Meanwhile, Germany has outlined its plans to reduce emissions by 40% on 1990 levels by 2020.
Nelson yesterday appointed Greg Hunt to the "critically important" portfolio of Shadow Minister for Climate Change, Environment and Urban Water.
He also cautioned Rudd against committing to the 2020 emission reduction cuts, saying it would have "a serious consequence for electricity bills and many other burdens borne by working families in day to day life".
Rudd confirmed he would wait until the Garnaut Review of Climate Change and its Economic Impact was released in mid-2008 before setting the medium-term target.
"I think it's really important that Australia act not just nationally but internationally on climate change," he said.
"Our job in the future is to do whatever we can to try and bridge the gap which is currently enormous between developed and developing countries."
David Pearce, director of the Centre for International Economics in Canberra, agreed it would be hasty to set a 2020 target before the results of the Garnaut Review.
"What may be hasty is that the process that Professor Garnaut's going through hasn't really finished yet, and it may be an issue for the government if he comes up with any surprises in his analysis," he told ABC radio yesterday.
"But on the other hand, his analysis may show that it's less costly, for example, than previously anticipated."
But climate change researcher Professor Matthew England from the University of NSW said targets should be set at 20-30% by 2020.
England is part of a group of 200 leading climate change scientists worldwide that issued the Bali Climate Declaration by Scientists in which they called on government representatives from the 180 nations at the meeting to reduce emissions by at least 50% below 1990 levels by 2050.
Germany, the world's third largest economy, has set an ambitious target to cut greenhouse emissions by 40% on 1990 levels by 2020.
To achieve this, it will increase the share of renewable energy in the electricity sector from 13% now to 25-30% by 2020, largely through the development of offshore wind energy.
Other measures include regulations to open the natural gas grid for feeding in biogas and improving the energy efficiency of electric appliances and the building sector.
