As many as three million Australians would be at high risk from cyclones, flooding and erosion by 2090, reflecting densely packed populations living along coastlines.
Losses in Australian property values could balloon to $770 billion by 2090 if little effort was made to adapt and relocate to lower-risk locations.
Average global temperatures have already risen 1.3°C above pre-industrial levels and are set to hit 2.71.3°C under current policies.
Federal Climate Change Minister Chris Bowen acknowledged many Australians would find the report “confronting” as he repeatedly stressed the economic opportunities of clean industries and decarbonisation.
Australia and other signatories to a global climate pact are getting ready to update their goals to slash emissions this month.
Australia’s highly anticipated 2035 targets are expected to be revealed in coming days after Mr Bowen confirmed he had received advice from the independent Climate Change Authority — guidance the government must consider before setting its goals.
Updated plans to curb carbon pollution come as the United States winds back its climate ambitions under the Trump administration.
Mr Bowen refused to comment directly on the policies of other countries, but said the majority remained committed to net zero “in some form”.
Monday’s risk assessment warns no community will be spared from the impacts of climate change, suggesting the effects will span areas as diverse as agriculture, health and national security.
“Future changes in Australia's climate will not occur gradually or smoothly,” the report’s overview warns.
The first-of-its-kind document modelled how global warming will impact individual communities, the nation’s economy and the environment under three different scenarios of warming.
An IPCC report notes that some areas of Australia may experience increased pasture growth, but others may experience a decrease that cannot be fully offset by adaptation.
In eastern parts of Queensland, climate change impacts on pasture growth are equivocal, with simple empirical models suggesting a decrease in net primary productivity, while mechanistic models that include increases in length of the growing season and the beneficial effects of CO2 fertilisation indicate increases in pasture growth.
“In Tasmania, annual pasture production is projected to increase by 13 to 16 per cent, even with summer growth projected to decline with increased inter-annual variability, resulting in a projected increase in milk yields by three to 16 per cent per annum,” the 2022 IPCC report states.
“Extreme climatic events (droughts, floods and heatwaves) are projected to adversely impact productivity for livestock systems.
“This includes reduced pasture growth rates between three and 23 per cent by 2070 from late spring to autumn and elevated growth in winter and early spring
“In Australia, the average number of moderate to severe heat stress days for livestock is projected to increase 12 to 15 days by 2025 and 31 to 42 days by 2050 compared to 1970-2000,” the IPCC sixth assessment report states.
– with AAP.