‘Sky graffiti’: Aircraft trails pose oft-overlooked problems

If I drew a tic-tac-toe board with chalk on a large stone wall, I might get away with it the first day. But if I got out the chalk every single day, sooner or later I would be caught, and the state might well charge me with graffiti, a form of vandalism. If I wielded that chalk for long enough, it would be hard to erase the graffiti and even harder to remove the residue from the wall.

Now what if we drew lines across the sky day and night, on an ever-increasing number of days each year? Take five minutes to look skyward and you are likely to witness chalk-like lines emerging from airplanes and crisscrossing the sky. Some people call these lines chem-trails, others say they are part of a covert solar radiation management (geo-engineering) program, while most consider them “just contrails.” Whatever you call them, these persistent trails in the sky cause significant issues.