Meteorological conditions deviate from the average climatological conditions, more or less. Condition generally are not in the focus of citizen’s interest until some extreme event occurs. Then the print and digital media are full of reports about the consequences of the storm. Citizens of all professions become active participants and express their observations and opinions with their comments. On the one hand, this is good, but on the other, the comments often confuse public opinion, and in some cases even disturb. The reason is that most analysts and commentators do not have proper professional education and therefore do not understand meteorological processes sufficiently. As a consequence, the comments make assumptions, even claims, that episodes of extreme meteorological phenomena are the result of considerable, deliberate human action (conspiracy). Many comments refer to contrails, which are claimed to be chemtrails as part of a secret dusting program. The claim is based on the presentation of images, films and opinions without sufficient evidence. These specific "records in the sky" are indeed the result of human action, and they were created by known chemical and meteorological processes. They have been known since before the Second World War. In the Cloud Atlas they are classified as Cirrus homogenitus and Cirrus homomutatus. By burning aircraft fuel (hydrocarbons), hydrogen and carbon are produced, and their chemical reaction with oxygen produces carbon dioxide and a molecule of water vapor. The water vapor molecule further binds to the nucleus, which consists mainly of solid particles of jet fuel combustion. Due to the very low temperature at the height of the plane's flight, the microscopic droplet almost immediately changes to a solid state (crystal) and becomes visible. The retention and movement of aircraft trails (clouds) depends on a number of thermodynamic properties of the atmosphere. High pressure, low humidity and downward air flow cause rapid disappearance, and low pressure, high humidity and upward flow cause long-term retention of traces. High wind speed carries the tracks in the direction of the wind. In addition to the condensation trails of the aircraft, citizens are also suspicious of "strange-looking clouds", and those rare cloud forms have also long been observed, classified and recorded in the Cloud Atlas.