Heatwaves for one month each year and 10 per cent less water Australia-wide are just some impacts predicted even if the globe meets the most optimistic goal of an international climate agreement.
New research, commissioned by the Climate Institute, found Australia would be significantly impacted if the globe warms by 1.5C - the aspirational target at last year's United Nations climate change conference.
At that temperature the north of the country would experience heatwaves for one month each year, while the south would be hit for about two weeks.
Coral reefs would be severely impacted and there would be 10 per cent less water nationwide, and up to 30 per cent less in some regions.
Last year, 196 parties signed the first binding international climate agreement, agreeing to limit global warming to well below 2C.
The globe is now experiencing warming of about 1C, a level the institute says is already dangerous.
"At two degrees, our global climate system would move from the upper end of present day climate variability into uncharted territory, resulting in extreme, costly and dangerous impacts for Australia," chief executive John Connor said.
The research by Climate Analytics found that at 2C northern residents can expect heatwaves for about two months of the year and the south will get them for about three weeks.
Virtually all tropical coral reefs would be severely degraded and sea level rise would hit about 50cm by 2100.
The institute has released a roadmap for cutting carbon emissions and ending up on a trajectory to net zero emissions by 2050.
The basic messages is, the longer the country puts off strong action, the harder it will become.
That's because the globe has a "carbon budget" to keep global warming under 2C and if Australia keeps using its allocation of that budget now, there will be less to access later.
It would mean drastic cuts to emissions, potentially impacting jobs and power prices.
The government has promised to cut emissions by 26 to 28 per cent by 2030 and review its direct action climate policy next year.
Mr Connor believes the review and government consideration of longer term targets is the first chance for credible climate policy conversation for five years.
