Global carbon emissions must be cut by at least 25 per cent by 2020 to give the Great Barrier Reef a better than 50/50 chance of survival, an alliance of Australia's reef and climate scientists says.
Representatives of the Federation of Australian Scientific and Technological Societies are in Canberra ahead of parliament's vote on the emissions trading scheme this sitting fortnight.
They also say emissions would need to be cut by up to 90 per cent below 2000 levels by 2050, if the reef is to survive the impacts of ocean temperature rises which contribute to coral bleaching and coral death.
"This is Australia's Great Barrier Reef and we must provide the leadership to help it survive," FASTS president Ken Baldwin told reporters today.
More than 100 nations have endorsed a goal to limit average global warming to no more than 2 degrees above preindustrial temperatures, he said.
And that would need to be done by limiting the concentration of carbon dioxide to below 450 parts per million.
"To achieve concentrations below this value of 450 parts per million will require emissions reductions of at least 25 per cent by 2020, so therefore to give the Great Barrier Reef a better than 50 per cent chance of survival, emissions must be reduced by 25 per cent," Professor Baldwin said.
Queensland University economics academic John Quiggin said the costs of acting on climate change would be "modest" for Australian households.
"There certainly will be a significant transformation of economic activity, but the economy's always changing," Professor Quiggin said.
"People are always adjusting to changes. The net impact on the rate of improvement in living standards will be very modest."
Economic growth runs at about two to three per cent economic growth each year on average, he said.
"You might reduce that by 0.1 per cent."
"The view that there is a massive economic cost associated with this is simply wrong and not supported."