Even Big Oil Wants a Carbon Tax

Now that six of the world's largest oil companies have essentially come out in favor of a carbon tax, it's getting harder to dismiss the idea as some kind of outlandish lefty plot. And those companies can help their cause by engaging Congress directly, instead of outlining their case in a polite letter to the United Nations.

None of the companies -- BP Plc, Royal Dutch Shell Plc, Total SA, Statoil ASA, Eni SpA and BG Group -- is based in the U.S. Still, their argument should resonate in Washington: "Clear, stable, long-term" policies that make carbon more expensive (the letter never uses the word "tax") are necessary to reduce uncertainty, stimulate investment and encourage the most efficient reductions in emissions. Only governments can make those changes, they say. And those national systems must eventually be connected to create a global system.