Over the past decade, there have been a growing number of people subscribing to what is known as the ‘chemtrail’ conspiracy. This conspiracy theory is based on the trails left behind by airliners flying through our skies. Everyone but the visually impaired has observed these trails and they are called contrails – condensation trails left in the sky by the exhaust of jet engines.
The chemtrail conspiracy theorists, however, propose that not all contrails are equal. They suggest that although some of these trails really are just the same old contrails we have been witnessing all of our lives, others are actually the result of large volumes of chemicals being sprayed into the upper atmosphere. These chemical trails, or ‘chemtrails’, are described as having different traits than contrails.
Although there isn’t much consensus amongst the chemtrail theorists as to exactly which trails are formed by condensation and which are formed by chemicals, the differentiation seems to hinge on just how long a trail lingers in the sky, and whether or not the trail becomes spread across the sky. At the root of this differentiation is the premise that if all the trails are just contrails then they should, in fact, linger for similar periods of time and exhibit consistent behavior in just how much they spread or don’t spread. To understand why this premise is unsound, we need only consider a rather technical description of contrails.
Jet engines produce a very large amount of water vapour: more vapour, in fact, than the actual jet fuel combusted. The large vapour mass is due to all the oxygen that is mixed with the fuel as it is combusted. What becomes of all this water vapour is highly dependent upon the conditions of the local atmosphere in which it is produced.
If the air is relatively warm and dry then the exhausted vapour dissipates rapidly, without forming a trail that can be observed from the ground. If the air is cold, the vapour freezes into ice crystals. These crystals form the long, thin, artificial cloud that we call a contrail. The conditions in the upper atmosphere determine how quickly such a cloud will linger.
In dry air, the ice crystals can sublimate to vapour, causing the cloud to dissipate in a short amount of time. In very cold and humid conditions, the crystals can actually accumulate mass by condensing and freezing water vapour out of the air. Under such conditions, not only will the cloud linger for a very long time, but it will actually grow. If the wind at that altitude runs perpendicular to the cloud, then the cloud can become spread out, like a cirrus cloud. Because of all of this, contrails exhibit a wide variation in their dissipation times and ‘spread behavior’.
Proponents of the chemtrail conspiracy also often point to observations where one or more jets have left thick dense trails while at the very same time one or more other jets have left only thin, quickly dissipating trails. Sometimes, they point out, certain trails become spread out, while other parallel trails do not. This, of course, is exactly what one might expect if the jets were flying at different altitudes.
The atmosphere can have very tightly delineated layers, and I have experienced this first hand as a skydiver. I once dove out at 10,000 feet and began a wonderful freefall, only to be pummeled by ice crystals from 7,000 feet down to 4,000 feet, while on the ground the temperature was about 20 Celsius and the skies were perfectly clear. I know first hand that wind direction at one altitude is not indicative of wind direction at other altitudes, and having to walk three miles with my parachute bunched in my arms after a cross-country jump drilled that lesson into my head clearly.
All of this means that observations of the different traits of concurrent contrails reveal nothing unless those observations include the altitude of each trail and the atmospheric conditions at those respective altitudes.
Even though chemtrail conspiracy theorists may disagree on which contrails they identify as chemtrails, they all seem to be alarmed by the sheer volume of trails in our skies. This has led to a growing number of people keeping a watchful eye out and it seems like new photos and videos get uploaded everyday by people who are concerned about the sheer number of contrails they are seeing. They seem to think that this high density of contrails is inconsistent with regular air traffic volume. Regular air traffic volume, however, is staggering. According to a 2009 Bureau of Transportation Satistics Report, “In November , U.S. airlines operated 765,100 scheduled domestic and international flights.” That’s over 25,000 flights through U.S. airspace per day!
With most airline flights departing in daylight, the average number of flights departing during each daytime hour is well over 1000. Even if fewer than half of this traffic is comprised of large airliners, it is easy to see just why our skies are so littered with contrails. Although a single jet is unlikely to create a contrail through its entire route, the airspace where contrails are generated will reveal all the jet engines passing through it. Consider a map of the United States overlaid with just 100 lines to represent airline routes between major cities and it quickly becomes apparent that high densities of contrails should be expected when and where conditions are conducive to contrail formation.
The map above also reveals another aspect about contrails that alarms chemtrail conspiracy theorists. Many of these theorists believe that when contrails form a grid pattern, or when multiple parallel lines can be seen, that these patterns indicate a plan to get maximum coverage over a targeted area. It is obvious from the map, though, that grids are readily formed by the multiple route intersections. Parallel lines are easily explained by pilots on similar routes simply shifting over a mile to avoid the obstructed visibility of flying through another jet’s contrail. Furthermore, the wide ground dispersal achieved by spraying from an altitude of over 30,000 feet would completely negate any practical benefit of spraying in a grid pattern.
There are people who report observing these high density patterns far from any major airport and cite this phenomenon as proof that that area is being targeted by flights that could serve no purpose other than laying out chemtrails. As the map indicates, however, you don’t need to be near a major airport to observe such a major intersection of contrails, you only need to be in a location where routes between major airports intersect.
On the contrary, however, one should not expect to observe major contrail intersections in the vicinity of major airports. All airliners on a route that would intersect with such a location will actually fly around that airspace rather than through it. The only airliners near an airport are either those that are landing or those that have just taken off, and their trails had better not be crisscrossing or your local air traffic controller is definitely not doing his or her job. Furthermore, airliners don’t leave contrails when they are landing or taking off because the vapour given off by the exhaust is only perceived as a haze – a cloud on the ground is no cloud at all, it’s called fog.
There may very well be some nefarious group of conspirators conducting a high altitude chemical assault on the United States, but cavalier observations of the various traits of contrails certainly offers no proof of such a conspiracy. I hope, however, that this little essay can at least quell the concerns of some people who have been alarmed by the growing chemtrail conspiracy panic.