The Australian capital cities of Adelaide, Melbourne and Canberra are already experiencing the hot weather conditions predicted for them for 2030, a report on heatwaves says.
The alarming revelation comes from a report released by The Climate Council which wants significant reductions in greenhouse gas emissions to limit further increases in heatwaves.
Its report, Heatwaves, Hotter, Longer, More Often, shows that over the decade of 2000-2009 the number of days above 35C has already reached the levels previously projected for 2030 in these three capital cities.
The report predicts that northern and southern Australia's current one-in-20 year extreme hot days are expected to occur every two to five years by the middle of the century.
Climate Council member Professor Tim Flannery says the report shows heatwaves are hotter, longer, more frequent and occurring earlier in the season.
They are also killing people and can be described as one of Australia's most dangerous natural hazards. Over the past 100 years heatwaves have caused more deaths than any other natural hazard.
Without action on greenhouse gas emissions they could cause an additional 6214 deaths by 2050 in Victoria alone, the report says.
Its other wide ranging consequences include extending bushfire seasons, impacts on public transport, electricity services, wildlife and Australia's coral reefs.
"A CSIRO study released just last week detailed coral bleaching due to a heatwave in Western Australia," Prof Flannery said.
The report says that limiting further increases in heatwaves can only be done by urgent and significant reduction in the emission of greenhouse gases.
"This is a critical decade if we want to prevent heatwaves getting even worse," Prof Flannery said.