Oliver Smith, writing in the unlikeliest section of Britain’s Telegraph newspaper (Travel), pooh-poohs the concept of chemtrails and, seemingly not satisfied with rubbishing that conspiracy theory, tries some other aviation-related theories out for size:
The seemingly random appearance of “contrails”, as these lines of condensation are commonly called, is considered by a small but vocal online minority to be evidence of government conspiracy. The clouds are, according to some, in fact “chemtrails” – chemical or biological agents sprayed at high altitude for any number of top secret reasons.
So persistent is the chemtrail theory that US government agencies regularly receive calls from irate citizens demanding an explanation. Pernilla Hagberg, the leader of Sweden’s Green Party, even raised the issue in parliament. The trails which arouse the most suspicion are those that remain visible for a long time, dispersing into cirrus-like cloud formations, or those from multiple aircraft which form a persistent noughts-and-crosses-style grid over a large area.
So what possible reason would the world’s governments have for secretly jettisoning vast quantities of chemicals into the stratosphere?
The conspiracy theory took root in the Nineties, with the publication of a US Air Force research paper about weather modification. The ability to change the weather isn’t mere pie-in-the-sky. Cloud seeding – where particles such as silver oxide are sprayed onto clouds to increase precipitation – is commonly used by drought-prone countries, and was part of the Chinese government’s efforts to reduce pollution ahead of the Beijing Olympics in 2008. Other proponents of the “chemtrails” theory say it is an attempt to control global warming, while some cite far more sinister goals, such as population control and military weapons testing.
Governments and scientific institutions have of course dismissed the theories, and claim those vapour trails which persist for longer than usual, or disperse to cover a wide area, are just normal contrails. The variety of contrails seen in the sky is due to atmospheric conditions and altitude, they say, while grid-like contrails are merely a result of the large number of planes that travel along the same well-worn flight lanes.
Patrick Smith, a pilot, also dismisses the theory in his book about air travel, Cockpit Confidential. “Contrails are formed when humid jet exhaust condenses into ice crystals in the cold, dry, upper-level air it’s not unlike the fog that results when you exhale on a cold day,” he says. “Contrails are clouds, you could say. Water vapor, strange as it might sound, is a byproduct of the combustion within jet engines, which is where the humidity comes from. Whether a contrail forms is contingent on altitude and the ambient atmospheric makeup – mainly temperature and something known as vapour pressure.”…
[continues at the Telegraph]