Environmental issues in Australia

Contamination and pollution

Australia is affected by significant contamination and pollution including soil and groundwater contamination as well as water and air pollution. Researchers currently estimate that between 16,000 and 80,000 significantly sites have been identified as affected by up to 7,500 different contaminants. Some of these are toxic byproducts of government land use and private industry. The country has several notable exclusion zones due to heavy contamination. Some substances have significant half-lifes, making remediation and sequestering expensive and complicated. There is also a serious ongoing risk of contamination incidents particularly from mining-related activities.

Significant types of contamination affecting Australia include:

• plastics – Australia produces 2.5m tonnes of plastic per year, about 84% is sent to landfill. Estimated 130,000 tonnes of plastic waste leaks into the environment annually.
• hydrocarbons – more than 16,000 significant sites
• herbicides and pesticides – more than 3,500 significant sites identified
• heavy metals – including lead, arsenic, cadmium and mercury across thousands of significant urban and remote sites
• radioactive elements in soils and radioactive waste – more than 100 significant sites including large exclusion zones due to high radiation levels from nuclear fallout, high risk of nuclear contamination due to a significant nuclear element mining industry, more than 5000 cubic metres of radioactive waste which requires long term safe handling, more than 46 cubic metres generated each year
• per- and polyfluoroalkyl substances (PFAS) – more than 90 significant sites identified requiring remediation particularly government training centres and surrounding catchments from use of fire fighting foams
• asbestos – over 6.2 million tonnes across more than 50 significant major urban sites and several exclusion zones in remote locations
• landfill leachate
• diesel exhaust and wood smoke persisting for long periods in ambient air in both urban areas and remote locations contribute to 4,880 premature deaths every year

Ozone depletion

Due to its position in the Southern Hemisphere close to Antarctica, Australia is one of the parts of the world most affected by ozone depletion, which results in dangerous increases to solar radiation, particularly ultraviolet radiation. Increased UV levels compromise the genetic integrity and immune systems of living organisms, impairs photosynthesis, contributes to climate change, and to one of the highest mortality rates of skin cancer in the world. It is generally believed that the Montreal Protocol (1987) has helped alleviate anthropogenic ozone depletion by banning destructive chlorofluorocarbon emissions, and this has helped protect Australia from exposure to catastrophic levels of UV radiation. Though the "hole" in the ozone which the Protocol sought to prevent has not reached Australia, it has experienced significant sustained thinning at its latitudes, causing elevated levels of solar irradiation. Increased incidence of large scale bushfires in Australia has contributed to recent ozone depletion, contributing to a sort of solar irradiation feedback loop.

Conservation

Conservation in Australia is an issue of state and federal policy. Australia is one of the most biologically diverse countries in the world, with a large portion of species endemic to Australia. Preserving this wealth of biodiversity is important for future generations.

In Australia forest cover is around 17% of the total land area, equivalent to 134,005,100 hectares (ha) of forest in 2020, up from 133,882,200 hectares (ha) in 1990. In 2020, naturally regenerating forest covered 131,614,800 hectares (ha) and planted forest covered 2,390,300 hectares (ha). Of the naturally regenerating forest 0% was reported to be primary forest (consisting of native tree species with no clearly visible indications of human activity) and around 18% of the forest area was found within protected areas. For the year 2015, 67% of the forest area was reported to be under public ownership, 32% private ownership and 1% with ownership listed as other or unknown.

A key conservation issue is the preservation of biodiversity, especially by protecting the remaining rainforests. The destruction of habitat by human activities, including land clearing, remains the major cause of biodiversity loss in Australia. The importance of the Australian rainforests to the conservation movement is very high. Australia is the only western country to have large areas of rainforest intact. Forests provide timber, drugs, and food and should be managed to maximise the possible uses. Currently, there are a number of environmental movements and campaigners advocating for action on saving the environment, one such campaign is the Big Switch.

