This January, Earth lost plants and peat soils that are remaining fragments of a ecosystem from the Cretaceous period. Found only in Tasmania, these particular plants and soils took a thousand years or more to grow and form, and in one month many disappeared in wildfires, perhaps forever. Scientists point at climate change as the underlying cause of recent wildfires in the UNESCO Tasmania Wilderness World Heritage Area (WHA) that preserves the last ecosystem remnants from the supercontinent Gondwana that broke apart 180 million years ago.
The fires began in mid-January when extensive dry lightning struck Tasmania’s high-altitude rainforests and bogs that were uncharacteristically dry due to record-breaking low rainfall. These ancient habitats survive on western Tasmania’s high central plateau protected by its wet climate and the absence of the fire-dependent vegetation found elsewhere in Australia. Fire hadn’t been a regular part of this environment for many millions of years.
The combination of a strong rainless lightning storm occurring in an unusually dry rainforest used to occur once in a millennium, or even less often. Yet such combinations have been happening with more frequency in the past fifteen years and now are viewed as a fire regime change that is the primary threat to continued survival of these Gondwana ecosystems.
Fires became more common after European colonization due to human activities like campfires, mining, and arson and have resulted in areas permanently changed from alpine vegetation to fire-dependent plant communities. This increases risks from the new regime of frequent dry lightning storms. The creation of the WHA protection brought more control of fires caused by direct human action, but those resulting from lightning have increased.
The Guardian explains why climate change is responsible for the combination of low rainfall, high desiccating temperatures, and dry lightning that created Tasmania’s wildfires.
The fires were preceded and aggravated by the coincidence of two natural climate events – the Indian Ocean dipole and the Pacific El Niño. The cooling of the east Indian Ocean caused Tasmania’s usually drenching spring rains to fail almost completely. El Niño also tends to bring hot, dry summers. These natural phenomena happen on a timeframe of decades, not centuries. Confluences have occurred before, yet the forests did not burn [….] One telltale sign of climate change is that these fires were set by storms not people. Lightning was expected to increase under climate modelling, says David Lindenmayer, a professor of ecology and conservation biology at the Australian National University in Canberra.
A 2011 Princeton study looked, for the first time, at day to day weather variations as opposed to comparing monthly averages. The researchers found that day-to-day weather is increasingly “erratic and extreme, with significant fluctuations in sunshine and rainfall affecting more than a third of the planet.”
… extremely sunny or cloudy days are more common than in the early 1980s, and swings from thunderstorms to dry days rose considerably since the late 1990s. These swings could have consequences for ecosystem stability and the control of pests and diseases, as well as for industries such as agriculture [….]
Although the most extreme weather variations in the study were observed in the tropics, spurts of extreme weather are global in reach [….] Storms are violent and significant events — while they are individually localized, their disturbance radiates," Rossow said.
In Tasmania, almost twice as many lightning-strike wildfires have happened in the past 13 years as in the prior ten years. In near-by Victoria, major fires that formerly occurred every 75 to 120 years now happen every 20 years, on average.
“That’s what other people have been forecasting is going to happen,” Lindenmayer says. “We are going to see more fires, over larger areas, that are more frequent and of higher severity. What we are seeing in Tasmania would appear to be a manifestation of that [….]
“The implications of this are, of course, goodbye Gondwana. Because Gondwana can’t live in this sort of world.”
Over 50 fires in the WHA have burned 177,915 acres, including bogland, peat soils, and unique alpine flora like pencil pines, king billy pines and cushion plants, some more than 1,000 years old. A report from the fire areas shows devastated landscapes with some vegetation that may not regenerate.
Ecologist Professor Jamie Kirkpatrick is also upset by the loss of alpine flora. "They're killed by fire and they don't come back," said Professor Kirkpatrick. "It's a species that would have been around in the cretaceous period. It's regarded as one of the main reasons for listing Tasmania as a world heritage area.”
Fire ecologist David Bowman said the fires burning in Tasmania were a sign of climate change.
"This is bigger than us. This is what climate change looks like, this is what scientists have been telling people, this is system collapse.”
Designation of the 9,818 square miles of old growth Gondwana ecosystems (20 percent of Tasmania) as a UNESCO Tasmania Wilderness World Heritage Area involved over 30 years of contentious battling among loggers, conservationists, and area paper mills. And some battles were re-fought and won during the administration of Australia’s previous Prime Minister when Abbott proposed delisting the WHA to allow logging. The presence of these ancient ecosystems and of 20,000 year old aboriginal remains supported the 1982 UNESCO protection. But what protects Tasmania's World Heritage Area from climate change consequences?