The Border Tax Adjustment idea has been kicked around for years by politicians, economists and environmentalists. It hit the European Union agenda last October, when its High Level Group on Competitiveness, Energy & Environment advised the European Commission on the long-term energy outlook.

Many figure BTAs might allow the EU to develop responsible climate policies without having to wait for other countries, since they would tax products imported from the U.S. to compensate for differences in production costs. Thus EU firms would be protected against unfair, carbon-careless competition from abroad.

BTAs are not a final solution, merely an interim measure as countries move to taxation systems that make labor cheaper and environmental damage more costly. Economies that lead the way in promoting energy and resource efficiency will become more efficient and stronger, and have greater export opportunities.