The population is aging, with more retirees and fewer people of working age. Much of Australia's diplomatic energy is focused on international trade liberalization. The federal government administers a separate area within New South Wales, the Jervis Bay Territory, as a naval base and sea port for the national capital. The treatment of indigenous people is hotly debated within Australia.
The most notable exercise of these powers was the dismissal of the Whitlam government in the constitutional crisis of 1975. It is one of the world's oldest federations, in which power is divided between the federal and state governments. The country has maintained its mostly unchanged constitution alongside a stable liberal democratic political system since Federation in 1901. In June 2021, over 1,000 animal and plant species were listed by Australian governments as endangered or critically endangered. Over the past two centuries, Australia has lost more mammal species than any other continent.
The Australian climate ranges from wet tropical in the northeast and northwest to arid in the centre. There were active volcanoes on the eastern mainland as recently as 4,600 years ago, and this is reflected in Aboriginal place names and creation stories. However, the Australian plate is moving north-northeast at a rate of about 6 to 7 cm a year and is currently in collision with the Eurasian plate and Pacific plate.
In 2019, 30% of the Australian resident population, or 7,529,570 people, were born overseas. At that time, the indigenous population was estimated to have been between 315,000 and 750,000. More than 400 distinct Australian Aboriginal peoples have been identified across the continent, distinguished by unique names designating their ancestral languages, dialects, or distinctive speech patterns. Dispersing across the Australian continent over time, the population expanded and differentiated into hundreds of distinct groups, each with its own language and culture. Indigenous Australians is an inclusive term used when referring to both Aboriginal and Torres Strait islanders (the "first peoples"). The Torres Strait Islanders are a distinct people of Melanesian ancestry, indigenous to the Torres Strait Islands, which are at the northernmost tip of Queensland near Papua New Guinea, and some nearby settlements on the mainland. Indian Australians are Australians of Indian ancestry, and are the second-largest Asian Australian ancestry, comprising 3.1% of the total population.
The Colony of New South Wales was established by the Kingdom of Great Britain in 1788, with the arrival of the First Fleet, and five other colonies were established in the 19th century, now forming the six present-day Australian states. Other influences include Australian Aboriginal culture, the traditions brought to the country by waves of immigration from around the world, and the culture of the United States. Immigration increased steadily, with an explosion of population in the 1850s following a series of gold rushes. Between European colonisation in 1788 and the Second World War, the vast majority of settlers and immigrants came from the British Isles (principally England, Ireland, Wales and Scotland), although there was significant immigration from China and Germany during the 19th century. Australian law does not provide for any racial or ethnic component of nationality, instead relying on citizenship as a legal status, though the Constitutional framers considered the Commonwealth to be "a home for Australians and the British race alone", as well as a "Christian Commonwealth". Each major city has daily newspapers, and there are two national daily newspapers, The Australian and The Australian Financial Review. In 1973, Patrick White was awarded the Nobel Prize in Literature, the only Australian to have achieved this.
The Great Barrier Reef, the world's largest coral reef, lies a short distance off the north-east coast and extends for more than 2,300 km (1,400 mi). Mainland Australia lies between latitudes 9° and 44° south, and longitudes 112° and 154° east. The indigenous population declined for 150 years following European settlement, mainly due to infectious disease. Following Tasman's voyages, the Dutch were able to make almost complete maps of Australia's northern and western coasts and much of its southern and south-eastern Tasmanian coasts. When the Dutch began visiting and mapping Australia in the 17th century, they called the continent New Holland.
Canberra is the nation's capital, while its most populous cities are Sydney and Melbourne, each with a population of more than five million. Australia's written history commenced with Dutch exploration of most of the coastline in the 17th century. The ancestors of Aboriginal Australians began arriving from Southeast Asia 50,000 to 65,000 years ago, during the Last Glacial Period.
International organisations such as Human Rights Watch and Amnesty International have expressed concerns in areas including asylum-seeker policy, Indigenous deaths in custody, the lack of entrenched rights protection, and laws restricting protesting. Similarly, the Parliament does not play a formal role in foreign policy and the power to declare war lies solely with the executive government. It also maintains an international aid program under which some 75 countries receive assistance. Internationally, the country is a member of the United Nations (of which it was a founding member), the Commonwealth of Nations, the OECD and the G20.
Australia has a federal form of government, with a national government for the Commonwealth of Australia and individual state governments (those of New South Wales, Victoria, Queensland, South Australia, Western Australia, and Tasmania). The country’s low relief results from the long and extensive erosive action of the forces of wind, rain, and the heat of the sun during the great periods of geologic time when the continental mass was elevated well above sea level. The American-style concept of a national “frontier” moving outward along a line of settlement is also inappropriate. At least 60,000 years before European explorers sailed into the South Pacific, the first Aboriginal explorers had arrived from Asia, and by 20,000 years ago they had spread throughout the mainland and its chief island outlier, Tasmania. Australia is separated from Indonesia to the northwest by the Timor and Arafura seas, from Papua New Guinea to the northeast by the Coral Sea and the Torres Strait, from the Coral Sea Islands Territory by the Great Barrier Reef, from New Zealand to the southeast by the Tasman Sea, and from Antarctica in the far south by the Indian Ocean. To the south, Australian jurisdiction extends a further 310 miles (500 km) to the southern extremity of the island of Tasmania, and in the north it extends to the southern shores of Papua New Guinea.