In China, they use artillery shells, rockets and airplanes to spray existing cloud systems with silver iodide, a compound that triggers moisture in the clouds to form ice crystals, which then fall to earth as snow or rain.

WSJ: Blizzard Renews Storm Over China Making Snow

Radioactive isotopes accumulate in milk after they spread through the atmosphere, fall to earth in rain or dust, and settle on vegetation, where they are ingested by grazing cattle.

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