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Living in Tasmania stories

SAM fires up our hottest summer

Edtion 170 Fire fighters spent six weeks in the bush battling blazes like this. Image courtesy of the Tasmanian Fire Service

Tasmania has just experienced its hottest summer ever recorded, with temperatures 1.8 degrees higher than average.

Seawater around our coasts was up to 3 degrees warmer than average and was linked to a crippling outbreak of Pacific Oyster Mortality Syndrome and a production challenge for salmon farmers in Macquarie Harbour.

Low rainfall and ferocious dry lightning strikes sparked bushfires that raged for a month and a half, while Hydro Tasmania’s dam storages have dived to an unprecedented 13.6 per cent.

While some simply rail against the Tassie weather, others are sure we're experiencing human-induced climate change.

As scientists work on answers, a phenomenon called SAM (the Southern Annular Mode) has emerged as a part-explanation for what is happening – if not for why.

Dr Michael-Shawn Fletcher and PhD student Michaela Mariani of the University of Melbourne have found that a southerly shift in prevailing westerly winds is disturbing weather patterns previously regarded as normal.

Dr Fletcher, who has built a career studying long-term interactions between humans, climate and vegetation, said: “My conviction is that the current trend is evidence of anthropogenic forces.”

During a negative SAM westerlies shift northward, but during a positive SAM, like the 2016 version, the winds move south. Tasmania then misses out on the moisture the winds carry and drier conditions prevail.

As the cold fronts that make our weather so changeable slip away to the south, the consequences can be grim.

The Melbourne study included an analysis of charcoal deposits from western Tasmanian fires over the past 1,000 years, including some that had occurred on the same ground as the 2016 fires.

The rise and fall in the amount of charcoal deposited since around 1,500AD closely matches a SAM index compiled by scientists.

There has been a particularly steep rise in charcoal in recent times.

“Correlation isn't causation,” Dr Fletcher said. “But it’s a well-described phenomenon that ozone depletion has caused a positive trend in SAM and we’ve got clear evidence that the SAM index in the 21st century has exceeded anything that’s occurred in the past 1,000 years.”

The researchers also found a close match between actual records of SAM and observed fire activity over the past 30 years.

“If you have a dry autumn, winter, spring you’ve got more fires in summer,” Dr Fletcher said.

The research, published in Geophysical Research Letters by the American Geophysical Union, concluded that "there had been a spike in fire activity in the 21st century in response to natural and anthropogenic SAM trends".

Dr Fletcher said while the impact of the Pacific Ocean’s El Niño (a seasonal warming of the sea surface) on fire frequency in Tasmania had been recognised, relatively little attention had been paid to the impact of SAM.

“We've ignored the fact that in Tasmania, at least, fires are also modulated by this other system,” he said.

“What we have here in this current year is the fifth-strongest El Niño event recorded and the second most positive SAM event on record. It’s a double whammy.”

UTAS’s senior fire ecologist, Professor David Bowman, said the Melbourne research opened up a possibility of using SAM to provide early warnings of severe fire conditions.

In a report in Environmental Research Letters, Professor Bowman, argues that Australia’s highly varied climate makes it difficult to predict fire activity.

Professor Bowman said: “You can’t predict precisely, but you can use climate modes like SAM to help you forecast bad fire seasons.

“It’s just a guide, but it’s important.”

Professor Bowman said: “Large-scale fire events in Tasmania in the past have been very rare and we're beginning to see them more frequently. There’s evidence we're seeing anthropogenic climate change.”

He described this summer’s fires in usually moist western regions as "an historically significant event".

Among those who strongly agree, is The Guardian’s Karl Mathiesen who went so far as to compare the Tasmania’s fires with the destruction of ancient Palmyra by ISIS.

He wrote: “On 13 January a huge, dry electrical storm set more than 70 fires rampaging across the island. Within days the flames tore through the dried-out defences and into the world heritage area above.

“For more than a month, fire has rolled back and forth across the fragile plains.

“The beginning of its end is a theft from us all. Two-thirds of the plant species on the plateau exist nowhere else on earth but Tasmania.

“According to one estimate, 4 per cent of the world’s remaining pencil pines – among the longest living of all trees – have been lost in these blazes.”

Mathiesen included in his report the important fact that damage has been limited to 22,000ha (about 1.4 per cent) of the vast World Heritage Area.

