All the evidence points toward human-made changes at both poles, she said, a conclusion that "further depletes the arsenals of those who insist that human-caused climate change is nothing to worry about."

Climatologist Gareth Marshall of the British Antarctic Survey said that while the term global warming is widely used, things are more complicated at the regional level.

In the Antarctic, he explained, climate change strengthened winds blowing around the continent, helping trap colder air. But that will decrease in the future, allowing warmer conditions to begin, he said.

And, Marshall added, all studies now show that human activities are the drivers of climate change in the Antarctic.

Asked if this summer will match last year's record low sea ice in the North, Overland that is likely.

"The tea leaves point to a minimal amount of sea ice next September, that would be the same as we had last summer, 40 percent loss compared to 20 years ago," he said. Overland added that the winter freeze got a late start last fall.