A «hard collar» on the price of emission permits of no less than $ 10 per ton of carbon emitted and no more than $ 30 per ton. (treehugger.com)
The money would come from either a carbon tax, or an auction of carbon emission permits. (dotearth.blogs.nytimes.com)
And if its cap is so tight that it fails to cut emission enough, it will have to pay other countries when it buys emission permits from them. (carbon-price.com)