Australian cities are expected to reach 50 degrees by 2040 even if the Paris climate change target is met, a study published on Wednesday has warned.
Australian National University researchers in Canberra said the heatwave highs are a possibility if the two degree target is reached, according to its study published in the science journal Geophysical Research Letters.
The researchers used observational data and simulated climate models to assess future extreme weather events in New South Wales and Victoria, examining what weather extremes might look like if the Paris agreement of a maximum two degree increase is met.
Lead researcher climate scientist Dr Sophie Lewis said Sydney and Melbourne could expect 50 degree temperatures under the climate change target.
“What previous studies have done is look at changes in the frequency of record-breaking temperatures, so for example, how much more common 40 degree days might be in future,” Dr Lewis said.
“Our study wanted to look at what the maximum temperatures in an extreme summer of the future would be. That is what we need to know to plan for the future.”
“We know that two degrees of global warming doesn’t sound like much of an increase but it in fact will lead to extreme weather events becoming more severe.”
They said however it could be prevented by limiting global warming to 1.5 degrees, the best-case scenario target set under the Paris agreement, but they did not project what temperatures could be reached under the reduced target.
She said governments needed to start thinking about how cities would cope including meeting energy requirements, how public transport systems could handle extreme temperatures and how emergency departments would respond to increased demand from people vulnerable to heatstroke.
“The only thing we can do to prevent these extremes is to reduce our greenhouse gas emissions as quickly and deeply as we can, though some warming is already locked in the system so we will see some increase in the extremity of temperatures,” Dr Lewis said.
However, Environment Victoria chief executive Mark Wakeham called the findings “alarming.”
“It’s preposterous that in the face of these warnings and clear signals that we don’t have a plan to cut emissions,” he told The Guardian.
“We must dramatically improve our built environment to cope.”
He said greater efforts needed to be made to keep cities cool, including incorporating more shade into cities and towns as well as improving energy efficiency and cooling in homes.
“We also need updated emergency management plans for extreme heatwaves,” he said.
“This study by respected researchers confirms that climate change is not just an environmental disaster but it presents an enormous challenge to human health and the economy.”
“I don’t think we have any plans in place that would be adequate to withstand days of 50 degrees and it is another urgent warning to our leaders and all levels of government that we need a strong plan to cut commissions and deal with climate change.”