But he left his readers to ponder the identity of the "ISIS" that had unleashed its vandalistic fires on a slice of Tasmania’s Palmyra.

Some less-circumspect critics of the stretched and heroic State Fire Service and Federal and State leaders talked about the "previously fire-free" World Heritage Area.

This ignored the scientific records used by Dr Fletcher and also disregarded what we know of Aboriginal land management in Tasmania over the past 30,000 years.

The role of Aborigines in managing landscapes with fire – using regular small-scale burns to avert mega-fires – is important in understanding our fire history and could offer a way to manage our fire future.

Author Bill Gammage suggests in his intricately researched book, The Biggest Estate on Earth, that Aborigines used skilfully controlled and frequent fires over long periods of time to shape the landscape from Cape York to Tasmania.

European settlers were generally unaware that the park-like gazing land they took over in eastern Australia was not a natural landscape, but a gigantic game park carefully constructed and maintained by thousands of generations of people with fire sticks.

The fine detail of how the Aborigines burnt different types of natural vegetation in Tasmania to encourage marsupials and to preserve plant diversity was lost forever in the post-settlement holocaust.

Modern Tasmanians, including Aborigines, need to do some re-learning in a vulnerable eco-system that is now at risk of having the moisture squeezed out of it again and again by further coincidences of SAM and El Niño.

In a recent article in Wild magazine, Melbourne-based writer and conservationist, Nick Rodway, wrote: “The conversation as to the implementation of fire stick farming will no doubt continue for some time.

“Fire stick farming has an ancient history and is not something that should be dismissed lightly, and nor should the influence of Aboriginal Australia on the landscape.

“Their lessons serve us well if we choose to embrace them.”

4 April 2016, Tasmania’s Stories Edition 170

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Facts about Tasmania

Tasmania

Tasmania is the southernmost state of Australia, located at latitude 40° south and longitude 144° east and separated from the continent by Bass Strait. It is a group of 334 islands, with the main island being 315 km (180 miles) from west to east and 286 km (175 miles) north to south.

Tasmania

Tasmanians are resourceful and innovative people, committed to a continually expanding export sector. In 2012–13, international exports from the state totalled $3.04 billion. USA, China, Taiwan, India, Japan and other Asian countries account for the bulk of exports, with goods and services also exported to Europe and many other regions.

Geography

Tasmania is similar in size to the Republic of Ireland or Sri Lanka. The Tasmanian islands have a combined coastline of more than 3,000 km.

Geography

The main island has a land area of 62,409 sq km (24,096 sq miles) and the minor islands, taken together, total only 6 per cent of the main island’s land area. The biggest islands are Flinders (1,374 sq km/539 sq miles), King, Cape Barren, Bruny and Macquarie Islands.

Geography

About 250km (150 miles) separates Tasmania’s main island from continental Australia. The Kent Group of Islands, one of the most northerly parts of the state, is only 55km (34 miles) from the coast of the Australian continent.

Climate

Twice named ‘Best Temperate Island in the World’ by international travel magazine Conde Nast Traveler, Tasmania has a mild, temperate maritime climate, with four distinct seasons.

Climate

In summer (December to February) the average maximum temperature is 21° Celsius (70° Fahrenheit). In winter (June to August) the average maximum is 12° C (52° F) and the average minimum is 4° C (40° F). Snow often falls in the highlands, but is rarely experienced in more settled areas.

Annual Rainfall

Tasmania’s west coast is one of the wettest places in the world, but the eastern part of the State lives in a rain-shadow. Hobart, the second-driest capital city in Australia, receives about half as much rain as Sydney.

Annual Rainfall

Annual rainfall in the west is 2,400 mm (95 inches), but hardy locals insist there is no such thing as bad weather, only inadequate clothing. If you travel 120 km east to Hobart, you experience a much drier average of 626 mm (24 inches) a year.

Population

The 512,875-strong community spreads itself across the land; less urbanised than the population of any other Australian state. Hobart, the capital city, is home to more than 212,000 people.

Capital City

Hobart nestles at the foot of kunanyi / Mount Wellington (1,270 m / 4,000 ft) and overlooks the Derwent Estuary, where pods of dolphins and migrating whales are sometimes seen from nearby beaches. Surrounded by thickly forested rolling hills, the city is home to the state parliament and the main campus of the University of Tasmania.

