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Why 95% of Australia is Empty

Jul 20, 2025

Overview

This lecture explains why Australia, despite its large land area, has a very low population density, outlining geographic, climatic, historical, and social factors that influence its unique population distribution.

Australia's Population and Urbanization

  • Australia is similar in size to the contiguous US but has a population of only about 26 million.
  • Two US states, California and Texas, each have more people than all of Australia.
  • Many islands and world cities surpass Australia's population despite being much smaller in area.
  • Nearly two-thirds of Australians live in five major cities: Sydney, Melbourne, Brisbane, Perth, and Adelaide.
  • About 90% of the population is concentrated in urban areas covering just 0.22% of Australia’s land.
  • 85% of Australians live within 50 km of the coastline; the interior is sparsely populated.

Geographic and Climatic Constraints

  • Australia's vast interior is largely uninhabited due to harsh geography and climate.
  • The west is affected by cold ocean currents, reducing rain cloud formation.
  • The Great Dividing Range blocks rain from the Pacific, creating a dry 'rain shadow' inland.
  • Australia has the lowest average elevation of any continent, further limiting rainfall.
  • The continent experiences high pressure belts and unpredictable El Niño/La Niña oscillations, causing droughts.
  • Australia is the driest inhabited continent, with desert or desert-like conditions across 35% of its land.
  • Rain mainly falls along the east coast, northern tropics, and a few other regions; much of the continent gets little rainfall.
  • Northern Australia receives rain mostly during a short, intense wet season, leading to highly variable annual totals.

Freshwater and Agriculture

  • Major rivers are limited; the Murray-Darling Basin is the main agricultural and water source.
  • The Murray-Darling Basin has the lowest water flow of any major river system globally.
  • Most of Australia’s interior soils are poor for agriculture due to ancient, unrenewed geology.
  • Only about 6% of land is arable, but this still provides more farmland than several populous Asian countries combined.
  • Australia has a high ratio of arable land per person but a small population due to other limiting factors.

Historical Population Growth and Immigration

  • Australia has been geographically isolated for millennia, limiting human migration.
  • Indigenous Australians arrived over 50,000 years ago and remained isolated until European contact.
  • Europeans (Dutch, then British) began settling in the 17th and 18th centuries, but growth was slow.
  • The "White Australia" policy restricted immigration to Europeans, especially Britons, until the 1970s.
  • Post-World War II policies diversified sources of immigrants, especially from Europe, and later Asia.
  • Today, over 30% of Australians are foreign-born, the highest proportion for any developed Western nation.

Economic and Agricultural Significance

  • Despite challenges, Australia is a major global producer of sheep, wool, beef, almonds, and has vast organic farmland.
  • The population is projected to grow to around 36 million by 2050, mainly through continued immigration.
  • Environmental challenges like drought, climate change, and water scarcity will impact future growth.

Key Terms & Definitions

  • Rain shadow — Dry area on the leeward side of a mountain blocking prevailing rain.
  • Great Dividing Range — Mountain range along eastern Australia affecting rainfall patterns.
  • Murray-Darling Basin — Australia’s largest river system supplying water to southeastern agriculture.
  • El Niño/La Niña — Pacific Ocean climate patterns causing fluctuating rainfall and droughts.
  • White Australia policy — Former immigration policy favoring white Europeans, ended in 1973.

Action Items / Next Steps

  • Review maps of Australia's rainfall and population distribution.
  • Read more about the Murray-Darling Basin and its significance for Australian agriculture.
  • Research current immigration policies and their effects on Australian demographics.