August 19, 2005
Same old rhetoric ... the Minister finally responds
Thank you for your email of March 28, concerning aircraft contrails. I regret the delay in responding.
Visible aircraft contrails are usually the result of water vapour from the hot engine-exhaust stream condensing into droplets in the cold outside air. The water originates from the combustion of the hydrogen content in hydrocarbon fuels. In addition, changes in air pressure across the wings and control surfaces of an aircraft can cause water vapour in the atmosphere to condense into visible droplets.
Exhaust-derived contrails contain carbon monoxide, unburned hydrocarbons, and oxides of nitrogen, as well as carbon dioxide, the primary greenhouse gas. These emissions, though invisible, may have a minor influence on the contrail appearance due to their effects on heat distribution, droplet coagulation or light refraction. Contrails caused by pressure changes will not contain pollutants, and therefore may appear different even though they originate from the same aircraft.
The appearance and behaviour of contrails depends on many factors, including the prevailing atmospheric conditions, type of aircraft and engine, wind direction, altitude, and amount of sunlight. Recent trends that may have affected the form and frequency of contrails include: higher operating altitudes; larger and more efficient engines; new traffic patterns (for example, in response to noise concerns); and extra flights or schedule changes at airports.
Environment Canada recognizes the need to include aircraft emissions as part of our overall mandate to assess and evaluate air pollution from the transportation sector. The Government of Canada is represented on International Civil Aviation Organization committees dealing with aircraft pollution, and my department's officials maintain contact with the leading researchers in this field. I am confident that government/industry cooperation will foster better understanding of high-altitude aircraft emissions, and point the way to measures for minimizing their effects on the environment.
I appreciate your interest in environmental protection, and hope the information provided is helpful.
Original signed by:
Sound familiar? More to come!
Finally a politician demonstrates courage:
April 2005 - Environment Canada's Meteorological Inquiry Specialist, Bernard Duguay, replied by email to a licensed pilot's inquiry about one of our gallery pictures. (Featured on home page).
Duguay's email reads, "Thank you for sending your message to Environment Canada and sorry about the long delay before replying. After making numerous phone calls I'm still not sure what those spraying [sic] are all about. I was told that those aircrafts are likely american air force tankers practicing for refueling aircrafts. Of course, they are not releasing fuel but water. Seems that they conduct that type of training in the Niagara Falls area and over Lake Erie. This is all I was able to learn".
Go to Holmestead.ca's Spring '05 Points to Ponder and scroll down to Topic #4 to see the startling response and more. Much thanks to Brian Holmes ... and the pilot!