Australia faces rising heat, floods and losses as warming increases

A landmark federal assessment released Monday warns that heatwave deaths, coastal flooding and widespread economic losses will accelerate across Australia as global temperatures rise, with some impacts rising sharply if warming reaches 3 degrees Celsius. The National Climate Risk Assessment, published alongside a National Adaptation Plan, models outcomes at 1.5, 2.0 and 3.0 degrees of warming and says no community will be immune from compounding and cascading climate risks.

The assessment projects that a 3 degree average rise would drive dramatic increases in heat related mortality, with heat deaths climbing about 444 percent in Sydney, 423 percent in Darwin and 250 percent in Melbourne compared with current baselines. It also finds that if populations remain unchanged more than 1.5 million people could face sea level rise and coastal flooding risks by 2050. Sydney, which now experiences about 31 days a year of coastal flooding, could see that rise to roughly 85 days at 1.5 degrees and more than 300 days at 3 degrees, the report says.

The document, which uses a global baseline of roughly 1.2 degrees warming and acknowledges Australia has warmed about 1.5 degrees since the...