First Sightings: Compare Years
Spring 2012 was the warmest on record. This spring's temperatures are closer to normal. How did it affect the robin migration and why is it happening? Meteorologist Paul Douglas explains:

A warmer, wetter atmosphere worldwide is flavoring all weather now, allowing weather to get stuck: longer, deeper drought, floods, record heat, even prolonged chill and snow.

A 2012 paper published at Cornell links record arctic melting last fall with changes in the "polar vortex," reducing the winds that swirl around the North Pole. "What goes on in the Arctic remotely forces our weather patterns here," said Dr. Charles Green. "What's happening now is that we are changing the climate system, especially in the Arctic, and that's increasing the odds for the negative conditions that favor cold air invasions and severe winter weather outbreaks." Global warming implies steady warming, worldwide. Global Weirding better describes what we are seeing.