The economic long-run impact increases with higher levels of warming , but there is a wide range in projections. Conservative estimates for the long-run impacts of a 1ºC, 2℃ or 3℃ global warming  on Australian GDP are -0.3, -0.6 and -1.1%/year, respectively, while for New Zealand the estimates are -0.1, -0.4 and -0.8%/year respectively . More detailed modelling indicates a loss in Australia's GDP of 6% by 2070 for 3ºC global warming, while a 2.6% GDP rise by 2070 is possible for 1.5°℃ global warming . The potential for much more severe effects on GDP is shown in recent estimates, which attempt to account for the increased severity of uncertain effects  .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report