Washington Post: For 140 years, the Rockefellers were the oil industrys first family, scions of a business empire that spawned companies called Exxon, Mobil, Amoco and Chevron. So it was no trivial matter when a group of Rockefeller heirs decided recently to begin severing financial ties to fossil fuels. There is a moral imperative to preserve a healthy planet, said Valerie Rockefeller Wayne, a great-great-granddaughter of oil magnate John D. Rockefeller Sr. and a trustee of the largest charitable foundation...