Scientists are increasingly keen to find out what's going on because they consider the Arctic the "canary in the mine" for global warming—a warning of what's in store for the rest of the world.

科学家们越来越想知道到底发生了什么，因为他们认为北极是全球变暖中“煤矿中的金丝雀”——是对世界其他地方即将发生的事情的警告。