I started taking pictures of contrails in 1995, not knowing what they were called and not realizing that they not just ugly but also (and mainly) hazardous to the health of our climate. In the beginning I scanned the photographs in order to obtain digital pictures. Later, I used a digital Olympus Camedia camera. Since May 2002, I use a Minolta Dimage X.. The picture underneath was taken in 1995. 

'What a beautiful evening' sighed the young couple at the table next to us, somewhere at the waterside in the centre of Amsterdam.. 
Some people actually like contrails and their grand designs in a once-blue sky. Other people love to watch car crashes or other incidents. Beauty is in the eyes of the beholder.

The debate should no longer be about the cosmetic value of contrails, but about their impact and their consequences. At the moment, the burden of proof lies with the people who worry about the harm contrails could do, not with those who cause these changes in the sky. 'It's the economy, stupid'.  
When the sky is cloudy or hazy with natural (?) cirrus, contrails are hard to see, even for the experienced contrail-watcher. On July 18th, contrails had been only vaguely visible during the greater part of the day. Only after the sky cleared and with the setting sun, the contrails became distinct. 'What a beautiful evening'.

July 31st, 1999:
KNMI predicts: 'The suns shines fully. Tomorrow there will be some more clouds. This morning the sky is clear and deepblue. [...] Some cumulus-clouds will hardly hinder the force of the sun'
MeteoConsult agrees: 'The weather becomes monotonous. No signs of change in the wheathercharts. [...] Tomorrow August 1st some high clouds will drift in from the South. These are the first signs of a change in the wheather.'

In reality the first contrails appeared yesterday afternoon,  after six days of  full sunshine and deep-bvlue skies. This morning the sky  was covered with persistent contrails, developing into milky cirrus-clouds, filtering the light of the sun.
Weather is hard to predict, so forecasts have a strong element of uncertainty. 
Not telling the truth is quite another matter, though.

The heavy and persistent contrails and aviation-induced cirrus-clouds of July 31st, 1999, were to be expected. Some meteorologists rather ignore them. They will have to learn the meteoroligical impact of this unmeteorological phenomenon.

Aviation brings vast amounts of water to the top of our troposphere, where it stays for a long time before mixing with lower levels. Raising of the level of vapour in our atmosphere cannot be without consequences.
     Part of the problem is that the contrails and 'cirrus aviaticus'  that you do not see, that should really worry you. In many cases this aviation-induced cloudiness can only be seen when the sun shines sideways 
     A meteorologist (who prefers to remain anonymous) writes that pilots report that contrails only occur in a very thin layer of our atmosphere, around the tropopause. This layer has a thickness of not more than a few thousand feet. This thinness makes the remnants of aircraft emissions almost invisible in the daytime, when the sun shines straight through this only partly visible layer of water (ice), CO2, soot (aerosols) and whatever more.. In the morning and evening, with the light of the sun coming from sideways, the thin coat of pollution becomes visible as a veil covering the sky.
     Most of the time only an experienced contrail-watcher can that aviation has caused the the sky to be a bit opaque and not of a deep and clear blue colour. Most people have grown used to this phenomenon, as the change happened very slowly and gradually. 
     It seems as if the quality of the sunlight has changed. It seems whiter, sharper, it has more 'bite'.  This may be caused by the thin layer of ice crystals that aviation is weaving around the world.
     Most of the time the thin layers of ice clouds at high altitude can only be seen in the mornings and evenings. The message is: Don't just look at the easily recognizable contrails and 'cirrus aviaticus', but read also the veiled message between these white lines.