SEA level rises and climate change are linked, say top scientists as they prepare the next major global climate change update.
More than 250 experts from 39 countries are in Hobart this week to review the latest draft of the Intergovernmental Panel on Climate Change's report including a new chapter on sea level.
The co-ordinating lead author on the new chapter, CSIRO's Dr John Church, said sea level is clearly linked to climate change.
"The sea level is rising, the rate of the rise has increased and will continue to increase," he said.
He said the rate had increased from a few tenths of a millimetre a year before the 20th century to more than 3mm a year in the past 20 years.
"It's clear the rate of sea level rise has already increased," he said.
"Whether that 3mm is a further acceleration or not is yet unclear but we do expect a further acceleration during the 21st century and it's clearly linked to greater levels of greenhouse gases."
He said thermal expansion because of ocean warming and the melting of glaciers were two key causes of sea level rise.
CSIRO's Dr Steve Rintoul, who is involved with the report's ocean observations chapter, said oceans were very important for climate because of the amount of heat they absorbed and stored.
He said the temperature of the ocean surface had increased by 0.3-0.5C over the past 50 years.
"There's no disputing the oceans are warming," he said.
"It's clear from the published literature that greenhouse gases as well as natural variability have contributed to this observed warming of the ocean."
He said oceans around Tasmania were changing, with recordings showing that temperatures around Maria Island have increased by 1.5C over the past 60 years.
"It's a very large number compared with other parts of the ocean," he said.
The Hobart conference is the last meeting before scientists prepare the final draft of the IPCC report's physical science section. The final report will be submitted in September.