If America and its allies put sanctions on Iran, the Iranian navy could block the Strait of Hormuz, an important channel for international oil shipments.

Have Republicans ensured the death of Keystone XL by pushing Obama to decide one way or another about the pipeline?

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The EPA is scaling back requirements for cellulosic ethanol in the coming years.

Presidential candidates are allowed to criticize ethanol now — even in Iowa.

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These NASA photos document the growth of the Athabasca tar sands pits in Alberta.