Our unusual cold weather is actually caused by global warming. Our extremely cold winter was outbalanced by simultaneous record-breaking heat in Australia. Meanwhile, the Arctic continues to be warmer than normal. That affects everything above the equator.
We had a 15-year period of intense evaporation followed by a cold snap (the Polar Vortex) in a sequence that was unprecedented. The weather turned. Quickly. This indicates a change. The range is new and the speed of the swing is new. “If you have events that are not part of your historical record that represent a change in conditions, that’s the definition of climate change,” said scientist Andrew Gronewold.