Explainer: Why Is It Sooooo Cold? (hint: a warmer North Pole)
Cold temperatures always have a way of reviving the once-dead notion that: "if the climate is changing why is it so cold outside?" And it's cousin: "we could sure use some of that global warming right now!"
Quick tutorial here so you can remind yourself--and others around the holiday table--that extreme cold isn't proof that climate isn't happening. It's rather the opposite, as you will soon see, and it's not hard to understand. At the Center for the Business of Sustainability we believe that "sustainability is a team sport" which means in large part that business must work with "teammates" in the sciences in order to understand the planet on which business is carried out.
First, we have to understand and appreciate that the planet is a system of interconnected parts: the atmosphere, oceans, topography, geography, temperature, heat, moisture, and even the shape of the planet all interact with one another constantly. So even though each of us experience our small part of the world, that small part is connected to everything else. This basic understanding is critical.
So keep in mind this basic fact of interconnectedness of life on earth. The "bomb cyclone"--manifested as extreme cold in the United States--is a time when we are forced to come to terms with this fact. It all comes down to how the warming of the poles--the north pole in this case--affects the jet stream and therefore the weather outside now snarling travel for 190 million people.
So even though each of us experience our small part of the world, that small part is connected to everything else. This basic understanding is critical.
1. Disappearing Arctic Sea Ice from Warming
Article sea ice has gone from 85% coverage in the 1980s to less than 12% today. And from 10 feet of thickness to 2-3 feet. The loss of sea ice is correlated with the frequency of extreme weather events in eastern North America and Eastern Asia.
2. The Breakdown of the Polar Vortex
The heating of the north pole causes the breakdown of the polar vortex, which exists as a byproduct of the high pressure pattern over the pole, with more heat coming from the ocean into the atmosphere.
Polar Vortex Consolidated Under "Normal" Historic Conditions at the North Pole
Polar Vortex Dispersed Due to Heating North Pole
3. Shoving the Jet Stream Right Into Our Face
This break down of the polar vortex causes the jet stream to be pushed and to dip further down. This creates this lobed structure of the polar vortex which dips into temperate latitudes with warmth on the upper ends ("ridges") and cold on the southern ends ("troughs").
Specifically, the sea ice loss north of Alaska builds up an upper air ridge in the early part of the winter and this creates the northwest to southeast flow that reaches midwest and eastern seaboard which is seen below.
It is really cold outside here in Pennsylvania with temperatures heading to 0 degrees. Understanding why doesn't make it warmer (only more coffee seems to be helping), but it does help us understand the planet we are living on and how our actions have consequences.
Source: Yale Climate Connections Explainer Video (5 minutes)....it's excellent!