Capital City

Its historic centre features Georgian and Regency buildings from colonial times. Hobart is home port for coastal fishing boats, Antarctic expeditions and vessels that fish the Southern Ocean.

Land Formation

Mountain ranges in the south-west date back 1,000 million years. Ancient sediments were deeply buried, folded and heated under enormous pressure to form schists and glistening white quartzites.

Land Formation

In the south-west and central highlands, dolerite caps many mountains, including Precipitous Bluff and Tasmania’s highest peak, Mt Ossa (1617 m / 5300 ft). More than 42 per cent of Tasmania is World Heritage Area, national park and marine or forest reserves.

Flora

Vegetation is diverse, from alpine heathlands and tall open eucalypt forests to areas of temperate rainforests and moorlands, known as buttongrass plains. Many plants are unique to Tasmania and the ancestors of some species grew on the ancient super-continent, Gondwana, before it broke up 50 million years ago.

Flora

Unique native conifers include slow-growing Huon pines, with one specimen on Mt Read estimated to be up to 10,000 years old. Lomatia tasmanica, commonly known as King’s holly, is a self-cloning shrub that may well be the oldest living organism on earth. It was discovered in 1937.

Fauna

Tasmania is the last refuge of several mammals that once roamed the Australian continent. It is the only place to see a Tasmanian devil or eastern quoll (native cat) in the wild and is the best place to see the spotted-tailed quoll (tiger cat), all carnivorous marsupials.

Fauna

The eastern bettong and the Tasmanian pademelon, both now extinct on the Australian continent, may also be observed.

Fauna

The Tasmanian tiger, or thylacine, was Australia’s largest surviving carnivorous marsupial and is a modern day mystery. The last documented thylacine died in captivity in 1936 and although the animal is considered extinct, unsubstantiated sightings persist.

History and Heritage

Aboriginal people have lived in Tasmania for about 35,000 years, since well before the last Ice Age. They were isolated from the Australian continent about 12,000 years ago, when the seas rose to flood low coastal plains and form Bass Strait.

History and Heritage

Descendants of the original people are part of modern Tasmania’s predominantly Anglo-Celtic population.

History and Heritage

Tasmania was originally named Van Dieman’s Land by the Dutch explorer Abel Janszoon Tasman in 1642. The island was settled by the British as a penal colony in 1803 and the original name was associated with the convict era. It was changed to Tasmania when convict transportation stopped in 1853.

Economy

A resourceful island culture has generated leading-edge niche industries, from production of high-speed catamaran ferries and marine equipment to lightning-protection technology.

Economy

Tasmanians produce winches and windlasses for some of the world’s biggest ocean-going pleasure craft; large-scale inflatable evacuation systems and provide specialist outfit-accommodation services to the marine industry.

Economy

The Wooden Boat Centre at Shipwrights Point has re-established the skills and traditions of another age and attracts students from around the world.

Economy

Tasmania is a world leader in natural turf systems for major sporting arenas and in areas of mining technology and environmental management. Its aquaculture industry has developed ground-breaking fish-feeding technology and new packaging.

Economy

Tasmanians sell communications equipment to many navies and their world-class fine timber designers and craftsmen take orders internationally for furniture made from distinctive local timber.

Economy

The state is a natural larder with clean air, unpolluted water and rich soils inviting the production of 100 varieties of specialty cheeses, as well as other dairy products, mouth-watering rock lobsters, oysters, scallops and abalone, Atlantic salmon, beef, premium beers, leatherwood honey, mineral waters, fine chocolates, fresh berry fruits, apples and crisp vegetables.

Economy

Tasmania is a producer of award-winning cool-climate wines, beers, ciders and whiskies. Other export products include essential oils such as lavender, pharmaceutical products and premium wool sought after in Europe and Asia. Hobart is a vital gateway to the Antarctic and a centre for Southern Ocean and polar research.

Economy

The industries in Tasmania which made the greatest contribution to the State’s gross product in 2010–11 in volume terms were: Manufacturing (9.4%), Health care and social assistance (8.2%), Financial and insurance services (7.2%), Ownership of dwellings and Agriculture, forestry and fishing (each 7.1%).

Getting to Tasmania

Travel is easy, whether by air from Sydney or Melbourne, or by sea, with daily sailings of the twin ferries Spirit of Tasmania 1 and 2 each way between Melbourne and Devonport throughout the year.

This site has been produced by Brand Tasmania © 2014–2019

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