Land management issues including clearance of native vegetation, reafforestation of once-cleared areas, control of exotic weeds and pests, expansion of dryland salinity, acid sulphate soils, and changed fire regimes. Intensification of resource use in sectors such as forestry, fisheries, and agriculture are widely reported to contribute to biodiversity loss in Australia. Coastal and marine environments also have reduced biodiversity from reduced water quality caused by pollution and sediments arising from human settlements and agriculture. In central New South Wales where there are large plains of grassland, problems have risen from—unusual to say—lack of land clearing.

The Daintree Rainforest, a tropical rainforest near Daintree, Queensland covering around 1200 square kilometres, is threatened by logging, development, mining and the effects of the high tourist numbers.

There are some government programs in Australia which are the opposite of conservation (such as killing wildlife); an example of this is shark culling, which currently occurs in New South Wales and Queensland.

Native fauna

Over a hundred species of fauna are currently under serious threat of extinction. The plight of some of these species receives more attention than others and recently the focus of many conservation organisations has been the critically endangered northern hairy-nosed wombat, the endangered Tasmanian devil, northern tiger quoll, south eastern red-tailed black cockatoo, southern cassowary, Tasmanian wedge-tailed eagle, Leadbeater's possum and southern corroboree frog.

Australia has a poor record of conservation of native fauna. The extinction of Australian megafauna is partially attributed to the arrival of humans and since European settlement, 23 birds, 4 frogs, and 27 mammal species are also known to have become extinct.

Marine conservation

One of the notable issues with marine conservation in Australia is the protection of the Great Barrier Reef. The Great Barrier Reef's environmental pressures include water quality from runoff, climate change and mass coral bleaching, cyclic outbreaks of the crown-of-thorns starfish, overfishing, and shipping accidents. The government of Queensland currently kills sharks in the Great Barrier Reef using drum lines, causing damage to the marine ecosystem.

In 2021 Australia announced the creation of 2 national marine parks in size of 740,000 square kilometres. With those parks 45% of the Australian marine territory will be protected.

Whaling

Whaling in Australia took place from colonisation in 1788. In 1979 Australia terminated whaling and committed to whale protection. The main varieties hunted were humpback, blue, right and sperm whales.

Shark culling

Western Australia culled sharks in 2014, killing dozens of tiger sharks and causing public protest. Later that year it was abandoned, and the government of Western Australia continued to shoot and kill sharks it believed to be an "imminent threat" to humans from 2014 to 2017; this policy was criticised by senator Rachel Siewart for being environmentally damaging.

From 1962 to the present, the government of Queensland has killed sharks on drum lines and shark nets, a process that also kills other animals such as dolphins and dugongs. From 1962 to 2018, Queensland's "shark control" program killed roughly 50,000 sharks, including sharks in the Great Barrier Reef. Queensland's shark-killing program has been called "outdated, cruel and ineffective".

New South Wales has a shark net program that kills sharks as well as other marine life. Between 1950 and 2008, 352 tiger sharks and 577 great white sharks were killed in the nets in New South Wales – also during this period, a total of 15,135 marine animals were killed in the nets, including whales and turtles. There has been a very large decrease in the number of sharks in eastern Australia in recent years, and the shark-killing programs in Queensland and New South Wales are partly responsible for this decrease.

Jessica Morris of Humane Society International calls shark culling a "knee-jerk reaction" and says, "sharks are top order predators that play an important role in the functioning of marine ecosystems. We need them for healthy oceans."

Oil spills

While there have been no oil spill environmental disasters of the scale of the Exxon Valdez in the country, Australia has a large oil industry and there have been several large oil spills . Spills remain a serious threat to the marine environment and Australian coastline. The largest spill to date was the Kirki tanker in 1991 which dropped 17,280 tonnes of oil off the coast of Western Australia.

In March 2009, the 2009 southeast Queensland oil spill occurred, where 200,000 litres were spilled from the MV Pacific Adventurer spilling more than 250 tonnes of oil, 30 tonnes of fuel and other toxic chemicals on Brisbane's suburban beaches. Premier Anna Bligh described the spill as "worst environmental disaster Queensland has ever seen".

