How Aus­tralia’s Ex­treme Heat Might Be Here To Stay

Fiji Sun - - Aust/nz News -

Asec­tion of high­way con­nect­ing Syd­ney and Mel­bourne started to melt. Bats fell dead from the trees, struck down by the heat.

On the north­ern Great Bar­rier Reef, 99 per cent of baby green sea tur­tles, a species whose sex is de­ter­mined by tem­per­a­ture, were found to be fe­male.

In outer sub­ur­ban Syd­ney, the heat hit 47.3C (117F) be­fore a cool change knocked it down - to the rel­a­tive cool of just 43.6C in a neigh­bour­ing sub­urb the fol­low­ing day.

Scenes from a sci-fi novel de­pict­ing a scorched future? No, just the first days of 2018 in Aus­tralia, where sum­mer is in fierce form. With parts of the US suf­fer­ing through a par­tic­u­larly grim win­ter, ex­tremes in both hemi­spheres have trig­gered dis­cus­sions about the links be­tween cur­rent events and the build-up of car­bon diox­ide in the at­mos­phere.

Cli­mate change ‘no brainer’

The cli­mate sys­tem is in­cred­i­bly com­plex and no weather event can be di­rectly at­trib­uted to ris­ing emis­sions, but ev­ery­thing that is ex­pe­ri­enced to­day hap­pens in a world that is about one de­gree warmer than the long-term mean. Prof Andy Pit­man, the di­rec­tor of the ARC Cen­tre of Ex­cel­lence for Cli­mate Ex­tremes at the Univer­sity of New South Wales, says given the av­er­age tem­per­a­ture has risen it is a “no brainer” that the like­li­hood of the sort of heat that hit Syd­ney last week has also in­creased.

“It was a me­te­o­ro­log­i­cal anom­aly, but the prob­a­bil­ity works a bit like if you stand at sea level and throw a ball in the air, and then grad­u­ally make your way up a moun­tain and throw the ball in the air again,” he says.

“The chances of the ball go­ing higher in­creases dra­mat­i­cally. That’s what we’re do­ing with tem­per­a­ture.”

Record break­ing news

While it is record-break­ing that tends to make news, sci­en­tists say it is the un­bro­ken run of hot days in the high 30s and 40s that causes the sig­nif­i­cant prob­lems for hu­man health, and other life.

Health of­fi­cials in Vic­to­ria high­lighted the threat of heat­waves when they found about 374 more peo­ple died dur­ing an ex­treme three-day pe­riod in Jan­uary 2009 than would have been ex­pected had it been cooler.

There has, how­ever, been rel­a­tively lit­tle in­vest­ment in re­search into the health im­pact of es­ca­lat­ing max­i­mum tem­per­a­tures.

Pa­per on cli­mate change

A pa­per pub­lished in the jour­nal Na­ture Cli­mate Change last year said while a gov­ern­ment re­port called for greater fo­cus on the area 25 years ago, less than 0.1 per cent of health fund­ing since has been ded­i­cated to the im­pact of cli­mate change.

Prof Pit­man says Aus­tralia is yet to prop­erly con­sider the health risks of a warm­ing planet. Last year was Aus­tralia’s third­warmest year since records be­gan, ac­cord­ing to the Aus­tralian Bureau of Me­te­o­rol­ogy.

Glob­ally, it was the sec­ond or third warm­est, and com­fort­ably the hottest year in which there was not an El Niño weather sys­tem help­ing push up tem­per­a­tures fur­ther.

Put an­other way: it is now hot­ter with­out an El Niño than it was with an El Niño just a few years ago.

Peo­ple es­cape the heat at the iconic Bondi beach in Syd­ney, Aus­tralia.

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