Significance
The United States has already committed, in an unprecedented deal with China in November 2014, to reducing its emissions to 26-28% below 2005 levels by 2025 (an improvement on its previous 17% goal). China in return pledged that its emissions would peak around 2030. This agreement is a game-changer for combating global climate change, since the two countries are the world's largest sources of carbon emissions, together accounting for 40% of the total, and were not covered under the now-expired Kyoto Protocol.
Impacts
Washington is poised to reclaim its place, lost after Kyoto, as a leader in global efforts against climate change.
US-China climate cooperation initiatives could serve as templates for other developing countries.
There are new opportunities for trilateral cooperation involving the EU.
Fears that the bilateral agreement makes the UNFCCC obsolete are unwarranted, but it could preclude more ambitious efforts.