The Morrison government's 128-page plan, released last month ahead of the COP26 talks, was described by many as lacking in ambition and detail, with repeated calls to release the modelling that underpinned it.
The modelling only charts emissions reduction down to 85%, based on achieving the government's technology goals, in areas such as hydrogen, CCS and solar, and a "voluntary abatement incentive of up to A$25 per tonne of CO2 equivalent", leaving a 15% gap.
The 15% gap is filled by "further technological breakthroughs" based on the assumption that falling technology costs, such as in battery and solar PV, will continue to exceed expectations.
The key findings in the modelling suggest that voluntary action is assumed to be supported by the government either through an emissions reduction fund-style incentive for abatement activities and that all action by the private sector is done so voluntarily, "even when there are marginal costs up to A$25 per tonne of CO2 equivalent".
Many companies already have adopted hypothetical carbon prices to ensure their investments stack up. Woodside Petroleum's internal price is set at $80/t.
Grattan Institute energy director Tony Wood described the government's assumed carbon price as "extraordinarily low", given that the carbon price that was in place between 2012 and 2014 never got above A$22/t.
The government's figures shows the LNG sector's output rising by some 13% between today and 2050, while coal exports sector output will fall by half over the same period. Commodity and manufacturing sectors are all expected to rise substantially, thanks to the expected demand increases in lithium, copper and critical minerals.
Meanwhile it expects 90% of vehicles by 2050 will be electric, a massive jump considering they currently make up 1% of Australian vehicles on the road today.
The modelling also explores an alternative scenario where Australia does reach net-zero emissions by 2050, however it found that the higher abatement costs would have "adverse impacts on fossil fuel based sectors, with A$4.9 billion lower output value from coal and gas in 2050 relative to the plan...and lower growth in heavy industry".
The 100% net-zero scenario would provide A$4.3 billion in additional revenue to participating land holders, given it would involve higher volumes of land sequestration, however it would require more extensive on-farm plantings, according to modelling.
Overall, GDP would be 0.001% lower in 2050 under the 100% net-zero emissions scenario compared to the plan.
The government took advice from the Treasury on analysing the effects of a capital risk premium if it chose not to commit to net-zero by 2050, saying investment in Australia would fall by an average of 5.5% over the period to 2050.
All eyes will be on Labor now, with the party saying it would release its own emissions reduction targets and policies at the end of the COP26 climate talks and when it could respond to the government's modelling.
"Labor will take the necessary time to consider this detail - as a responsible alternative government should," Labor energy spokesman Chris Bowen said.
The release of the modelling follows criticism from CSIRO staff that the government outsourced parts of the modelling to McKinsey Group to the tune of A$6 million.
"For all the talk of this plan representing ‘the Australian way', it's actually US-based consultants who are providing the modelling, at considerable cost, limited transparency and ultimately at the expense of homegrown expertise, be that CSIRO or Treasury," CSIRO Staff Association acting secretary Susan Tonks told InnovationAus.
The modelling is availiable here.
