Cold snaps result of global warming, study says

This year's uncommonly cold winter has put to bed the notion global warming is anything but a myth, right? 

Wrong, says a group of researchers out of New Jersey's Rutgers University, who have put out a new study that suggests the prolonged cold snaps we’ve experienced could be a direct result of climate change.  

The 2012 paper says melting Arctic ice is weakening the jet stream. This weakening causes the jet stream to dip further south, which in Canada brings severe cold temperatures for prolonged periods of time.

Jet streams are ribbons of wind that blow from west to east in the northern hemisphere, and are formed when cold air from the Arctic comes in contact with warm air from the south.

When there is a big difference between the temperatures of the air masses, the jet stream moves faster and dip far less, said Altaf Arain, director of McMaster University's Centre for Climate Change.

But as the Arctic air warms, the difference in the temperatures is less severe. The jet stream is now moving slower and pulling more Arctic air into southern latitudes.

Although weakening the jet stream causes extended cold snaps in Canada, in other areas of the world, there may be “an increased probability of extreme weather events that result from prolonged conditions such as drought, flooding, cold spells and heat waves,” says the study.

In Canada, the jet stream dipped farther south this year, but in other areas, it peaked farther north to cause heat waves and drought.

Arain said the bottom line is that one cannot draw conclusions about climate change based on temperatures on a particular day.

“If we have a large snowstorm or very cold weather spell, it does not mean the climate is not warming. The global mean temperature has been warming, with more record warm years over the past 10 to 12 years,” he said. “We have -25 temperatures around Canada, but [around the world] we see a warming trend.”

Temperatures in Hamilton are scheduled to dip as low as –17 C on Monday.