2°C OF WARMING COULD WIPE OUT RARE AUSTRALIAN BIRD

But holding warming to 1.5°C gives the species a fighting chance

A new report from the World Wide Fund for Nature-Australia, in collaboration with Deakin University, predicts if climate change causes a 2°C increase in temperature, one of the nation’s rarest and most colourful birds will lose 62% of its habitat.

That loss of habitat, combined with other human-caused impacts, could wipe out the purple-crowned fairy-wren.

But holding warming to 1.5°C would retain 61% of its habitat – enough to give the species a fighting chance.

At 2°C, far north Queensland’s rainforest ringtail possums, like the green ringtail and lemuroid ringtail, also face an extinction threat.

Globally, scientists predict devastating harm to nature, people and communities at 2°C of warming.

The loss of individual, cherished species is another way to show what’s at stake in the lead up to a crucial climate target announcement by the Australian government due in 2025.

“Our research shows that for some vulnerable Aussie species, the difference between 1.5°C and 2°C is huge. At 2°C, purple-crowned fairy-wrens and our cloud forest possums could be gone forever. Their survival depends on what we do over the next five years,” said Dr Leonie Valentine, Senior Manager, Species Conservation, WWF-Australia.

“Modelling shows that fractions of a degree in warming can make an enormous difference to many species. For the species we looked at, stabilising warming to 1.5°C, rather than letting it hit 2°C, would retain more suitable habitat,” said Deakin University’s Dr Carla Archibald who completed much of the modelling for the report.

“More habitat means a better chance to persist, especially as species will also face additional threats such as land use change, invasive species, and other challenges,” Dr Archibald said.

Dr Valentine explained why purple-crowned fairy-wrens, which weigh less than a 50 cent piece, are threatened with extinction.

“These birds require dense vegetation beside waterways for survival, but that type of riparian habitat only occurs in patches throughout northern Australia.. At 2°C of warming these already small areas of habitat will reduce by such an extent that populations will become increasingly unviable.

“Droughts and heatwaves diminish breeding success, fairy-wrens perish after bushfires destroy habitat, and floods wash away nests and nesting habitat. As climate change causes these events to become more frequent and intense, many populations could be wiped out one by one,” Dr Valentine said.

Green ringtail and lemuroid ringtail possums are now restricted to cool, moist, high-altitude rainforests which have already been significantly degraded through changing climates and land use.

Rainforest ringtails previously occurred from 350-450 metres altitude and higher. Over the last 20 years, because of climate change, they have retracted to cooler habitat at higher altitudes and are now rarely observed below 700 metres.

At 1.5°C of warming, these species will experience serious challenges, but their habitats could still offer some refuge.

But at 2°C, the increased frequency of extreme heatwaves is predicted to trigger crashes in populations as the ringtails struggle to survive for more than 4 days above 30 degrees.

Previous research from James Cook University has shown that lemuroid ringtail possum numbers have declined by 68% since 2011 and are expected to decline by 80% in the next 8 years. This species could be extinct in the next decade.

Under the Paris Agreement, Australia must submit emissions reduction commitments known as Nationally Determined Contributions (NDCs). A new 2035 NDC is due in 2025.

The best available climate science shows that for Australia’s new 2035 NDC to be aligned with pursuing efforts to stabilise temperatures to 1.5°C it must be at least 90% below 2005 levels by 2035 and net zero before 2040.

“Australia needs strong, science-based targets aligned with stabilising warming at 1.5°C. It’s a crucial step towards climate action to give our unique wildlife a future and provide us with a chance of maintaining the ecological balance that sustains life in this country,” said Ariane Wilkinson, Senior Manager, Climate and Energy Policy, WWF-Australia.

“When we have our house in order then we must encourage and support all other countries to do the same.

“At 1.5°C we’ll still be in for a rough ride but within the lifespan of our youngest children, we could return the global climate to a stable state,” she said.