As cold as it was this past week, inquiring minds want to know: Was the extreme cold we just experienced last week due to “climate change,” aka “global warming?”
Many people, including President Trump, like to joke that “it’s cold where I am, therefore global warming isn’t real.” But most scientists do believe that the recent cold snap was a symptom of global warming. They point out that while our recent bitter cold snap was caused by a shifting “polar vortex,” many parts of the world were simultaneously experiencing record warm temperatures. This was happening from Australia to the actual Arctic.
The polar vortex has become entrenched in our everyday vocabulary and served as a butt of jokes for late-night TV hosts and politicians thanks to previous cold waves.
I did a little research to see how, specifically, global warming fits into the whole vortex thing. One of the best explanations from the scientific community that I could get my head around came from Professor Jennifer Francis of Rutgers University.
In a nutshell, this is what I learned: Francis explains that there are rivers of air. Actually, there are two polar vortices in the Northern Hemisphere, which are stacked on top of each other. The lower one is usually and more accurately called the jet stream. It’s a meandering river of strong westerly winds around the Northern Hemisphere, about seven miles above Earth’s surface, near the height where jets fly.
The jet stream exists all year and is responsible for creating and steering the high- and low-pressure systems that bring us our day-to-day weather. Way above the jet stream, around 30 miles above the Earth, is the stratospheric polar vortex. This fairly circular river of wind also rings the North Pole during the winter months.
Both of these wind features exist because of the large temperature difference between the cold of the Arctic and warmer areas to the south. Uneven heating creates pressure differences and air flows from high-pressure to low-pressure, creating winds. The spinning Earth then turns winds to the right in the northern hemisphere, creating these belts of westerlies, and the cold air plunges south.
Still with me? There will be a quiz ... just kidding.
Scientists like Francis believe that “greenhouse” gas emissions from human activities have warmed the globe by about 1.8 degrees Fahrenheit over the past 50 years. The Arctic itself has warmed twice that much, due mainly to the dramatic melting of ice and snow in recent decades. This causes darker ocean and land surfaces to absorb more of the sun’s heat.
The bottom line, according to Francis and many other scientists, is that the large north/south undulations in the jet stream generate wave energy in the atmosphere. This disrupts the stratospheric polar vortex. Swirling “eddies” wander southward like the one that froze us to the bone last week.
These shifting streams of air could be causing other abnormal weather manifestations, such as the wildfires caused by droughts in California. I know from friends of mine in the horse farming business that Australia has been severely impacted by drought this year, and they blame it on global warming.
On my own horse farm (yes, I do have a life other than this one!), we have been battling the consequences of the wettest year on record. Not only muddy fields, but weird fungus and bugs resulted from all the rain.
Does such anecdotal evidence prove anything? No. But I have to admit that, to me, the evidence of this becoming a real problem is beginning to get pretty convincing. Even if true, what we actually should or can do about it is certainly open to debate.
Usually, I have been pretty cynical, but I am beginning to become a global warming believer. At least I am at the time of this writing because it is -8! How about you? “Do you think the ‘polar vortex’ from this week and the extremely wet year had anything to do with global warming?” That is our Post online reader poll question for the week.
Last week we asked, “Should the British government ask its citizens for a re-vote on Brexit or just follow the wishes from the first vote?” A pretty solid majority of you (59.6 percent) agreed with me and said go with the first vote, compared to 40.4 percent that wanted to see a re-vote on Brexit. My guess is that this week’s vote totals will be closer. I guess that it will depend on how hot or cold it is on the day you vote!