THE INTERNATIONAL CLEAR-SKY ASSOCIATION

Evidence from many sides suggests a rapidly increasing level of cloudiness, due to degenerated aircraft contrails. Astronomers working under the most heavily trafficked regions have already detected a loss of quality of day-time, as well as night-time observations. We fear that, if this trend is allowed to continue, the value of ground-based astronomical observations could be compromised. We are also concerned that the public's perception of the clear, blue day-time sky and the starry night sky, is being hampered by these man-made clouds. We wish to discuss this topic with relevant authorities, aiming to find solutions acceptable by all parts. A very positive contact has already been established with the International Civil Aviation Organization's Committee for Aviation Environmental Protection. For further information and statements of interest, write to holger@astro.ku.dk