Leading Australian environmental scientist Tim Flannery says he is happy with the outcome of the Copenhagen climate change negotiations.

World leaders failed to secure a binding agreement instead opting for a non-binding accord which relies on countries setting their own emissions targets.

Professor Flannery says while the current commitments are not enough to halt dangerous climate change, the outcome is an important first step.

"My overview would be in the absence of any shift in the American target we're likely to be a few gigatonnes of carbon short of a satisfactory target for 2020," he said.

"[It] doesn't mean we won't achieve it. The agreement as it looks at the moment is good, but not perfect."

The former Australian of the Year says that it will take a few days for the full implications of the accord to become apparent.

"I think that these sort of agreements in the details really only become more evident with time," he said.

"Perhaps in the next few days we'll get to see a little bit more of precisely what has been agreed, and what it means overall.

"[But] if I was to sum it up in a single phrase I'd say this has been a good, successful meeting.

"It's only one step on the road but we are now really in the throes of tackling this very difficult problem and this meeting has been a very significant step forward. I wouldn't like anyone to undersell what's been achieved. I think it is very significant."

Professor Flannery said amid the commentary on whether or not the deal should have been binding, it was important not to lose sight of the gains made at the conference.

"We've made a huge advance at this meeting on a number of fronts, one being those pledged emissions, another being the funding we've got for adaptation and mitigation in developing countries, and of course the REDD Negotiations, the world's efforts to protect the tropical rainforests," he said.

"That seems to be going very well indeed. I'm just waiting to hear the final status of REDD but I'm very hopeful we'll get a good agreement."

'Outstanding role'

Professor Flannery also praised Prime Minister Kevin Rudd's efforts in securing the agreement.

"I think that our Prime Minister has played an outstanding role," he said.

"I was at a briefing he gave on Thursday morning. He was quite frank and honest in his opinion that he was doing his best but there was absolutely no guarantee of success.

"I think he was a little more downbeat than what we now know of the outcome would suggest he could have been.

"But he's been working very hard for the last few months ... and he's just been fantastic all the way, he just shines at it ... he's been really important through these meetings.

"We've had a number of problems with Denmark [hosting the conference]... and I think the Australian position as Friend of the Chair has really helped them through some of that."

He also maintained while many in the scientific community will be disappointed with the outcome, the inherent restrictions of the conference meant binding targets were unfeasible.

"It depends on who hoped for what. The scientists would like to see an accord which would cut emissions to the point where we'd have a very good chance of avoiding dangerous climate change," he said.

"But you know the political reality of this is, it's really tough to do that and this is a step on a road, that's the way I'd look at it, it's a step on a long road.

"It's a particularly important step and I'm not entirely dissatisfied with the agreement. I think it is a significant step forward and it could have been a lot worse."