A blizzard shuts down New York and pundits start shouting, "See I told you global warming was a hoax!" Here's an explanation of why it is global warming that is causing these huge snowstorms. Most fifth graders should get it.
The normal cycle: water evaporates from the ocean. Cold artic air makes that moisture fall as snow.
The difference today: There is less polar ice, thus more open ocean from which water can evaporate. When the cold air hits it there is more moisture to fall as snow.
Note the snow has been falling where it always does (Atlanta might object to that statement), we're just getting a lot more of it.