Australia has always been a land of extremes. In a single year, we can experience heatwaves, floods, fires, cyclones and drought.
Australia’s highly variable climate is influenced year to year by large-scale drivers in the atmosphere and ocean, such as the El Niño–Southern Oscillation (ENSO). This variability is now occurring against a background trend of increasing mean temperatures because of anthropogenic climate change.
Since 1950, the number of heatwave days each year has been increasing in many urban centres and across Australia as a whole (Perkins & Alexander 2013, Steffen et al. 2014); 2013 was the hottest year since temperature records began in 1990. Since the 1970s, the increases in fire-danger weather have been significant across south-eastern Australia (Clarke et al. 2013, CSIRO & BoM 2014). The millennium drought, which saw much of southern Australia experience dry conditions between 2000 and 2010 (although in some areas the drought began as early as 1997 and ended as late as 2012), was followed by heavy rainfall (and associated flooding) across much of Australia during 2010 and 2011 (BoM 2015).
As the Australian climate continues to warm, the droughts and flooding rains of Dorothea Mackellar’s poetic description of our sunburnt country are projected to become more severe. Climate change could be considered as the greatest environmental challenge facing Australia.