Australian farm profits could be slashed by up to 50 per cent over the next three decades without more climate change adaptation.
A new Australian Bureau of Agricultural and Resource Economics and Sciences report has modelled the potential impacts of climate change on farmers.
The study uses Bureau of Meteorology and CSIRO projections based on two scenarios of pollution reduction by 2050.
With limited curbing of global carbon emissions, farm profits could fall by 10 to 50 per cent across Australia.
If emissions peak by 2040, farm profits are projected to fall between two and 32 per cent.
WA cropping farmers could face more pressure than those in eastern states.
More severe impacts could be experienced in lower rainfall and inland areas including central Queensland and parts of western NSW.
Livestock producers may face more pressure under severe climate scenarios due to higher temperatures.
Climate projections suggest farmers could experience reductions in average winter season rainfall from three to 30 per cent by 2050 compared with pre-2000 levels.
"At present, there's still a lot of variation in projected outcomes, due largely to uncertainty over future rainfall levels," ABARES executive director Jared Greenville said.
"This uncertainty over future rainfall is itself an important constraint on farmer adaptation.
"While farmers have made significant progress to date, further adaptation will be required to maintain our competitiveness, particularly if other nations are not impacted to the same extent."
Dr Greenville said investing in research, development, climate data and other information would be crucial in preparing the sector for the future.
The analysis does offset potential positive effects of farm adaptation or technological improvement, but identifies regions and farm types which will be under more pressure.
ABARES' report also looks at the impact of lower rainfall and higher temperatures over the past 20 years.
Profits fell by an average of 23 per cent, or $29,000 per farm annually, relative to conditions between 1950 and 2000.
"Seasonal conditions over the last 20 years have been pretty rough for Australian farmers," Dr Greenville said.
"The good news is that farmers have made some remarkable progress in adapting to these hotter and drier conditions."
He said after accounting for climate impacts, productivity growth of about 28 per cent in broadacre farming had been achieved since 1989.
"The cropping sector has seen a huge gain of 68 per cent," Dr Greenville said.
"New technologies and practices mean that farmers are able to grow crops under lower rainfall conditions than they could in the past."
Australian Associated Press