Stabilising greenhouse gases at a level that would limit global warming to between 2°C and 4°C will cost between 0.2% and 3.0% of annual GDP, says the latest UN report on climate change. That is up to $1830 billion

Such a treaty would succeed the Kyoto Protocol, which ends in 2012.

China is projected to become the world's top emitter before 2010 according to the International Energy Agency. However, it and other developing countries argue that policies to battle climate change should not come in the way of their efforts to develop their economies