WASHINGTON - A major international study recently concluded there was overwhelming evidence that humans were causing global warming. But that didn't quiet the skeptics. They continue to raise doubts, suggesting that everything from sunspots to cattle flatulence is causing the earth to warm, and insisting that scientists were stretching the truth. "Every weather extreme is global warming!" said radio host Rush Limbaugh three days after the release of the report. "These people, they're brilliant little socialists and communists. They know how to propagandize; they know how to keep this alive." Global warming has been called the most dire issue facing...