A look at the global deal and how volunteers will be kept accountable
The big idea of companies trading rights to emit greenhouse gases has floundered in Europe.
Making an energy pledge is one thing, following through is a whole different story
Does China's political system help in setting long-term goals to reduce emissions?
Some environmentalists question Britain's claim to be a leader on climate change.
In Paris, representatives of some 200 countries will work towards a climate change deal.
Some countries do little to cut emissions and benefit as others do the heavy lifting.
