RESEARCH

IN THE FIELD

En route to a field trip on Lizard Island
Cave excavation in Indonesia
Drilling for sample cores
Amazing rock art discoveries

People

Human history is written in the land. We obtain sustenance from our surroundings, we interact with each other across the landscape, and we make sense of our lives through where we came from and where we are heading.

The CABAH Humans research theme explores these varied dimensions of our species’ history over the past 60,000 years and more, from Island SE Asia across the seas to Australia and Papua New Guinea.

How did our species get onto the ‘Southern Continent’, and when? How did these early pioneers survive, and flourish, in their new environments? How did they engage with each other, and what ingenious social and cultural practices did they devise along the way? How did they interact with their surroundings, including the giant megafauna that once populated the Australian landscape? And to what extent did human actions affect the long-term trajectories of environmental change across the ‘Anthropocene’, a landscape now occupied and actively engaged by people?

Climate

The timing and impacts of past, and future, abrupt and extreme climate change remains highly uncertain.

A key challenge is that historical records of change are too short (since CE 1800) and their amplitude too small relative to projections for the next century. The recent geological record offers considerable potential. Taking an interdisciplinary approach, the Climate Theme aims to better understand changes over the past 130,000 years ago, from the last interglacial when Australia was apparently warmer and wetter than present day, to the last two millennia, during which the continent experienced spatial and temporal extremes in hydroclimate.

By integrating a host of climate-sensitive proxies preserved in lakes, peats, ocean sediments and trees (so-called ‘natural archives’) with climate models, we are investigating the magnitude, timing and mechanisms of abrupt and extreme change, and provide a context to Australia’s rich ecological and archaeological record.

Landscapes

Our ‘wide brown land’ seems timeless and unchanging. But if we look back across the last 130,000 years we discover that the Australian landscape has changed  dramatically and constantly.

Sea level during the last ice age, 20,000 years ago was 120m lower than now. The Australian mainland was joined to New Guinea and Tasmania forming the single continent of ‘Sahul’, 20-25% bigger than Australia today. In the south, large rivers drained icecaps around Mt. Kosciousko keeping the Willandra Lakes in NSW full, where they are now dry. In the centre, the deserts expanded and the sand shifted constantly. In the north, the monsoon turned off – Darwin was a dry grassland 300km from the coast. Before the Ice Age, sea level rose and fell, rivers flooded and dried, forests advanced and retreated. Up until 40,000 years ago Lakes Eyre and Frome in South Australia were the size of Israel, and up to 25m deep.

This we know, but there is a lot more to learn – what drove these changes? How did the first people adapt to this alien ’sunburnt country’? and what can our past tell us about our shared future?

Wildlife

Australia’s unique wildlife is a heritage of immense value.

The current diversity and distribution of species is the result not only of millions of years of evolution in isolation, but a history of dramatic change resulting from fluctuations in ice-age climates and interactions with people over thousands of years. CABAH will answer the following questions such: how did wildlife species respond to climate change in the past? What was the impact of human arrival on populations and species of vertebrate animals, and how did this affect the functioning of ecosystems? Can we reconstruct the diversity and distribution of species before arrival of Aboriginal people, and before European arrival?

The answers to these questions will strengthen our ability to manage and conserve our wildlife heritage for the future.

Time

Time is fundamental to understanding the story of Australia’s natural and Indigenous history and heritage.

Control of time is crucial to precisely and accurately align datasets acquired from different data capture techniques and disciplines (e.g. archaeology, geomorphology, palynology) into robust sequences that can be compared.

CABAH’s transdisciplinary research program is connected via a timeline starting 130,000 years ago – during the last interglacial period when Australia was devoid of modern humans (Homo sapiens) and the climate was broadly similar to today’s – and extending to the time of initial European contact in the 17th century. This covers the entire period of Indigenous occupation prior to European arrival.

When did people arrive in Australia? In New Guinea? In Wallacea? How long did it take for people to get from the top of the Australia to the bottom of Australia? How quickly did people reshape their environments through occupation and the use of technologies like fire?