English: The image on the left shows the sky above Würzburg, Germany without contrails after the grounding of air traffic in 2010 and the image on the right shows the sky with regular air traffic on a day when conditions were right for contrails to form.
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{{Information |Description={{en|1=sky in Wuerzburg, Bavaria, Germany during (left, 18.04.2010) and after (right, 29.04.2010) the air traffic reduction due to the ash cloud caused by the eruption of the Eyjafjallajökull}} |Source={{own}} |Author=[[User:We