Setting the scene
The current state of South Australia’s (SA) environment is a legacy of the ways in which natural (geological and biological) processes and human activities have transformed the landscape.
The Earth is over 4.5 billion years old and the first life on Earth (single-celled organisms) began about 3.8 billion years ago. It is only in the last 570 million years that the kind of life forms we now know began to evolve. Mammals did not evolve until 200 million years ago and our own species, Homo sapiens, only 200,000 years ago. Humans have only been around for a mere 0.004% of the Earth's history.
Human impacts on the environment started even more recently, commencing with the transition from hunter-gatherer to agrarian societies about 10,000 years ago, followed by the industrial revolution in about 1760. It is estimated that Australia has been populated by Aboriginal people for at least 65,000 years, with approximately 200 language groups. Aboriginal people shaped the landscape with fire and existed in close harmony with the land.
From 1836, South Australia was progressively settled by European migrants. Large-scale landscape modification resulted from this more recent settlement and continues today. Landscape change is not just the result of the actions (in the form of land clearing and pollution) of a comparatively small population, but also the consequence of the cumulative impact on the global climate from worldwide greenhouse gas emissions, mainly from the burning of fossil fuels.
South Australia has adopted a series of measures since the early 1970s, some of them groundbreaking, to protect our remaining natural resources and improve environmental quality. Not all efforts to protect and improve our environment have been equally successful. This is complicated by the difficulty in objectively valuing aspects such as biodiversity, and in formulating a shared vision of our aspirations for the natural environment. Some changes are irreversible and others have very long lag times before the full impacts are felt.
This is the 7th five-yearly report since 1988 that reviews how environmental conditions are changing and what we are doing about the key challenges in SA.