Archaeology seeks to understand human societies by studying their material remains. These remains might be individual artefacts, like tools, pots or ornaments, or might be entire landscapes, like gardens, agricultural fields or towns. Each type of object or place provides different information about the people who used or created it, and by weaving together these separate strands of information, archaeologists can assemble amazingly detailed accounts of human societies.
As the sea levels stabilised around 5000 years ago, Aboriginal people exploited new marine resources with fish spears, traps and shell hooks like this one.
Within archaeology there are numerous specialities or sub-disciplines, one of which is ‘environmental archaeology’. Environmental archaeologists use the evidence gained from individual artefacts, whole landscapes, and everything in between to understand how humans relate to their environment.
Since modern humans evolved around 200,000 years ago, they have inhabited a radically changing world. One of the major influences on global climates and environments are the naturally occurring glacial cycles which periodically plunge the earth into ice ages. During the glacial maxima – the very coldest parts of the ice ages – temperatures hover near freezing and massive glaciers cover up to a third of the globe. With so much of the world’s water trapped in the ice, rainfall decreases sharply and the seas shrink, exposing large tracts of land. As a result, islands and continents grow and, in some cases, even join up: during the glacial maxima Australia was joined to Papua New Guinea, and Tasmania was part of the mainland. Visit http://sahultime.monash.edu.au/ to see how the shape of Australia has changed over the last 100,000 years.
Environmental Archaeology in Australia
From around 4500 years ago, Aboriginal people in north Queensland began to use grindstones like this to process cycad nuts.
It was during one of these glacial maxima, probably at around 60,000 years ago, that Aboriginal people first settled Australia. Taking advantage of the lower sea levels, the first Australians likely ‘island hopped’ from South East Asia, arriving on the north west coast of Australia. However, we will probably never know exactly how people made this journey because all of these earliest sites are now lost, drowned by the seas that rose when the ice age ended.
The first evidence that Aborigines had been in Australia since the last ice age came from the early environmental archaeology of Sydney Skertchly. In the 19th and early 20th centuries, it was thought that Australia had only been inhabited for a few hundred years but Skertchly, a geologist by training, was able to show that this was not the case. Studying the location of Aboriginal tools found at a site near the Gold Coast, he was able to demonstrate that were deposited before the last ice age – many thousands of years in the past. In the 1960s, excavations at Kenniff Cave in Central Queensland confirmed Skertchly’s findings.
During the time that Aboriginal people have been in Australia, the climate has continued to change, with another intensely cold ice age at around 22,000 years ago, much warmer and wetter conditions in the last 10,000 years, and thousands of fluctuations in between. These climate shifts inevitably altered the environment and Aboriginal people adapted to this, moving in and out of different areas of the continent and learning to exploit new resources.
It is against this background of natural environmental shifts that we now face human-caused (or anthropogenic) climate change. Fuelled by increasing levels of green house gases, this period of climate change threatens to be the most dramatic, and possibly the most perilous, that humans have ever faced.
Consequently, it is now more important than ever to understand the ways that humans interact with the environment. Environmental archaeologists hope to aid this process by exploring how past human societies have created, avoided or responded to environmental change and how we too might deal with these challenges.
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