One example is from NASA. They have a few project that ask people to observe contrails:
MY NASA DATA - Contrail Watching for Kids
Science Project: Contrail Watching for Kids
Web Id: P3
Purpose: Contrails are long clouds made by high-flying aircraft. Because kids are so good at watching clouds, they can be easily taught to identify contrails.
Age Range: 6 – 10
Time Required: Young children can observe and report on contrails in only a few minutes a day.
Significance: Kids know that some clouds signal rain and other mean fair weather. They need to know that contrails are actually manmade clouds and that they can cause measurable changes in the temperature far below where they live and go to school.
MY NASA DATA - Contrail Studies
Science Project: Contrail Studies
Web Id: P4
Purpose: Serious students, citizen scientists and regular weather watchers can use a camera and simple weather instruments to monitor and study contrails and to determine their possible environmental effects.
Age Range: 11 to adult
Time Required: Contrails can be observed, photographed and reported in only a few minutes a day. Scientific studies of contrails take more time and can provide important scientific information.
Significance: Contrails are often more difficult for satellites to detect than clouds, especially when they remain narrow and do not spread outward. Students, home weather station operators and citizen scientists can provide important scientific information by documenting the contrails they observe and reporting their findings. It is important simply to know the number of days contrails were present over a particular location in a given year.
National Aeronautics and Space Administration - The Contrail Education Project - Observing, Describing, and Identifying Contrails
Purpose: To enable students to observe contrails, describe them using a common vocabulary, and compare their descriptions with the official contrail types.
Overview: Students can observe contrails and identify which of the three contrail types they are observing. The students can sketch the contrails, developing personal and scientific vocabulary, and descriptions of contrails.
Student Outcomes: Students will be able to identify contrail types using standard contrail type names and descriptions.
NASA - Langley Research Center - NASA and GLOBE: Observing the Sky for Science
NASA and GLOBE, an international student Earth science program, invite the public to join in a scientific experiment on Oct. 13. It's simple: observe the sky over your area and report on the presence or absence of contrails.
Image Left: The Contrail Education program at NASA Langley Research Center works to educate students around the world about atmospheric science research and teach fundamental science concepts. The program is led by Lin Chambers of the Science Directorate, in collaboration with other NASA scientists and professionals, as well as with the National Science Foundation and the GLOBE program.
Teachers, students and anyone interested in helping to develop a better understanding of the Earth are welcome to participate in the second annual Fall Contrail Count-a-Thon by submitting contrail observations through an Internet Data Entry Form. Designed to give students and adults an opportunity to collaborate with scientists in a hands-on, real-world science experiment, the Count-a-Thon will also teach participants about contrails, a unique feature of our atmosphere.
Contrails are cirrus clouds formed when water vapor condenses and freezes around small particles (aerosols) in aircraft exhaust. Some of the water vapor comes from the surrounding air; some from the aircraft exhaust itself. Contrails, especially thin ones, are very hard to see from satellites and may have an impact on Earth's atmosphere.
"To augment what we can see from satellite, we hope to receive visual observation reports from lots of people all over the world. Both reports of contrails and reports with no contrails are equally valuable for this research," said Lin Chambers, director of the GLOBE contrail education project at Langley Research Center.
Contrails increase Earth's cloudiness while impacting the atmosphere and climate. Observations in the U.S. and around the globe may help scientists better understand the atmospheric conditions that enable the formation of contrails.
They also mention the importance of observing contrails:
National Aeronautics and Space Administration - The Contrail Education Project - Importance of Student Data in the Study of Contrails
"Why is it important to study contrails?
Clouds are the largest variable controlling Earth's atmospheric temperature and climate. Any change in global cloud cover may contribute to long-term changes in Earth's climate (see The Role of Clouds from the S'COOL Project). Likewise, any change in Earth's climate may have effects on natural resources. Contrails, especially persistent contrails, represent a human-caused increase in high thin clouds in the Earth's atmosphere, and are likely to be affecting climate and ultimately our natural resources."
National Aeronautics and Space Administration - The Contrail Education Project - Contrail Science
What are contrails?
Contrails are clouds formed when water vapor condenses and freezes around small particles (aerosols) that exist in aircraft exhaust. Some of that water vapor comes from the air around the plane; and, some is added by the exhaust of the aircraft.
The exhaust of an aircraft contains both gas (vapor) and solid particles. Both of these are important in the formation of contrails. Some elements of the exhaust gasses are not involved in contrail formation but do constitute air pollution. Emissions include carbon dioxide, water vapor, nitrogen oxides (NOx), carbon monoxide, hydrocarbons such as methane, sulfates (SOx), and soot and metal particles.
Some important point from those link are:
- NASA do not call the trails geoengineering, they call it contrails. If you talk to people affiliated with NASA, you should not refer chemtrails as geoengineering. You must refer chemtrails as at least contrails.
- While the government may ignore it, science have a great concern for contrails.
- Contrails pose serious risk to the environment.
- Contrails happen because particles are being released from aircraft.