CSIRO reseearcher Dr Paul Fraser will deliver a paper on the research tomorrow afternoon, speaking at Greenhouse 2005: Action on Climate Change, an international multidisciplinary conference taking place in Melbourne this week.

Fraser said the unique record would enable scientists to calculate more precisely how much greenhouse gases contribute to global warming.

"This information is used in computer models to simulate past and future temperature changes, which can be compared with past temperature records to confirm the reliability of the models," Fraser said.

"In general, the scenarios suggesting continued global warming resulting from increased levels of greenhouse gases stand up to this scrutiny."

According to Fraser, the greatest increase in greenhouse gases as an element of global warming occurred in the 1980s.

"This is because of the near zero growth of methane and the ozone depleting gases, which are also greenhouse gases, over the past five to 10 years," he said.

Fraser said carbon dioxide's contribution to global warming was showing accelerating growth.

"In looking back over such a long period, in such detail, we can also detect variations in the levels of greenhouse gases that have previously been missed," Fraser said.

"In particular, we have detected changes during the 'Little Ice Age' (about AD1350-1850) and an unexplained slow-down in the greenhouse gas growth rate in the 1940s."

CSIRO researcher Dr David Etheridge will also make a presentation at Greenhouse 2005, displaying research that identifies – through the analysis of air bubbles in ice core samples from Antarctica – how and why concentrations of the major greenhouse gases have increased significantly over the industrial period.

The research is derived from measurements taken at the Cape Grim Baseline Air Pollution Station in Tasmania, as well as air from the Cape Grim Air Archive, and from air trapped in Antarctic ice.

The ice was drilled by the Australian Antarctic Division from a unique site in coastal Antarctica.

The Cape Grim Program, to monitor and study global atmospheric composition, is a joint responsibility of the Bureau of Meteorology and CSIRO.

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