Every winter for the last few years there have been reports of blocks of ice mysteriously falling from the sky. Many of them are large enough to crash through the roofs of houses. People have accused airplanes of emptying chemical toilets while in flight (which they don’t do), but the truth is, this is yet another symptom of global warming.
Contrails from airplanes remain in the atmosphere longer these days, because the lower atmosphere is retaining more heat, making the upper atmosphere colder. Also, gigantic hailstones occur when cloud tops reach extreme heights, and hit the cold air above the stratosphere. Pieces of these icy clouds and contrails fall through the atmosphere, getting bigger and bigger as they fall.