Another method is the emissions trading system.

另一种方法是排污权交易制度。

Even India and China have adopted versions of carbon taxes or emissions trading.

即使是印度和中国也已实行了其它形式的碳排放税或污染物排放交易细则。

Critics of emissions trading will undoubtedly say the US is better off without it.

毫无疑问，排放交易计划的批评者会说，美国最好不搞这个。

EMISSIONS trading, says Ian Johnson of IDEAcarbon, a research firm, "is not an easy concept to understand".

IDEAcarbon(一个研究公司)的Ian Johnson说，排污权交易这个概念不容易理解。

Although it is not yet common in North America, emissions trading has been gaining popularity in parts of Europe.

尽管排污权交易在北美还不普遍，但在欧洲一些地区却非常受欢迎。