In the last Ice Age, Australia endured very dry conditions and sea levels were up to 125m lower compared to today. Since then, life on Earth has enjoyed ~12,000 years of the more accommodating climatic conditions of the Holocene.
This comfortable epoch has nonetheless demonstrated significant variability due to interactions between the major drivers of the Earth’s climate system. Understanding these interactions can help us to anticipate how the current rapid change in climate will affect regional conditions.
Acclaimed palaeontologist Professor Patrick De Deckker explores:
*The dominant influence of the Southern Annular Mode (SAM) on rainfall and temperature in Australia, driven by the powerful westerly winds that circumnavigate the southernmost third of the globe and drive the Antarctic Circumpolar Current around Antarctica.
*The Holocene Hypsithermal, a period spanning about 8,200 to 5,500 years ago that marks the natural peak in temperatures and rainfall of our interglacial period, despite having the lowest atmospheric CO2 levels for the entire Holocene.
*The establishment of the El Niño-Southern Oscillation following the Holocene Hypsithermal across the entire Pacific region, a contemporary phenomenon that is only about 5,500 years old.
*How the changing climate in Australia in turn changed the pattern of human habitation and activity, with more sedentary activities along major rivers and an enhancement of food production in organised settings suggestive of villages.
About the Speaker:
Professor Patrick De Deckker AM FAA is an Emeritus Professor based at the @ANUchannel's College of Science. Patrick pioneered the study of the Quaternary (the last 2 million years) history of the oceans bordering Australia and has principally used microfossils and their chemical composition to reconstruct past changes. He was also first to link patterns of environmental change on land (through salt lake records) and at sea, again using microfossils and other proxies. He has found that during the Holocene, the oceans have become progressively warmer. His most recent innovative research deals with the microbiological and geochemical fingerprinting of airborne dust with the aim at linking dust events with changes in the oceans.
In recognition of his efforts and achievements, he has been awarded the Verco Medal (1992), the Australian Society for Limnology Medal (2005), the Christoffel Plantin Medal (2008), the Mawson Medal (2010) and the Brady Medal (2019). In 2007, he was appointed a Member of the Order of Australia (AM) for his research and teaching efforts, and an Officer of the Order of Leopold II by the Kingdom of Belgium (2018) for outstanding achievements in science. Patrick is also a Fellow of the Australian Academy of Science.
Professor Patrick De Deckker AM, FAA is the 2023 recipient of the Royal Society of Victoria’s Medal for Excellence in Scientific Research in Category III: Earth Sciences.
Produced by the Royal Society of Victoria with the support of the Inspiring Victoria program. Professor De Deckker's full presentation is also available at • Holocene Climatic Fluc... .