While in Europe winter temperatures were very balmy, the United States plunged into a deep freeze and skeptics were having a field day. The United States government was apparently not amused and made a video, starring John Holren, to assure the public that global warming is still there. The video is called “The Polar Vortex explained in 2 minutes” and it starts like this:
If you have been hearing that extreme cold spells, like the one we are having in the United States now, disproves global warming, don’t believe it.
Logically I can agree with that. A cold spell doesn’t disprove global warming, although this statement is not a big deal anyway. But I don’t think it is used this way in this video. Probably the author meant to say something like this: “global warming is still true, despite the cold snap, so don’t believe those who question it”. But global warming still being a theory, it is something that can’t be proved nor disproved yet. A single weather event can not disprove it, but when it is contradictory to the theory, it can weaken its case.
The fact is that no single weather episode can either prove or disprove global climate change. Climate is the pattern of weather that we observe geographically and over the seasons and is described in terms of averages, variations and probabilities. But a growing body of evidence suggest that the kind of extreme cold being experienced by much of the United States as we speak, is a pattern that we can expect to see with increasing frequency as global warming continues.
Also here, indeed, I can agree that a single weather episode can neither prove nor disprove global climate change. Yet this new event is promoted to climate…because there is a growing body of evidence that suggest this pattern is expected to increase when global warming continues.
See the carefully change from global warming to “global climate change”, whatever that means. Climate changes all the time and there is not one global climate as there is not one global temperature. That seems replacing one meaningless term by another. Why the shift? Probably because global warming sounds a bit silly in the face of 12-17 years of no global warming.
Now this cold spell that was portrayed a couple sentences ago as a single weather event is suddenly a pattern? How many times such a similar event happened in the last decade or so? It surely doesn’t prove anything, but promoting it to something that is going to happen frequent in the future on basis of an accumulation of assumptions is a bridge too far.
And the reason is this: in the warming world that we’re experiencing the far north, the Arctic, is warming roughly twice as rapidly as the mid latitudes, such as the United States. That means that the temperature difference between the Arctic and the mid latitude is shrinking. And that temperature difference is what drives what is called circumpolar vortex, which is the great counterclockwise wise swirling mass of cold air that hovers over the Arctic. As the temperature difference between the Arctic and mid latitudes declines the polar vortex weakens and it becomes wavier. The waviness means that there can be increased larger excursions of cold air southward, that is into the mid latitudes. And in the other face of the wave increased excursions of relatively warmer mid latitude air in the far north.
What struck me is the mixing of “global and “local”. He definitively uses global warming/global climate change to describe the process, but if you read it carefully it is not about global warming at all, but about LOCAL warming! It is the warming of the Arctic, twice the rate of the mid latitudes. That is not global warming, that is local warming. And how can GLOBAL warming increase cold patterns when the global temperature didn’t change in 12-17 years and the pattern is dependent on LOCAL warming?
Computer models tell us that there are many different factors influencing these patterns. And as in all science there will be continuous debate about exactly what is happening. But I believe that the odds are we can expect, as a result of global warming, to see more of this pattern of extreme cold in the mid latitudes and some extreme warmth in the far north.
Couldn’t help chuckling when hearing the “computer models tell us” phrase. What he didn’t want to say is that computer models have it difficult to model these patterns. What he also didn’t tell with that many words is that not all different factors are known yet. He unveils it a bit in the next sentence in which he states that there is a continuous debate about what is happening (not with skeptics I think) and also he believes that the odds are that we can expect more of these things. Hey, but that is suddenly something different. He is not sure, but maybe, just maybe, this could be true. Or not.
But not only the words are important, what is being seen is as well. Let’s look at the first thing in the background that caught my eye:
Polar vortex in 2 minutes video sceencap – hurricanes?
Are this the tracks of hurricanes? What are they doing in this video? Sure, it has being said that hurricanes are on the increase because of global warming, but observational evidence is stacked against this. So do they want to keep the suggestion that hurricanes are still a threat?
Polar vortex in 2 minutes video sceencap – Glowing earth
And what is it with the red glowing earth? Europe, most of Asia/Russia and almost complet of Africa has a close to maximum anomaly of somewhere around 5 – 6 °C? And do I see it right that the North Pole region is blue?!?! That is contrary what Holdren was telling all along. I don’t know any dataset with 5-6 °C anomaly in such large regions. Is this the result of a model?
Polar vortex in 2 minutes video sceencap – Sea ice extent
Of course the mandatory Arctic sea ice … until 2012! We are in 2014, The data of 2013 should already known. Looking for the source, it seemed that NASA is the source for the graph and animation (see “Arctic Sea Ice”). It is the annual Arctic sea ice minimum area from 1979 to 2012. Looking further they seem to mix area with extent and omit that the data is about the yearly minimum extent. They got their data from NSIDC (which uses extent, not area). In 2012 the extent was indeed 3.413 million km2. In 2013 the lowest extent was 5.103 km2 on September 16, 2013. This makes the omission of the data point of 2013 even worse: the minimum extent of 2013 at the time of the video is already known for almost 4 months!
So being curious, when drawing the minimum extent of 2013 on this graph we get this:
Sea ice data + added extent of 2013 to the graph
That is not really convenient when one tries to explain that this cold snap was caused by the Arctic ice melt. That obviously didn’t melt as much as the last years and now on the level of 2005.
Again being curious, I found an animation of the Arctic Ice extent in September 2013 by NASA and made a screenshot of the extent of September 12, 2013 (a few days before minimum extent):
Arctic Ice extent on September 12, 2013
Quite a diffence when one compares it with low 2012 extent from the video. It is obvious they couldn’t possibly show that. It wouldn’t advance their cause.
The video shows us that the voices of those who question global warming start getting threatening to the party line. That became so uncomfortable that they had to do something. Like making a video. Questioning the party line, we can’t have that, can’t we?