But it hasn't reduced CO2 emissions (up about 25% since 1990), and many signatories (签字国) didn't adopt tough enough policies to hit their 2008-2012 targets. (08.6 Passage 1)

　　分析主干:it hasn't reduced emissions and signatories didn't adopt policies

　　本句是and 连接两个分句构成的并列句.前一分句中,括号里的内容是插入成分,用以说明二氧化碳排放量不仅没有减少,反而增加了。后一个分句的宾语是policies，它有一个形容词短语tough enough 作修饰语。

　　译文：但是它并没有起到减少二氧化碳的排放量(自从1990 年以来上升了25%)的作用，并且许多签字国并没有采取足够严格的政策来尽力完成他们所制定的2008-2012 年度的目标。