Climate scientists are warning that Melbourne and Sydney should prepare for sweltering days when the temperature reaches 50 C degrees, if the current global warming trend is not reversed.

"If we have the globe warming by 1.5 degrees, we're going to get very extremely hot days in Australia and they do have very serious consequences," said Dr. Sophie Lewis of Australia National University, co-author of a new study on the coming heatwaves.  "We're going to end up where we really have to be prepared and have alert systems for those hot days, just as people do in North America or Europe in terms of blizzards," she added.

It means that even if the world somehow comes together around the goals of the Paris Climate Accord - limiting global warming to no more than 2 C Degrees above pre-industrial levels - Australia is still going to get quite a bit hotter.  The Bureau of Meteorology says Melbourne's hottest day was in 2009 when the temperature reached 46.4 C degrees, while Sydney peaked at 45.8 C in 2013. 

But Dr. Lewis says this sort of thing "could be an average year by 2025".  And if global warming tracks at 2 C, heatwaves for the major cities could come between the year 2040 and 2050. 

These heatwaves will take their tolls on education, productivity, and infrastructure, as well as the environment.  Unless Australia prepares for the eventuality, students will have to stay home rather than venture out in the searing heat; businesses will have to close; and buckling roads will become commonplace.

"We'll only be ready for those if we take that seriously and start planning for them now, just like we would for bushfires," Dr. Lewis said.