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 2050.
The IPCC was silent, however, on how much investment there should be in each source of energy. It said it was up to each country to decide on the mix of energy sources it needed to meet its share of the global emissions target.
Countries that relied on exports of coal and oil could see their revenues decline if the world took collective action on emissions, it said. Yet exports of gas, which has about half the emissions of coal per unit of energy produced, could increase.
The report said: “Greenhouse gas emissions from energy supply can be reduced significantly by replacing current world average coal-fired power plants with modern, highly efficient natural gas combined‐cycle power plants.”
It added that “fugitive emissions” from gas extraction, such as methane, that can leak from poorly constructed wells, would need to be tightly controlled to ensure that a switch to gas cut overall emissions.
Ottmar Edenhofer, co-chairman of the IPCC report and professor of climate change economics at the Technical University Berlin, said: “The shale gas revolution… can be very consistent with low-carbon development… Gas can be very helpful as a bridge technology.”
He cautioned however that burning more gas would cut emissions only if it displaced coal. If more gas were burnt as well as coal, overall emissions would rise.
The report said that the world economy would continue to grow if countries made “ambitious” emissions cuts but the annual growth rate would be 0.06 per cent lower than it would otherwise have been.
It added that this estimate did not include the expected economic benefits of cutting emissions, including the health benefits of reduced air pollution.
Emissions could be reduced by planting trees across vast areas to absorb carbon dioxide and then harvesting the wood to burn in power stations fitted with carbon capture systems, the IPCC said.
It added, however: “As of today this combination is not available at scale, permanent underground carbon dioxide storage faces challenges and the risks of increased competition for land need to be managed.”
Almost all power stations burning fossil fuels would have to be fitted with carbon capture systems by the end of the century to avoid catastrophic climate change, the report said. [….]
Benny Peiser, director of the Global Warming Policy Foundation, said: “This is the first IPCC report that will be largely ignored by most policymakers. It will have no influence on governments’ energy policies that are now almost completely dominated by energy security and economic considerations. Around the world the climate issue is being pushed to the margins of decision making.”