In the weeks leading up to the Copenhagen climate conference, countries from China to Singapore have pledged cuts to their greenhouse-gas emissions.Short answer: no one. So any agreements made in Copenhagen will pretend to cut emissions but will not impose any mechanism for achieving those cuts.
One question still lurks unanswered: Who is going to pay for it?
More broadly, no international agreement will ever achieve meaningful reductions in emissions because the costs created and the cross-country transfers implied would require a level of coercion that the relevant powers are not willing to utilize.
So it is time to accept that whatever climate change is going to happen is going to happen, and learn to adapt to whatever costs this creates.