CNN  —  “Everybody complains about the weather, but no one does anything about it,” Mark Twain used to quip, back when humans had only just begun digging fossil fuel out of the ground and burning it for energy. It was a borrowed joke — and good thing for Twain, since it hasn’t aged well. Nearly a century and a half after “The Adventures of Tom Sawyer” was published, humanity’s fossil fuel pollution is changing nearly everything about our weather, and with early voting underway, American voters