A Massachusetts city is suing the makers of firefighting foam blamed for water contamination. Westfield's Democratic Mayor Brian Sullivan announced the federal lawsuit against the 3M Co., Chemguard Inc. and Tyco Fire Protection Products on Thursday.
Cloud seeding has been going on for decades as a tool to boost water supplies. Only now has a scientific study proven the process actually works. But as atmospheric scientist Jeffrey French explains, another big question looms: How effective is it?