Another hypothesis is that the current weather patterns are triggered by events in the western tropical Pacific Ocean -- where the infamous climatic twins El Niño and La Niña are born. While New York was feeling like the Canadian Arctic, there were torrential rains in Indonesia, for instance, as a result of high surface temperatures and air temperatures, which leads to a lot of evaporation rainfall, Trenberth explained.
That unusual situation, which starts with warm oceans -- the reservoir of Earth's excess atmospheric heat -- propagates around the world just like El Niño and La Niña.
"So yeah, there are signs that climate change plays a role in all of these things," said Trenberth.
What's also been reported a lot is the idea that that intense cold events have always happened, and always will, but will become less frequent as the earth warms. But how does that jive with the loopy jet stream/polar vortex, which ought to cause more polar leaking?
"The answer is that we may be seeing the consequence of both effects simultaneously," said Mann. "Record cold is on the decrease just about everywhere, and record warmth is on the increase. That is just as we expect to be the case with global warming -- no surprises there. The latest winter in no way contradicts that."
Despite all of the claims about record cold, there wasn't a single location in the United States that broke a record for all-time cold this winter, Mann said. Over the past several summers, on the other hand, there have been many locations around the country. that have broken all-time heat records, he said.
"What is also possible is that persistent weather anomalies (long stretches of unusually cold conditions in some places, typically counterbalanced by long-stretches of unusual warmth somewhere else) could become a bit more common," Mann said.
"The models are unclear on this, and they might not be up to the task of modeling this effect, because it depends on subtle phenomena."
These include things like how changes in sea ice influence the overlying atmosphere, which the climate models still are not very good at capturing, he said.
"Unlike much of the manufactured debate about whether climate change is real and caused by human activity, this is an area of the science where there is a genuine, good faith debate within the scientific community," said Mann.