Ice meteors are falling from the sky in growing numbers. And while some skeptics still think the phenomenon a hoax or the result of ice from planes passing overhead, a Spanish scientist says they are neither. Though he doesn’t know precisely how the meteors form, Jesus Martinez-Frias, director of planetary geography at Spain’s Astrobiology Center in Madrid, notes that their results can be dramatic. The falling ice blocks tend to weigh upwards of 20 pounds and have smashed in cars, destroyed roofs and caused general mayhem where they land. But Martinez-Frias says he isn’t concerned so much about the terrestrial damage they can cause, but the atmospheric damage he believes they portend. “I’m not worried that a block of ice might fall on your head … but that great blocks of ice are forming where they shouldn’t exist,” he said. “Components of the atmosphere, like ozone and water, are changing in different levels of the atmosphere. … We think these signs could be evidence of climate change,” he told Reuters.