Oceans in the southern hemisphere are warming faster than anticipated, with implications for rising sea levels and climate modelling.

A team of scientists in California has studied rising temperatures of the southern hemisphere over the decades between 1970 and 2004, and recommended lifting estimates of ocean heat content by between 48 and 152 per cent.

Heating up: Ocean temperatures are a key component of measuring climate change.

Lead author Paul Durack said it was the first time scientists have been able to quantify how big the gap is between earlier estimates and the reality of rising ocean temperatures.

Sea temperatures are a crucial yardstick for global warming as the ocean stores more than 90 per cent of human-induced excess heat.