Ocean dumping

A serious issue to the Australian marine environment is the dumping of rubbish from ships. There have been a number of cases, particularly involving the navy of Australian and other countries polluting Australian waters including the dumping of chemical warfare agents. Recently documented cases include the aircraft carrier USS Ronald Reagan in 2006 which was found to be dumping rubbish off the shores of Moreton Island. In Victoria, a large number of toxic drums containing 1,2-Dichlorobenzene xylenol, a substance very toxic to aquatic creatures washed up on beaches during May 2009 presumably fallen off a passing container ship.

Invasive species

Australia's geographical isolation has resulted in the evolution of many delicate ecological relationships that are sensitive to foreign invaders and in many instances provided no natural predators for many of the species subsequently introduced. The introduction and prolific breeding of animal species such as the cane toad (Rhinella marina) and rabbit (Oryctolagus cuniculus) had greatly disrupted native species populations. Introduced species in Australia are problematic in that they may outcompete or, in the case of the can toad, red fox (Vulpes vulpes) and feral domestic cats (Felis catus), directly kill native species. Rabbits in Australia along with feral beasts of burden disrupt native species by destroying vulnerable habitat requiring drastic pest-exclusion measures such as the Rabbit-proof fence. The cane toad invasion is particularly concerning due to them having few predators and apart from extensively outcompeting native species their toxicity kills thousands of native apex predators each year. The threat of the ongoing cane toad invasion has seen the establishment of a national taskforce despite its potential range being limited to the north of the continent. Likewise Tasmania takes the threat of the species so seriously that it has a government sponsored taskforce to prevent fox populations from taking hold on the island. The species has single-handedly caused the extinction of several native species on the mainland.

Australia is also vulnerable to invasive weeds. Controlling the invasion of prickly pears in Australia is one of the success stories of invasive species control. The government maintains a Weeds of National Significance (WONS) list of problematic plant species.

Land degradation

According to Jared Diamond, "Australia's number-one environmental problem [is] land degradation". Land degradation results from nine types of damaging environmental impacts:

• Clearance of native vegetation
• Overgrazing by sheep
• Rabbits
• Soil nutrient exhaustion
• Soil erosion
• Man-made droughts
• Weeds
• Misguided governmental policies
• Salinisation

Logging and woodchipping

Clearcutting of old-growth forests is continuing in parts of Australia primarily in the eastern states of Tasmania, Victoria and New South Wales. This often involves the destruction of natural ecosystems and the replacement with monoculture plantations.

Australia had a 2018 Forest Landscape Integrity Index mean score of 7.22/10, ranking it 46th globally out of 172 countries.

Land clearing and soil salinity

In the prehistory of Australia the Indigenous Australians used fire-stick farming which was an early form of land clearing which caused long term changes to the ecology. With European colonisation land clearing continued on a larger scale for agriculture – particularly for cattle, cotton and wheat production. Since European settlement a total of 13% of native vegetation cover has been lost. The extinction of 20 different mammals, 9 bird and 97 plant species have been partially attributed to land clearing. Land clearing is a major source of Australia's greenhouse gas emissions, and contributed to approximately 12 percent of Australia's total emissions in 1998.

The consequences of land clearing include dryland salinity and soil erosion. These are a major concern to the landcare movement in Australia. Soil salinity affects 50,000 km² of Australia and is predominantly due to land clearance.

The clearing of native vegetation is controlled by Federal laws (indirectly), State law and local planning instruments. The precise details of regulation of vegetation clearing differ according to the location where clearing is proposed.

Waterway health

The protection of waterways in Australia is a major concern for various reasons including habitat and biodiversity, but also due to use of the waterways by humans.

