It is relentless, this cold.

In the twin cities of Minneapolis and St. Paul, the National Weather Service issued a wind chill warning, saying it was a “particularly dangerous situation.”

In Indianapolis, driving was declared illegal, except for emergencies. In Florida’s Everglades, there was a frost warning. It was likely the first for both.

In the Maritimes, just smacked by a blizzard, power is still out for thousands while weather advisories for freezing rain and wind chills continue.

And closer to home, parts of Ontario were hit with heavy snow, while other areas, including the Toronto region, dealt with snow and freezing rain.

So if temperatures keep falling, along with the snow, does that mean global warming is a myth?

No, says Michael E. Mann, a well-known climatologist and director of the Earth System Science Centre at Pennsylvania State University.

A single winter cold air outbreak doesn’t negate the reality of global warming, he says.

“If you take a step back and look at how extreme temperatures are actually changing over time, you see that in North America over the past decade, we have broken all-time records for warmth at twice the rate as records for cold,” Mann points out.

A month ago, “we reported the warmest conditions the globe has ever seen in November, and Australia is in the midst of a record heat wave to finish out what we have now learned was the warmest year on record for the entire continent of Australia.”

The increased tendency in some regions for particularly heavy snowfall events is not evidence against climate change and global warming, “but evidence in support of it, a consequence of the increased moisture content of warmer air.”

This cold snap, he acknowledges, has provided fodder for climate change deniers to distract people with misinformation.

Mann is also the author of the recently released book The Hockey Stick and the Climate Wars, in which he explains the science of global warming to the layman and argues that the Earth is warming up.

This spectacular winter weather we are witnessing is likely because of the Arctic’s rapidly disappearing ice, says Jennifer Francis, a researcher at the Institute of Marine and Coastal Sciences, Rutgers University.

The loss of ice is leaving behind warmer open water that is much less reflective to incoming sunlight than ice. That is one reason why the northern polar region is warming at a faster rate than the rest of the hemisphere.

That is impacting the behaviour of the jet stream, leading to more frequent extreme weather.

“It is causing the west-to-east winds jet stream to become weaker and when that happens, it takes a wavy path,” says Francis.

Loading... Loading... Loading... Loading... Loading... Loading...

When an exceptionally wavy jet stream pattern occurs in the middle of the winter, it means cold air will likely get sucked southward.

Francis says it is hard to say if this wacky weather is directly related to climate change “but we have seen that the jet stream is taking on this very wavy type of pattern more often now.”

Any weather pattern happening now is different than what it used to be, she adds.

Simply put, global warming can make cold snaps even worse.

When the Intergovernmental Panel on Climate Change released its fifth assessment report last September, it pointed toward a global trend of warmer temperatures but did not exclude sporadic cold-weather extremes. In fact, the report said there will be more extreme weather events. Among other things, we will see stronger hurricanes, longer heat waves and, in some parts of the world, more snow and hail.

This snowfall and record temperatures have added new terms to our weather lexicon: polar vortex and frost quakes.

In the summer, we learned about atmospheric rivers and derechos.

Meanwhile, as parts of North America are being walloped by snow, there is the other story, says Francis.

Alaska is warm, the U.S. West Coast is experiencing a prolonged drought. England is being pummelled by rainstorms, while Scandinavia is extremely warm.

“All these extreme events, at the same time, are related to the way the jet stream is shaped right now with big north and south swings,” she says.

To all the climate change skeptics out there, she says: “Talk to those in Alaska or Scandinavia.”

Read more about: