Shale gas can help the world to avoid dangerous climate change if it replaces coal in power stations, according to a United Nations report.
Global emissions need to fall by at least 40 per cent by 2050 and almost to zero by 2100 to have a good chance of limiting the increase in the average temperature to 2C, above which the UN says there could be catastrophic impacts.
The report by the Intergovernmental Panel on Climate Change (IPCC) will underpin negotiations over a global climate change treaty that the UN hopes will be signed in Paris next year.
The share of energy from low-carbon sources, such as wind, solar, nuclear and fossil fuel plants which capture carbon, will have to increase three or four-fold by