The Australian Greens has formally adopted a policy to reduce Australia's greenhouse gas emissions by 75 per cent on 2005 levels by 2030 and to net zero by 2035, saying it is the only way Australia can feasibly meet its contribution to the Paris Agreement goal to keep global warming to as close to 1.5 degrees as possible.

Greens leader Adam Bandt said the policy was based upon a new analysis of Australian carbon emissions showing that should Australia's current targets remain in place the nation would exceed the budget required for the Paris goal of 1.5 degrees Celsius as soon as 2027 and exceed the budget for the Paris goal of 2 degrees as soon as 2032.

Describing the new targets as "Climate Emergency Targets", Mr Bandt said he hoped they would influence voters' decisions in the crucial Eden-Monaro byelection and that the party would use them to apply pressure to the major parties to set more ambitious emissions reduction targets.

"Going to the next election with anything less than a 48 per cent cut by 2030 means abandoning the Paris Agreement," said Mr Bandt. "The only pathway for climate action is to turf the government out, put Greens into balance of power and implement a Green New Deal."