A NYPD police car sits in deep snow

Scientists have proven that certain parts of the world are actually getting colder

New York has just suffered one of the coldest winters on record. With schools closed, ferries frozen in ice and the lowest temperatures at the ball drop in 55 years, the city was in the midst of a deep freeze. However, January started with a record-breaking blizzard - further cementing this winter as one of the most ruthless in America’s history. So as the Big Apple thaws, should we not be asking ourselves some serious questions about global warming?

As it happens, there are other areas which appear to be bucking the trend. While an emotive video of a starving polar bear was used to spread awareness of the melting polar ice caps, at the other pole, Antarctic sea ice has not only stayed strong but actually increased.

Snow Credit: Pixabay/Jarmoluk

“The oceans around Antarctica - if you look at temperature trends over the last 50 years - that’s the one place that hasn’t been showing a lot of warming,” explains University of Washington Professor of Oceanography Kyle Armour. “It’s actually shown a little bit of cooling in the last 30 years.”

Furthermore, with frozen sharks washing up on Massachusetts’ Cape Cod and climate change scripture as prominent as Al Gore’s The Inconvenient Truth found to contain errors, it seems that environmentalists have some questions to answer.

The phrase “bomb cyclone” has been used in the media to try to explain the freezing conditions which hit New England over the festive period. “Bombogenesis is the technical term. Bomb cyclone is a shortened version of it, better for social media,” stated Weather.US meteorologist Ryan Maue. “There's nothing exploding or detonating,” he assured.

A woman trudges through the snow in New York

Storms are measured by central pressure - the lower the central pressure, the stronger the storm. A bomb cyclone is a storm where the central pressure has dropped by at least 24 millibars in 24 hours. The bomb cyclone which hit New England was especially bad because it drew cold air from our old friend, the polar vortex. Effectively an arctic cyclone, NASA defines the polar vortex as “a whirling and persistent large area of low pressure, found typically over both North and South poles”.

However, the polar vortex isn’t getting stronger. It’s actually getting weaker - and it’s this which is causing colder winters. “In winter, the freezing Arctic air is normally ‘locked’ by strong circumpolar winds several tens of kilometers high in the atmosphere, known as the stratospheric polar vortex, so that the cold air is confined near the pole,” stated Marlene Kretschmer, co-author of a study published in the journal Bulletin of the American Meteorological Society. “We found that there’s a shift towards more persistent weak states of the polar vortex. This allows frigid air to break out of the Arctic...”

A map showing the polar vortex Credit: University of Maine Climate Change Institute

More importantly, some scientists - including those behind this recent study - believe that global warming is to blame. As the Arctic ice melts, the ocean absorbs more heat, which is then released into the atmosphere. This, along with other Arctic feedback loops, is known as “Arctic Amplification”.

"Several types of weather extremes are on the rise with climate change," the researchers add, "and our study adds evidence that this can also include cold spells, which is an unpleasant surprise for these regions." As can be seen below, these regions suffering an "unpleasant surprise" in December were Canada and the US. They were the most usually cold countries in the world on 28 December.

A map showing Canada and the US to be the most unusually cold places in the world in December Credit: University of Maine Climate Change Institute

Furthermore, the cooling temperatures in the Antarctic are caused by surface waters being pushed north by gale-force westerly winds. This water is then replaced with water from the depths of the ocean which hasn’t seen daylight since before the Industrial Revolution. It is - understandably - very cold.

It’s certainly true that a number of countries are seeing colder winters, but this is a consequence of the destabilisation of complex weather systems. It could be said that “global warming” is a misleading phrase but regardless of the terminology, climate change is real.

However, the power to create change is in our hands. This month, for instance, we heard news that the ozone layer is recovering. After decades of damage caused by CFCs and other gasses, our change in behaviour has created a distinct, positive effect.

In the post-truth age we’re living in, climate change denial is becoming worryingly prevalent. However, the overwhelming majority of the scientific community agrees this is a manmade problem. It is not a linear, straightforward issue but a gradual yet pervasive problem which humankind needs to address.