The Murray-Darling Basin is under threat due to irrigation in Australia, causing high levels of salinity which affect agriculture and biodiversity in New South Wales, Victoria and South Australia. These rivers are also affected by pesticide run-off and drought. Low oxygen levels in the water combined with high temperatures has led to fish kills in the Darling River in 2018, 2019 and 2023. The worst was in March 2023 in which millions of dead bony bream, golden perch silver perch and some Murray cod flowed down the river.

Australian waterways facing environmental issues

Rivers and creeks in urban areas also face environmental issues, particularly pollution.

Victoria

• Port Phillip (contamination – silt; sediment; toxins; household chemicals; garden chemicals; E. coli; litter; flotsam and jetsam)
• Yarra River (contamination – E. coli; litter – 13 traps; logging; erosion; salinity)
• Maribyrnong River (contamination – arsenic and heavy metals; litter – 1 trap)
• Mullum Mullum Creek (contamination – E. coli; litter)
• Moonee Ponds Creek (contamination - predominantly plastic and polystrene; multiple traps)
• Murray River (salinity, erosion)

New South Wales

• Parramatta River (contamination – dioxins, arsenic, coal tars, chromium, lead and phthalates)
• Darling River (salinity, erosion)
• Murray River (salinity, erosion)
• Cooks River (pollution, algal blooms)

Queensland

• Bremer River (water grading F – lowest possible)
• Brisbane River
• Oxley Creek (water grading D)
• Bulimba Creek (threatened species due to land degradation; pollution; litter)

South Australia

• River Torrens (contaminants – E. coli; algal bloom)

Urbanisation

Australia is one of the most urbanised countries in the world. Many Australian cities have large urban footprints and are characterised by an unsustainable low density urban sprawl. This places demand on infrastructure and services which contributes to the problems of land clearing, pollution, transport related emissions, energy consumption, invasive species, automobile dependency and urban heat islands.

The urban sprawl continues to increase at a rapid rate in most Australian cities, particularly the state capital cities, all of which (with the exception of Hobart) are metropoleis. In some centres, such as Sydney and Greater Western Sydney, Greater Melbourne and South East Queensland large metropolitan conurbations threaten to extend for hundreds of kilometres and based on current population growth rates are expected to become megacities in the 21st century. Most Australian cities population growth is a result of migration in contrast to the birth rate and fertility rate in Australia, which is contributing to the ongoing trend of urbanisation.

In recent years, some cities have implemented transit-oriented development strategies to curb the urban sprawl. Notable examples include Melbourne 2030, South East Queensland Regional Plan and the Sydney Metropolitan Strategy. There are also population decentralisation programs at state and federal levels aimed at shifting populations out of the major centres and stemming the drivers to rapid urbanisation. Albury-Wodonga was part of the federal government's program of decentralisation begun in the 1970s, which has at times had relocation policies for immigration. The Victorian government has run a decentralisation program since the 1960s, having had a ministerial position appointed and ongoing promotional and investment programs for stimulating growth in Regional Victoria. However policy has swung over the decades, primarily due to local development priorities and agendas and a lack of federal co-ordination to the problem.

Issues include large quantities of e-waste and toxic waste going into landfill. Australia does not have restrictions on the dumping of toxic materials that are common in other countries, such as dumping cathode-ray tubes which leach heavy metals into water catchments. Due to the lack of sufficient sites for toxic waste disposal large quantities of toxic waste are trucked between states to remote dumping grounds or exported overseas in ships.

Mining issues

Australia has some of the largest mining operations in the southern hemisphere and is a major exporter of several resources that have significant environmental effects, most notably coal and uranium.

Australia has the largest reserves of uranium in the world and there has been a number of enquiries on uranium mining. The anti-nuclear movement in Australia actively opposes mining and seeks to prevent the construction of nuclear power plants.

At least 150 leaks, spills and licence breaches occurred at the Ranger uranium mine between 1981 and 2009.

Controversial land use projects

The following is a list of development projects that have been controversial due to concerns of environmental effects. This list includes projects required to submit an Environmental Effects Statement.