Put perhaps as simply as possible, that's the speculation among some experts about the cold snowy winters experienced this year in many Northern hemisphere climates, such as New York.
Here's the most concise, detailed explanation I've found so far, from Climate Central:
Recent scientific studies have shown that the dramatic warming that has been occurring in the Arctic during the past few decades, along with the associated loss of sea ice cover, may be changing atmospheric circulation patterns throughout the northern hemisphere. This could be contributing to the recent outbreaks of unusually cold and snowy weather. Sea ice loss during the spring and summer melt season, which leaves a thinner and more sparse ice cover throughout the fall and early winter, is a key suspect in influencing winter weather patterns. When the ice melts, it allows incoming solar radiation to warm water and air temperatures, which in turn has an influence on atmospheric pressure and circulation, and may help shift Arctic air southward, while the Arctic remains unusually warm.
One meteorologist has described the pattern this way: "This pattern is kind of like leaving the refrigerator door ajar — the refrigerator warm up, but all the cold air spills out into the house."
It's important not to overlook the ancient planetary cycles, of course. Down here in SoCal, it feels the past few days as if La Niña has taken hold. It's cold and dry, with no sign of precip in sight.
Kit Stolz 