“They said that they had the oldest air and I thought, no they haven't, I've got the oldest air," The air archive maintained by CSIRO started in 1978, and contains samples of clean air from a station at Cape Grim, Tasmania. It’s the oldest such archive in the world. Now with Allport’s tank, last used in 1970, the record has been extended further.

The air contained traces of propellants, refrigerants and emissions form aluminium smelters. Paul Fraser, who leads CSIRO’s greenhouse gas research team says that the scuba tank is going to be really useful: “If tanks were filled in a clean coastal environment their usefulness in measuring greenhouse gases such as carbon dioxide, methane, nitrous oxide and chloro-flurocarbons (CFCs) is much broader,” The old air means that ice-core data can be cross-checked. It also feeds into better predictions of future atmospheric compositions.

Their report includes some interesting quotes from Allport and his wife, Marg. Allport doesn’t seem too enamoured with the UN climate change conference in Copenhagen, saying it is “A lot of hot air I think, I don't believe what they say, I think the world's just rolling around and it changes in big seasons, but the seasons are like a hundred years apart.”

Marg seems to think that there might be something in it all, but doesn’t sound all that convinced to me: "We're not complete sceptics though really are we?"

Tags:  CSIRO,Beaumaris, Australia,Cape Grim,Atmospheric.