Australis - a sunburnt country

Scorchers: the reality of a sunburnt country

As searing temperatures swept across the country this week, Australians got a strong indication of summers to come. Peter Hannam asks if we are prepared for hotter days.

Peter Hannam

SMH,

18 January, 2014

Before the 2009 heatwave that primed Victoria for the Black Saturday bushfires, Melbourne had never recorded a day where the temperature averaged above 35 degrees. That event delivered two of them.

This week's heatwave, which halted play at the Australian Open tennis and pushed the state's power sector to its limits, delivered three more such days with average temperatures over 35 - and a record four days with maximums over 41 - in a row.

"Most people want to know what's going to happen."

While the severity of the blistering conditions across southern Australia over the past week will fall short of the ferocity of the event five years ago, this hot spell will likely join 2009, 1939 - also a bad year for bushfires - and 1908 as recording the country's most significant heatwaves, said David Jones, head of climate monitoring at the Bureau of Meteorology.

"How intense is the heat, how long does it last, what's its spatial extent - it's up there with those three historical events," Jones said.

Heat-related deaths were predicted to come close to the 2009 tally, with reported cardiac arrests by Friday running four times that of a typical summer day in Victoria.

Sarah Perkins, a heatwave expert at the University of NSW, says heatwaves in Australia are arriving earlier in the season, are more frequent, more intense, and more prolonged. Previous major heatwaves, such as in 1939, are also linked to major bushfires. Along with the projections for more intense heat, research also shows fire-danger ratings are on the increase across south-eastern Australia. Australians will need to adapt to major changes in their lives - along with much of the world.

"For the first half of this century, we expect these [heatwave] trends to continue," said Lesley Hughes, a professor studying climate change and ecosystems at Macquarie University. "Whether they continue beyond 2050, will be really up to how well we've reduced [greenhouse gas] emissions,''she said.

While sea-breezes spared much of Sydney and the coastal strip north from this week's heat, few other affected regions were so lucky. Adelaide, Melbourne and Canberra each reached 40 degrees on Thursday for a second day in a row, and had only done that before on single days over the past 70 years of records. Canberra's Friday maximum just missed making it three days in a row.

No El Nino this time

The 2009 heat cell was so extreme, it set maximum readings so high that only a few sites will break those records this week. But 2009 was also part of an El Nino year, when climate conditions over the Pacific Ocean tend to trigger higher temperatures over eastern Australia.

The El Nino-Southern Oscillation was in a neutral phase during January 2013's continent-wide heat dome, which set up that month as Australia's hottest in more than a century of standardised records, making events over the past two years even more remarkable.

"That's what I'm most concerned about - we're seeing these record-breaking events in non-climate conducive years," said Perkins. "A lot more of it is the climate signal because in an El Nino year we could attribute some of it to natural variability."

Despite those signals - and significant research into climate change - Australians remain poorly prepared for the likelihood that conditions such as intense and prolonged heatwaves will become more common.

Wang Xiaoming, a senior principal scientist at CSIRO, said lip-service is often paid to the issue but little more.

"If you're looking at the current building codes, if you're looking at engineering design standards, actually there's nothing considering future climate change at the moment," Wang said.

Building standards and design can make a big difference. According to CSR, a building materials producer, lax standards in the past mean the power system is strained each time an extreme event - hot or cold - arrives.

A prototype home design by CSR in western Sydney shows what can be achieved with products already on the market. When the city was breaking its maximum heat record on January 18 last year the house remained about 15-16 degrees cooler than outside temperatures without the need for any airconditioning, the company says.

Energy strains

Soaring airconditioning demand was key to power demand surging close to the record 2009 high this week in Victoria, prompting Premier Denis Napthine to plea for consumers to turn off unnecessary appliances.

For the past two years, Australian standards have required all new airconditioners to be fitted with devices that allow power companies to remotely switch off power-sapping compressors to ease strain on the system. Many older devices also have the capability, but it has not been used except in limited trials, said Hugh Saddler, from energy consultants Pitt & Sherry.

"You can take a hell of a load off the system," Saddler said. "It needs to be seriously looked at and coupled with some price incentives."

There are other ways communities and infrastructure can cope with heatwave-related extremes. The penetration of solar photovoltaic panels helped limit wholesale power prices and provide a supply buffer during the past week's demand surge.

According to the Australian Renewable Energy Agency, solar PV contributed more than 11 per cent of SA's power on Monday, and more than 9 per cent on other days of the heatwave. Victoria, with a much lower PV penetration, still got more than 3 per cent of its power from rooftop panels, based on data collected from some 1700 systems.

New research by the Alternative Technology Association suggests that even with modest assumptions for technology improvements in solar power many communities and households will find it attractive to drop off the grid within a few years in "a quick and dramatic" change.

"A shift to cost-effective standalone power solutions appears highly plausible by 2020, in a wide range of market segments," the report said, citing a study of Bendigo, Werribee and parts of inner Melbourne.

'Silent killer'

Adjustments in other parts of society may be a lot more painful, with heatwaves dubbed the "silent killer" because they led to more deaths than other natural events such as fires and cyclones but with much less publicity.

Excessive heat during the run-up to Black Saturday probably killed about 500 people in SA and Victoria.

John Nairn, a global authority on heatwaves who works at the Bureau of Meteorology in Adelaide, said the toll from this week's heat will probably be "a little lower than in 2009 but not much less".

While the maximum temperatures are significant, the lack of cooling overnight can be critical. "If there's not sufficient relief, the burden of excessive heat keeps on building on people," Nairn said. "Eventually…they crumble."

Crops and creatures

The impacts of climate change are showing up in other fields. Grain prices globally are two or three times more volatile in the past decade than over the previous 40 years or so, said Steven Crimp, an agricultural crops expert at CSIRO. "We're starting to get changes in the frequency [of temperature extremes] and that's playing havoc with established ways farmers have timed their plantings," he said.

Rising temperatures and possible lower rainfall have the potential to cut future farming output sharply. Average temperature increases of 4 degrees - not beyond the range of some forecasts for this century - and a 10 per cent drop in rain, could cut output by 50-60 per cent, Crimp said.

Livestock also tend to fare worse as temperatures rise. An increase in the so-called "pant rate" - when animals spend more time panting than eating - hurts milk output from cows and does little good for their overall health.

Longer-term planning to cope with an increased frequency of heatwaves won't come cheap. Ignoring the signs, though, will probably be more difficult as information becomes more refined.

Smaller scale

Daniel Argueso, a post-doc researcher at UNSW, is part of a team developing the NSW/ACT Regional Climate Modelling system that will deliver resolution of impacts down to a 10-kilometre scale, compared with the 150 kilometres used now.

Sydney, for instance, is given the same climate under the large-scale model as the Blue Mountains despite its quite different topography.

Such a system will be rolled out by the end of this year - with similar information eventually available nationwide - and made public.

"We're going to improve the description of climate greatly," Argueso said. "Most people want to know what's going to happen here where we live."