The government's hand-picked climate change advisor will today outline his reduction targets.
Professor Ross Garnaut will once again front the press club to outline his vision for combating greenhouse gas emissions in Australia.
Already Professor Garnaut has warned the cost will hit households hard - today we'll get a clearer idea of the financial pain.
Environmentalists are urging Prof Garnaut to back deep emissions cuts by 2020 to be part of a global effort to avoid catastrophic climate change.
But the government's climate advisor has promised his target will be "very soundly based" and take into account both economic and environmental points of view.
Entitled Targets and Trajectories, the paper is the government adviser's last before releasing the final version of his landmark report later this month.
The federal government has a 60 per cent greenhouse target for 2050 and may set a 2020 target later this year.
The Australian Greens are calling for a 40 per cent emissions cut by 2020 from 1990 levels, with the aim of becoming carbon neutral as soon as possible.
