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.

For a period spanning ~8,200 to ~5,500 years ago, temperatures were higher than today, including in the oceans. Lake levels and postulated rainfall were extraordinarily high, and vegetation spectra were very different to today in many places. In contrast, air temperatures recognised in Antarctic ice cores are at the opposite to those recognised in Australia, and atmospheric CO2 levels were at their lowest for the entire Holocene. We refer to this period as the Holocene Hypsithermal.

Climatic conditions then progressively deteriorated everywhere, a little after ~6,000 years BP until recent times, as El Niño-Southern Oscillation signals with alternating El Niño and La Niña conditions were established across the entire Pacific region.

Join acclaimed palaeontologist Professor Patrick De Deckker, who will illustrate how human activities in south-eastern Australia changed well after the Hypsithermal, with more sedentary activities along the major rivers and an enhancement of food production in organised settings suggestive of villages, in stark contrast with human migrations across North Africa during the Holocene.