The Polar Vortex
Turn on any news channel in early 2014, and aside from the apocalyptic threats and warnings, you'll hear another buzzword surrounding the terrible cold which brought temperatures well below 0°F for most of North America: The Polar Vortex. This sci-fi-sounding phenomenon sounds more like a minor-league hockey team than the driving force behind deathly cold weather, but don't let the name fool you. This vortex, although has had profound effects on the United States as far south as the Florida panhandle, is nothing out of the ordinary. In fact, the polar vortex always exists during the winter; it just normally stays in it home of the North Pole. So what gives, you may ask? How did this air make its way down well below 40°N latitude? This can be answered with another climactic index, the Arctic Oscillation.
In the positive phase (right), winter storms, which form over the northern Pacific/Atlatnic Oceans can be brought further north into Alaska and Scandinavia, making the winters there much more snowy. On the other hand, we can see that the jet stream does not dip as far south, meaning the winters most of us experience in the United States and central Europe are quite mild.
In the negative phase (left), the jet stream becomes amplified. This makes it possible to bring significantly warmer air to Alaska, Canada, and Scandinavia, while the frigid arctic air down to the United States and central Europe. This is what brought the nasty weather we've seen in the first week of 2014. The negative phase can often bring with it more cold, wet, blizzard-like storms. Since in the late 1990s, we have been in the midst of a negative phase, with a record AO index set in the 2009-2010 winter.
So how about that "Global Warming"?
This is by far the biggest confusion point you will see on both sides. Climate skeptics are laughing at the notion that the Earth is warming when in fact we are experiencing the coldest weather in roughly 20 years. On the other hand, if a climate advocate tries pointing to the record breaking warm winters we've had in the last 5 years, that too is merely weather. Our lives are simply not long enough to experience any change in our climate.
- Weather is not climate
A classic argument advocating for climate change is that weather events will become more extreme. With the above information, although the cataclysmic news headlines and media firestorm suggested otherwise, we should note that what happened this week, although fascinating, is not new. The Polar Vortex has, and will continue to make shifts from the polar region down into the mid-latitudes that we call home. Also, there is a very good chance that the extreme cold was indeed a record-breaker. I therefore challenge you this: when was that record set? Chances are it was from a weather event dating back to 1988. On this date over 25 years ago, a similar storm, which started off by dumping more than a foot of snow in many parts of the country was followed by sub-zero temperatures that set the records that we now are beating today. But even that isn't that "extreme". Just 5 years ago today, it reached -20°F in Germany. Weather like this happens quite often, yes, but we should remember that again, weather is not climate.
- This weather was not all that abnormal
Another key point to consider before engaging in a keyboard flame-war on the validity of the climate change theory is that the Earth is always changing. Climate is a tough issue to debate, as we have only been keeping formal weather records for around 150 years. Although things like ice cores have proven to be good sources of climactic history, there are well-documented concerns of factors which may make them inaccurate. Secondly, humans have only truly been affecting the Earth for about 300 years, since the days of the Industrial Revolution. With climate processes being on the scales of as much as 30,000 years, we can't be sure if what we're doing today is severely altering the course of naturally-occurring climate change. This time scale is the equivalent of a 1-year old baby eating an unknown food and wondering if it will make it unhealthy at the end of its life 100 years later. While evidence currently suggests that humans do have the ability to impact our Earth, not every single degree of change can nor should be blamed on a big oil company or a power company burning coal.
- Whether or not we're to blame, the Earth is always changing
|Making eco-friendly choices reduce a lot of the "what ifs" of climate change|