Extract from ABC News
Fire authorities say Australians should not hang the risk of a hot, dry summer on the declaration of El Niño, with rampant vegetation growth through parts of Australia heightening this year's chance of bushfires.
Key points:
- The Bureau of Meteorology has again held off on declaring an El Niño event underway
- Experts say Australians should be preparing for a bad bushfire season regardless
- Heavy rainfall has increased the risk of fires this year
The potential onset of the major climate driver has made headlines for months, with most international meteorological organisations, including the World Meteorological Organisation, announcing the event is already underway in the Pacific.
But to date Australia's Bureau of Meteorology has been reluctant to agree, keeping the odds at a 70 per cent chance of developing in their climate update on Tuesday afternoon.
The event has a major and lasting influence on the world's weather, with Australia particularly vulnerable to its impacts.
But how much difference does an El Niño declaration actually make?
When it comes to preparedness, experts say not much.
Dry spring likely
In Australia, El Niño favours hotter, drier weather — particularly in the eastern states, with links to some of the worst bushfires in Australian history, including Ash Wednesday.
But it is not the be all and end all of Australia's climate.
Should an El Niño be declared, climatologists have said it would give the Bureau and emergency services more predictability about dry and hot conditions during the summer.
But the long-range outlook for the next three months, which takes into account all influences from the oceans and atmosphere, shows a dry signal for spring regardless.
That dry signal softens slightly for the October-December outlook.
These models are factoring in the likely development of El Niño, however, and would change if it did not develop as expected.
But a Bureau climatologist said in a statement there were still other drivers for warmers temperatures at play, including global warming.
"This is supported by observations where there is a lot of warmth around the globe currently.
"The models are more confident of a warmer spring and summer, than they are about whether rainfall will be wetter or drier."
'Large amount of fuel'
After three subdued fire seasons under the La Niña climate pattern, this season is likely to see an increased number of active fires across the country, according to Australasian Fire Authorities Council (AFAC) chief executive Rob Webb.
Mr Webb said recent wet years had triggered excessive regrowth of vegetation, increasing the fire risk, particularly in grassland areas.
"We often think of La Niña and we equate it with flood conditions across the eastern part of Australia, but what it also brings is large amounts of grass growth," he said.
"What we've seen over three years is a large amount of fuel over central and northern New South Wales, and into Queensland, and into the Northern Territory.
"So eventually, when the climate dries out, that grass fuel tends to become like tinder and that increases the risk."
Australia's most intense bushfires are often associated with forest fires.
But grass fires are equally as dangerous, according to the Climate Council, as they can start easily and spread quickly – up to three times faster than bushfires.
High fuel loads, particularly grasses, have caused fires to rip through the Top End and Central Australia over the past week, with authorities expecting 80 per cent of the Northern Territory to burn from bushfires by March.
Mr Webb said this season was unlikely to be another Black Summer, but that didn't negate the risk of bushfires and Australians needed to prepare.
"We'll be watching closely to see how quickly those fuels dry out, how quickly the temperatures increase into the summer months," he said.
"It only takes a short time of the 40-plus temperatures and very windy conditions to create that tinderbox that you need to drive bushfires."
Data from the Bureau shows rainfall over the past year has been above average on the whole, but July was drier than average for much of southern Australia.
AFAC will release its official spring bushfire outlook next week, and its summer outlook at the end of November.
If an El Niño is declared it would make it the first event in eight years.
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