Farming
Land cleared for farming has been a major cause of loss of habitat and hence biodiversity. Agriculture uses two-thirds of Australia's freshwater, and water taken for irrigation has had a negative effect on the ecology of Australia's rivers, such as the Murry-Darling. Agricultural run-off drains chemicals from pesticides and fertiliser into waterways - run-off from banana plantations has been cited as a threat to the Great Barrier Reef. Soil depletion and increasing salinity are other problems caused by overusing marginal land.
Yet farmers have a key role to play in developing more sustainable, water-efficient, chemical-free farming that restores natural flows to waterways and incorporates regeneration of bushland. And farmland might generate much of Australia's future energy with wind farms and biofuels.