How much is 11 degrees of warming? For help, let's inventory the warming we've already seen on our planet. Already, the Arctic Ocean has lost 40 percent of its ice mass since the 1970s. Already, wildfires in the American West destroy six times more forest land per year than 40 years ago. Already, the biggest hurricanes come more frequently, and the city of Virginia Beach is starting to plan a methodical retreat from its shoreline due to sea-level rise. Already, Allstate insurance company won't issue any new homeowners policies in coastal Maryland and Virginia because of stronger storms.