RISING temperatures in the Tasman Sea have shocked scientists, who have identified an area off Tasmania as a global warming hotspot.

Oceanographers say sea temperatures east of the island state are as much as two degrees warmer than they were 60 years ago, while other ocean hotspots around the world have warmed at two to three times the average over the past century.



"We would expect natural change in the oceans over decades or centuries but change with such elevated sea surface temperatures, in a growing number of locations and in a synchronised manner, was definitely not expected," said the CSIRO's Dr Wenju Cai, co-author of a paper published in the journal Nature Climate Change.



"We have been able to reconstruct an ocean history in which warming over the past century is two to three times faster than the global average ocean warming rate."



The international scientific team working on the project said the ocean hotspots were a result of strengthening wind systems caused by greenhouse gases which had driven ocean currents beyond their known boundaries.



The East Australian Current was around 350km further south, explaining the warming in the Tasman Sea.



The team said the warming of the oceans would limit their ability to absorb heat and carbon from the atmosphere.

Originally published asScientists shocked by Tasman sea heat up