“In cloud seeding, very small particles of Silver Iodide (AgI) are used

as artificial ice nuclei to form ice crystals and initiate the Bergeron-

Findeisen mechanism.  

An alternative method is to use dry ice (solid Carbon Dioxide, CO2)

which as it passes through the cloud cools the surrounding air.

Link to Article

As scientists concentrate on the processes involved in the weather, we

will be able to improve the present method of cloud seeding, and

change the weather around us.”

“It was in Pennsylvania that one of the first laws was
passed with the intent of curbing possible
harm to nature by changing the weather. In discussing the
bill, which became the 1967
Pennsylvania law, one of its sponsors on the House of
Representatives stated: ” Cloud seeding
involves silver iodide, and silver iodide, Mr. Speaker, is
highly poisonous. AgI used in seeding falls
everywhere, on trees, in vegetation, roofs, people and in its
synergistic action joins with motor
exhaust to become lead iodide.”