Australia's intense heat and catastrophic bushfires are likely to become a yearly occurrence - with one Australian scientist saying global temperatures have been rising for a consecutive 333 months.
Professor Jeremy Williams, an ecological economist from Griffith University in Brisbane, said yesterday that the heat seen in Hobart and other areas of Australia was a direct example of the trend in global temperatures and climate change.
"If you're 27 or younger, rising monthly temperatures is all you've ever known.
"The chances of that happening randomly is one in 100,000," he said.
"If it is 42 degrees in Hobart, there is something seriously wrong. Climate change is here now. While this upward trend continues we have to face the inevitable prospect that there will come a point when societies will not be able to function effectively."
While seven of 20 of Australia's hottest days recorded since 1950 have occurred this year, temperatures there have yet to reach the record 50.7C recorded in 1960. The highest temperature recorded on Earth is 6C higher than Australia's record.
Niwa climate scientist Brett Mullan said the heatwave was being made worse by a lack of rain and clear skies. He said hot air was being dragged to the coast from the centre of Australia.
It was possible the near-record high of 34C in Dunedin at the weekend was caused through extreme hot air that saw record temperatures in Tasmania and ignited fires across the island state.
As temperatures soar across the Tasman, a New Zealand environment expert says no one can survive being out in such extreme heat for long.
Auckland University associate professor Chris de Freitas said it was crucial anyone exposed to the heat sought shelter.
"The effects are what we called extreme physiological strain - dehydration is the main symptom, the other, of course, is overheating, which is hyperthermia, which is an acute illness which over time that could even lead to death."
Dr de Freitas said the body would react quickly in extreme heat. "Without any cooling mechanism it would not take very long. It would depend on how well acclimated the person is, their fitness, health, age, body size - but you are talking hours rather than days."
- additional reporting: AAP