Washington - Climate scientists are investigating why Antarctic sea ice reached its largest extent on record in 2013 even though the Earth's temperature was among the 10 hottest years since 1880.
Two of the top US federal science organisations on Tuesday released their joint climate findings for 2013, which found Australia had its hottest year ever.
The National Oceanic and Atmospheric Administration (NOAA) said 2013 was tied for the fourth hottest year on record. The National Aeronautic and Space Administration (NASA) said it was tied only for seventh place.
But unlike the rapidly melting ice at the North Pole, sea ice in the Antarctic is actually growing, especially according to measurements made in September.
"Last year, it was the greatest expansion we've seen on record," Thomas Karl, director of NOAA's national climate data centre in North Carolina, told a press briefing."That's something being investigated."