AUSTRALIA is under pressure to explain how it and other wealthy nations will find the billions of dollars needed to help poor countries tackle climate change - seen as crucial to securing a climate treaty in Copenhagen.
Treasurer Wayne Swan yesterday said this weekend's meeting of G20 finance ministers in London would not discuss a figure but rather ''the early framework of the policy design''.
But with less than 100 days until the key Copenhagen climate summit, developing countries including China and India are pressuring wealthy nations to commit funds to help developing nations cut greenhouse gas emissions and adapt to unavoidable climate change.
US President Barack Obama has said he expects the finance ministers to produce a funding blueprint before a G20 leaders' meeting in the US later this month.
It is understood the Rudd Government wants agreement at the Pittsburgh meeting on how much money is needed and who should run the global climate fund.
Climate Institute policy and research director Erwin Jackson said finance ministers needed to end the near ''deathly silence'' on how to unlock rich nations' public and private funding if Copenhagen was to be a success.
British Prime Minister Gordon Brown is the only developed world leader to have put a figure to the climate fund, estimating it will cost $US100 billion a year by 2020.
''If we don't get to Copenhagen with momentum, we're not going to get a deal that is in our national interest,'' Mr Jackson said.
A draft Australian report on financing prepared for the G20 - leaked to a US website on the weekend - suggests rich countries will rely heavily on carbon markets and less on public money to pay for climate change programs in developing countries.
Australia's report, which had input from Indonesia and South Africa, is one of three G20 reports on climate change financing; none offered a specific proposal or figure. The Australian report is being reworked by Treasury officials after India and China raised concerns about its assumptions on how much they would commit to doing under a climate treaty.
Though it receives less attention than emissions targets, the creation of a climate fund is just as crucial, to get developing nations to sign up to a treaty to replace the Kyoto Protocol.