Reuters Carbon pricing will not be on the agenda in Paris (Dec. 2015) because the cap-&-traders have convinced the world that the only path to a global price is international cap and trade. And that would mean there would be huge random payments between countries as they fall short and exceed their targets over a period of 15 years (if Kyoto is any guide).
No, the US does not want to end up sending billions to China because they negotiated a lenient cap. And no China would not want to send billions to India if they had a hard time with their cap and India got the better deal. This kind of international gambling serves no purpose and will never be accepted.
But it would be very easy to set a global price on carbon and let countries implement it their own way and keep any revenues from selling carbon allowances or taxing carbon.