16 December 2016, The Conversation, Climate change played a role in Australia’s hottest October and Tasmania’s big dry in 2015. Climate change made some of Australia’s 2015 extreme weather events more likely, according to research published today in the Bulletin of the American Meteorological Society. As part of an annual review of global weather extremes, these studies focused on October 2015, which was the hottest on record for that month across Australia. It was also the hottest by the biggest margin for any month. October 2015 was also the driest for that month on record in Tasmania, which contributed to the state’s dry spring and summer, and its bad fire season. El Niño events usually drive global temperatures higher, and 2015 had one of the strongest on record. So were these records due to El Niño, or climate change? The research shows that while El Niño had some influence on Australia’s weather, it was not the only culprit. El Niño packed a punch – or did it? In 2015, a strong El Niño developed, with record high temperatures in the central equatorial Pacific Ocean contributing to 2015 being the hottest year on record globally (although 2016 will smash it). The Indian Ocean was also very warm. El Niño is often associated with warm and dry conditions across eastern Australia, particularly in spring and summer. The new studies found that for Australia as a whole, while El Niño did make the continent warmer, its direct contribution to record temperatures was small. Only in the Murray Darling Basin did El Niño make it more likely that the October 2015 heat would be a record. El Niño also played a small but notable role in the dry October in Tasmania. Read More here
Tag Archives: Bushfire
6 December 2016, Climate Home, Fire bombs: British Columbia prepares for infernos. The second part of our series on vulnerable communities finds BC taking radical action in the face of a pile up of fire threats. Can it move fast enough? Tasmania and British Columbia are kindred lands; wild outposts of Britain’s empire, never fully tamed by settlers, with cool capital cities and a laid-back reputation that attracts nature lovers and marijuana connoisseurs. But the two share a less merry distinction – they are both sitting ducks for catastrophic fire. The first article in this series found Tasmania’s capital Hobart facing the twin threats of climate change and a landscape over brimming with fuel because traditional fire management by Aborigines had ceased with colonialism. There are strong parallels in BC. As the climate warms, fires are predicted to become more severe, larger and occur more frequently in unusual times of the year. The times call for bold ideas. Here, authorities are attempting to avert danger with a scheme so radical that one fire scientist in Tasmania calls it “crazy”, although not as crazy as living in a tinderbox. “Almost every year for the last five years we’ve said: wow, this is the earliest start to a fire season in a long time or ever,” says Lori Daniels, a forest scientist at the University of British Columbia’s tree ring lab. The coastal region in BC gets more rain than the interior. Even so, the capital Vancouver’s northern slopes, where Daniels lives, are desperately exposed once the perennial summer drought arrives. Here the city has made trouble for itself. The hills around the harbour were once lined by old wet forests. But those have been logged and replaced by more flammable woods. “The forests that have grown back are very productive and are a really different structure and now we have more than a million people who live in the vicinity of those forests and are very active ignition sources,” said Daniels. In other words, Vancouverites have laid their bed and manage to set fire to it every chance they get. Read More here
5 December 2016, Climate Home, Fire bombs: Hobart lies in the path of climate disaster. Around the world, communities are living obliviously close to climate-driven fire disaster. In the first in a series of reports, Karl Mathiesen visits Hobart, Tasmania. Looking down on the Tasmanian capital of Hobart from Knocklofty – one of its surrounding hills – David Bowman describes a truly frightening scenario. A hot, northerly gale and rolling fireball turn the forest around us into a blast furnace. The oil-filled eucalyptus canopies explode. One by one, the hills around the city catch alight. Then with a great sweep the fire runs up the slopes of Mount Wellington. Chunks of burning w1ood are flung into the air and rain down on the city. Office buildings, churches, schools and homes (perhaps the one I grew up in) randomly burn. In all, he says, four or five suburbs are destroyed. That’s the catastrophe, Bowman says, that the residents of Hobart live blithely beside every summer. And the odds are steadily getting worse. Both on land, and in the atmosphere, humans are creating bigger and bigger problems for ourselves. This Climate Home series will examine a dangerous trend in three distinct but related landscapes – Australia, western North America and the Mediterranean. In each of these places, climate change adds what Bowman, a professor in fire ecology from the University of Tasmania, calls “the plus”: a dialling up of danger as weather patterns shift towards a more fire prone future. Read more here
11 November 2016, The Conversation, Firestorms: the bushfire/thunderstorm hybrids we urgently need to understand. Fire has been a driving force across Australia for millennia. Indeed, the health of many of our ecosystems is intrinsically dependent on fire. But bushfires are also one of our most frequent natural hazards, with a total cost estimated at A$340 million per year. In the past decade or so, extreme bushfires in southeastern Australia have burned more than a million hectares, claiming more than 200 lives and over 4,000 homes. Similar losses in other major urban areas have prompted questions about whether we are seeing a shift towards a significantly more hazardous fire regime, characterised by increasing fire frequency and intensity, and the development of catastrophic “firestorms”. While these extreme bushfires account for only a very small percentage of fire events, they are responsible for the lion’s share of bushfire-related losses. In contrast to typical bushfires, which spread across the landscape as well-defined burning fronts with smoke plumes perhaps a few kilometres high, extreme bushfires exhibit deep and widespread flaming and produce smoke plumes that can extend 10-15km into the atmosphere. At these altitudes, bushfire plumes can actually develop into thunderstorms (hence the term “firestorm”). As such, extreme bushfires become much more difficult for emergency services to handle, making them all but impossible to suppress and their spread difficult to predict. Read More here