Occupying an entire continent of some 7.6 million square kilometres, Australia is the sixth largest country in the world. Its ocean territory is the world’s third largest, spanning three oceans and covering around 12 million square kilometres.
Nearly seven million square kilometres, or 91 per cent of Australia, is covered by native vegetation. Although this figure may seem high, many of Australia’s desert landscapes are covered by native plants such as saltbush, albeit sparsely.
There are 17 Australian properties on the World Heritage List. The Great Barrier Reef, the Tasmanian Wilderness, the Wet Tropics of Queensland and Shark Bay meet all four World Heritage criteria for natural heritage, with Kakadu National Park, Uluru–Kata Tjuta National Park, Purnululu National Park, Willandra Lakes region and the Tasmanian Wilderness listed for both natural and cultural criteria. The Australian Fossil Mammal Sites (Naracoorte/Riversleigh), Lord Howe Island Group, Central Eastern Rainforest Reserves (Australia), Fraser Island, Macquarie Island, Heard Island and McDonald Islands and the Greater Blue Mountains Area are listed under the World Heritage criteria for natural heritage.
For tens of thousands of years, the lives and sense of cultural identity of Indigenous Australians were inextricably linked to the land, its forms, flora and fauna. Today, the identity of all Australians is shaped by a relationship with the natural environment.
Australia is one of the most urbanised and coast-dwelling populations in the world. More than 80 per cent of Australians live within 100 kilometres of the coast.
10.5 per cent of mainland Australia’s natural environment is protected by national environmental legislation.
Australia has some of the oldest land surface on earth and while rich in biodiversity its soils and seas are among the most nutrient poor and unproductive in the world. This is due mainly to the country’s geological stability, which is a major feature of the Australian land mass, and is characterised by, among other things, a lack of significant seismic activity.
Only six per cent of the Australian landmass is arable. Large volumes of water are required from both surface and groundwater supplies. Australian soils are highly dependent upon vegetation cover to generate nutrients and for stability. Land clearing, water extraction and poor soil conservation are all causes of a decline in the quality of Australia’s soils.
Australia is the driest inhabited continent on earth, with the least amount of water in rivers, the lowest run-off and the smallest area of permanent wetlands of all the continents.
One third of the continent produces almost no run-off at all and Australia’s rainfall and stream-flow are the most variable in the world.
Human activity continues to exert pressure on marine environments. Pollution is the most serious problem and the vast majority of marine pollution is caused by land based activities—soil erosion, fertiliser use, intensive animal production, sewage and other urban industrial discharges.
Australia currently has 65 Ramsar (an international convention that provides the framework for conservation of wetlands) listed wetlands covering 7.5 million hectares and more than 850 of national importance. Australia’s marine environment is home to 4000 fish species, 500 coral species in the northern reefs alone, 50 types of marine mammal and a wide range of seabirds. It is estimated that as many as 80 per cent of marine species found in southern Australian waters occur nowhere else.
Around seven per cent of Australia’s marine jurisdiction is identified marine protected areas.
Australia is one of the most biologically diverse countries on the planet. It is home to more than one million species of plants and animals, many of which are found nowhere else in the world, and less than half have been described scientifically.
About 85 per cent of flowering plants, 84 per cent of mammals, more than 45 per cent of birds, and 89 per cent of inshore, freshwater fish are unique to Australia.
Australia is richly endowed with marsupials— there are more than 140 species.
At least 18 exotic mammals have established feral populations in Australia, with cats and foxes responsible for the decline and extinction of several native animals.
At least 2700 non-native (introduced) plants have established populations in Australia. Sixty-eight per cent of these introduced plants are considered a problem for natural ecosystems.
Australia is one of the world’s least densely populated countries (after Mongolia and Namibia), with fewer than three people per square kilometre, but the effects of climate change have been felt across the continent. From 1910 to 2004, average temperatures in Australia rose 0.9°C. The country has experienced more heat waves and fewer frosts. Since 1950, annual rainfall has declined on the eastern seaboard and in the south of the continent, but increased in the northwest. Droughts have become more intense and extreme rainfall events have increased in the northeast and southwest since the early 1970s.
- Department of Sustainability, Environment, Water, Population and Communities
- Department of Climate Change
last updated May 2008