Chemtrails - conspiracy theory or not?

A couple of people locally have called on the Green party to take up the issue of 'Chemtrails'. It is hard to see how best to proceed in the face of many official denials that they even exist.

Photo above and below: contrails over Whiteshill? Why do they sometimes disperse and othertimes not? What atmospheric conditions effect these trails?

Our own MP David Drew asked the Secretary of State for Environment, Food and Rural Affairs over a year ago what research the Department has undertaken into the polluting effects of chemtrails for aircraft. Hansard records the reply as:

"Mr. Morley: The Department is not researching into chemtrails from aircraft as they are not scientifically recognised phenomena. However, condensation trails (contrails) are known to exist and have been documented since the 1940s. Contrails are composed of ice crystals forming on the small particles and water vapour emitted by aircraft as the result of the combustion process, they form behind high-flying aircraft depending on the temperature and humidity of the atmosphere."

Contrails are certainly being looked at - particularly in the light of aviations impact on climate change - but Chemtrails??

A brief look at the web and the more wacky websites have much to say on this phenomena - but there is also clearly a growing number of people with real concerns about this. I've not made my mind up - but here's a taster of some of the issues people are trying to raise...

Perhaps I'd better start with 'What is a chemtrail?'

Jack Blood's website writes: "A chemtrail has many similarities with a contrail or condensation trail created by an aircraft under certain atmospheric and meteorological conditions. However, chemical trails or chemtrails appear to last a lot longer, and apparently they seem to accumulate more moisture than contrails. In some cases, chemtrails may actually turn into clouds due to the moisture they absorb. Additionally, it is said that chemtrails differ in their flight pattern configuration from contrails; they do not appear to show aircraft trajectories from point A to point B, but rather crisscross-like patterns."

If we accept these trails are not produced normally by the aircraft then perhaps the most likely explanation for the chemtrails is weather modification. There is evidence to show that NASA have tried this in the past with many experiments looking at altering the weather patterns. There are also allegedly companies like Weather Modification Inc that publicise their weather modification activities. Are these companies real?

There have been strong suggestions that the US are not alone in these tests or programmes. The 1952 floods at Lynmouth claimed 35 lives - a BBC report found that cloud seeding had been going on days before 90 million tonnes of water swept down the valley - 250 times the usual rainfall for August. Read more here and in The Guardian.

Photo: Lynmouth 1952

De-classified War Office documents also suggest that the military had been interested in using rain to cause downpours to hamper enemy movements, clear fog from airfields, and even increase the fallout range of atomic weapons. Certainly since then, cloud seeding has been carried out in attempts to relieve drought and to encourage snowfall in ski resorts.

How does it work?

Chemicals including heavy metals that are used to accelerate the formation of clouds by increasing the size of the cloud moisture droplets. The accumulation of cloud droplets, and thus the increase in size of a cloud, is the first step in the development of precipitation. The droplets at such an early stage are too small to precipitate. In order for precipitation to occur, the droplets must grow much larger; they need to increase in density so they can actually fall and not evaporate after coming in contact with dry air. This is where allegedly the aerosols containing calciumchloride and silver iodide come in place; they cause the droplets to attract more moisture. This process requires freezing temperatures in order to work. The anti-freeze properties of calcium chloride would prevent the droplets from turning into hail.

Clearly if this is going on then we have a potential health hazard - to say nothing of the other concerns about what this will do to the environment.

So are they happening here in Gloucestershire?

Photo: contrails over Randwick?

Well there are those who are convinced that chemtrails are regularly occuring locally. I don't know, but I have become intrigued by how the vapour trails of aircraft sometimes disappear quickly and other times disperse and seem to extend creating cloud over larger areas. On some originally clear days like last week the sky is full of criss-crossings of trails, while other days the sky is empty.

I don't know enough about how atmospheric conditions alter contrails or about how flight patterns change. Could such experiments be taking place? Could creating cloud cover like that postpone climate change? Or make it worse? I would be interested in views.