The UFOs (for a moment assume they exist) use ionization techniques to blast the atmospheric air from in front of their immediate path and around their space craft with criss crossed microwaves to delete gravity and lasers to pummel the air from in front of the craft so they can fly within a tube of virtual space within the atmosphere? Now then judging by the sightings of said UFOs this is one possible technology being deployed. Now then if such a craft were to exit and enter the higher upper atmosphere it would in fact put a small hole in the ozone during each time of transfer. This ozone area would expand as the day went on, causing depletion of the ozone right? Thus our ozone problems could be blamed on the aliens and not the aerosol industry? Which could be good for that industry?
We know that each time we launch a satellite into orbit a small hole is temporarily created from the rockets, yet if we are to ionize the air in front of the rocket a bigger hole may in fact be created temporarily, this would have an adverse temporary effect on gamma rays and X-rays entering the atmosphere, which could cause weather changes, heating of upper atmosphere which would in fact change somewhat the weather patterns also could cause skin cancer too.
Anyway a man who was a conspiracy theorist introduced this idea to me recently at a coffee shop and perhaps it is way out of this world, however might be a warning to us later as we deploy new spacecraft, hypersonic transglobal airline flights to the other side of the planet. It also makes sense to understand as we practice with weaponry to defeat incoming ICBM future technologies or develop such technologies to defeat incoming asteroids or even trips to the Lunar Base Station or future tourist hotel.