Launching the first of eight updates to his landmark 2008 climate change review, Professor Ross Garnaut said Australia was seeing an intensification of extreme weather events consistent with warnings from climate scientists.
But Professor Garnaut said any intensification of weather events experienced to date, when the world has warmed by about 1 degree since industrialisation, was only a fraction of what could be expected under higher rises.
''The science says that without mitigation - and with the sorts of emissions growth that my analysis shows will follow the industrialisation of China, of India, of Indonesia and the acceleration of economic growth in Africa - then that first degree is just the beginning,'' Professor Garnaut said.
''So if we are seeing an intensification of extreme weather events now, you ain't seen nothing yet.''
Professor Garnaut said scientists predicted there would be more frequent extreme cyclones - though not necessarily more frequent cyclones - due to greenhouse gas emissions.
He said despite concern that a carbon price would increase electricity prices, it would be only a small part of the total price rise, which was mainly due to rising coal and gas prices, infrastructure upgrades and the resources boom.
