What do authorities have to say about chemtrails?
Here's a very typical response, received last year by a Canadian who wrote to a government website, Environment Canada, about the issue.
From: Peter Zaza
Sent: Monday, May 25, 2009 5:35 PM
To: Enviroinfo [NCR]
Subject: INC-MSC-MAY 518-LM/02 inquiry regarding Chemtrails
I would like you to tell me your official explanation for the Chemtrail spraying program of our atmosphere which occurs almost daily in our country. These trails have been studied and found to contain heavy metals, polymers, Barium, and many other elements harmful to our species. Please explain.
The reply he received:
Thank you for sending your inquiry to Environment Canada.
We receive numerous public enquiries concerning the composition and appearance of contrails and whether or not contrails pose a public health risk. Recent years have seen the emergence of popular opinions often carried by the media and seen on many websites suggesting that these visible contrails from planes are chemically laden. Hence, the term “chemtrail”. However, there is currently no scientific evidence to support the existence of chemtrails and Environment Canada cannot provide any scientific evidence.
The phenomena that you are referring to are commonly called aircraft condensation trails or contrails. Airplane contrails are long white condensation trails made up of ice crystals left behind by aircraft flying primarily at high altitudes. They form when hot water vapour produced by the burning of aviation fuel cools rapidly as it comes into contact with the much colder air. The airplane’s exhaust increases the amount of moisture in the air. As the moist air cools it reaches saturation and the water vapour sublimates to form ice crystals. The cooling of the air and subsequent formation of ice crystals is very rapid so that the contrails appear almost immediately behind the aircraft. This process is analogous to seeing one’s breath on a winter day. Because visible contrails are composed primarily of water/ice, they do not pose a health risk to humans. The appearance of contrails depends on many factors including the prevailing atmospheric conditions, type of aircraft and engine, wind direction, altitude and amount of sunlight. If the air at high altitude is very dry, the condensation trails will dissipate rapidly. If the air at high altitude is relatively moist, the contrails typically last from minutes to hours. Under certain atmospheric conditions, contrails can linger in the air for more than a day and usually grow wider and more dissipated over time. Some of these contrails change in appearance by the presence and the strength of the upper level winds. If the wind is very strong, contrails will move away from the area where they were formed, often changing in appearance and opacity as they are moving. Contrails can sometimes appear to stop and start as the aircraft encounters areas in the upper atmosphere that contain different amounts of moisture. The paths of aircrafts criss-crossing each other may explain the unusual appearance of contrails. Increase in air traffic in the last two decades has inevitably caused an increase in the number of visible contrails in the sky, especially in the vicinity of larger airports.
With respect to aircraft emissions, aircraft engines and fuel have very stringent emissions standards set by national and international organizations. To minimize the impact of aircraft emissions on the environment, these organizations constantly update their standards to ensure that aircraft engine manufacturers use the best available technology. In Canada, aviation fuel specifications are controlled by the Canadian General Standards Board (CGSB) which includes fuel suppliers, fuel users and other stakeholders. CGSB sets limits on all important fuel parameters and prescribes test methods for ensuring consistent fuel quality. Aviation fuel such as petrol/gasoline (piston engines) or paraffin/kerosene (jet engines) consists primarily of hydrocarbons. When the fuel is burned, the carbon combines with oxygen to form carbon dioxide; the hydrogen also combines with oxygen to form water, which emerges as steam (i.e. water vapour) in the exhaust. There have been no new fuel additives in recent years that could suggest that new foreign substances are being injected into the atmosphere by aircraft engines.
Finally, the web sites that discuss chemtrails contain numerous suggestions that chemtrails are a form of weather or climate modification. Under the Weather Modification Information Act, any weather modification experiments legally require that Environment Canada be formally notified. Environment Canada has no such notification from any group, and has no knowledge of any weather modification experiments related to aircraft contrails.
In conclusion, there is no scientific evidence, data or information related to aircraft emissions that supports the idea that contrails from aircraft are chemically laden. Similarly, there is no evidence that aircraft contrails pose a health risk. I hope that this information adequately addresses your concerns.
Meteorological Inquiry Specialist – National Inquiry Response Team (NIRT) ISO 9001:2000
Environnement Canada/Environment Canada
Notice how this "specialist" (1) insists Peter is seeing what are normal contrails; (2) gives an accurate explanation for how contrails form; (3) states that contrails pose no health risks; (4) states that contrails can last for hours if the air at high altitude is "relatively moist" -- which it is not; (5) talks about strong winds moving contrails around and changing their appearance; (6) concludes by stating that there is no information or evidence relating to fuel additives for aircraft or "chemically laden" contrails. Remember (from our Basic Facts page) that true contrails evaporate in sunlight and do not form in high humidity. If high humidity were to be found at high altitude, maybe contrails WOULD last longer, but the reality is that they don't. Thus the above reply is deft in its construction -- nicely evasive.