BOB HIRSHON (host):
Is cloud seeding misleading? I’m Bob Hirshon and this is Science Update.
Cloud seeding has been practiced for over half a century, but it’s always been scientifically controversial. Now, scientists at Tel Aviv University in Israel have found new reason to doubt it. Environmental scientist Pinhas Alpert and his colleagues applied recent insights in large-scale weather patterns to supposedly successful instances of cloud seeding. They found that the rainfall that was attributed to cloud seeding could actually be explained naturally.
PINHAS ALPERT (Tel Aviv University, Isreal):
I think what we show really is settling the issue, in a point that is different from the main line of discussion.
He says that past research focused on whether the seed particles, like frozen carbon dioxide, were effective in forming raindrops. His team was able to take a big step back and ask if the seeding really made a difference. I’m Bob Hirshon, for AAAS, the science society.