Chemtrails - Fact or Fiction?

                Talk of “chemtrails” has become an increasingly hot topic in certain public arenas. While there is some truth to the issue, there are also so many falsehoods, contradictions, and nonsensical arguments surrounding the topic that it has unfortunately become difficult to discern fact from fiction without expertise in environmental pollution or atmospheric science. Since my focus in graduate school happens to be environmental pollution, and even more specifically atmospheric pollution, I thought it natural, if not my responsibility, to finally shed light on this issue.
              There are a number of ways to dive into the topic, but I thought it best to take the main claims by chemtrail theorist, analyze them one by one, and ultimately discern whether we have “chemtrails” or “chemspiracy.” As I began writing, it soon became apparent that I would need to divide this into three different blogs. There are so many claims, and therefore so much to discuss. Below, I have briefly introduced the idea of chemtrails and explained the physics that leads to either the forming or not forming of condensation trails in the sky. In my next blog, I will discuss the prospect of chemtrails being a government conspiracy to target certain populations. Later, I will address other claims surrounding chemtrails, such as high aluminum in the soil and the issue of geoengineering the atmosphere, some of which has merit, and some of which does not.

What is a “Chemtrail?”

              The word “chemtrail” is a spin off the word “contrail,” short for “condensation trail,” which refers to the long trails of condensation that airplanes and jets sometimes leave in the sky. The word “chemtrail” was adopted to reflect the idea that contrails are not mere trails of condensation, but rather trails of toxic chemicals that are purposely sprayed into the atmosphere. Some suggest that the government is behind the spraying while others suggest it is industry. This is where different theories split off, but you get the point. By the way, while I may use the term “chemtrail theory” for simplicity in this blog, we are not actually talking about a true theory by definition, but rather an idea or belief discussed among the public.

Why Some Planes Leave Trails, and Others Do Not

              That some planes leave trails while other planes flying nearby do not is often used as support for the idea of chemtrails. However, there is another explanation. One that is no mystery at all, and certainly no conspiracy. These planes are flying at different altitudes and therefore areas of different relative humidity (RH). Condensation forms under conditions of high RH. That is, when the atmosphere is saturated with water. This condition is more likely when the air is cold. I’m sure you’ve noticed your car exhaust, or your own breath for that matter, to be visible on cool mornings or after a rain. This has nothing to do with the chemical makeup of your breath or your car exhaust, except that both contain water vapor. Yes, when your car burns fuel, it produces water vapor. This is one of the chemical products of hydrocarbon combustion. When this warm water vapor, either from your breath or car, is released into a cool or otherwise humid environment, the vapor condenses into visible water droplets. This is the same reason airplanes form contrails in the sky!
              Although a rare occurrence, some people say that even when planes are flying at the same altitude, one plane may produce a trail while another does not. First, a person at ground level cannot truly tell that two planes are at equal altitudes unless he/she knows the relative sizes of the two planes. You may think you can, but you cannot. Even when planes seem very close to one another, they can easily be thousands of feet apart. Second, even if two planes were hypothetically flying at very similar altitudes, or near each other, they could still be flying through parcels of air that are meteorologically different, leaving a condensation trail in one case and no trail in the other case. If you do not believe that two adjacent parcels of air can be so meteorologically different as to produce differences in visible condensation, then you do not believe in clouds in the sky.
              Lastly, you will notice that on some days there are visible trails all over the sky, while on other days there are none. This is not because on some days every plane has suddenly become a “chemtrail” plane, but rather because on some days the local atmosphere suddenly becomes relatively humid throughout (a weather front has arrived), while on other days it is dry. In short, science can easily explain contrails without the need of a “chemtrail” theory. That said, being able to explain condensation trails on a scientific basis is not in and of itself enough to completely refute the chemtrail theory. However, it certainly does not provide evidence for it and should not be used to support the existence of chemtrails. What remains to be dissected of chemtrails will be left for discussion in my next series of blogs.  

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                                                                                                                     -Shahir Masri, M.S. 


