article_snippet: (CNN)Although much of the United States has been shivering this winter, there's been another worrying sign of warming temperatures farther north.  
article_snippet: Barring a late spurt of ice growth -- possible but unlikely, according to a NASA news release -- this sets a new precedent.
article_snippet: The analysis is based on data from the NASA-supported National Snow and Ice Data Center (NSIDC) at the University of Colorado, Boulder.
article_snippet: If the summer is cool, the melt rate will slow down.
article_snippet: And the opposite is true, too: even if you start from a fairly high point, warm summer conditions make ice melt fast.
article_snippet: But this isn't cause for much optimism faced with evidence of a warming planet.