Global heating of 3C would more than double the number of annual heatwaves in some parts of Australia, leave properties uninsurable due to flood and fire risk, and make many of the country’s ecosystems “unrecognisable”, according to Australia’s leading scientists.
The Australian Academy of Science is calling on the Morrison government to accelerate the country’s transition to net zero greenhouse gas emissions in a report that examines what Australia could look like in a 3C world.
The analysis paints a grim picture in which heatwaves in states such as Queensland would occur seven times a year and last for 16 days at a time, and unprecedented fire seasons such as the 2019-20 fire disaster become a regular occurrence.
The report’s authors said what Australia and other countries did to reduce emissions over the next decade would be critical as it would determine what occurred in the second half of this century.
“When we sum up what’s happening, we’re not doing enough and we have to change the game to avoid a very consequential future,” Prof Ove Hoegh-Guldberg, a biologist and climate scientist at the University of Queensland, said.
The planet has already warmed by 1.1C since pre-industrial times and, based on current commitments by countries under the Paris agreement, is on track for an average 3C temperature rise.
The report considers how that would affect Australia’s ecosystems, food production, cities and towns, and health and wellbeing – and what Australia’s contribution must be to ensure global heating remains well below 2C, as promised under the 2015 global climate deal.
Prof Mark Howden, from the Australian National University Climate Change Institute, said Australians had already experienced increased heat and reductions in rainfall as a result of the climate crisis.
He said a 3C world could lead to “heat stress” temperatures being a daily occurrence in northern parts of Australia. Nationally, what was once considered a hot year would become a cool year.
He said this would pose significant challenges for food systems and human health but “there are adaptive measures we can put in place”, such as better warning systems for managing the health effects of heatwaves and floods, and designing clean and green hospitals “for the future and not the past”.
While its assessment of a 3C world is bleak, the report paints a much more positive picture of what governments can do now and over the next decade to keep global heating to within 2C.
The scientists write that Australia lags behind the best practice demonstrated by many other countries. Their 10 recommendations include a call for the Morrison government to accelerate the transition to net zero emissions “given how much Australia stands to lose if GHG [greenhouse gas] emissions are not reduced”.
They also recommend governments improve their understanding of climate impacts, including tipping points and the compounding effects of multiple stressors at global heating of 2C or more, so that Australia can develop effective adaptation responses.
The report calls for a systematic exploration of how Australia should prepare its food production and supply for a worsening climate crisis, and improved understanding of the risks of climate change to human health.
Prof Frank Jotzo, from ANU’s Crawford School of Public Policy, said achieving the goals of the Paris agreement would require accelerated investment in renewable energy, energy storage and electricity transmission.
He said reducing transport emissions, which account for about 19% of Australia’s current carbon pollution, was the next major and necessary step, and that an electric vehicle fleet would also present “a handy opportunity for decentralised electricity storage”.
“The costs of reducing global emissions are much less than the cost of adapting to the impacts of unrestrained global warming,” Jotzo said.
Prof Lesley Hughes, an ecologist and pro vice-chancellor at Macquarie University, said there were steps the Morrison government could take immediately to encourage the uptake of electric vehicles, rather than inhibit it.
“Delay is as dangerous as denial,” she said.
“The main message we would have for the federal government is that what we do, as well as the rest of the world, in the next decade … that’s the critical thing.”