. ‘In the northern hemisphere, CO2 levels dip when spring plant growth uses more CO2 – it’s like the planet’s breathing – but that doesn’t happen here, since the oceans are so large and there is not much land. We could show that the southern oceans are a major carbon sink, soaking up CO2.

‘Dave Keeling pioneered the analysis of stable isotopes to trace the source of CO2. That’s essentially a distinctive fingerprint for different sources. We do similar work now with methane,’ says Dave Lowe.