Here's a quick summary: The Antarctic and Greenland ice shelves are melting more quickly than we realized. Year-round Arctic sea-ice levels reached their lowest levels in 30 years, which is how long we've been keeping records. The seawater beneath Antarctica is freshening, which indicates ice melt. Global ocean currents are beginning to shift. "We're beginning to get hints of change in ocean circulation; that'll have a dramatic impact on the global climate system," IPY director David Carlson told reporters in Geneva.