Ice in the Arctic is melting even faster than before, and some scientists fear the area could be completely free of ice in summer by 2013.
Even though there was more ice at the start of this year than the start of 2007, it is already down to the level of last June.
Scientists from the US National Snow and Ice Data Center reckon the ice melts so quickly because it is so thin.
It's feared losing ice could speed up climate change.
Because ice reflects more heat than liquid water, as more ice melts, the sea could get warmer, speeding up global warming, and causing more ice to melt.
A few years ago, scientists were predicting ice-free Arctic summers by about 2080. Then computer models started projecting earlier dates, around 2030 to 2050.
But summer 2007 saw Arctic sea ice shrink to the smallest level ever recorded, down to 4.2 million sq km from 7.8 million sq km in 1980.