到本世纪中期，发达国家承诺将碳排放量减少到1990年水平的80 % ， 目前，很多国家已经做到了这一点。
Developed countries will be able to commit to reducing their emissions by 80% versus 1990 by mid-century, as many have already done, and provide the necessary financial and technology support for developing countries’ adaptation and mitigation efforts.