Antarctic sea ice is expected to grow into unprecedented territory in the next two weeks, a scientist has said.

Last week, sea ice in the south pole covered more than 20 million square kilometres for the first time since records began.

Dr Jan Lieser from the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC), based in Hobart, said sea ice extent in the Southern Ocean was expected to peak within the next fortnight.

"This is the third year in a row that sea ice extent in the Antarctic has reached a recorded maximum, and the first time on record that it has exceeded 20 million square kilometres," Dr Lieser said.

Antarctic sea ice hit its all time record on September 13 and has continued to grow ever since.

The findings were seized upon by climate change sceptics such as Australian commentator Andrew Bolt and US radio talk show host Rush Limbaugh.

Mr Limbaugh, a popular conservative commentator, used his Facebook page to make his point.

"The Antarctic ice sheet has reached record levels in the midst of so-called climate change and global warming. "It's the same thing at the North Pole. Arctic ice sheet levels are at record levels. The North Pole is supposed to have been melted by now, according to Al Gore."

But Dr Lieser said the growing extent of sea ice was, in fact, a symptom of global warming.

"The increase in Antarctic sea ice extent might seem paradoxical given changes in the global climate, but it's not when we consider some of the other factors at play," he said.

Record Antarctic sea ice: Antarctic sea ice covers 19.619 million sq km.

Antarctic sea ice covers 19.619 million sq km. Maximum area recorded on September 12, 2014.

Maximum area recorded on September 12, 2014. Coverage expected to peak in early October, 2014.

Coverage expected to peak in early October, 2014. Third year in a row a record has been reached.

Third year in a row a record has been reached. There has been a 1.5 per cent increase each decade since records began in 1979.

There has been a 1.5 per cent increase each decade since records began in 1979. Increase believed to be linked to strong westerly winds.

Scientists said it was important to make the distinction between the ice shelf and sea ice.

Changed climatic conditions have seen the Antarctic ice shelf shrink an average rate of about 100 gigatonnes per year.

"Fresher water freezes at a higher temperature, and we know that the sea water around Antarctica is becoming less salty partly due to the rapid shrinking of the thick Antarctic ice sheet over land," Dr Lieser said.

Dr Lieser said it was important to understand the various processes at work.

"Factors like wind, snowfall and the saltiness of the water all play an important role in this process, and we know that all of these inputs have been changing as part of larger changes in the global system," he said.