Other Impacts of El Niño in Australia

Drought, of course, has devastating consequences, particularly for the farming community within Australia. Likewise, bushfires can take lives and destroy property on a frightening scale, not only in rural areas but also in the forested fringes of our major cities. It is then that we take notice of the role that the El Niño phenomenon plays in our weather. However, the less obvious impacts of El Niño can be just as important in terms of their consequences for human life and for the long term health of our environment.

Sometimes El Niño episodes bring heatwaves to parts of Australia, as for example in the period preceding the Ash Wednesday bushfires during the 1982-83 El Niño. The impacts of such heatwaves include death from hyperthermia and excessive demand on the power supply due to increased use of air-conditioning. The elderly, the very young, and those who are sick or obese are at risk of heat-related illness during such events. Death rates in cities tend to peak and, according to research evidence, aggressive behaviour (street offences, riots) escalates during heatwaves.

Prolonged drought conditions associated with El Niño episodes can also cause long term soil erosion and loss of biodiversity.  In the severe drought conditions of 2005-2007, there was risk of irreparable damage to the extensive River Red Gum habitats of the Murray-Darling Basin of eastern Australia owing to reductions in river flow. Without the diversion of waters to refuge areas such as at Hattah Lakes and on the Chowilla floodplain and Lindsay-Walpolla Islands, the loss of habitat could have been total. Similar well documented impacts of the recent droughts exacerbated by negative human impacts include those on the bird habitat of the Macquarie Marshes of NSW and on native fish populations along the whole of the Murray Darling Basin.  Often such impacts are relatively short term (years only) and reversible. However, when combined with the rising mean atmospheric temperatures arising from global warming, the oscillating pattern of droughts associated with the El Niño phenomenon increases the risk of savage destruction beyond our capacity to manage.