“Theoretically, we could see an Arctic that is ice-free in summer months a lot sooner than most people previously thought. Some people think that it could happen in five or six years.”
Putting that into perspective, David Barber, a University of Manitoba sea ice physicist, notes that the Arctic hasn’t been seasonally ice-free for at least the past 1.1 million years.
“Let that sink in for a moment,” he suggests. “The medieval warm period occurred about 1,000 years ago; the Egyptian civilization peaked about 4,000 years ago; the last ice age was 18,000 years ago; heck, there have been several ice ages within this 1.1-million-year period, and we have always had sea ice in the northern hemisphere in summer.”
