Ice around the South Pole has expanded to cover a record area, scientists revealed yesterday - a month after saying that the North Pole had lost an unprecedented amount of its ice. Researchers say - rather confusingly - that both occurrences are down to the 'complex and surprising' effects of global warming. The record Antarctic sea ice cover was revealed in satellite images from the US National Snow and Ice Data Center in Colorado.
September 26, 2012, when ice covered more of the Southern Ocean than at any other time in the satellite record.
At the end of the southern winter in September, ice covered 7.51million square miles of sea - more than at any time since records began in 1979. For the last 30 years the amount of Antarctic sea ice has been increasing by 1 per cent each decade. While the rest of the world has been getting warmer over the last 50 years, large parts of the Eastern Antarctic have been getting cooler. Scientists say a cooler Antarctic fits in with the unpredictable nature of climate change.

Dr Ted Scambos, of the National Snow and Ice Data Centre in Colorado, said: 'It sounds counterintuitive, but the Antarctic is part of the warming as well.'

Dr Ted Maksym, of the Woods Hole Oceanographic Institution in Massachusetts, added: 'A warming world can have complex and sometimes surprising consequences.' Unlike the Arctic - which is open sea surrounded by land - the Antarctic is a massive continent surrounded by water.

The area of land and the surrounding sea covered by ice peaks each September and retreats to its minimum in February - towards the end of the southern summer.

Temperatures at the South Pole are also being kept down by the hole in the ozone layer - caused by the release of now banned CFC gases from aerosols - which opens each year in the atmosphere.

The hole causes more westerly winds which, through a complex interaction between ice, sea and wind, lower temperatures.

Nasa chief scientist Dr Waleed Abdalati said the increase in Antarctic sea ice was dwarfed by the decline in Arctic sea ice.

Satellite images show the Arctic is losing 4 per cent each decade. Last month saw the summer ice cap of the Arctic shrink to a record low of 1.32million square miles.

For the last 30 years, the Arctic has been losing an average of 5.7 square miles of sea ice for every square mile gained in Antarctica.

Dr Abdalati said: 'The change in the Antarctic is nowhere near as substantial as what we see in the Arctic. But that doesn't mean we shouldn't be paying attention to it and talking about it.'