One metric that we custom developed for this implementation was the Carbon Efficiency metric.

我们为这个实现开发的一个指标是碳效率(Carbon Efficiency)。

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The European Happy Planet Index used carbon efficiency, life satisfaction and life expectancy to rate the countries.

此项“欧洲快乐星球指数”主要是综合碳效率、人民的生活满意度及预期寿命三个指标对这些国家（country）进行评分成。

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Efficiency is also a great way to lower carbon emissions and help slow global warming.

提高效率也是减少碳排放和帮助减缓全球变暖的好方法。

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He said Russia will none-the-less continue to push for domestic energy efficiency and cuts in carbon emissions.

VOA: standard.2009.12.25

Alaska Airlines came in second with three leafs, scoring well in recycling, building design and carbon efficiency.

BBC: How eco is your airline?

Each car was scored for its performance in terms of air pollution, fuel efficiency and carbon footprint ratings.

FORBES: Magazine Article

"It has been suggested to us that some of the claims about fuel efficiency and carbon issues are fundamentally deceiving, " he said.

CNN: It's not easy being green