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.