evidence: Because of melting sea ice, it is likely that more polar bears will soon starve, warns a new study that discovered the large carnivores need to eat 60 percent more than anyone had realized. Turns out they are high-energy beasts, burning through 12,325 calories a day—despite sitting around most of the time, according to a unique metabolic analysis of wild bears published Thursday in Science. [...] "They’re far more successful doing this than any other method of hunting," Pagano said. That’s why the melting of the Arctic sea ice threatens polar bear survival. [...] Climate change is heating up the Arctic faster than anywhere else, and sea ice is shrinking 14 percent per decade. Even today, in the middle of the bitter cold Arctic winter, satellites show there is about 770,000 square miles less sea ice than the 1981 to 2010 median (That's an area larger than Alaska and California combined). In the late spring, the ice is breaking up sooner and forming later in the fall, forcing bears to burn huge amounts of energy walking or swimming long distances to get to any remaining ice. Or they stay on land longer, spending the summer and, increasingly, the fall fasting, living off their fat from the seals they caught in the spring.