Before deciding, let's get an Overview, courtesy of World-Action:

Chemtrails — Aerial Spraying
By World-Action

Chemtrails are laid down in a similar way to normal contrails, but do not evaporate; instead they linger in the air, disperse widely and form a greyish, streaky cloud-like cover which can last all day. They are not made of ice crystals, but of solid, very fine, particulate matter. And will therefore land on the ground, water, sea, and in our lungs, as widely dispersed, but nevertheless, solid physical matter.

Contrails are the normal trails of jets and comprise of ice crystals formed from moisture emitted in the engine exhaust and usually evaporate within a few minutes of appearing. Contrails are usually only made and observed at fairly high altitudes, in most cases, in temperate regions, above 25,000 feet. Contrails are ice.

Chemtrails: Chemtrails are widely observed in most NATO countries: Britain, USA, Canada, New Zealand, Australia, France, Switzerland, etc. Military and civil authorities in these countries are reluctant to give information on exactly what is being sprayed by aircraft to cause this new, man-made type of 'cloud' cover. One suggested explanation is that it is to reduce the effects of 'Global Warming'.

Health: There appear to be serious consequences to the health of human, animal and vegetable life onto which the spray falls. There are reports of Chemtrail spraying going back to 1991. Around 1993, many countries began to experience a large increase in illness of many types, especially connected with respiratory conditions. Also: pneumonia, influenza, viruses, allergies, etc. From around 1998, there seems to have been an increase in Chemtrail spraying, and likewise, an increase in illness in humans and animals, and abnormalities to vegetation.

Notice the spray is coming from the tailplane, and not the engines. Other planes spray from nozzles along the wings

United Kingdom: Chemtrails are badly affecting the British Isles. On many days you will notice the trails of planes linger in the sky for many hours, forming a wispy, dispersed 'cloud' cover, obscuring the sky above and reducing sunlight. A large increase in illness occurred in the British Isles around 1993/94. In recent years, there has been a large increase in the incidence of asthma. Also, colds, nagging coughs, flus, and viruses which are very severe and never seem to clear up.

Worldwide: All NATO countries are being sprayed extensively with Chemtrails. Therefore, due to the global distribution of major wind currents, the whole world is being affected.

"Overview" text and photograph
reproduced by permission of World-Action

If the various accounts and reports that have been published on the web are even remotely accurate (that is to say, if they have some sort of basis in reality) then clearly something very strange is going on, and has been going on for a number of years now. Sufficiently strange in fact to merit asking some fairly penetrating questions.

Moreover, if the many claims that the effects of these occurrences represent a serious hazard to health and well-being are well-founded, then not only is this an issue that concerns us all, its also an issue that demands immediate and meaningful action.

Even superficial research of the topic uncovers many weird and wonderful theories, where ideas of vast governmental and/or militaristic conspiracies abound. Many of the ideas may seem preposterous or just simply paranoid to the average "man in the street".

However, let's not get sidetracked and start confusing the all-important "whether" with the more speculative "whats" and "whys".
In other words, all we really need to know initially is whether its actually happening or not. And if it is, then its imperative for our own safety and peace of mind that we act, and act straightaway!