"The soot particle emissions from the aircraft engines determine the size of the ice crystals and how many there will be when the vapor trail forms". 1212 The effects of clouds from aircraft contrail on the climate can triple by 2050, German Aerospace Center, Institute for Atmospheric Physics, July 15, 2019. Retreived from hier."While rain flushes these particles out of the lower layers of the atmosphere, they can linger in the uppermost layers for three to ten years. Over time, thousands of tons of soot can accumulate there. The particles fundamentally alter the way solar radiation interacts with the atmosphere: soot absorbs sunlight, while aluminum reflects it, but both types of particles absorb long-wave thermal radiation from Earth on their way into space.” 1313 Sibylle Anderl: Thousands of tons of soot, in: Frankfurter Allgemeine Zeitung, 20. Juli 2021. Retreived from hier