The forecast expansion of Australian coal mining and exports would be the world's second-largest contributor of new carbon dioxide emissions from fossil fuels if fully realised, research by Greenpeace International has found.

An analysis of the planet's 14 largest proposed, coal, oil and gas developments - to be released on Wednesday by Greenpeace - finds if Australian coal production expands as projected, the mining, production and burning of the extra resources would by 2020 result in 759 million tonnes of new global carbon dioxide emissions a year over 2011 levels.

But emissions from Australian coal growth would be eclipsed by proposed coal production in western China, projected to result in 1400 million tonnes of annual CO2 emissions by 2020.

Greenpeace says development of the 14 fossil fuel projects would put significant pressure on the world's ability to meet a target, agreed to by nations through the United Nations, to limit global warming to a global average of two degrees. ''Burning the coal, oil and gas from these 14 projects would significantly push emissions over what climate scientists have identified as the 'carbon budget', the amount of additional CO2 that must not be exceeded if we are to keep climate change from spiralling out of control,'' the report says.