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A red flag should go up over one effort in Congress to make America go green.

The main global-warming bill on Capitol Hill calls for the president to slap stiff barriers on imports from other countries that don't reduce their carbon emissions in comparable ways.

Such a trade restriction is aimed at helping US industries stay competitive once they are forced to pay higher energy costs under a climate-change law. The US could see many of its industries move to other countries with lesser or no curbs on greenhouse gases, a possibility called "carbon leakage."