The blanket of sea ice atop the Arctic is at its smallest size in recorded history. The 2007 record was broken on Sunday when satellites determined that the ice extent was at 1.58 million square miles. While that may sound like a lot, it’s about a million square miles less than the average minimum cover in the 1980s and 1990s.

The immediate cause for the break-up was a large storm and the strong waves it created. But scientists say that a single weather event couldn’t have triggered such a major decline in sea ice without warmer climate conditions in the region.

National Snow and Ice Data Center scientist Walt Meier compares the Arctic to a fighter with a glass jaw. He says that every year that the Arctic loses thick, multi-year ice, it becomes more vulnerable to storms that can further shrinkage and contribute to a powerful feedback loop.

"It’s almost like at least parts of the Arctic have become like a giant slushie at this time of year," says Meier. "That can melt pretty quickly."

Since the first satellite analysis was done in 1979, the Arctic has lost more than 40 percent of its summer sea ice. That ice cover plays an important role in moderating the Earth’s climate by reflecting sunlight and keeping the ocean cool.

According to the National Snow and Ice Data Center, the Arctic could still lose more sea ice in the next few weeks. Usually, the minimum extent isn’t until September. Meier says that the region could lose up to another 150,000 square miles in the event of another major storm.

The data center will release a full analysis of the summer sea decline in October.