  1. Hi Shahir,

    I have seen these contrails and have also heard the "chemtrail" conspiracy. Thank you for explaining the altitude difference often invisible to the human eye. I found it interesting that we cannot always tell how high or low a plane may be and why one may create a contrail and another may not. On that point, approximately what temperature range is most conducive for this cloud formation?

    Thank you,

  2. I was hoping for a conspiracy...but I like science more. The one thing I learn was the idea of "chemtrail" conspiracy theory. I had NEVER heard of it and thought conspiracies first started with proof or evidence prior to there being a possibility of a conspiracy. I'm curious to know if there is an impact difference of CO2 being emitted on days with high RH? I know folks with asthma have difficult days when it's humid...would the impact of the CO2 be higher on humid days?

    1. This is Pinky Rhone' (Pinky Jacqueline Rhone) from your Public Health and Environment class

  3. Hello Professor,
    I have to say, I've only really ever heard the "chemtrail" conspiracy and never any fact, so I very much enjoyed your blog. What I learned were the facts and it makes perfect sense. If you ever watch the weather report, it shows all of the different flows of the air depending on their location in the country, which seems similar to that of the different parcels of air in the atmosphere. Conspiracy theorists tend to leave out facts such as standing on the ground, it is highly unlikely that you can tell how close two planes are flying.
    My main question would still be, how did this conspiracy theory come to be? I always find them fascinating because it usually has to do with the government, or "the man" being against us, but I have always been curious as to what caused the rise of this particular theory.

  4. Hi Professor,

    I can honestly say I am really into learning about conspiracy theories. My husband and I can binge watch all different types of research videos on the weekends on the different theories people have. We do not really believe them but just interested in how they come up with the concepts of why they believe what they believe. This is not the first I have heard of chemtrails. It is the first time I have heard of the difference in the altitudes of planes making a difference in what can be seen. How do we educate those who believe these theories to make them understand the science?

    1. This is Caroline Prine in your COH 608 class

  5. While I do not support conspiracy theories, I did find this article to be interesting and informative. Prior to this reading I did not had prior knowledge of airplane skeptical byproducts from conspiracy theories. However it is interesting to learn that the environment plays an important role in chemical trails. Also, did not know that altitudes play a major role in the condensation therefore allowing some airplanes to leave a trail behind. Has anyone ever collected sample data from these chemtrail and analyze their composition?

    Moises Moreida- COH 608 Environmental Class

  6. I have a good friend who is a huge believer in the chemtrail conspiracies, I typically spend these conversations nodding and thinking about what my next meal will be! I really didn't know anything about how chemtrails worked and why they were there. This article things a lot more clear and actually makes the reason behind these contrails make sense! When you think about how distance makes things appear different sizes, it makes sense that planes that look like they are near each other are actually drastically far apart and flying at different altitudes. The one question that this article leaves me with is how these conspiracies get started in the first place and how they gain so much attention. If people spent half as much time working on issues that were real that they spent on conspiracies, we might actually be able to make big changes in the environment.

  7. I have never heard of the "chemtrail" theory until I read this post. That is quite an interesting conspiracy theory someone can come up with. Interesting but not believable. One question I have is whether some theorists do not believe it is just the government that is behind the "chemtrails."

  8. 1. At least one thing new and interesting you learned from the article.
    I have never heard of the chemtrail theory so this was very interesting indeed! This makes complete sense as to how there is a variation in the air even if the planes are flying "close". The condensation in the air is ever changing, so how can one assume that the results will be the same every time the planes fly.

    My question is, those who believe in this conspiracy theory, what exactly are they claiming is being harmed by these chemicals? Also is there any scientific data that the believers have done?
    - Ana Barragan

    2. At least one question that you have relating to the article or topic.


    1. Hello Ana Barragan,

      While there is not hard evidence that Chemtrails are the cause of soil erosion and damage to the rainforest. There are videos and witnesses that claim to be evidence of the damage behind Chemtrails. Not many scientists will claim that Chemtrails are a problem. However, Allan Buckman, a biologist with the department of fish and game for 38-years, discusses the damage to trees and plants extensively in a video exposing Chemtrails. So far most of the data collected is land and forest exposure. Finally, the most concrete data, as the article mentioned before have been from condensation. Astronomers have confirmed that Chemtrails are pure conspiracies.