Arctic sea ice has melted to a level not recorded since satellite observations started in 1972, and almost certainly not experienced for at least 8,000 years, say polar scientists. German researchers say the sea-ice retreat can no more be explained by the natural variability from one year to the next—the record melt is due to human-made global warming.
What’s the Big Idea?
If current trends continue, a largely ice-free Arctic in the summer months is likely within 30 years, up to 40 years earlier than previously anticipated. The last time the Arctic was uncontestably free of summertime ice was 125,000 years ago. Floating Arctic sea ice naturally melts and re-freezes annually, but the speed of change has shocked scientists—it is now twice as great as it was in 1972.